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Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.

This repository contains the data and analyses scripts accompanying the paper "Material constancy in perception and working memory".

The colors that people see depend not only on the surface properties of objects but also on how these properties interact with light as well as on how light reflected from objects interacts with an individual’s visual system. Because individual visual systems vary, the same visual stimulus may elicit different perceptions from different individuals. #thedress phenomenon drove home this point: different individuals viewed the same image and reported it to be widely different colors: blue and black versus white and gold. This phenomenon inspired a collection of demonstrations presented at the Vision Sciences Society 2015 Meeting which showed how spatial and temporal manipulations of light spectra affect people’s perceptions of material colors and illustrated the variability in individual color perception. The demonstrations also explored the effects of temporal alterations in metameric lights, including Maxwell’s Spot, an entoptic phenomenon. Crucially, the demonstrations established that #thedress phenomenon occurs not only for images of the dress but also for the real dress under real light sources of different spectral composition and spatial configurations.

This work was supported by the Leverhulme Trust (grant number RPG-2017-232) awarded to Constanze Hesse and Julie Harris and the Biotechnology and Biological Sciences Research Council (BBSRC) (grant number BB/M010996/1), EastBIO Doctoral Training Partnership awarded to Karina Kangur. Visually perceived roughness of 3D textures varies with illumination direction. Surfaces appear rougher when the illumination angle is lowered resulting in a lack of roughness constancy. Here we aimed to investigate whether the visual system also relies on illumination-dependent features when judging roughness in a crossmodal matching task or whether it can access illumination-invariant surface features that can also be evaluated by the tactile system. Participants ( N = 32) explored an abrasive paper of medium physical roughness either tactually, or visually under two different illumination conditions (top vs oblique angle). Subsequently, they had to judge if a comparison stimulus (varying in physical roughness) matched the previously explored standard. Matching was either performed using the same modality as during exploration (intramodal) or using a different modality (crossmodal). In the intramodal conditions, participants performed equally well independent of the modality or illumination employed. In the crossmodal conditions, participants selected rougher tactile matches after exploring the standard visually under oblique illumination than under top illumination. Conversely, after tactile exploration, they selected smoother visual matches under oblique than under top illumination. These findings confirm that visual roughness perception depends on illumination direction and show, for the first time, that this failure of roughness constancy also transfers to judgements made crossmodally. Publisher PDF

1. Engineering resilience, a forest’s ability to maintain its properties in the event of disturbance, comprises two components: resistance and recovery. In human-dominated landscapes, forest resilience depends mostly on recovery. Forest recovery largely depends on autogenic regulation, which entails a negative feedback loop between rates of change of forest state variables and state variables themselves. Hence community dynamics changes in response to deviations from forest equilibrium state. Based on the premise that autogenic regulation is a key aspect of the recovery process, here we tested the hypothesis that combined old-growth forest (OGF) and secondary forest (SF) dynamics should show autogenic regulation in state variables, and thus convergence towards OGF-based reference points, indicating forest resilience. 2. We integrated dynamic data for OGF (11-year monitoring) and SF (16-year monitoring) to analyse three key state variables (basal area, tree density, species richness), their annual rates of change, and their underlying demographic processes (recruitment, growth, mortality). We examined autogenic regulation through generalized linear mixed-effects models (GLMMs) to quantify functional relationships between rates of change of state variables (and underlying demographic processes), and their respective state variables. 3. State variables in OGF decreased moderately over time, against our prediction of OGF constancy. In turn, the three state variables analysed showed negative relationships with their respective rates of change, which allows the return of SF to OGF values after disturbance. In all cases, recruitment decreased with increasing values in state variables, while mortality increased. 4. The observed negative relationships between state variables, their rates of change and their underlying demographic processes support our hypothesis of integrated OGF and SF dynamics showing autogenic regulation for state variables. Competition seems to be a major driver of autogenic regulation given its dependence on a resource availability that declines as forest structure develops. 5. Synthesis. Based on a straightforward and comprehensive approach to quantify the extent to which tropical forest dynamics is self-regulated, this study highlights the role of autogenic regulation in tropical dry forest as a basic component of its resilience. This approach is potentially valuable for a generalised assessment of engineering resilience of forests worldwide.

Making sense of the world requires perceptual constancy—the stable perception of an object across changes in one’s sensation of it. To investigate whether constancy is intrinsic to perception, we tested whether humans can learn a form of constancy that is unique to a novel sensory skill (here, the perception of objects through click-based echolocation). Participants judged whether two echoes were different either because: (a) the clicks were different, or (b) the objects were different. For differences carried through spectral changes (but not level changes), blind expert echolocators spontaneously showed a high constancy ability (mean d′ = 1.91) compared to sighted and blind people new to echolocation (mean d′ = 0.69). Crucially, sighted controls improved rapidly in this ability through training, suggesting that constancy emerges in a domain with which the perceiver has no prior experience. This provides strong evidence that constancy is intrinsic to human perception., Public Significance Statement This study shows that people who learn a new skill to sense their environment - here: listening to sound echoes - can correctly represent the physical properties of objects. This result has implications for effectively rehabilitating people with sensory loss.

Timbre is that property of a sound that distinguishes it other than pitch and loudness, for instance the distinctive sound quality of a violin or flute. While the term is obscure, the concept has played an important, implicit role in recent philosophy of sound. Philosophers have debated whether to identify sounds with properties of waves, events, or objects. Many of the intuitive considerations in this debate apply most clearly to timbre qualities. Two prominent forms of timbre physicalism have emerged: one identifying timbre with the spectral composition of proximal waves; the second identifying timbre with the mechanical vibrations at a sound source. I demonstrate that the first possibility is conceptually unsatisfying, while the second fails to meet the standards of rigor established by the color physicalism literature. One response to these worries might be to adopt a more modest, non-reductive realism about timbre, such as the ecological view of J. J. Gibson.

Microbial communities drive many processes which affect human well-being directly, as in the human microbiome, or indirectly, as in natural environments or in biotechnological applications. Due to their complexity, their dynamics over time is difficult to monitor, and current sequence-based approaches are limited with respect to the temporal resolution. However, in order to eventually control microbial community dynamics, monitoring schemes of high temporal resolution are required. Flow cytometry provides single-cell-based data in the required temporal resolution, and we here use such data to compute stability properties as easy to interpret univariate indicators of microbial community dynamics. Such monitoring tools will allow for a fast, continuous, and cost-effective screening of stability states of microbiomes. Applicable to various environments, including bioreactors, surface water, and the human body, it will contribute to the development of control schemes to manipulate microbial community structures and performances., Natural microbial communities affect human life in countless ways, ranging from global biogeochemical cycles to the treatment of wastewater and health via the human microbiome. In order to probe, monitor, and eventually control these communities, fast detection and evaluation methods are required. In order to facilitate rapid community analysis and monitor a community’s dynamic behavior with high resolution, we here apply community flow cytometry, which provides single-cell-based high-dimensional data characterizing communities with high acuity over time. To interpret time series data, we draw inspiration from macroecology, in which a rich set of concepts has been developed for describing population dynamics. We focus on the stability paradigm as a promising candidate to interpret such data in an intuitive and actionable way and present a rapid workflow to monitor stability properties of complex microbial ecosystems. Based on single-cell data, we compute the stability properties resistance, resilience, displacement speed, and elasticity. For resilience, we also introduce a method which can be implemented for continuous online community monitoring. The proposed workflow was tested in a long-term continuous reactor experiment employing both an artificial and a complex microbial community, which were exposed to identical short-term disturbances. The computed stability properties uncovered the superior stability of the complex community and demonstrated the global applicability of the protocol to any microbiome. The workflow is able to support high temporal sample densities below bacterial generation times. This may provide new opportunities to unravel unknown ecological paradigms of natural microbial communities, with applications to environmental, biotechnological, and health-related microbiomes. IMPORTANCE Microbial communities drive many processes which affect human well-being directly, as in the human microbiome, or indirectly, as in natural environments or in biotechnological applications. Due to their complexity, their dynamics over time is difficult to monitor, and current sequence-based approaches are limited with respect to the temporal resolution. However, in order to eventually control microbial community dynamics, monitoring schemes of high temporal resolution are required. Flow cytometry provides single-cell-based data in the required temporal resolution, and we here use such data to compute stability properties as easy to interpret univariate indicators of microbial community dynamics. Such monitoring tools will allow for a fast, continuous, and cost-effective screening of stability states of microbiomes. Applicable to various environments, including bioreactors, surface water, and the human body, it will contribute to the development of control schemes to manipulate microbial community structures and performances.

The present experiment, carried out in nine production fields of reed canary grass (Phalaris arundinacea) grown for energy purposes, evaluated the effect of plantation age on the occurrence and species composition of weeds. The selected plantations were divided into 3 groups that were conventionally called “young” (1–2 years old), “middle-aged” (3–5 years old), and “older” plantations (6–8 years old). Regardless of plantation age, altogether 43 species were found in the experimental fields. Moreover, 6 species were common for all the plantations and were found in them regardless of plantation age. The least species, only 18, were found on the “young” plantations, almost twice more on the “older” ones (30 species), whereas the largest spectrum of species was found in the “middle-aged” plantations (33 species). In the “young” plantations, annual weeds were the most common, with the highest constancy and coverage index found for Chenopodium album, Matricaria maritima ssp. inodora and Echinochloa crus-galli. The greatest variation in species was found in the “middle-aged” plantations. However, only 4 species achieved the highest constancy and coverage index: Matricaria maritima ssp. inodora, Cirsium arvense, Poa trivialis and Taraxacum officinale. Furthermore, perennial weeds were found to be dominant in the “older” plantations. Within this group, Poa trivialis, Taraxacum officinale, Urtica dioica, Plantago maior, and Cirsium arvense had the highest constancy and coverage index.

This thesis offers an original account of the idea of constancy (heng 恆) in the Confucian-oriented Yi Jing through a creative rendition of heng in light of ideas in the Analects of Confucius. It argues that Confucian practices exemplify characteristics of heng which are communicated in the Yi Jing, namely, responsiveness, flexibility and timeliness. That is to say, a person who might be said to have the characteristic of heng responds to situations fittingly, taking into account the salient features of circumstances. To demonstrate this, the thesis starts from the analysis of heng in the Yi Jing, where heng is understood as human responsiveness. In particular, changes in the world where one is situated in one's position (wei 位), occur in time (shi 時). Therefore, a person must respond to events in his or her social-political context with flexibility -- remaining constant in a changing world. Following the analysis of heng in the Yi Jing, themes in the Analects, such as benevolence (ren 仁) and trustworthiness (xin 信), are selected to demonstrate the characteristics of heng. Both ren and xin are context- and practice -oriented, allowing us to focus more sharply on how a person can maintain his or her ultimate commitments in light of changing situations. This thesis presents a new interpretation of heng as human responsiveness that is valuable for understanding the Confucian-oriented Yi Jing and the Analects, and it also discloses the nature of Confucian ethical commitment and practices.

espanolEl secreto de Ser y tiempo y de su constante presencia cultural y filosofica descansa en su particular riqueza hermeneutica. Ser y tiempo es un sismografo capaz de detectar con una asombrosa precision los corrimientos y las fallas de la era contemporanea, ofreciendonos a la par una radiografia exacta de nuestra situacion moral y etica. Este libro no desarrolla una teoria filosofica mas, sino que se embarca en la aventura de pensar a fondo el problema central de la filosofia, a saber, la cuestion de la existencia humana y de su relacion con el ser. Desde este punto de vista se plantea la posibilidad de leer la obra magna de Heidegger en terminos de una etica del cuidado, es decir, como obra que promueve un cultivo de si. EnglishThe secret of Being and Time and of its constant cultural and philosophical presence lies in its unusual hermeneutical richness. Being and Time becomes, so to speak, a precise seismometer capable of detecting the slips and falls of the contemporary era with surprising accuracy. It offers us an exact scan of the ethical and moral conscience of our time. Being and Time does not develop a philosophical theory among others, rather it faces the challenge of thoroughly reflecting upon the dilemma that is constantly present in philosophy, namely the question of human being and its relation to being in general. From this point of view, I would like to consider the possibility of reading this fundamental work of Heidegger as an ethics of existence, that is, as book that promotes a cultivation of the self.

A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

The spectral sensitivity of the visual system varies markedly between the fovea and surrounding periphery owing in part to the rapid fall in macular pigment density with eccentricity. We examined how colour appearance changes between the fovea and near periphery (8°) by measuring achromatic loci and the loci of unique and binary hues. Chosen colours remained much more similar at the two locations than predicted by the change in spectral sensitivity. Compensation for white may reflect long-term gain changes within the cones that equate sensitivity for the local average stimulus in the fovea and periphery. However, adjusting only to the average stimulus cannot correct for all of the effects of a spectral sensitivity change, and predicts differences in colour percepts between the fovea and periphery that were not observed. The similarities in hue percepts at 0 and 8° thus suggest that additional processes help compensate colour appearance to maintain constancy in the near periphery. We model the results of previous studies to show that similar adjustments are implied by age-related changes in lens pigment, and to show that these adjustments are consistent with previous measurements of peripheral colour appearance based on hue cancellation.

The term simultaneous lightness constancy describes the capacity of the visual system to perceive equal reflecting\ud surfaces as having the same lightness despite lying in different illumination fields. In some cases, however, a\ud lightness constancy failure occurs; that is, equal reflecting surfaces appear different in lightness when differently illuminated. An open question is whether the luminance profile of the illumination edges affects simultaneous lightness constancy even when the ratio invariance property of the illumination edges is preserved. To explore this issue, we ran two experiments by using bipartite illumination displays. Both the luminance profile of an illumination edge and the luminance ratio amplitude between the illumination fields were manipulated. Results revealed that the simultaneous lightness constancy increases when the luminance profile of the illumination edge is gradual (rather than sharp) and homogeneous (rather than inhomogeneous), whereas it decreases when the luminance\ud ratio between the illumination fields is enlarged. The results are interpreted according to the layer decomposition\ud schema, stating that the visual system splits the luminance into perceived lightness and apparent illumination\ud components. We suggest that illumination edges having gradual and homogeneous luminance profiles facilitate\ud the luminance decomposition process, whereas wide luminance ratios impede it.

In the present study, discrete trial familiarization/novelty techniques were used to study lightness constancy in 4-month-old infants. The test stimuli were real objects (paper smiley faces) of two different reflectances, dark gray (17% reflectance) and light gray (54% reflectance). In Experiment 1, the test stimuli were viewed against a white (90% reflectance) surround, and in Experiment 2, against a black (4.6% reflectance) surround. In Experiments 1 and 2, the illumination was changed between familiarization and test phases of each trial. In Experiment 3, the reflectance of the surround was changed from white to mid gray (28.5% reflectance) between familiarization and test phases of each trial. With the white surround, the infants preferred the face with the novel reflectance, consistent with the presence of lightness constancy. With the black surround, the infants showed no preference between faces with novel reflectance vs. novel luminance. With the changing surround, the infants showed a small preference for the stimulus with the novel ratio, as opposed to the stimulus with the novel reflectance and the novel luminance. The results are discussed in the context of adult cues for lightness constancy, including white anchor points and local luminance ratios.

Humans can identify the colors of objects fairly consistently, despite considerable variations in the spectral composition of the illumination. It has been suggested that the correlation between luminance and color within a scene helps to disentangle the influences of illumination and reflectance, because the surfaces that reflect the light of the illuminant well will normally be bright. Because the reliability of the luminance-color correlation as an indicator of the chromaticity of the illuminant depends on the number of surfaces that are considered, we expected the correlation to be determined across large parts of the scene. To examine whether this is so, we compared different scenes with matched luminance and chromaticity, but in which the correlation between luminance and chromaticity was manipulated locally. Our results confirm that there is a bias in perceived color away from the chromaticity of bright surfaces. However, the results show that only the correlation within about 1degrees of the target is relevant. Thus, it is unlikely that the visual system uses the correlation between luminance and color to explicitly determine the chromaticity of the illuminant. Instead, this correlation is presumably implicitly considered in the way that the color contrast at borders is determined.

Genetic and environmental components were analysed in 32 Argentinian populations of Bromus catharticus. The research was based on 39 vegetative and reproductive characters. Constancy (rc) and heritability (h2) ratios were calculated. ANOVAS showed differences between populations for 14 traits, most of them reproductive. Total phenotypic variation was mostly due to the environmental component. Microfloral attributes showed the highest values of rc and h2. The traits average length of the spikelets (LS), average number of florets per spikelet (NFS), and lemma length (LL), which simultaneously reach rc values higher than 1 and h2 values higher than 0.60, could be considered useful in systematic studies. Leaf, stem, and some reproductive characters, linked to propagule production, had plastic responses. However, traits associated with size and shape of propagules and spikelets remained constant. Results suggest that a double strategy is operating: plasticity in some traits (to give greater adaptability), and constancy in other traits related to species stability that are of systematic significance., Facultad de Ciencias Agrarias y Forestales

For the surface reflectance of an object to be a useful cue to object identity, judgments of its color should remain stable across changes in the object's environment. In 2D scenes, there is general consensus that color judgments are much more stable across illumination changes than background changes. Here we investigate whether these findings generalize to real 3D objects. Observers made color matches to cubes as we independently varied both the illumination impinging on the cube and the 3D background of the cube. As in 2D scenes, we found relatively high but imperfect stability of color judgments under an illuminant shift. In contrast to 2D scenes, we found that background had little effect on average color judgments. In addition, variability of color judgments was increased by an illuminant shift and decreased by embedding the cube within a background. Taken together, these results suggest that in real 3D scenes with ample cues to object segregation, the addition of a background may improve stability of color identification.

The secret of Being and Time and of its constant cultural and philosophical presence lies in its unusual hermeneutical richness. Being and Time becomes, so to speak, a precise seismometer capable of detecting the slips and falls of the contemporary era with surprising accuracy. It offers us an exact scan of the ethical and moral conscience of our time. Being and Time does not develop a philosophical theory among others, rather it faces the challenge of thoroughly reflecting upon the dilemma that is constantly present in philosophy, namely the question of human being and its relation to being in general. From this point of view, I would like to consider the possibility of reading this fundamental work of Heidegger as an ethics of existence, that is, as book that promotes a cultivation of the self. El secreto de Ser y tiempo y de su constante presencia cultural y filosófica descansa en su particular riqueza hermenéutica. Ser y tiempo es un sismógrafo capaz de detectar con una asombrosa precisión los corrimientos y las fallas de la era contemporánea, ofreciéndonos a la par una radiografía exacta de nuestra situación moral y ética. Este libro no desarrolla una teoría filosófica más, sino que se embarca en la aventura de pensar a fondo el problema central de la filosofía, a saber, la cuestión de la existencia humana y de su relación con el ser. Desde este punto de vista se plantea la posibilidad de leer la obra magna de Heidegger en términos de una ética del cuidado, es decir, como obra que promueve un cultivo de sí.

Some of the knock-down factors applied in design of rocket launcher structures are based on design recommendations which rely on lower-bound curves from experimental data. The best known example is the NASA guideline SP 8007, published in 1965 and revised in 1968, which is applied for cylindrical structures in the space industry. This guideline is based on test data, computational methods and resources from the 1930–1960's. At that time the application of less empirical methods for the design of actual cylindrical shells could not count with the current computational power, and the available methods led to quite large discrepancies between experiments and test observations. Significant improvement on the available analyses approaches and manufacturing techniques since 1960's have not been taken into account in design processes using the NASA SP-8007, and many authors have recognized that for the current standards this guideline is leading to conservative structures. Another aspect for attention regarding application of the NASA SP-8007 for composite shells is that it does not consider the laminate stacking sequence. Moreover, physical observations regarding how does the imperfection sensitivity of unstiffened cylindrical shells change with the presence of an induced geometric imperfection have also suggested that the current applied design rules are too conservative. This conservativeness is confirmed by many tests carried out recently. This study presents an overview of the problem and a detailed description of the physical observations regarding the buckling mechanism of the thin shells under consideration. It is discussed how these observations can be used for less conservative, laminate dependent, knock-down factors accounting for geometric imperfections. The single perturbation load approach is studied in detail and a physically based definition for the minimum perturbation load (P1) is given, paving the way for the development of semi-analytical methods to calculate this minimum perturbation load.

Previous research has shown that accurate stepping involves the fixation of gaze on the intended step location. One possible explanation for this visual strategy is that the fixation of locations that are eccentric relative to the step target, results in systematic localization errors, as has previously been demonstrated in pointing. To test this idea, we assessed the possible role of gaze stabilization in the spatial planning of accurate steps, and determined whether the direction of mediolateral stepping errors depended on the direction of gaze. Final foot position was recorded from ten healthy participants when making steps towards prints of their own foot, in light and in darkness, and fixating their gaze on (i) the stepping target or (ii) locations 30 cm to the left or right of the target. The results showed that accuracy and precision of foot placement were reduced when stepping in darkness or when fixating eccentric gaze targets, demonstrating that visual feedback on the target and/or foot facilitates spatial control of the foot, and that foveal information is superior to perifoveal information in this respect. Crucially, the direction of the mediolateral stepping errors depended on the direction of gaze: on average participants overstepped 12 mm contralateral to the direction of gaze when fixating eccentric locations, indicating that the fixation of locations eccentric to the stepping target results in inaccuracies in foot placement. These results provide new insights into the contributions of foveal vision to the spatial planning of precise steps, and explain why it is important to look where you step when accurate foot placement is required. (C) 2012 Elsevier B. V. All rights reserved.

Density-dependent selection is expected to lead to population stability, especially if r and K tradeoff. Yet, there is no empirical evidence of adaptation to crowding leading to the evolution of stability. We show that populations of Drosophila ananassae selected for adaptation to larval crowding have higher K and lower r, and evolve greater stability than controls. We also show that increased population growth rates at high density can enhance stability, even in the absence of a decrease in r, by ensuring that the crowding adapted populations do not fall to very low sizes. We discuss our results in the context of traits known to have diverged between the selected and control populations, and compare our results with previous work on the evolution of stability in D. melanogaster. Overall, our results suggest that density-dependent selection may be an important factor promoting the evolution of relatively stable dynamics in natural populations.

The purpose of this work is to describe how the visual system groups surfaces of unequal lightness under complex patterns of illumination. We propose that the Gestalt principle of Grouping by Regularity explains this process better than the more often cited principle of Grouping by Similarity. In our first experiment we demonstrate that in a perceptual organization task, pitting proximity against illumination gradients, discounting the illuminant was contingent upon the periodicity of the illuminant. Traditional theories of lightness constancy and discounting the illuminant (Rock, Nijhawan, Palmer, & Tudor, 1992) cannot account for such effects. Three more experiments show that grouping is affected more by local luminance ratios than constant reflectance ratios. We conclude from these findings that Grouping by Regularity is a powerful grouping principle that operates pre-constancy.

Individuals differ in their susceptibility to simultaneous contrast. Are the underlying differences in neural machinery conserved across different stimulus dimensions? We measured the extent to which 101 subjects perceived simultaneous contrast on the dimensions of luminance, colour, luminance contrast, colour contrast, orientation, spatial frequency, motion and numerosity. Individual differences showed re-test reliability for each dimension (0.32⩽ICC(c,1)⩽0.78, p⩽0.05), but susceptibility to simultaneous contrast, with a few exceptions, was not correlated across dimensions. Either susceptibility to contrast arises empirically from an individual’s interactions with the environment, or it is genetically determined but independently for different dimensions.

Change-point problems arise in a variety of practical situations including engineering and health science applications. There are generally two approaches for these problems. One is the likelihood approach, and the other is the Bayesian approach. The Bayes-type test statistics, which are derived as the marginal likelihood ratio with appropriate prior distributions on the nuisance parameters, have been shown to provide higher power than likelihood ratio tests in linear regression models and first order autoregressive models. The change-point problem in logistic models has not been investigated extensively. The aim of this thesis is to provide a unified approach of Bayes-type and Rao's Score test to the problem of testing for constancy of parameters in logistic regression models, and explore the connection between Bayes-type tests and Rao's Score tests. Test Statistics are derived for changes at unknown times in the parameters of a logistic regression model. Asymptotic distribution theory for the tests is discussed. Simulations are carried out to compare the power with other options from the literature. An application of the test procedure on a real data set has been discussed.

En este articulo vuelvo a visitar algunos de los temas que antes he abordado, hace mucho tiempo. Necesitan reiteracion porque han sido re-examinados. El tema trata esencialmente sobre aprender del pasado y de la amplia gama de entornos que conocemos. Este es un recurso increible, un registro de como el ser humano ha creado ambientes, patrones y sus exitos y fracasos, entre otros. La suposicion que uno puede aprender del pasado, que hay valor en la tradicion, presupone alguna constancia de las personas y el entorno. Esto se discute brevemente y el punto alcanzado es que tal aprendizaje debe estar a cierto nivel de abstraccion. El trabajo a ese nivel tambien abre muchos campos nuevos e inesperados (y “poco probables”), se torna importante involucrar nuevos campos y sus evoluciones en la investigacion EBS (Environment-Behavior Studies). Un ejemplo reciente de este tipo de campos “poco probables” se discute brevemente. ABSTRACT In this paper I revisit some themes I have addressed before, some a very long time ago. They need reiterating because they are being re-examined. The topic is essentially about learning from the past and from the full range of environments about which we know. These are an incredible resource, a record of how human have created environments, their successes and failure, patterns, etc. The assumption that one can learn from the past, that there is value in tradition, presupposes some constancy regarding both people and environments. This is discussed briefly and the point made that such learning need to be at some level of abstraction. Working at that level also makes relevant many new and unexpected (and “unlikely”) fields, it then becomes important to involve new fields, and developments in them in EBS (Environment-Behavior Studies) research, one recent example of such on “unlikely” field is discussed briefly.

Lepidoptera pest species from eucalyptus were collected in Eucalyptus urophylla plantations in the region of Três Marias, State of Minas Gerais, Brazil, every 15 days from June 1989 to June 1994 with five light traps. Twelve primary and 15 secondary pest species were collected in the period with an average of 13 387 and 812 individuals per light trap, respectively. Most collected primary pest species were Stenalcidia grosica (Geometridae), Iridopsis subferaria (Geometridae), Eupseudosoma aberrans (Arctiidae) and Psorocampa denticulata (Notodontidae), totalizing for the study period an average of 5 450, 2 162, 2 436 and 1 458 individuals per light trap, respectively. Idalus admirabilis (Arctiidae) was the most collected secondary pest species, averaging 652 individuals/trap. Most primary pest species were collected during the dry season, from April to July, whereas most secondary pest species were collected during the rainy season, from January to March. These differences on seasonal occurrence between the two groups could be due to the fact that many secondary pest species of Eucalyptus in Brazil pupate in the soil, and they need humidity to complete its pupal stageLa ocurrencia de plagas primarias y secundarias del orden Lepidoptera fue estudiada desde junio de 1989 hasta junio de 1994 en plantaciones de Eucalyptus urophylla, localizadas en la region de Tres Marias, Estado de Minas Gerais, Brasil. Durante este periodo, las colectas de lepidópteros fueron realizadas quincenalmente usando cinco trampas de luz. Después de cinco años de recolección la media total por trampa fue de 13 387 especímenes de plagas primarias y 812 de plagas secundarias, pertenecientes a 12 y 15 especies diferentes respectivamente. Las cuatro especies de plagas primarias más comunes fueron Stenalcidia grosica (Geometridae), Iridopsis subferaria (Geometridae), Eupseudosoma aberrans (Arctiidae) e Psorocampa denticulata (Notodontidae) con media de 5 450; 2 162; 2 436 y 1 458 especímenes, respectivamente. A su vez, la plaga secundaria más comun entre las colectadas fue Idalus admirabilis (Arctiidae) con media de 652 especímenes. Por outro lado, durante la estación seca (marzo a julio) fue la época más adecuada para la presencia de plagas primarias, mientras que durante la época lluviosa (enero a marzo) fue la más apropriada para las plagas secundarias