Baldwin Effect Research Articles

Manipulation of Nanson's and Baldwin's Rules

Nanson's and Baldwin's voting rules selecta winner by successively eliminatingcandidates with low Borda scores. We showthat these rules have a number of desirablecomputational properties. In particular,with unweighted votes, it isNP-hard to manipulate either rule with one manipulator, whilstwith weighted votes, it isNP-hard to manipulate either rule with a small number ofcandidates and a coalition of manipulators.As only a couple of other voting rulesare known to be NP-hard to manipulatewith a single manipulator, Nanson'sand Baldwin's rules appearto be particularly resistant to manipulation from a theoretical perspective.We also propose a number of approximation methodsfor manipulating these two rules.Experiments demonstrate that both rules areoften difficult to manipulate in practice.These results suggest that elimination stylevoting rules deserve further study.

THE BLUESHIFTING AND BALDWIN EFFECTS FOR THE [O III] λ5007 EMISSION LINE IN TYPE 1 ACTIVE GALACTIC NUCLEI

We use homogeneous samples of radio-quiet Seyfert 1 galaxies and QSOs selected from the Sloan Digital Sky Survey to investigate the connection between the velocity shift and the equivalent width (EW) of the [O III] λ5007 emission line, and their correlations with physical parameters of active galactic nuclei (AGNs). We find a significant and negative correlation between the EW of the core component, EW(core), and the blueshift of either the core (the peak), the wing, or the total profile of [O III] emission; it is fairly strong for the blueshift of the total profile in particular. However, both quantities (EW and velocity shift) generally have only weak, if any, correlations with fundamental AGN parameters such as the nuclear continuum luminosity at 5100 A (L 5100), black hole mass (M BH), and the Eddington ratio (L/L Edd); these correlations include the classical Baldwin effect of EW(core), an inverse Baldwin effect of EW(wing), and the relationship between velocity shifts and L/L Edd. Our findings suggest that both the large object-to-object variation in the strength of [O III] emission and the blueshift-EW(core) connection are not governed primarily by fundamental AGN parameters such as L 5100, M BH, and L/L Edd. We propose that the interstellar medium conditions of the host galaxies play a major role instead in the diversity of the [O III] properties in active galaxies. This suggests that the use of [O III] λ5007 luminosity as a proxy of AGN luminosity does not depend strongly on the above-mentioned fundamental AGN parameters.

Rules for Anionic and Radical Ring Closure of Alkynes

This work reexamined the stereoelectronic basis for the "favored attack trajectories" regarding the nucleophilic and radical cyclizations of alkynes. In contrast to the original Baldwin rules, the acute attack angle of a nucleophile leading to the proposed endo-dig preference for the formation of small cycles is less favorable stereoelectronically than the alternative obtuse trajectory leading to the formation of exo-dig products. For smaller cycles, this intrinsic stereoelectronic preference can be masked by the greater thermodynamic stability of the less strained endo-products. Unbiased comparison of competing cyclization attacks has been accomplished via dissection of the activation barrier into the intrinsic barrier and thermodynamic component via Marcus theory. Intrinsic barriers of thermoneutral reactions strongly favor exo-dig closures, in full accord with the greater magnitude of two-electron bond forming interactions for the obtuse trajectory. This analysis agrees very well with experimental observations of efficient 3-exo-dig and 4-exo-dig cyclizations predicted to be unfavorable by the Baldwin rules and with the calculated 3-exo-/4-endo-, 4-exo-/5-endo-, and 5-exo-/6-endo-dig selectivities in the cyclizations of carbon-, nitrogen-, and oxygen-centered nucleophiles. The generality of these predictions is confirmed by analogous trends for the related radical cyclizations where the stereoelectronically favorable exo-closures are also preferred kinetically, with a few exceptions where a large difference in product stability skews the intrinsic stereoelectronic trends.

A Game-Theoretic Analysis of the Baldwin Effect

The Baldwin effect is a process by which learnt traits become gradually incorporated into the genome through a Darwinian mechanism. From its inception, the Baldwin effect has been regarded with skepticism. The objective of this paper is to relativize this assessment. Our contribution is two-fold. To begin with, we provide a taxonomy of the different arguments that have been advocated in its defense, and distinguish between three justificatory dimensions—feasibility, explanatory relevance and likelihood—that have been unduly conflated. Second, we sharpen the debate by providing an evolutionary game theoretic perspective that is able to generalize previous results. The upshot of this paper is that the mechanism envisaged by Baldwin is less puzzling than commonly thought.

A novel sexual adaptive genetic algorithm based on Baldwin effect for global optimization

PurposeA novel sexual adaptive genetic algorithm (AGA) based on Baldwin effect for global optimization is proposed to overcome the shortcomings of traditional GAs, such as premature convergence, stochastic roaming, and poor capabilities in local exploring. This paper seeks to discuss the issues.Design/methodology/approachThe proposed algorithm simulates sexual reproduction and adopts an effective gender determination method to divide the population into two subgroups of different genders. Based on the competition, cooperation, and innate differences between two gender subgroups, the proposed algorithm adjusts adaptively sexual genetic operators. Furthermore, inspired by the acquired reinforcement learning theory based on Baldwin effect, the proposed algorithm guides individuals to forward or reverse learning and enables the transmission of fitness information between parents and offspring to adapt individuals' acquired fitness.FindingsGlobal convergence of the proposed algorithm is proved in detail. Numerical simulations are conducted for a set of benchmark functions with different dimensional decision variables. The performance of the proposed algorithm is compared with that of the other evolutionary algorithms published recently. The results indicate that the proposed algorithm can find optimal or closer‐to‐optimal solutions, and is more competitive than the compared algorithms.Originality/valueThe proposed algorithm introduces, integrates and simulates correctly and adequately, for the first time, the mechanisms of sexual reproduction, Baldwin effect and adaptation to GAs by referring to the latest research results of modern biology and evolution theory.

INTERPLAY BETWEEN STELLAR SPIRALS AND THE INTERSTELLAR MEDIUM IN GALACTIC DISKS

We use homogeneous samples of radio-quiet Seyfert 1 galaxies and QSOs selected from the Sloan Digital Sky Survey to investigate the connection between the velocity shift and the equivalent width (EW) of the [OIII] 5007 emission line, and their correlations with physical parameters of active galactic nuclei (AGNs). We find a significant and negative correlation between the EW of the core component, EW(core), and the blueshift of either the core (the peak), the wing, or the total profile of [OIII] emission; it is fairly strong for the blueshift of the total profile particularly. However, both quantities (EW and velocity shift) generally have only weak, if any, correlations with fundamental AGN parameters such as the nuclear continuum luminosity at 5100 L_{5100}, black hole mass (M_{BH}), and the Eddington ratio (L/L_{Edd}); these correlations include the classical Baldwin effect of EW(core), an inverse Baldwin effect of EW(wing), and the relationship between velocity shifts and \lratio. Our findings suggest that both the large object-to-object variation in the strength of [OIII] emission and the blueshift--EW(core) connection are not governed primarily by fundamental AGN parameters such as L_{5100}, M_{BH} and L/L_{Edd}. We propose that the ISM conditions of the host galaxies play a major role instead in the diversity of the [OIII] properties in active galaxies. This suggests that the use of[OIII] 5007 luminosity as proxy of AGN luminosity does not depend strongly on the above-mentioned fundamental AGN parameters.

The interplay between genetic and learned components of behavioral traits

This article considers the evolution of behavioral traits that have both a genetic basis and can be modified. The modifications considered concern an adaptive (learnt) response to environmental influences. In theory, the evolution of such traits may lead to two extreme outcomes; one where the trait becomes genetically fixed (and phenotypically invariable) and the other where it is entirely shaped by environmental influences. Between these extremes lies a spectrum of traits containing a genetic component, but also, to differing degrees, a modifiable component. We review theory considering how learning may affect the genetic evolution of a behavioral trait (commonly referred to as the Baldwin effect). We claim behavioral interactions in tritrophic systems, such as the responses of natural enemies to herbivore-induced plant volatiles, provide an excellent model system to study the Baldwin effect and we illustrate this with recent findings on the searching behavior of the predatory mite Phytoseiulus persimilis.

CORRELATIONS OF QUASAR OPTICAL SPECTRA WITH RADIO MORPHOLOGY

(Abridged) With the largest homogeneous quasar sample with optical spectra and robust radio morphology classifications assembled to date, we investigate quasar radio and optical properties with unprecedented statistical power. The data consist of 4714 radio quasars from FIRST with S_{20}>2mJy and SDSS spectra. Radio morphology classes include core-only (core), core-lobe (lobe), core-jet (jet), lobe-core-lobe (triple), and double-lobe. We examine the optical colors of radio-morphology subsamples and find that radio quasars with core emission unresolved by FIRST (on 5" scale) have a redder color distribution than radio-quiet quasars (S_{20}<1mJy); other classes of radio quasars have optical color distributions similar to the radio-quiet quasars. This analysis also suggests that optical colors of z<2.7 SDSS quasars are not strongly (<0.1mag) biased blue. We show that the radio core-to-lobe flux density ratio (R) and the radio-to-optical (i-band) ratio of the quasar core (RI) are correlated, suggesting that both parameters are indicative of line-of-sight orientation. We investigate spectral line equivalent widths as a function of R and RI, including the [OIII] narrow line doublet and the CIV {\lambda}1549 and MgII {\lambda}2799 broad lines. We find that the rest equivalent widths (EWs) of the broad lines correlate positively with RI at the 4-8{\sigma} level. But we find no strong dependence of EW on R, in contrast to previous results. One interpretation is that EWs increase as the line-of-sight angle to the radio-jet axis decreases. These results are in stark contrast to commonly accepted orientation-based theories, which suggest that continuum emission should increase as the angle to the radio-jet axis decreases, resulting in smaller EW of emission lines (assumed isotropic). Finally, we find that the Baldwin effect in our sample does not depend on quasar radio morphology.

UNIFICATION OF LUMINOUS TYPE 1 QUASARS THROUGH C IV EMISSION

Using a sample of 30,000 quasars from SDSS-DR7, we explore the range of properties exhibited by high-ionization, broad emission lines, such as CIV 1549. Specifically we investigate the anti-correlation between L_UV and emission line EQW (the Baldwin Effect) and the "blueshifting" of high-ionization emission lines. The blueshift of the CIV emission line is nearly ubiquitous, with a mean shift of 810 km/s for radio-quiet (RQ) quasars and 360 km/s for radio-loud (RL) quasars, and the Baldwin Effect is present in both RQ and RL samples. Composite spectra are constructed as a function of CIV emission line properties in attempt to reveal empirical relationships between different line species and the SED. Within a two-component disk+wind model of the broad emission line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL quasars are consistent with being dominated by the disk component, while BALQSOs are consistent with being dominated by the wind component. Some RQ objects have emission line features similar to RL quasars; they may simply have insufficient black hole (BH) spin to form radio jets. Our results suggest that there could be significant systematic errors in the determination of L_bol and BH mass that make it difficult to place these findings in a more physical context. However, it is possible to classify quasars in a paradigm where the diversity of BELR parameters are due to differences in an accretion disk wind between quasars (and over time); these differences are underlain primarily by the SED, which ultimately must be tied to BH mass and accretion rate.

Biological Adaptations for Functional Features of Language in the Face of Cultural Evolution

Although there may be no true language universals, it is nonetheless possible to discern several family resemblance patterns across the languages of the world. Recent work on the cultural evolution of language indicates the source of these patterns is unlikely to be an innate universal grammar evolved through biological adaptations for arbitrary linguistic features. Instead, it has been suggested that the patterns of resemblance emerge because language has been shaped by the brain, with individual languages representing different but partially overlapping solutions to the same set of nonlinguistic constraints. Here, we use computational simulations to investigate whether biological adaptation for functional features of language, deriving from cognitive and communicative constraints, may nonetheless be possible alongside rapid cultural evolution. Specifically, we focus on the Baldwin effect as an evolutionary mechanism by which previously learned linguistic features might become innate through natural selection across many generations of language users. The results indicate that cultural evolution of language does not necessarily prevent functional features of language from becoming genetically fixed, thus potentially providing a particularly informative source of constraints on cross-linguistic resemblance patterns.

Biological Adaptations for Functional Features of Language in the Face of Cultural Evolution

Although there may be no true language universals, it is nonetheless possible to discern several family resemblance patterns across the languages of the world. Recent work on the cultural evolution of language indicates the source of these patterns is unlikely to be an innate universal grammar evolved through biological adaptations for arbitrary linguistic features. Instead, it has been suggested that the patterns of resemblance emerge because language has been shaped by the brain, with individual languages representing different but partially overlapping solutions to the same set of nonlinguistic constraints. Here, we use computational simulations to investigate whether biological adaptation for functional features of language, deriving from cognitive and communicative constraints, may nonetheless be possible alongside rapid cultural evolution. Specifically, we focus on the Baldwin effect as an evolutionary mechanism by which previously learned linguistic features might become innate through natural selection across many generations of language users. The results indicate that cultural evolution of language does not necessarily prevent functional features of language from becoming genetically fixed, thus potentially providing a particularly informative source of constraints on cross-linguistic resemblance patterns.

Ring-Closure Reactions of 1,2-Diaza-4,5-benzoheptatrienyl Metal Compounds: Experiment and Theory

2-Alkenylbenzylidene hydrazones 5a-m, which are accessible in good to excellent yields in a four-step synthesis, are converted into 1,2-diaza-4,5-benzoheptatrienyl metal compounds 1a-m by treatment with KO-t-Bu as base. These metal compounds undergo the various types of reactions in good yields and exclusively depending on the nature of substituents R(1) and R(3). Thus, metal compounds 1a-c carrying alkyl substituents R(1) and R(3) form 3H-benzodiazepines 6a-c after electrophilic quench of the intermediate cyclic anion 7 in a 7-endo-trig electrocyclic reaction with a möbius aromatic transition structure 1(-)-TS. Similarly, a benzothienyl derivative 5n is converted into diazepine 6d. Potassium compounds 1d-h, which are N-methyl and aryl substituted at R(3), form 1,2-dihydrophthalazines 8a-e in a predominantly charge-controlled 6-exo-trig cyclization reaction. In contrast, aryl-aryl-substituted systems 5i-m did not lead to cyclic products upon deprotonation, but the intermediate open-chain metal compounds 1i-m were trapped by acid chlorides at N1 to yield the hydrazides 10a-e. We interpret thermodynamics and kinetics of these reactions in the context of the Baldwin rules on the basis of quantum chemical calculations and discuss the transition structures considering the results of NICS and NBO-charge calculations. Examples of the products 6, 8, and 10 could be characterized by X-ray diffraction.

Naming Game and Computational Modelling of Language Evolution

Computational modelling with multi-agent systems has become an important technique in studying language evolution. We present a brief introduction into this rapidly developing field, as well as our own contributions, which include an analysis of the evolutionary naming game model. In this model, communicating agents, which try to establish a common vocabulary, are equipped with an evolutionarily selected learning ability. Such a coupling of biological and linguistic ingredients results in an abrupt transition: upon a small change of the model control parameter, a poorly communicating group of agents with small learning abilities transforms into almost perfectly communicating group of agents with large learning abilities. Genetic imprinting of the learning abilities progresses through the Baldwin effect: initially linguistically unskilled agents learn a language, which creates a niche where there is an evolutionary pressure for the increase of learning ability. Under the assumption that communication intensity increases continuously with finite speed, the transition is split into several transition-like changes. It shows that the speed of cultural changes, that sets an additional characteristic time scale, might be yet another factor affecting the evolution of language. In our opinion, this model shows that linguistic and biological processes have a strong influence on each other and this influence certainly has contributed to an explosive development of our species.

THEXMM-NEWTONX-RAY SPECTRA OF THE MOST X-RAY LUMINOUS RADIO-QUIETROSATBRIGHT SURVEY-QSOs: A REFERENCE SAMPLE FOR THE INTERPRETATION OF HIGH-REDSHIFT QSO SPECTRA

We present the broadband X-ray properties of four of the most X-ray luminous (L{sub X} {>=} 10{sup 45} erg s{sup -1} in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe K{alpha} fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe K{alpha} centroids and the line widths indicate emission from neutral Fe (E = 6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L{sub X} {approx} 10{sup 44} erg s{sup -1} (2-10more » keV band) where an almost constant (EW) of {approx}100 eV is found. We confirm the assumption of having very similar X-ray active galactic nucleus properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.« less

COSMIC RAY ACCELERATORS IN THE LARGE MAGELLANIC CLOUD

We present the broadband X-ray properties of four of the most X-ray luminous (L_X >= 10^{45} erg/s in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe K-alpha fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe K-alpha centroids and the line widths indicate emission from neutral Fe (E=6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L_X ~ 10^{44} erg/s (2-10 keV band) where an almost constant <EW> of ~100 eV is found. We confirm the assumption of having very similar X-ray AGN properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.

Relaxation of Selection, Niche Construction, and the Baldwin Effect in Language Evolution

Deacon has suggested that one of the key factors of language evolution is not characterized by an increase in genetic contribution, often known as the Baldwin effect, but rather by a decrease. This process effectively increases linguistic learning capability by organizing a novel synergy of multiple lower-order functions previously irrelevant to the process of language acquisition. Deacon posits that this transition is not caused by natural selection. Rather, it is due to the relaxation of natural selection. While there are some cases in which relaxation caused by some external factors indeed induces the transition, we do not know what kind of relaxation has worked in language evolution. In this article, a genetic-algorithm-based computer simulation is used to investigate how the niche-constructing aspect of linguistic behavior may trigger the degradation of genetic predisposition related to language learning. The results show that agents initially increase their genetic predisposition for language learning—the Baldwin effect. They create a highly uniform sociolinguistic environment—a linguistic niche construction. This means that later generations constantly receive very similar inputs from adult agents, and subsequently the selective pressure to retain the genetic predisposition is relaxed.

Detecting the intrinsic Baldwin Effect of the optical FeII complex in luminous Seyfert 1 galaxy fairall 9

We analyze the optical spectra of Fairall 9, a luminous Seyfert 1 galaxy. They are obtained from the AGN Watch program that has monitored this object for 9 months. The flux and variation of the optical FeII complex is measured using multi-component profile modeling with FeII templates. A convincing intrinsic Baldwin Effect (BEff) of optical FeII emission blends in Fairall 9 is discovered for the first time. The variation of FeII/Hβ (R Fe) in Fairall 9 is obtained. We also detect a marginal anti-correlation between R Fe and the continuum flux in its spectra. This anti-correlation and the relatively broad profile of Hβ in this galaxy support the dichotomy reported by Wang et al. (2005).

ChemInform Abstract: Stereoelectronic Factors in the Synthesis of Tetrahydrofurans by Hydroxyl Participation in Phenylthio Migration.

Abstract The factors controlling the title reaction were investigated with two tethered hydroxyl nucleophiles and include preferential attack at the more highly substituted carbon atom, preferential formation of the more highly substituted five-membered ring, and preferential closure in the 5- exo-tet sense according to Baldwin's rules.

Universal grammar and the Baldwin effect: a hypothesis and some philosophical consequences

Grammar is now widely regarded as a substantially biological phenomenon, yet the problem of language evolution remains a matter of controversy among Linguists, Cognitive Scientists, and Evolutionary Theorists alike. In this paper, I present a new theoretical argument for one particular hypothesis—that a “Language Acquisition Device” of the sort first posited by Noam Chomsky might have evolved via the so-called “Baldwin Effect”. Close attention to the workings of that mechanism, I argue, helps to explain a previously mysterious feature of the Language Acquisition Device—the sheer variety of languages it allows the child to learn—thereby revealing a far stronger case than adherents of the hypothesis have previously supposed. A further unheralded consequence of the hypothesis is a conceptual shift in the Chomskyan understanding of language, wherein the essentially public nature of language is freshly emphasised. This has the effect of bringing the Chomskyan view into closer accord with Saussurean accounts of language, as well as with recent trends in evolutionary theory.

ANALYSIS OF OPTICAL Fe II EMISSION IN A SAMPLE OF ACTIVE GALACTIC NUCLEUS SPECTRA

We present a study of optical Fe ii emission in 302 active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey. We group the strongest Fe ii multiplets into three groups according to the lower term of the transition (b4F, a6S, and a4G terms). These approximately correspond to the blue, central, and red parts, respectively, of the "iron shelf" around Hβ. We calculate an Fe ii template that takes into account transitions into these three terms and an additional group of lines, based on a reconstruction of the spectrum of I Zw 1. This Fe ii template gives a more precise fit of the Fe ii lines in broad-line AGNs than other templates. We extract Fe ii, Hα, Hβ, [O iii], and [N ii] emission parameters and investigate correlations between them. We find that Fe ii lines probably originate in an intermediate line region. We note that the blue, red, and central parts of the iron shelf have different relative intensities in different objects. Their ratios depend on continuum luminosity, FWHM Hβ, the velocity shift of Fe ii, and the Hα/Hβ flux ratio. We examine the dependence of the well-known anti-correlation between the equivalent widths of Fe ii and [O iii] on continuum luminosity. We find that there is a Baldwin effect for [O iii] but an inverse Baldwin effect for the Fe ii emission. The [O iii]/Fe ii ratio thus decreases with Lλ5100. Since the ratio is a major component of the Boroson & Green Eigenvector 1 (EV1), this implies a connection between the Baldwin effect and EV1 and could be connected with AGN evolution. We find that spectra are different for Hβ FWHMs greater and less than ∼3000 km s−1, and that there are different correlation coefficients between the parameters.