bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: C2‐Symmetrical Nickel Complexes Derived from α‐Amino Amides as Efficient Catalysts for the Enantioselective Addition of Dialkylzinc Reagents to Aldehydes.
Authors: Escorihuela Jorge , Altava Belen , Burguete M. Isabel , Luis Santiago V. 
Published: May 2013

AbstractAliphatic aldehydes reacting with lower yields and enantioselectivities than the aromatic ones.
ChemInform Abstract: Pd‐Catalyzed Decarboxylative ortho‐Acylation of O‐Methyl Oximes with Phenylglyoxylic Acids.
Authors: Yang Zhiyong , Chen Xiang , Liu Jidan , Gui Qingwen , Xie Kai , Li Miaomiao , Tan Ze 
Published: May 2013

AbstractTwenty examples of the title reaction using (NH4)2S2O8 as the oxidant are presented.
ChemInform Abstract: FeSO4‐Promoted Direct Arylation of Benzoquinones with ArB(OH)2 or ArBF3K.
Authors: Komeyama Kimihiro , Kashihara Tetsuya , Takaki Ken 
Published: May 2013

AbstractFeSO4 can be used in catalytic amounts by addition of ascorbic acid as reductant or by replacement of benzoquinones with the corresponding hydroquinones.
ChemInform Abstract: N‐Heterocyclic Carbene Mediated Reformatsky Reaction of Aldehydes with α‐Trimethylsilylcarbonyl Compounds.
Authors: Zou Xiao‐Lei , Du Guang‐Fen , Sun Wan‐Fu , He Lin , Ma Xiao‐Wei , Gu Cheng‐Zhi , Dai Bin 
Published: May 2013

AbstractIt is assumed that the NHC attacks the silicon atom of (II) in order to form a possible hexavalent silicon intermediate, that could initiate the addition to the respective aldehyde.
ChemInform Abstract: Synthesis of Imides by Palladium‐Catalyzed C—H Functionalization of Aldehydes with Secondary Amides.
Authors: Bian Yong‐Jun , Chen Chao‐Yue , Huang Zhi‐Zhen 
Published: May 2013

AbstractVarious aromatic aldehydes and N‐substituted N‐heteroarene‐2‐carboxamides react effectively to generate secondary imides tolerating a wide range of functionalities.
ChemInform Abstract: The Use of Aqueous Potassium Dichloroiodate for the Synthesis of Ureas.
Authors: Viana Gil Mendes , de Sequeira Aguiar Lucia Cruz , de Araujo Ferrao Jonas , Simas Alessandro Bolis Costa , Guariento Vasconcelos Marcela 
Published: May 2013

AbstractThioureas are converted into the corresponding ureas under conditions A).
ChemInform Abstract: Magnetic Fe—Ni Alloy Catalyzed Suzuki Cross‐Coupling Reactions of Aryl Halides with Phenylboronic Acid.
Authors: Zhang Rongzhao , Miao Chengxia , Wang Shoufeng , Xia Chungu , Sun Wei 
Published: May 2013

AbstractThe catalyst can be easily recovered using a permanent magnet.
ChemInform Abstract: Enantioselective Synthesis of Optically Active 3,3‐Diarylpropanoates by Conjugate Hydrosilylation with Chiral Rh‐Bis(oxazolinyl)phenyl Catalysts.
Authors: Itoh Kengou , Tsuruta Ayae , Ito Jun‐ichi , Yamamoto Yoshihiko , Nishiyama Hisao 
Published: May 2013

AbstractRHC efficiently promotes the asymmetric hydrosilylation of 3,3‐diarylacrylates.
ChemInform Abstract: Ruthenium‐Catalyzed Intermolecular Hydroacylation of Internal Alkynes: The Use of Ceria‐Supported Catalyst Facilitates the Catalyst Recycling.
Authors: Miura Hiroki , Wada Kenji , Hosokawa Saburo , Inoue Masashi 
Published: May 2013

AbstractThe method using Ru—CeO2 is environmentally friendly due to the high recyclability of the catalyst and low contamination of the products with the metallic species.
ChemInform Abstract: Pd(II) Complexes with Mono‐ and Bis‐chelate Carbene Ligands Tagged with Pyridinium Cation: Synthesis, Structures, and Their Catalytic Activities Toward Heck Reaction.
Authors: Lee Chen‐Shiang , Lai Yong‐Bin , Lin Wan‐Jung , Zhuang Rui Rui , Hwang Wen‐Shu 
Published: May 2013

AbstractA novel palladium complex with chelating NHC ligand is prepared and efficiently applied as a reusable catalyst for the Heck reaction.
ChemInform Abstract: Highly Diastereoselective Multicomponent Cascade Reactions: Efficient Synthesis of Functionalized 1‐Indanols.
Authors: Jiang Jun , Guan Xiaoyu , Liu Shunying , Ren Baiyan , Ma Xiaochu , Guo Xin , Lv Fengping , Wu Xiang , Hu Wenhao 
Published: May 2013

AbstractThis is the first Rh(II)‐catalyzed intramolecular three‐component cascade Michael‐aldol‐type reaction yielding 1‐indanol compounds.
ChemInform Abstract: Diastereoselective Multicomponent Cascade Reaction Leading to [3.2.0]‐Heterobicyclic Compounds.
Authors: Ausmees Kerti , Kriis Kadri , Pehk Tonis , Werner Franz , Jaerving Ivar , Lopp Margus , Kanger Tonis 
Published: May 2013

AbstractTreatment of secondary amines with α,β‐unsaturated aldehydes and 4‐hydroxycrotonates or 4‐aminocrotonates allows a diastereoselective access to trisubstituted [3.2.0]‐heterobicyclic systems.
ChemInform Abstract: Regio‐ and Stereoselective Synthesis of Cyclic Imidates via Electrophilic Cyclization of 2‐(1‐Alkynyl)benzamides. A Correction.
Authors: Mehta Saurabh , Yao Tuanli , Larock Richard C. 
Published: May 2013

AbstractThe iodocyclization of 2‐(1‐alkynyl)benzamides and related compounds results in regio‐ and stereoselective formation of cyclic imidates.
ChemInform Abstract: Synthesis of 3‐Alkyl‐ or 3‐Allenyl‐2‐amidobenzofurans via Electrophilic Cyclization of o‐Anisole‐Substituted Ynamides with Carbocations.
Authors: Kong Yulong , Jiang Kezhi , Cao Jian , Fu Lingzi , Yu Lian , Lai Guoqiao , Cui Yuming , Hu Ziqiang , Wang Guanhai 
Published: May 2013

AbstractA novel carbocation‐induced electrophilic cyclization reaction of o‐anisole‐substituted ynamides is described.
ChemInform Abstract: Site‐Selective Mono‐Oxidative Addition of Active Zinc into Carbon—Bromine Bond of Dibrominated‐Thiophenes: Preparation of Thienylzinc Reagents and Their Applications.
Authors: Jung Hye‐Soo , Cho Hyun‐Hee , Kim Seung‐Hoi 
Published: May 2013

AbstractThiophenes (I) and (VIII) are selectively converted into 2‐thienylzinc bromides according to A).
ChemInform Abstract: Iron‐Catalyzed Tandem One‐Pot Addition and Cyclization of the Blaise Reaction Intermediate and Nitroolefins: Synthesis of Substituted NH‐Pyrroles from Nitriles.
Authors: Zhao Mi‐Na , Liang Hao , Ren Zhi‐Hui , Guan Zheng‐Hui 
Published: May 2013

AbstractThe presented new method tolerates a wide range of functional groups starting from various (hetero)aromatic and aliphatic nitriles and several nitroolefins.
ChemInform Abstract: Synthesis of Functionalized 2‐Pyrrolidinones via Domino Reactions of Arylamines, Ethyl Glyoxylate and Acetylenedicarboxylates.
Authors: Gao Hong , Sun Jing , Yan Chao‐Guo 
Published: May 2013

AbstractDiethyl acetylenedicarboxylate can be used as starting material giving similar results as dimethyl acetylenedicarboxylate.
ChemInform Abstract: Direct One‐Pot Cobalt(II) Phthalocyanine Catalyzed Synthesis of N‐Substituted Isoindolinones.
Authors: Kumar Vishal , Sharma Upendra , Singh Bikram , Kumar Neeraj 
Published: May 2013

AbstractThis reaction proceeds via a reductive amination / intramolecular amidation sequence to give the title compounds in good yields.
ChemInform Abstract: Efficient Synthesis of Bulky 4‐Substituted‐isatins via Microwave‐Promoted Suzuki Cross‐Coupling Reaction.
Authors: Liu Yu‐Chao , Ye Chen‐Jin , Chen Qiong , Yang Guang‐Fu 
Published: May 2013

AbstractElectronic and steric modifications have only small effects on the reactions of 4‐iodoisatins with aryl‐ and alkenyl boronic acids.
ChemInform Abstract: Practical Synthesis of Polysubstituted Imidazoles via Iodine‐Catalyzed Aerobic Oxidative Cyclization of Aryl Ketones and Benzylamines.
Authors: Huang Huawen , Ji Xiaochen , Wu Wanqing , Jiang Huanfeng 
Published: May 2013

AbstractThe presented new method tolerates a broad range of substrates to prepare polysubstituted imidazole derivatives in a one‐pot manner.
ChemInform Abstract: An Efficient Ecofriendly Protocol for the Synthesis of Novel Fluoro Isoxazoline and Isoxazolidines Using N‐Benzyl Fluoro Nitrone via Cycloaddition Reactions.
Authors: Chakraborty Bhaskar , Luitel Govinda Prasad 
Published: May 2013

AbstractNitrones, generated in situ from aldehydes and N‐benzylhydroxylamine (II), undergo rapid 1,3‐dipolar cycloadditions with internal alkynes or methacrolein to give isoxazolines or endo‐isoxazolidines in excellent yields.
ChemInform Abstract: Copper(I)‐Catalyzed Tandem Reaction of 2‐Iodophenols with Isothiocyanates in Room Temperature Ionic Liquids.
Authors: Yao Fang , Hao Wenyan , Cai Ming‐Zhong 
Published: May 2013

AbstractPerforming the title reaction in a hydrophobic ionic liquid offers some advantages such as reaction rate acceleration and yield increasing as compared with the reaction run in common solvents.
ChemInform Abstract: Mono‐ and Trifluorination of the Thiazole Ring of 2,5‐Diarylthiazoles Using N‐Fluorobenzenesulfonimide (NFSI).
Authors: Hatfield Julie M. , Eidell Cheryl K. , Stephens Chad E. 
Published: May 2013

AbstractA direct selective halogenation of the heterocycle becomes possible under optimized conditions; however, only low yields of the targets are isolated.
ChemInform Abstract: Rhodium‐Catalyzed Enantioselective Addition to Unsymmetrical α‐Diketones: Tandem One‐Pot Synthesis of Optically Active 3‐Tetrasubstituted Isochroman Derivatives.
Authors: Zhu Ting‐Shun , Chen Jian‐Ping , Xu Ming‐Hua 
Published: May 2013

AbstractVarious biologically relevant enantio‐enriched 1,4‐isochromanediones [cf.
ChemInform Abstract: Synthesis of Multisubstituted Pyridines.
Authors: He Zhi , Dobrovolsky Dennis , Trinchera Piera , Yudin Andrei K. 
Published: May 2013

AbstractBy utilizing amino allenes, aldehydes, and aryl iodides as readily available building blocks, a simple and modular synthesis of multisubstituted pyridines with flexible control over the substitution pattern is achieved.
ChemInform Abstract: Addition of Cyclic Ureas and 1‐Methyl‐2‐oxazolidone to Pyridynes: A New Approach to Pyridodiazepines, Pyridodiazocines, and Pyridooxazepines.
Authors: Saito Nozomi , Nakamura Ken‐ichi , Shibano Sayako , Ide Soichiro , Minami Masabumi , Sato Yoshihiro 
Published: May 2013

AbstractThe reaction of in situ generated pyridynes with cyclic ureas or 1‐methyl‐2‐oxazolidone is studied.
ChemInform Abstract: One‐Pot Synthesis of N‐(Imidazo[1,2‐a]pyridin‐3‐yl)‐ and N‐(Imidazo[2,1‐b][1,3]thiazol‐5‐yl)sulfonamides.
Authors: Rozentsveig Igor B. , Serykh Valery Y. , Chernysheva Gulnur N. , Chernyshev Kirill A. , Kondrashov Evgeniy V. , Tretyakov Evgeny V. , Romanenko Galina V. 
Published: May 2013

AbstractThe ring closure to afford the title compounds is achieved in a one‐pot, two‐step procedure under mild conditions.
ChemInform Abstract: Iron(III) Tosylate Catalyzed Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones/thiones via the Biginelli Reaction.
Authors: Starcevich Jacob T. , Laughlin Thomas J. , Mohan Ram S. 
Published: May 2013

AbstractThe title agent is an attractive catalyst for both aldehydes and acetals.
ChemInform Abstract: Dual Role of the Polymer‐Supported Catalyst PEG‐OSO3H in Aqueous Reaction Medium: Synthesis of Highly Substituted Structurally Diversified Coumarin‐ and Uracil‐Fused Spirooxindoles.
Authors: Paul Sanjay , Das Asish R. 
Published: May 2013

AbstractA one‐pot protocol is developed for the synthesis of various title systems via three‐ component domino coupling of 6‐aminouracil or 4‐aminocoumarin with 1,3‐diketo compounds and isatins.
ChemInform Abstract: New and Concise Syntheses of the Bicyclic Oxamazin Core Using an Intramolecular Nitroso Diels—Alder Reaction and Ring‐Closing Olefin Metathesis.
Authors: Watson Kyle D. , Carosso Serena , Miller Marvin J. 
Published: May 2013

AbstractThe successful approach to bicyclic oxamazins (III) relies on a Mitsunobu reaction to form β‐lactams (II) selectively, followed by a ring closing metathesis (RCM).
ChemInform Abstract: Benzothiazines in Organic Synthesis: Formation of a Cyclopropane via Neighboring Group Participation.
Authors: Cai Zhengxin , Harmata Michael 
Published: May 2013

AbstractIn connection with a research on the synthesis of antitubercular natural product pseudopteroxazole, the conversion of mesylate (I) to the intermediate iodide (II) is attempted.
ChemInform Abstract: Unusual Stereo‐ and Chemoselective Photocyclization of Chiral α‐Aminoacid‐Incorporated 2‐Acyl Benzamides by Control of Chiral Memory.
Authors: Liu Cai‐E , Han Qiang , Ma Nan , Geng Zheng‐Song , Zhang Rong‐Hua , Jiang Zhi‐Qin 
Published: May 2013

AbstractThe facile photolytic electron transfer cyclization includes concomitant decarboxylation to give benzoxazepine skeletons in a diastereoselective manner.
ChemInform Abstract: Synthesis of Aryl and Arylmethyl Phosphonates by Cross‐Coupling of Aryl or Arylmethyl Halides (X: I, Br and Cl) with Diisopropyl H‐Phosphonate.
Authors: Xu Kai , Hu Hao , Yang Fan , Wu Yangjie 
Published: May 2013

AbstractThe new method for the palladacycle‐catalyzed arylation reaction is applicable to a wide range of substrates as aryl iodides, bromides and chlorides tolerating diverse substitution pattern including several ortho‐substituents.
ChemInform Abstract: One‐Step Synthesis of Racemic α‐Amino Acids from Aldehydes, Amine Components, and Gaseous CO2 by the Aid of a Bismetal Reagent.
Authors: Mita Tsuyoshi , Higuchi Yuki , Sato Yoshihiro 
Published: May 2013

AbstractThis sequential reaction proceeds via two intermediates, an imine and an α‐amino stannane.
ChemInform Abstract: Graphene Oxide Nanoribbons (GNO), Reduced Graphene Nanoribbons (GNR), and Multi‐layers of Oxidized Graphene Functionalized with Ionic Liquids (GO‐IL) for Assembly of Miniaturized Electrochemical Devices
Authors: Valentini F. , Carbone M. , Palleschi G. 
Published: May 2013

AbstractReview: 171 refs.
Patterns of cortical reorganization in the adult marmoset after a cervical spinal cord injury
Authors: Bowes Charnese , Burish Mark , Cerkevich Christina , Kaas Jon 
Published: May 2013

ABSTRACTIn the present study, we used microelectrode recordings of multiunit responses to evaluate patterns of the reactivation of somatosensory cortex after sensory loss produced by spinal cord lesions in the common marmoset (Callithrix jacchus). These New World monkeys have become a popular model in studies of cortical organization and function. Primary somatosensory cortex and adjoining somatosensory areas can become extensively deactivated by lesions of somatosensory afferents as they ascend in the dorsal columns of the cervical spinal cord. Six to 7 weeks after complete lesions of the cuneate fasciculus subserving the forelimb at cervical levels 5–6, the hand region in contralateral areas 3b and 1 was reactivated by inputs from the forelimb, but excluded representations of some or all digits. In a similar manner, recording sites from the forelimb region of areas 2–5 responded to parts of the forelimb but not to digits after an extensive lesion of the contralateral cuneate fasciculus at C5–C6. Lesions that damaged only the gracile fasciculus or a small percentage of the cuneate fasciculus did not produce changes in the gross hand representation in contralateral areas 3b, 3a, 1, and 2. Finally, a complete but lower lesion of the cuneate fasciculus at C8 produced some abnormalities in the reactivation, but the digits were represented. The results indicate that areas 3a, 3b, 1, and 2–5 of the somatosensory cortex are extensively reactivated after large, apparently complete lesions of the contralateral cuneate fasciculus, but afferents from the digits may not contribute to their reactivation. J. Comp. Neurol. 521:3451‐3463, 2013. © 2013 Wiley Periodicals, Inc.
Upregulation of insulin‐like growth factor and interleukin 1β occurs in neurons but not in glial cells in the cochlear nucleus following cochlear ablation
Authors: Fuentes‐Santamaría Verónica , Alvarado Juan Carlos , Gabaldón‐Ull María Cruz , Manuel Juiz José 
Published: May 2013

ABSTRACTOne of the main mechanisms used by neurons and glial cells to promote repair following brain injury is to upregulate activity‐dependent molecules such as insulin‐like growth factor 1 (IGF‐1) and interleukin‐1β (IL‐1β). In the auditory system, IGF‐1 is crucial for restoring synaptic transmission following hearing loss; however, whether IL‐1β is also involved in this process is unknown. In this study, we evaluated the expression of IGF‐1 and IL‐1β within neurons and glial cells of the ventral cochlear nucleus in adult rats at 1, 7, 15, and 30 days following bilateral cochlear ablation. After the lesion, significant increases in both the overall mean gray levels of IGF‐1 immunostaining and the mean gray levels within cells of the cochlear nucleus were observed at 1, 7, and 15 days compared with control animals. The expression and distribution of IL‐1β in the ventral cochlear nucleus of ablated animals was temporally and spatially correlated with IGF‐1. We also observed a lack of colocalization between IGF‐1 and IL‐1β with either astrocytes or microglia at any of the time points following ablation. These results suggest that the upregulation of IGF‐1 and IL‐1β levels within neurons—but not within glial cells—may reflect a plastic mechanism involved in repairing synaptic homeostasis of the overall cellular environment of the cochlear nucleus following bilateral cochlear ablation. J. Comp. Neurol. 521:3478‐3499, 2013. © 2013 Wiley Periodicals, Inc.
Migration of Bone Marrow‐Derived Cells Into the Central Nervous System in Models of Neurodegeneration
Authors: Lampron Antoine , Pimentel‐Coelho Pedro M. , Rivest Serge 
Published: May 2013

AbstractMicroglia are the brain‐resident macrophages tasked with the defense and maintenance of the central nervous system (CNS). The hematopoietic origin of microglia has warranted a therapeutic potential for the hematopoietic system in treating diseases of the CNS. However, migration of bone marrow‐derived cells (BMDC) into the CNS is a marginal event under normal, healthy conditions. A busulfan‐based chemotherapy regimen was used for bone marrow transplantation in wild‐type mice before subjecting them to a hypoxic–ischemic brain injury or in APP/PS1 mice prior to the formation of amyloid plaques. The cells were tracked and analyzed throughout the development of the pathology. The efficacy of a preventive macrophage colony‐stimulating factor (M‐CSF) treatment was also studied to highlight the effects of circulating monocytes in hypoxic–ischemic brain injury. Such an injury induces a strong migration of BMDC into the CNS, without the need for irradiation. These migrating cells do not replace the entire microglial pool but rather are confined to the sites of injury for several weeks, suggesting that they could perform specific functions. M‐CSF showed neuroprotective effects as a preventive treatment. In APP/PS1 mice, the formation of amyloid plaques was sufficient to induce the entry of cells into the parenchyma, though in low numbers. This study confirms that BMDC infiltrate the CNS in animal models for stroke and Alzheimer's disease and that peripheral cells can be targeted to treat affected regions of the CNS. J. Comp. Neurol. 521:3863–3876, 2013. © 2013 Wiley Periodicals, Inc.
A Chemical Lift‐off Process: Removing Non‐Specific Adsorption in an Electrochemical Epstein–Barr Virus Immunoassay
Authors: Stratmann Lutz , Gebala Magdalena , Schuhmann Wolfgang 
Published: May 2013

AbstractUpon contact of sensor surfaces with complex biological samples containing a variety of different proteins, non‐specific adsorption hampers the high‐sensitive detection of the analyte in question. To substantially decrease the impact of non‐specific adsorption at thiol‐based self‐assembled monolayers, a chemical lift‐off process is introduced. A sequence of local hydrolysis of isooctyl 3‐mercaptopropionate, covalent binding of an antigen against the Epstein–Barr virus (EBV), stepwise incubation with a serum sample possibly containing the EBV antibody and an enzyme‐labeled anti‐human antibody is completed with a lift‐off by integral hydrolysis of the remaining ester groups at the self‐assembled monolayer. The cleavage of the ester removes any non‐specifically bound protein during a following stringent washing step. The substantial improvement of the detection limit of an electrochemical immunoassay against EBV using native recombinant antigens, their immobilization after local deprotection using a scanning electrochemical microscope (SECM) and the local read‐out using the generator–collector mode of SECM with redox cycling amplification demonstrates the successful application of the proposed lift‐off procedure.
Value and information: A profit maximizing strategy for Maxwell's demon
Authors: Morck Randall , Morowitz Harold 
Published: May 2013

AbstractApplications of Lagrange's method of undetermined multipliers in physics and economics suggest some analogies between the two disciplines. Applying Jaynes' approach to information theory reveals the long standing problem of Maxwell's demon in thermodynamics as a constrained optimization problem where information and energy are dual concepts. Temperature emerges as the energetic price of information. This approach highlights the economic features of the Maxwell demon discussed by Bridgman. It also suggests that an analog to temperature (or the price of information) should be present in any optimization problem constrained by costly information. A trivial economics example is presented where generalized temperature measures informational efficiency in the sense of Grossman and Stiglitz.
Order‐disorder transitions in the behavior of ant societies
Authors: Miramontes Octavio 
Published: May 2013

AbstractSystems of many interacting elements may exhibit both optimal information processing capabilities and optimal adaptive capacity when poised in a state at the boundary separating chaos from order. Ant societies, composed of interacting chaotic individuals, which can generate regular cycles in the activity of the colony, provide one of the very first examples of this phenomenon. They self‐organize to attain nest densities at which the transfer of information, per capita activations and the information capacity of the colonies are maximal. At such densities, ant colonies are poised in the neighborhood of a chaos‐order phase transition.
Complex systems in drug research: II. The ligand—active site—water confluence as a complex system
Authors: Kier Lemont B. , Testa Bernard 
Published: May 2013

AbstractThree partners are involved in any pharmacological phenomenon examined at the molecular level, namely a functional biomacromolecule (e.g., receptor or enzyme), a ligand molecule whose binding to the active site of the macromolecule triggers a response, and water which acts as a structural component and as a solvent. Some of the molecular events involved in initial steps of pharmacological responses are examined here as emergent properties of the triad active site‐ligand‐water, a complex system seldom viewed as such. For example, the exquisite selectivity and efficiency of long‐ and short‐range recognition of ligands may rest on more than simple random encounters. The emergent property of function suggests the possibility that active sites are maintained near criticality by low‐levels of endogenous ligands.
Genetic learning in strategic form games
Authors: Dawid Herbert , Mehlmann Alexander 
Published: May 2013

AbstractWe analyze the learning behavior of a Simple Genetic Algorithm in symmetric 3 × 3 Strategic‐Form‐Games. In cases of contests within one population and also between two populations the behavior of the SGA is compared with the behavior of the replicator dynamics and is analyzed with respect to equilibrium concepts in evolutionary game theory. Furthermore conservative non‐adaptive strings are added to the population which lead to convergence to an equilibrium even in “GA‐deceptive” games where the equilibrium can not be reached by GAs using only selection and crossover.