76 Matching Annotations
  1. Oct 2021
    1. Cada aspecto de la visión, desde las proteínas de opsina hasta los ojos y las formas en que sirven al comportamiento animal, es increíblemente diverso. Solo con una perspectiva evolutiva se puede comprender y apreciar plenamente esta diversidad. En esta revisión, describo y explico la diversidad en cada nivel y trato de transmitir una comprensión de cómo el origen de la primera ops en hace unos 800 millones de años pudo iniciar la avalancha que produjo la asombrosa diversidad de ojos y visiones que vemos hoy. A pesar de la diversidad, muchos tipos de fotorreceptores, ojos y roles visuales han evolucionado varias veces de forma independiente en diferentes animales, revelando un patrón de evolución ocular estrictamente guiado por limitaciones funcionales e impulsado por la evolución de comportamientos gradualmente más exigentes.
  2. Sep 2021
    1. We propose a venture into an existential opportunity for establishing a world ‘good enough’ for humans to live in. Defining an existential opportunity as the converse of an existential risk—that is, a development that promises to dramatically improve the future of humanity—we argue that one such opportunity is available and should be explored now. The opportunity resides in the moment of transition of the Internet—from mediating information to mediating distributed direct governance in the sense of self-organization. The Internet of tomorrow will mediate the execution of contracts, transactions, public interventions and all other change-establishing events more reliably and more synergistically than any other technology or institution. It will become a distributed, synthetically intelligent agent in itself. This transition must not be just observed, or exploited instrumentally: it must be ventured into and seized on behalf of entire humanity. We envision a configuration of three kinds of cognitive system—the human mind, social systems and the emerging synthetic intelligence—serving to augment the autonomy of the first from the ‘programming’ imposed by the second. Our proposition is grounded in a detailed analysis of the manner in which the socio-econo-political system has evolved into a powerful control mechanism that subsumes human minds, steers their will and automates their thinking. We see the venture into the existential opportunity described here as aiming at the global dissolution of the core reason of that programming’s effectiveness—the critical dependence of the continuity of human lives on the coherence of the socially constructed personas they ‘wear.’ Thus, we oppose the popular prediction of the upcoming, ‘dreadful AI takeover’ with a call for action: instead of worrying that Artificial Intelligence will soon come to dominate and govern the human world, let us think of how it could help the human being to finally be able to do it.
  3. Aug 2021
    1. Furthermore, we prove that a maximally coherent network with constant interaction strengths will always be linearly stable. We also propose a simple model that, by correctly capturing the trophic coherence of food webs, accurately reproduces their stability and other basic structural features. Most remarkably, our model shows that stability can increase with size and complexity. This suggests a key to May’s paradox, and a range of opportunities and concerns for biodiversity conservation.
  4. Jul 2021
  5. Jun 2021
    1. BACKGROUNDThe interdisciplinary field of animal coloration is growing rapidly, spanning questions about the diverse ways that animals use pigments and structures to generate color, the underlying genetics and epigenetics, the perception of color, how color information is integrated with information from other senses, and general principles underlying color’s evolution and function. People working in the field appreciate linkages between these parallel lines of enquiry, but outsiders need the easily navigable roadmap that we provide here. ADVANCESIn the past 20 years, the field of animal coloration research has been propelled forward by technological advances that include spectrophotometry, digital imaging, computational neuroscience, innovative laboratory and field studies, and large-scale comparative analyses, which are allowing new questions to be asked. For example, we can now pose questions about the evolution of camouflage based on what a prey’s main predator can see, and we can start to appreciate that gene changes underlying color production have occurred in parallel in unrelated species. Knowledge of the production, perception, and evolutionary function of coloration is poised to make contributions to areas as diverse as medicine, security, clothing, and the military, but we need to take stock before moving forward. OUTLOOKHere, a group of evolutionary biologists, behavioral ecologists, psychologists, optical physicists, visual physiologists, geneticists, and anthropologists review this diverse area of science, daunting to the outsider, and set out what we believe are the key questions for the future. These are how nanoscale structures are used to manipulate light; how dynamic changes in coloration occur on different time scales; the genetics of coloration (including key innovations and the extent of parallel changes in different lineages); alternative perceptions of color by different species (including wavelengths that we cannot see, such as ultraviolet); how color, pattern, and motion interact; and how color works together with other modalities, especially odor. From an adaptive standpoint, color can serve several functions, and the resulting patterns frequently represent a trade-off among different evolutionary drivers, some of which are nonvisual (e.g., photoprotection). These trade-offs can vary between individuals within the same population, and color can be altered strategically on different time scales to serve different purposes. Lastly, interspecific differences in coloration, sometimes even observable in the fossil record, give insights into trait evolution. The biology of color is a field that typifies modern research: curiosity-led, technology-driven, multilevel, interdisciplinary, and integrative.
  6. May 2021
    1. Aposematic signals are often characterized by high conspicuousness. Larger and brighter signals reinforce avoidance learning, distinguish defended from palatable prey and are more easily memorized by predators. Conspicuous signalling, however, has costs: encounter rates with naive, specialized or nutritionally stressed predators are likely to increase. It has been suggested that intermediate levels of aposematic conspicuousness can evolve to balance deterrence and detectability, especially for moderately defended species. The effectiveness of such signals, however, has not yet been experimentally tested under field conditions. We used dough caterpillar-like baits to test whether reduced levels of aposematic conspicuousness can have survival benefits when predated by wild birds in natural conditions. Our results suggest that, when controlling for the number and intensity of internal contrast boundaries (stripes), a reduced-conspicuousness aposematic pattern can have a survival advantage over more conspicuous signals, as well as cryptic colours. Furthermore, we find a survival benefit from the addition of internal contrast for both high and low levels of conspicuousness. This adds ecological validity to evolutionary models of aposematic saliency and the evolution of honest signalling.

      Las señales aposemáticas a menudo se caracterizan por una gran notoriedad. Las señales más grandes y brillantes refuerzan el aprendizaje de la evitación, distinguen a las presas defendidas de las apetecibles y los depredadores las memorizan más fácilmente. Sin embargo, la señalización llamativa tiene costos: es probable que aumenten las tasas de encuentro con depredadores ingenuos, especializados o con estrés nutricional. Se ha sugerido que los niveles intermedios de notoriedad aposemática pueden evolucionar para equilibrar la disuasión y la detectabilidad, especialmente para las especies moderadamente defendidas. Sin embargo, la efectividad de tales señales aún no se ha probado experimentalmente en condiciones de campo. Usamos cebos en forma de oruga para probar si los niveles reducidos de visibilidad aposemática pueden tener beneficios de supervivencia cuando son depredados por aves silvestres en condiciones naturales. Nuestros resultados sugieren que, al controlar el número y la intensidad de los límites de contraste internos (rayas), un patrón aposemático de visibilidad reducida puede tener una ventaja de supervivencia sobre las señales más conspicuas, así como los colores crípticos. Además, encontramos un beneficio de supervivencia de la adición de contraste interno tanto para niveles altos como bajos de notoriedad. Esto agrega validez ecológica a los modelos evolutivos de prominencia aposemática y la evolución de la señalización honesta.

    1. Frequency-dependent predation may maintain or prevent colour pattern polymorphisms in prey, and can be caused by a variety of biological phenomena, including perceptual processes (search images), optimal foraging and learning. Most species are preyed upon by more than one predator species, which are likely to differ in foraging styles, perceptual and learning abilities. Depending upon the interaction between predator vision, background and colour pattern parameters, certain morphs may be actively maintained in some conditions and not in others, even with the same predators. More than one kind of predator will also affect stability, and only slight changes in conditions can cause a transition between polymorphism and monomorphism. Frequency-dependent selection is not a panacea for the explanation of variation in animal colour patterns, although it may be important in some systems.

      La depredación dependiente de la frecuencia puede mantener o prevenir polimorfismos de patrones de color en la presa y puede ser causada por una variedad de fenómenos biológicos, incluidos los procesos de percepción (búsqueda de imágenes), la búsqueda de alimento y el aprendizaje óptimos. La mayoría de las especies son atacadas por más de una especie depredadora, que probablemente difieran en estilos de alimentación, habilidades de percepción y de aprendizaje. Dependiendo de la interacción entre la visión del depredador, el fondo y los parámetros del patrón de color, ciertos morfos pueden mantenerse activamente en algunas condiciones y no en otras, incluso con los mismos depredadores. Más de un tipo de depredador también afectará la estabilidad, y solo pequeños cambios en las condiciones pueden causar una transición entre polimorfismo y monomorfismo. La selección dependiente de la frecuencia no es una panacea para la explicación de la variación en los patrones de color de los animales, aunque puede ser importante en algunos sistemas.

    1. Many organisms use warning, or aposematic, coloration to signal their unprofitability to potential predators. Aposematically colored prey are highly visually conspicuous. There is considerable empirical support that conspicuousness promotes the effectiveness of the aposematic signal. From these experiments, it is well documented that conspicuous, unprofitable prey are detected sooner and aversion learned faster by the predator as compared with cryptic, unprofitable prey. Predators also retain memory of the aversion longer when prey is conspicuous. The present study focused on the elements of conspicuousness that confer these benefits of aposematic coloration. Drawing on current understanding of animal vision, we distinguish 2 features of warning coloration: high chromatic contrast and high brightness, or luminance, contrast. Previous investigations on aposematic signal efficacy have focused mainly on the role of high chromatic contrast between prey and background, whereas little research has investigated the role of high luminance contrast. Using the Chinese mantid as a model predator and gray-painted milkweed bugs as model prey, we found that increased prey luminance contrast increased detection of prey, facilitated predator aversion learning, and increased predator memory retention of the aversive response. Our results suggest that the luminance contrast component of aposematic coloration can be an effective warning signal between the prey and predator. Thus, warning coloration can even evolve as an effective signal to color blind predators.

      Muchos organismos usan coloración de advertencia, o aposemática, para señalar su falta de rentabilidad para los depredadores potenciales. Las presas de colores aposemáticos son muy llamativas a la vista. Existe un apoyo empírico considerable en el sentido de que la notoriedad promueve la eficacia de la señal aposemática. A partir de estos experimentos, está bien documentado que las presas notorias y no rentables se detectan antes y que el depredador aprende la aversión más rápido en comparación con las presas crípticas y no rentables. Los depredadores también retienen la memoria de la aversión por más tiempo cuando la presa es conspicua. El presente estudio se centró en los elementos de notoriedad que confieren estos beneficios de la coloración aposemática. Basándonos en el conocimiento actual de la visión animal, distinguimos 2 características de la coloración de advertencia: alto contraste cromático y alto brillo, o luminancia, contraste. Las investigaciones anteriores sobre la eficacia de la señal aposemática se han centrado principalmente en el papel del alto contraste cromático entre la presa y el fondo, mientras que poca investigación ha investigado el papel del alto contraste de luminancia. Utilizando la mantis china como depredador modelo y los insectos algodoncillo pintados de gris como presa modelo, encontramos que el aumento del contraste de luminancia de la presa aumentaba la detección de presas, facilitaba el aprendizaje de la aversión al depredador y aumentaba la retención de la memoria de la respuesta aversiva del depredador. Nuestros resultados sugieren que el componente de contraste de luminancia de la coloración aposemática puede ser una señal de advertencia eficaz entre la presa y el depredador. Por lo tanto, la coloración de advertencia puede incluso evolucionar como una señal efectiva para los depredadores daltónicos.

    1. Demonstrations of interactions between diverse selective forces on bright coloration in defended species are rare. Recent work has suggested that not only do the bright colours of Neotropical poison frogs serve to deter predators, but they also play a role in sexual selection, with females preferring males similar to themselves. These studies report an interaction between the selective forces of mate choice and predation. However, evidence demonstrating phenotypic discrimination by potential predators on these polymorphic species is lacking. The possibility remains that visual (avian) predators possess an inherent avoidance of brightly coloured diurnal anurans and purifying selection against novel phenotypes within populations is due solely to non-random mating. Here, we examine the influence of predation on phenotypic variation in a polymorphic species of poison frog, Dendrobates tinctorius. Using clay models, we demonstrate a purifying role for predator selection, as brightly coloured novel forms are more likely to suffer an attack than both local aposematic and cryptic forms. Additionally, local aposematic forms are attacked, though infrequently, indicating ongoing testing/learning and a lack of innate avoidance. These results demonstrate predator-driven phenotypic purification within populations and suggest colour patterns of poison frogs may truly represent a ‘magic trait’

      Las demostraciones de interacciones entre diversas fuerzas selectivas sobre coloración brillante en especies defendidas son raras. Un trabajo reciente ha sugerido que los colores brillantes de las ranas venenosas neotropicales no solo sirven para disuadir a los depredadores, sino que también juegan un papel en la selección sexual, y las hembras prefieren a los machos similares a ellos. Estos estudios informan de una interacción entre las fuerzas selectivas de la elección de pareja y la depredación. Sin embargo, se carece de evidencia que demuestre la discriminación fenotípica por depredadores potenciales en estas especies polimórficas. Existe la posibilidad de que los depredadores visuales (aviares) posean una evitación inherente de anuros diurnos de colores brillantes y la selección purificadora contra nuevos fenotipos dentro de las poblaciones se deba únicamente al apareamiento no aleatorio. Aquí, examinamos la influencia de la depredación en la variación fenotípica en una especie polimórfica de rana venenosa, Dendrobates tinctorius. Usando modelos de arcilla, demostramos un papel purificador para la selección de depredadores, ya que las formas novedosas de colores brillantes tienen más probabilidades de sufrir un ataque que las formas aposemáticas y crípticas locales. Además, las formas aposemáticas locales son atacadas, aunque con poca frecuencia, lo que indica pruebas en curso

    2. Demonstrations of interactions between diverse selective forces on bright coloration in defended species are rare. Recent work has suggested that not only do the bright colours of Neotropical poison frogs serve to deter predators, but they also play a role in sexual selection, with females preferring males similar to themselves. These studies report an interaction between the selective forces of mate choice and predation. However, evidence demonstrating phenotypic discrimination by potential predators on these polymorphic species is lacking. The possibility remains that visual (avian) predators possess an inherent avoidance of brightly coloured diurnal anurans and purifying selection against novel phenotypes within populations is due solely to non-random mating. Here, we examine the influence of predation on phenotypic variation in a polymorphic species of poison frog, Dendrobates tinctorius. Using clay models, we demonstrate a purifying role for predator selection, as brightly coloured novel forms are more likely to suffer an attack than both local aposematic and cryptic forms. Additionally, local aposematic forms are attacked, though infrequently, indicating ongoing testing/learning and a lack of innate avoidance. These results demonstrate predator-driven phenotypic purification within populations and suggest colour patterns of poison frogs may truly represent a ‘magic trait’.

      Las demostraciones de interacciones entre diversas fuerzas selectivas sobre coloración brillante en especies defendidas son raras. Un trabajo reciente ha sugerido que los colores brillantes de las ranas venenosas neotropicales no solo sirven para disuadir a los depredadores, sino que también juegan un papel en la selección sexual, y las hembras prefieren a los machos similares a ellos. Estos estudios informan de una interacción entre las fuerzas selectivas de la elección de pareja y la depredación. Sin embargo, se carece de evidencia que demuestre la discriminación fenotípica por depredadores potenciales en estas especies polimórficas. Existe la posibilidad de que los depredadores visuales (aviares) posean una evitación inherente de anuros diurnos de colores brillantes y la selección purificadora contra nuevos fenotipos dentro de las poblaciones se deba únicamente al apareamiento no aleatorio. Aquí, examinamos la influencia de la depredación en la variación fenotípica en una especie polimórfica de rana venenosa, Dendrobates tinctorius. Usando modelos de arcilla, demostramos un papel purificador para la selección de depredadores, ya que las formas novedosas de colores brillantes tienen más probabilidades de sufrir un ataque que las formas aposemáticas y crípticas locales. Además, las formas aposemáticas locales son atacadas, aunque con poca frecuencia, lo que indica una prueba

    1. An experiment was performed to assess the relative survival of two forms of 5th instar larvae of Lygaeus equestris (Heteroptera, Lygaeidae) — the normal red form, called aposematic, and a mutant grey form, called cryptic — when given to hand-raised great tits (Parus major).Sixteen birds were presented with aposematic larvae and 16 were presented with cryptic larvae in 10 consecutive trials. One attack per trial was allowed. Both larval forms were presented against a background matching the grey larvae, but since both prey types were presented in a specific place known to the predator, detection rate for both was assumed to be unity.Birds learned to avoid both prey types. However, the survival of the aposematic larvae was higher than that of the cryptic ones due to three aspects of predator behaviour: i) a greater initial reluctance to attack, ii) a more rapid avoidance learning, and iii) a lower frequency of killing in an attack, when the prey was aposematic. Moreover, a greater number of birds learned to avoid prey without killing any individual, when the prey was aposematic. This result is considered to be due to prey coloration alone, since, in a separate test, no difference in prey distastefulness could be detected.This experiment shows that individual prey can benefit from being aposematic and indicates that individual selection can be a sufficient explanation for the evolution of aposematic coloration. It was concluded that, since the survivorship was 6.4 times higher for the aposematic prey, it could have a detection rate that is correspondingly higher than the cryptic in order for the two forms to have equal fitness.

      Se realizó un experimento para evaluar la supervivencia relativa de dos formas de larvas de quinto estadio de Lygaeus equestris (Heteroptera, Lygaeidae), la forma roja normal, llamada aposemática, y una forma gris mutante, llamada críptica, cuando se administran a grandes herrerillos criados a mano. (Parus mayor).

      Se presentaron 16 aves con larvas aposemáticas y 16 con larvas crípticas en 10 ensayos consecutivos. Se permitió un ataque por ensayo. Ambas formas larvarias se presentaron sobre un fondo que coincidía con las larvas grises, pero dado que ambos tipos de presas se presentaron en un lugar específico conocido por el depredador, se supuso que la tasa de detección de ambas era la unidad.

      Las aves aprendieron a evitar ambos tipos de presas. Sin embargo, la supervivencia de las larvas aposemáticas fue mayor que la de las crípticas debido a tres aspectos del comportamiento del depredador: i) una mayor reticencia inicial al ataque, ii) un aprendizaje de evitación más rápido, y iii) una menor frecuencia de matanza en un ataque, cuando la presa era aposemática. Además, un mayor número de aves aprendieron a evitar a las presas sin matar a ningún individuo, cuando la presa era aposemática. Se considera que este resultado se debe únicamente a la coloración de la presa, ya que, en una prueba separada, no se pudo detectar ninguna diferencia en el desagrado de la presa.

      Este experimento muestra que las presas individuales pueden beneficiarse de ser aposemáticas e indica que la selección individual puede ser una explicación suficiente para la evolución de la coloración aposemática. Se concluyó que, dado que la supervivencia fue 6,4 veces mayor para la presa aposemática, podría tener una tasa de detección correspondientemente más alta que la críptica para que las dos formas tengan la misma aptitud.

    1. The theory of warning signals dates back to Wallace but is still confusing, controversial and complex. Because predator avoidance of warningly coloured prey (aposematism) is based upon learning and reinforcement, it is difficult to understand how initially rare conspicuous forms subsequently become common. Here, we discuss several possible resolutions to this apparent paradox. Many of these ideas have been largely ignored as a result of implicit assumptions about predator behaviour and assumed lack of variation in the predators, prey and the predation process. Considering the spatial and temporal variation in and mechanisms of behaviour of both predators and prey will make it easier to understand the process and evolution of aposematism.

      La teoría de las señales de advertencia se remonta a Wallace, pero sigue siendo confusa, controvertida y compleja. Debido a que la evitación por parte de los depredadores de presas con colores de advertencia (aposematismo) se basa en el aprendizaje y el refuerzo, es difícil comprender cómo las formas llamativas inicialmente raras se vuelven comunes posteriormente. Aquí, discutimos varias posibles soluciones a esta aparente paradoja. Muchas de estas ideas se han ignorado en gran medida como resultado de suposiciones implícitas sobre el comportamiento de los depredadores y la supuesta falta de variación en los depredadores, las presas y el proceso de depredación. Tener en cuenta la variación espacial y temporal y los mecanismos de comportamiento tanto de los depredadores como de las presas facilitará la comprensión del proceso y la evolución del aposematismo.

    1. The question, “Why should prey advertise their presence to predators using warning coloration?” has been asked for over 150 years. It is now widely acknowledged that defended prey use conspicuous or distinctive colors to advertise their toxicity to would-be predators: a defensive strategy known as aposematism. One of the main approaches to understanding the ecology and evolution of aposematism and mimicry (where species share the same color pattern) has been to study how naive predators learn to associate prey’s visual signals with the noxious effects of their toxins. However, learning to associate a warning signal with a defense is only one aspect of what predators need to do to enable them to make adaptive foraging decisions when faced with aposematic prey and their mimics. The aim of our review is to promote the view that predators do not simply learn to avoid aposematic prey, but rather make adaptive decisions about both when to gather information about defended prey and when to include them in their diets. In doing so, we reveal what surprisingly little we know about what predators learn about aposematic prey and how they use that information when foraging. We highlight how a better understanding of predator cognition could advance theoretical and empirical work in the field.

      La pregunta: "¿Por qué las presas deberían anunciar su presencia a los depredadores con coloración de advertencia?" se ha solicitado durante más de 150 años. Ahora se reconoce ampliamente que las presas defendidas usan colores llamativos o distintivos para anunciar su toxicidad a los posibles depredadores: una estrategia defensiva conocida como aposematismo. Uno de los principales enfoques para comprender la ecología y la evolución del aposematismo y el mimetismo (donde las especies comparten el mismo patrón de color) ha sido estudiar cómo los depredadores ingenuos aprenden a asociar las señales visuales de las presas con los efectos nocivos de sus toxinas. Sin embargo, aprender a asociar una señal de advertencia con una defensa es solo un aspecto de lo que los depredadores deben hacer para permitirles tomar decisiones de alimentación adaptables cuando se enfrentan a presas aposemáticas y sus imitadores. El objetivo de nuestra revisión es promover la opinión de que los depredadores no solo aprenden a evitar presas aposemáticas, sino que toman decisiones adaptativas sobre cuándo recopilar información sobre las presas defendidas y cuándo incluirlas en sus dietas. Al hacerlo, revelamos lo sorprendentemente poco que sabemos sobre lo que los depredadores aprenden sobre presas aposemáticas y cómo usan esa información cuando buscan alimento. Destacamos cómo una mejor comprensión de la cognición de los depredadores podría impulsar el trabajo teórico y empírico en el campo.

  7. Mar 2021
    1. The concrete nouns include people, plants, animals, materials and objects while the abstract nouns refer to concepts such as qualities, actions, and processes.
    1. Evolution via natural selection has continually shaped the coloration of numerous organisms. One coloration of particular importance is the eyespot: a phylogenetically widespread, conspicuous marking that has been shown to effectively reduce predation, often through its resemblance to the eye. Although widely studied, most research has been experimental in nature. We approach eyespots using a comparative phylogenetic framework that is global in scope. Herein, we identify the potential drivers of eyespot evolution in coral reef fishes; essentially the rules that govern their appearance in this group of organisms. We surveyed 2664 reef fish species (42% of all described reef fish species) and found that eyespots are present in approximately one in every 10 species. Most eyespots occur in closely related species and have been present in some families for over 50 million years. Focusing on damselfishes (family: Pomacentridae) as a study group, we reveal that eyespots are rare in planktivorous species, which is likely driven by the predation risk associated with their feeding location. Using a heatmapping technique, we also show that the location of eyespots is fundamentally different in active fishes that swim above the benthos vs. cryptobenthic fishes that rest on the benthos. These location differences may reflect different functions of eyespots among reef fish species.

      La evolución a través de la selección natural ha moldeado continuamente la coloración de numerosos organismos. Una coloración de particular importancia es la mancha ocular: una marca conspicua y filogenéticamente extendida que se ha demostrado que reduce eficazmente la depredación, a menudo a través de su parecido con el ojo. Aunque se ha estudiado ampliamente, la mayor parte de la investigación ha sido de naturaleza experimental. Nos acercamos a las manchas oculares utilizando un marco filogenético comparativo de alcance global. Aquí, identificamos los impulsores potenciales de la evolución de la mancha ocular en los peces de los arrecifes de coral; esencialmente las reglas que gobiernan su aparición en este grupo de organismos. Encuestamos 2664 especies de peces de arrecife (42% de todas las especies de peces de arrecife descritas) y encontramos que las manchas oculares están presentes en aproximadamente una de cada 10 especies. La mayoría de las manchas oculares ocurren en especies estrechamente relacionadas y han estado presentes en algunas familias durante más de 50 millones de años. Centrándonos en los peces damisela (familia: Pomacentridae) como grupo de estudio, revelamos que las manchas oculares son raras en las especies planctívoras, lo que probablemente se deba al riesgo de depredación asociado con su ubicación de alimentación. Utilizando una técnica de mapa de calor, también mostramos que la ubicación de las manchas oculares es fundamentalmente diferente en los peces activos que nadan por encima del bentos frente a los peces criptobentónicos que descansan sobre el bentos. Estas diferencias de ubicación pueden reflejar diferentes funciones de las manchas oculares entre las especies de peces de arrecife.

  8. Feb 2021
    1. AbstractMany organizations are drowning in a flood of corporate bullshit, andthis is particularly true of organizations in trouble, whose managers tend to makeup stuff on the fly and with little regard for future consequences. Bullshittingand lying are not synonymous. While the liar knows the truth and wittingly bendsit to suit their purpose, the bullshitter simply does not care about the truth. Man-agers can actually do something about organizational bullshit, and this ExecutiveDigest provides a sequential framework that enables them to do so. They cancomprehend it, they can recognize it for what it is, they can act against it, and theycan take steps to prevent it from happening in the future. While it is unlikely thatany organization will ever be able to rid itself of bullshit entirely, this article arguesthat by taking these steps, astute managers can work toward stemming its flood
    1. AbstractIn this study we focus on late Holocene primaryproductivity (PP) variability in the western Barents Sea and itsresponse to variable sea ice coverage by combining PPreconstructed from several sediment cores with regional PPtrends simulated with a well-constrained organic faciesmodel, OF-Mod 3D. We find that modern production ratesreconstructed from buried marine organic matter (‘‘bottom-up’’) resemble simulated export production at 50 m waterdepth inferred from numerical simulations of surface waterPP in a 3D ocean model, SINMOD (‘‘top-down’’). Paleo-productivity rates in the northern Barents Sea are more vari-able and generally higher (30–150 gC m-2year-1)thaninthe SW Barents Sea region (\75 gC m-2year-1)throughoutthe last 6000 years BP. In the SW Barents Sea, PP rates andterrestrial organic matter (TOM) supply remain constantlylow indicating present-day-like oceanographic conditions

      This is an interesting abstract

  9. Jan 2021
    1. The abstract shapes in the brackets symbolize the "OK" from the boot up screen, services running inside systemd, and our overall optimistic outlook.
  10. Oct 2020
    1. The following roles are used to support the WAI-ARIA role taxonomy for the purpose of defining general role concepts. Abstract roles are used for the ontology. Authors MUST NOT use abstract roles in content.
    2. Abstract roles are the foundation upon which all other WAI-ARIA roles are built.
    3. Abstract roles are provided to help with the following: Organize the role taxonomy and provide roles with a meaning in the context of known concepts.Streamline the addition of roles that include necessary features.
    1. The problem is that the since both the JSX transpiler and the traceur compiler are actually parsing the full javascript AST, they would have to mutually agree on the syntax extensions you use: traceur can't parse the faux-xml syntax JSX adds, and JSX can't parse the async or await keywords, for example, or generator functions.
  11. Sep 2020
    1. We analyze the structural elements which comprise a standard scientific paper. Previous analysis generally has focused on one element of a paper at a time. However, the title, author list, affiliation, abstract, text, tables, graphs, charts, photographs and references all represent possible data resources for investigation. After specifying those elements, we focus successively on the history, normative tradition, and sociological analysis of a selection of those elements.
    1. Scientific knowledge constitutes a complex system that has recently been the topic of in-depth analysis. Empirical evidence reveals that little is known about the dynamic aspects of human knowledge. Precise dissection of the expansion of scientific knowledge could help us to better understand the evolutionary dynamics of science. In this paper, we analyzed the dynamic properties and growth principles of the MEDLINE bibliographic database using network analysis methodology. The basic assumption of this work is that the scientific evolution of the life sciences can be represented as a list of co-occurrences of MeSH descriptors that are linked to MEDLINE citations. The MEDLINE database was summarized as a complex system, consisting of nodes and edges, where the nodes refer to knowledge concepts and the edges symbolize corresponding relations. We performed an extensive statistical evaluation based on more than 25 million citations in the MEDLINE database, from 1966 until 2014. We based our analysis on node and community level in order to track temporal evolution in the network. The degree distribution of the network follows a stretched exponential distribution which prevents the creation of large hubs. Results showed that the appearance of new MeSH terms does not also imply new connections. The majority of new connections among nodes results from old MeSH descriptors. We suggest a wiring mechanism based on the theory of structural holes, according to which a novel scientific discovery is established when a connection is built among two or more previously disconnected parts of scientific knowledge. Overall, we extracted 142 different evolving communities. It is evident that new communities are constantly born, live for some time, and then die. We also provide a Web-based application that helps characterize and understand the content of extracted communities. This study clearly shows that the evolution of MEDLINE knowledge correlates with the network’s structural and temporal characteristics.
    1. The NLM Catalog provides access to NLM bibliographic data for journals, books, audiovisuals, computer software, electronic resources and other materials. Links to the library's holdings in LocatorPlus, NLM's online public access catalog, are also provided.
  12. Aug 2020
    1. One way to think about "core" biodiversity data is as a network of connected entities, such as taxa, taxonomic names, publications, people, species, sequences, images, and collections that form the "biodiversity knowledge graph". Many questions in biodiversity informatics can be framed as paths in this graph. This article explores this futher, and sketches a set of services and tools we would need in order to construct the graph. New information In order to build a usable biodiversity knowledge graph we should adopt JSON-LD for biodiversity data, develop reconciliation services to match entities to identifiers, and a use a mixture of document and graph databases to store and query the data. To bootstrap this project we can create wrappers around each major biodiversity data provider, and a central cache that is both a document store and a simple graph database. This power of this approach should be showcased by applications that use the central cache to tackle specific problems, such as augmenting existing data.
    1. The success of distributed and semantic-enabled systems relies on the use of up-to-date ontologies and mappings between them. However, the size, quantity and dynamics of existing ontologies demand a huge maintenance effort pushing towards the development of automatic tools supporting this laborious task. This article proposes a novel method, investigating different types of similarity measures, to identify concepts’ attributes that served to define existing mappings. The obtained experimental results reveal that our proposed method allows to identify the relevant attributes for supporting mapping maintenance, since we found correlations between ontology changes affecting the identified attributes and mapping changes.
    1. As the amount of scholarly communication increases, it is increasingly difficult for specific core scientific statements to be found, connected and curated. Additionally, the redundancy of these statements in multiple fora makes it difficult to determine attribution, quality, and provenance. To tackle these challenges, the Concept Web Alliance has promoted the notion of nanopublications (core scientific statements with associated context). In this document, we present a model of nanopublications along with a NamedGraph/RDF serialization of the model. Importantly, the serialization is defined completely using already existing community developed technologies. Finally, we discuss the importance of aggregating nano-publications and the role that the ConceptWiki plays in facilitating it.
    1. SKOS—Simple Knowledge Organization System—provides a model for expressing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, folksonomies, and other similar types of controlled vocabulary. As an application of the Resource Description Framework (RDF), SKOS allows concepts to be composed and published on the World Wide Web, linked with data on the Web and integrated into other concept schemes. This document is a user guide for those who would like to represent their concept scheme using SKOS. In basic SKOS, conceptual resources (concepts) are identified with URIs, labeled with strings in one or more natural languages, documented with various types of note, semantically related to each other in informal hierarchies and association networks, and aggregated into concept schemes. In advanced SKOS, conceptual resources can be mapped across concept schemes and grouped into labeled or ordered collections. Relationships can be specified between concept labels. Finally, the SKOS vocabulary itself can be extended to suit the needs of particular communities of practice or combined with other modeling vocabularies. This document is a companion to the SKOS Reference, which provides the normative reference on SKOS.
  13. Jun 2020
    1. In contrast, theorems in Abstract Cryptography can be provedat a (high) level of abstraction without the instantiation ofthe lower levels. The lower levels inherit these theorems ifthey satisfy the postulated axioms of the higher level. Eachabstraction level can thus focus on specific aspects, such ascomposability or efficiency.

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  14. May 2020
  15. Mar 2020
  16. Feb 2020
    1. Exchange value

      Exchange value appears as the property of a commodity that is exchangeable for other commodities. It also presupposes societies who produce commodities and exchange them. While all societies have things with use values, exchange value is relative to a specific time and place.

      Additionally, exchanging commodities must also presupposes a way to determine proportionality between different commodities, so that they can be exchanged in the first place.

      Exchange therefore requires some other measure that stands above the two commodities meant to be exchanged. If there were no ways in which iron and corn were found similar to a society, for example, then we would not exchange them and they would have no exchange value.

      Marx will contend that what each commodity must contain crystalized within it is value (formally) and that the substance of value is labor (viz. the common factor of both iron and corn is labor). Marx will call this kind of labor abstract labor.

  17. Dec 2019
    1. Is an Abstract Logo Good for your Business? December 2, 2019 shivkumar Logo & Branding An abstract logo is a logo that is known to be the most valiant logo that instantly grabs attention. These logos are stylized but simple and can create curiosity among its viewer. Every business wants to stand out to ensure they are perceived as the best in the market and this type of logo symbolizes just that. People have high expectations from these logos as it demands professionalism. Branding using this type of logo is different than the other logo types. In this type of logo, you have to invest highly in brand recognition. Your marketing plans should be more focused on creating a brand rather than selling. This type of logo requires a long term business plan and a big budget to make your brand recognized by the customer. In this article, we will discuss is using an abstract log for your business a good idea and the traits it offers along with how it is perceived by customers but before that let’s find out what is an Abstract Logo? What is an Abstract Logo? The Abstract logo is a logo that uses a symbol or icon to represent a brand. This symbol can be a letter or any symbol that may or may not mean something. It deliberately uses colors, shapes, and forms to create a symbol to attain its effect. One of the best examples that use an abstract logo is NIKE (Swoosh symbol). Key Traits of Abstract Logo Abstract logo can make your brand big and recognized all over the world. It is unique and has many traits that speak for it. The following are the traits that abstract logos have – Lasting Impression The goal of any business is to create a space in the mind and heart of their customers. This type of logo helps in creating this emotion and leaves a lasting mark on the customer.  Curiosity The first and simplest emotion which we discover in the human mind is curiosity. Edmund Burke This quote beautifully explains the basic human nature. Human beings are curious which resulted in the discovery of many advanced technologies. When someone becomes curious, then person persuades and research about that topic. The same effect can be introduced into the logo by using the abstract logo.  The abstract logo creates curiosity that leads to more brand search and more brand recognition. Ultimately, an abstract logo can create a huge fan following and authority in your market. Creativity It is difficult to design a brand image using abstract design. There is no guide that can be used for creating abstract logo. The designers have to rely on his/her experience and creativity to design this type of logo but the results that you get are some of the most creative designs. Modernism The abstract logo is forever fresh and requires less to not at all change. This logo can be used again and again over the years to represent the logo as the brand image. Modern and creative logos are an approach that can induce professionalism into the picture hence, giving a fresh look forever. When to Use the Abstract Logo? Abstract logos are best for businesses that can revolutionize a market. Nike is a brand that is well known for the athleisure wear they make. The Swoosh logo used by them makes them stand out and create a presence. If your business has similar traits then you can use this logo. The marketing of this type of business can be costly but is very effective. Psychology behind the Abstract Logo Abstract logo is a unique type of logo that affects the customer psyche in a distinct way. Abstract logo influences the customer to search about the business. But, why? This happens due to Association Principles. According to this principle, a customer creates a mental connection between the shape, color and patterns to some emotions. This emotion further triggers the person to take action regarding that event and this principle is called trigger theory. If your logo evokes some connections from person’s past then the trigger principle works and the person transfers the same emotion towards the business. The emotion can be negative and positive so, it is advised not to use any negative imagery in your logo. You can use these psychological principles to increase your sales and get recognized by your customers. Conclusion Many people, who start a business or redesign their logo, easily overlook the type of logo to use. Good logo design services are good at understanding the needs of that business. Many people design the logo without considering the goal and future projection of the business. This is a huge mistake that businesses make. The best way to get a logo designed is by taking a professional’s help and taking consultation from them.

      Find details about abstract logo and get an answer for various questions like should you use the abstract logo for your business? and much more.

  18. Nov 2019
    1. Neonatal Hypopituitarism: Approaches to Diagnosis and Treatment

      Abstract
      Hypopituitarism is defined as a decreased release of hypophyseal hormones, which may be caused by disease of the pituitary gland disease or hypothalamus.

      The clinical findings of neonatal hypopituitarism depend on the causes and on presence and extent of hormonal deficiency. Patients may be asymptomatic or may demonstrate non-specific symptoms, but may still be at risk for development of pituitary hormone deficiency over time. Patient history, physical examination, endocrinological, radiological and genetic evaluations are all important for early diagnosis and treatment. Links: Neonatal Hypopituitarism

      Septo-optic Dysplasia-Nature

  19. Oct 2019
    1. Abstract

      Abstract is a sale's pitch, I would say. It summarizes the whole article, and helps the audiences like you and me, to determine whether/how this work might be relevant.

      In the following abstract, identify the research question, highlight it, and state it in your own words (because the authors ask something quite different from what they propose in the beginning).

  20. Sep 2019
    1. Abstract

      Abstract typically follows the cover page with the title, author name(s), contact information, and other relevant information. Abstract is a sales pitch. It is a short summary (200 words or so) of the entire paper that follows. It is supposed to contain the following information -- a research question(s), a theoretical argument, a research design, findings, and a conclusion.

      Does this abstract contain all the essential information listed above? Is this, thus, a good abstract or not?

  21. Feb 2019
    1. As with neoliberalism more generally, New Public Management is invisible, part of a new “common sense” that has somehow become hegemonic, whereby the “entrepreneurial spirit” has infused the public sector, leading to “businesslike government”. As with the claims of neoliberalism more generally as to its positive outputs in terms of prosperity, NPM has never been shown to have been successful even in its own terms. NPM “introduced punishments and rewards to produce better services with lesser staff. Instead of having freed energies and creativity of employees formerly shackled by their bureaucratic turfs, NPM reforms have bound energies into theatrical audit performances at the cost of work and killed creativity in centralizing resources and hollowing out professional autonomy... Fundamental deprivation of the legitimacy of public employees . . .has traumatized many most-committed employees and driven others toward a Soviet-type double standard.” (Juha Siltala, New Public Management : The evidence-based worst practice?, Administration; Vol. 45, No. 4.; 2013 pp. 468-493) Sekera quotes Christopher Pollitt et al., who “after compiling a database of 518 studies of NPM in Europe, determined that “more than 90% of what are seen by experts as the most significant and relevant studies contain no data at all on outcomes” and that of the 10% that had outcomes information, only 44% of those, or 4% of the total, found any improvements in terms of outcomes.” But in the end, the point of NPM is less that of measureable outcomes, and more that of the ideological victory of turning the public and its good into customers exercising their “choices” (see tax revolt example in Duggan), along of course with the radical disempowering of public administration workers and their unions, instituting “cost savings” by cutting their real income and putting more and more of the public sector’s production directly into the profit-making market.
  22. Dec 2018
    1. When Hilma af Klint began creating radically abstract paintings in 1906, they were like little that had been seen before: bold, colorful, and untethered from any recognizable references to the physical world

      I heard a fascinating story about her on NPR today.

  23. Oct 2018
    1. if you replace the idea that life is a narrative with the idea that life is a vision

      It's an interesting thought to replace the idea of life as a narrative vs a vision, it kind of goes along with the idea of technology being concrete of fluid. A narrative is something more concrete and a vision seems for fluid because a narrative is bound by the progression of time and in a vision things can happen simultaneously.

    1. (1) Describing what was done.(2) Describingwhat was found(key results)

      Two main things for effective abstract: 1) describe what was done 2) describe what was found

  24. Jun 2018
    1. Abstract

      Schlechtes Abstract. Es wird zu wenig Gewicht auf die Darstellung der Ergebnisse gelegt. Diverse Unterschiede und Anknüpfungspunkte müssen wenigstens angedeutet werden.

  25. May 2018
    1. Two patients complaining of insomnia had sleep-related periodic leg movements (nocturnal myoclonus) on polysomnographic evaluation. Both also complained of cold feet and had abnormal peripheral pulse examinations. Treatment with phenoxybenzamine, alpha-adrenergic blocker, normalized the peripheral pulse responses, reduced the complaint of insomnia, and reduced the sleep related leg movements but resulted in only mild sleep improvements. Peripheral pulse examinations of ten other patients with sleep-related periodic leg movements revealed abnormal responses in four. From these and other results, it is hypothesized that the sympathetic nervous system may mediate the periodicity of sleep related periodic leg movements.
  26. Feb 2018
    1. There are two related issues that we have seen when it comes to mis‐understandings about the roles of data scientists. In one case, excessivehype leads people to expect miracles, and miracle-workers. In the oth‐er case, a lack of awareness about the variety of data scientists leadsorganizations to waste effort when trying to find talent. These casestudies are based on collective experiences from many of our friends,colleagues, and Meetup members.
  27. Aug 2015
    1. Summary. — A new subspecies of Amazilia Hummingbird Amazilia amazilia is described from the Ecuadorian Andes. It appears to be closest related to A. a. dlticola from southern Loja and adjacent parts of Zamora-Chinchipe provinces in southern Ecuador.
  28. Apr 2014
    1. Clouds establish a new division of responsibilities between platform operators and users than have trad itionally e x- isted in computing infrastructure. In private clouds, where all participants belong to the same organization, this cr e- ates new barriers to effective communication and resource usage. In this paper, we present poncho , a tool that i m- plements APIs that enable communication between cloud operators and their users, for the purposes of minimizing impact of administrative operations and load shedding on highly - utilized private clouds.

      Poncho: Enabling Smart Administration of Full Private Clouds

      http://www.mcs.anl.gov/papers/P5024-1013.pdf

  29. Jan 2014
    1. approaches to establish permanent, quantitative datasets—atlases
    2. A rigorous understanding of these developmental processes requires automated methods that quantitatively record and analyze complex morphologies and their associated patterns of gene expression at cellular resolution.

      Rigorous understanding requires automated methods using quantitative recording and analysis.

  30. Sep 2013
    1. reasoning.

      But is the abstractness associated with words really a lesser knowledge? It may be less precise, but that also might create more options