Academic literature on the topic 'Biological Metamorphosis'

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts ( Lissotriton helveticus ) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the ‘male escape hypothesis’) and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis.

The three modes of insect postembryonic development are ametaboly, hemimetaboly and holometaboly, the latter being considered the only significant metamorphosis mode. However, the emergence of hemimetaboly, with the genuine innovation of the final moult, represents the origin of insect metamorphosis and a necessary step in the evolution of holometaboly. Hemimetaboly derives from ametaboly and might have appeared as a consequence of wing emergence in Pterygota, in the early Devonian. In extant insects, the final moult is mainly achieved through the degeneration of the prothoracic gland (PG), after the formation of the winged and reproductively competent adult stage. Metamorphosis, including the formation of the mature wings and the degeneration of the PG, is regulated by the MEKRE93 pathway, through which juvenile hormone precludes the adult morphogenesis by repressing the expression of transcription factor E93, which triggers this change. The MEKRE93 pathway appears conserved in extant metamorphosing insects, which suggest that this pathway was operative in the Pterygota last common ancestor. We propose that the final moult, and the consequent hemimetabolan metamorphosis, is a monophyletic innovation and that the role of E93 as a promoter of wing formation and the degeneration of the PG was mechanistically crucial for their emergence. This article is part of the theme issue ‘The evolution of complete metamorphosis’.

Metamorphosis is a cycle of biological animal growth. Learning Metamorphosis is a part of learning for students in schools specifically in the area of biology subjects. Unfortunately, the observing activities take time, and finding an animal specimen is limited to study the metamorphosis cycle. This research proposes an innovative solution to overcome these problems which is the implementation of augmented reality technology. The animal metamorphosis cycle process is visualized into 4-dimensional objects to improve interaction for the student on learning metamorphosis during learning sessions. The Marker-Based Tracking method is used as an approach where the location of the tracking pattern on the marker has been determined in advance as the place where the augmented reality object appears. The results of this study indicate that using a marker-based tracking method can improve students' understanding of metamorphosis.

ABSTRACT To biologically explain why the orthodontic treatment does not induce pulp necrosis and calcific metamorphosis of the pulp, this paper presents explanations based on pulp physiology, microscopy and pathology, and especially the cell and tissue phenomena that characterize the induced tooth movement. The final reflections are as follows: 1) the orthodontic movement does not induce pulp necrosis or calcific metamorphosis of the pulp; 2) there is no literature or experimental and clinical models to demonstrate or minimally evidence pulp alterations induced by orthodontic movement; 3) when pulp necrosis or calcific metamorphosis of the pulp is diagnosed during orthodontic treatment or soon after removal of orthodontic appliances, its etiology should be assigned to concussion dental trauma, rather than to orthodontic treatment; 4) the two pulp disorders that cause tooth discoloration in apparently healthy teeth are the aseptic pulp necrosis and calcific metamorphosis of the pulp, both only induced by dental trauma; 5) the concussion dental trauma still requires many clinical and laboratory studies with pertinent experimental models, to increasingly explain its effects on the periodontal and pulp tissues.

Since it would have been feasible for Kafka to call his story ‘Die Metamorphose’, the article first considers why most translators render Die Verwandlung as (The) Metamorphosis and not literally as The Transformation. Given the widespread impact of Darwinism and Social Darwinism when Kafka wrote the work in 1912, particular attention is paid to socio-biological factors that may have influenced his choice of title. The article further considers the possible impact of Yiddish theatre and Nietzschean philosophy upon Kafka's decision. It then examines how translators have tackled the story's opening sentence, given the difficulties of rendering the phrase ‘ungeheures Ungeziefer’ (literally ‘monstrous vermin’) in a way that does justice to the sentence's original structure and vocabulary. Finally, the article offers a possible solution to this problem.

In this paper, we first give a short discussion of the macroevolution viewing life as information-directed, complex, dynamic systems. On this basis, we give our explanation of the origin of life and discuss the top-down evolution of molecules, proteins, and macroevolution. We discuss these subjects according to our new holistic biological paradigm. In view of this, we discuss the macroevolution of the organism, the species, the biosphere, and human society. After this, we discuss the shift in evolution from natural selection to a new proposed process of nature called the “metamorphous top-down” evolution. We discuss the capability of the evolutionary shift to govern some of the processes that lead to the formation of new species. We discuss the mechanisms we think are behind this proposed shift in evolution and conclude that this event is able to explain the huge biological diversity of nature in combination with evolutionary natural selection. We also discuss this event of nature as an isolated, but integrated, part of the universe. We propose the most important genetic and biochemical process that we think is behind the evolutionary shift as a complicated symbiosis of mechanisms leading to metamorphosis in all biological individuals, from bacteria to humans. The energetic superorbital that manifests the consciousness governs all these processes through quantum chemical activity. This is the key to evolutionary shift through the consciousness, and we propose to call this process “adult human metamorphosis”.

In a new series of papers, we address a number of unsolved problems in biology today. First of all, the unsolved enigma concerning how the differentiation from a single zygote to an adult individual happens has been object for severe research for decades. By uncovering a new holistic biological paradigm that introduces an energetic-informational interpretation of reality as a new way to experience biology, these papers will try to solve the problems connected with the events of biological ontogenesis involving a fractal hierarchy, from a single cell to the function of the human brain. The problems discussed are interpreted within the frames of a universe of roomy fractal structures containing energetic patterns that are able to deliver biological information. We think biological organization is guided by energetic changes on the level of quantum mechanics, interacting with the intention that again guides the energetic conformation of the fractal structures to gain disorders or healthiness. Furthermore, we introduce two new concepts: “metamorphous top down” evolution and “adult human metamorphosis”. The first is a new evolutionary theory involving metamorphosis as a main concept of evolution. The last is tightly linked to the evolutionary principle and explains how human self-recovery is governed. Other subjects of special interest that we shall look deeper into are the immunological self-nonself discrimination, the structure and function of the human brain, the etiology and salutogenesis of mental and somatic diseases, and the structure of the consciousness of a human being. We shall criticize Szentagothai’s model for the modulated structure of the human cerebral cortex and Jerne’s theory of the immunological regulatory anti-idiotypic network.

Cassiopea xamachana jellyfish are an attractive model system to study metamorphosis and/or cnidarian–dinoflagellate symbiosis due to the ease of cultivation of their planula larvae and scyphistomae through their asexual cycle, in which the latter can bud new larvae and continue the cycle without differentiation into ephyrae. Then, a subsequent induction of metamorphosis and full differentiation into ephyrae is believed to occur when the symbionts are acquired by the scyphistomae. Although strobilation induction and differentiation into ephyrae can be accomplished in various ways, a controlled, reproducible metamorphosis induction has not been reported. Such controlled metamorphosis induction is necessary for an ensured synchronicity and reproducibility of biological, biochemical, and molecular analyses. For this purpose, we tested if differentiation could be pharmacologically stimulated as in Aurelia aurita, by the metamorphic inducers thyroxine, KI, NaI, Lugol’s iodine, H2O2, indomethacin, or retinol. We found reproducibly induced strobilation by 50 μM indomethacin after six days of exposure, and 10–25 μM after 7 days. Strobilation under optimal conditions reached 80–100% with subsequent ephyrae release after exposure. Thyroxine yielded inconsistent results as it caused strobilation occasionally, while all other chemicals had no effect. Thus, indomethacin can be used as a convenient tool for assessment of biological phenomena through a controlled metamorphic process in C. xamachana scyphistomae.

In this study, the effects of environmental variables on larval metamorphosis of the solitary ascidianCiona savignyiwere investigated in a laboratory setting. The progression of metamorphic changes were tracked under various temperature, photoperiod, substrate, larval density, and vessel size regimes. Metamorphosis was maximised at 18 °C, 12:12 h subdued light:dark, smooth polystyrene substrate, and 10 larvae mL−1in a twelve-well tissue culture plate. Eliminating the air-water interface by filling culture vessels to capacity further increased the proportion of metamorphosed larvae; 87 ± 5% of larvae completed metamorphosis within 5 days compared to 45 ± 5% in control wells. The effects of the reference antifouling compounds polygodial, portimine, oroidin, chlorothalonil, and tolylfluanid onC. savignyiwere subsequently determined, highlighting (1) the sensitivity ofC. savignyimetamorphosis to chemical exposure and (2) the potential to useC. savignyilarvae to screen for bioactivity in an optimised laboratory setting. The compounds were bioactive in the low ng mL−1to high µg mL−1range. Polygodial was chosen for additional investigations, where it was shown that mean reductions in the proportions of larvae reaching stage E were highly repeatable both within (repeatability = 14 ± 9%) and between (intermediate precision = 17 ± 3%) independent experiments. An environmental extract had no effect on the larvae but exposing larvae to both the extract and polygodial reduced potency relative to polygodial alone. This change in potency stresses the need for caution when working with complex samples, as is routinely implemented when isolating natural compounds from their biological source. Overall, the outcomes of this study highlight the sensitivity ofC. savignyimetamorphosis to environmental variations and chemical exposure.

Trabajos previos llevados a cabo en el laboratorio de acogida, usando como modelo el insecto basal Blattella germanica, mostraron que los microRNAs (miRNAs) son cruciales para completar la metamorfosis. El objetivo general de esta tesis fue identificar miRNAs que estuviesen implicados en este proceso. Como primer paso, se estableció un catálogo general de miRNAs en B. germanica mediante secuenciación con Solexa. A partir de ahí, se prepararon dos librerías de miRNAs, una en la etapa metamórfica y otro en la etapa no metamórfica, para distinguir miRNAs diferencialmente expresados entre las dos etapas y evaluar la influencia de las hormonas principales de la metamorfosis sobre la expresión de estos miRNAs. Nuestros experimentos también mostraron que los factores de transcripción Broad-complex inducen la expresión de let-7 y miR-100, y que estos miRNAs desempeñan un papel en la regulación del tamaño y del patrón de venas e intervenas de las alas de B. germanica. Por último, se estudió el papel de miR-8-3p y miR-8-5p en la regulación de los niveles de transcrito de atrofina, un factor implicado en la coordinación neuromuscular, que es importante para asegurar una adecuada ecdisis en la muda metamórfica.
Previous work carried out in the host laboratory, using the basal insect Blattella germanica as model, showed that microRNAs (miRNAs) are crucial to complete metamorphosis. The general goal of this thesis was to identify particular miRNAs involved in this process. As a first step, we established a general catalogue of miRNAs in B. germanica using high throughput Solexa sequencing. Thereafter, we prepared two miRNA libraries; one in the metamorphic stage and other one in the non-metamorphic stage, to distinguish miRNAs differentially expressed between the two stages, and to assess the influence of the main metamorphosis hormones on the expression of these miRNAs. Our experiments also showed that Broad complex transcription factors induce the expression of let-7 and miR-100, and that these miRNAs play a role in regulating the size and the vein-intervein patterning of B. germanica wings. Finally, we studied the role of miR-8-3p and miR- 8-5p in regulating the transcript levels of atrophin, a factor involved in neuromuscular coordination, which is important to ensure a proper ecdysis in the metamorphic molt.

Made available in DSpace on 2015-03-26T12:10:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1584074 bytes, checksum: 9f5933c0ddc882411ad84b3276bfaa43 (MD5) Previous issue date: 2014-03-14
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The larvae of the yellow fever mosquito Aedes aegypti live in the water, feeding on microorganisms and organic matter decomposition. After metamorphosis, adults emerge and feed on sap. However, for the maturation of eggs, the A. aegypti females need a blood meaL This variation of the diets is possible due to the midgut remodeling undergoes during metamorphosis, allowing adaptation to different diets depending on life stages. After ingestion, the blood is stored and digested into midgut, which is the fírst organ víruses, such as Dengue, yellow fever and other infect. The midgut epithelium of A. aegypti Compríses three Cell typesz digestive (responsible for digestion and absorption of nutrients), regenerative (stem, undifferentiated Cells) and enteroendocrine (neuropeptides secretory) Cells. During metamorphosis, the digestive Cells are replaced by new adult digestive Cells by differentiation of regenerative ones. In the present study morphological and biochemical aspects of the metamorphosis of the midgut were investigated, íncluding the differentíation and the quantificatíon of dividing regenerative and enteroendocrine cells at different developmental stages [fourth ínstar larvae - L4, female whíte pupae - WP and pupae 24 and 48 h (P24 and P48, respective1y) after ecdysis, and 50 newly-emerged (NE) adult females] by means líght microscopy and transmission electron microscopy. In addition, the proteins synthesized by the midgut in these stages and in sugar- and b1ood-fed adult females (SA and BA, respective1y) were also studied. The lysis of digestive Cells, as well as the proliferation of regenerative Cells, begin in the anterior region of L4 midgut Simultaneously, the proliferation of regenerative Cells begins in the anterior region of the larval midgut, moving to the posterior region in P48 and NE. The effects of the neocotinoid insectícíde imídacloprid Was also tested in the mosquito midgut Third instar larvae (L3) were treated with two subletal Concentratíons (3 and 15 ppm) of insecticide, and the midgut was examined in L4, P24, P48 and NE. Subletal Concentrations of imidacloprid inhíbít the proliferation and differentíation of regenerative Cells, often leading to cell damaged through their nuclear DNA fragmentation. This inhibition has led to the reduction of the digestive and endocrine Cell numbers, and the mídgut of NE Consists of mostly vacuolatedlincompletely formed digestive Cells. Therefore, the imidacloprid exposition during juvenile stages, impair the normal midgut development in NEs, and they may not be able to get/digest a blood meaL The mídgut of NE has higher expression of proteins related to energy and protein metabolisms, cell signaling and transport. The mídgut of SA and BA express more proteins associated to the protein biosynthesis process. In the mídgut of pupae, several proteins essential for the organ remodeling are expressed, but the peak expression of these proteins occurs at the end of remodeling process in NE. Not surprising1y, in SA and BA there is a high expression of proteins associated to the digestion of sugar and blood, respective1y. In the present Work, several morphological and biochemical aspects of the mídgut of A. aegypti are investigated, íncluding the repertoire of differentially expressed proteins during mídgut development and in the midguts of individuals under different feeding conditions. Morpho-physiological processes that occur during the development and functioning of this organ are Crucial to the survival of this vector mosquito and are discussed.
Ao longo do seu desenvolvimento pós-embrionário, 0 mosquito Aedes aegypti passa parte do seu Cíclo de vida no ambíente aquático, sendo que suas larvas se alimentam de microrganismos e matéria orgâníca em decomposição. Após a metamorfose, os adultos alados emergem, e passam a se alimentar de seiva. Para maturação dos ovos, as fêmeas de A. aegypti necessitam do repasto sanguíneo. Essa plasticidade quanto ao tipo de alimentação só é possível graças às modificações que 0 íntestíno médio sofre ao longo da metamorfose, permitindo a adaptação do ínseto a diferentes dietas dependendo da fase do desenvolvimento. Após a ingestão, 0 sangue é armazenado e digerido no intestino médio, que é 0 primeiro órgão do ínseto que diversos vírus, Como por exemp10, vírus Dengue e da febre amarela, são Capazes de infectar 0 hospedeiro. No epitélio do intestino médio de A. aegypti há três tipos Celularesz Células digestivas (responsáveis pela digestão e absorção de nutrientes), regenerativas (Células indiferencíadas) e enteroendócrinas (secretoras de neuropeptídeos). Durante a metamorfose, as Células digestivas de A. aegypti são substituídas por novas Células digestivas adultas através da diferenciação das Células regenerativas. No presente trabalho aspectos morfológicos e bioquímicos referentes à metamorfose do íntestíno médio foram investígados, incluindo a diferenciação e a divisão das Células regenerativas, e 0 número de Células enteroendócrinas em diferentes fases do desenvolvimento de A. aegypti (1arva 4° instar - L4, pupa branca - PB, pupas 24h -P24 e 48h -P48 após a ecdise e adultos recém-emergidos - RE). Adicíonalmente, a expressão de proteínas sintetizadas pelo órgão nessas fases e em fêmeas adultas submetidas às dietas à base de açúcar (AA) e de sangue (AS) foi estudada. A morte das Células digestivas e a proliferação das Células regenerativas ocorrem de forma ordenada, em regiões específicas do órgã0, ínícíando na região anterior das L4 e passando para a região posterior nas P48 e RE. Os efeitos subletaís do inseticida neocotinoide imídacloprid também foram testados no processo de remodelargem do íntestino médio de A. aegypti. Para ísso, larvas 3° instar (L3) foram tratadas Com duas Concentrações (3 e 15 ppm) do inseticida e 0 intestino médio foi analisado nas fases seguintes. Mesmo em Concentrações subletaís, 0 imídacloprid alterou 0 processo de remodelação do intestino médio, inibindo a proliferação e diferenciação das Células regenerativas, e Causando danos ao DNA nuclear delas, Como atestado pela reação de TUNEL. Essa íníbíção acarretou a diminuição das populações das Células digestivas e enteroendócrinas, sendo que 0 intestino médio dos RE é Constituído, na maior parte, por Células digestivas vacuolizadas e mal formadas. O ímidacloprid possui potencíal no Controle de A. aegypti, pois, mesmo que 0 índivíduo Chegue à fase adulta, do ponto de vista morfológico, seu intestino aparentemente não está apto para 0 processo de digestã0. O intestino médio dos RE possui maior expressão de proteínas ligadas à produção de energia, metabolismo de proteínas, sinalização e transporte Celulares. Os intestinos médios de AA e AS expressam maís proteínas ligadas ao processo de bíossíntese de proteínas. Nas pupas se inicia a síntese das múltiplas proteínas essenciais para a formação e Constítuição do novo epitélio do órgã0, mas 0 pico da expressão dessas proteínas ocorre no final do processo de formação do órgão no adulto recém- emergido. Já nos AA e AS há alta expressão de proteínas ímportantes para a digestão de açúcar e sangue, respectivamente. O presente trabalho é amp10, tratando de aspectos morfológicos e bioquímicos do intestino médio de A. aegypti, incluindo parte do repertórío de proteínas diferencialmente expressas no órgão durante 0 desenvolvimento pós-embríonário e em díferentes Condições alimentares. Processos morfofisiológicos que ocorrem ao longo do desenvolvimento e funcionamento desse órgão são Cruciais para a sobrevivência dessa espécíe vetora e são discutidos aqui neste trabalho.

Orientador: Mary Anne Heidi Dolder, Clovis Andrade Neves
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-10T19:24:09Z (GMT). No. of bitstreams: 1 Cruz_LilianCota_M.pdf: 6744301 bytes, checksum: 728821086751ef70a46cd6df9152a7a4 (MD5) Previous issue date: 2008
Resumo: As abelhas são insetos holometábolos, pois apresentam metamorfose completa. Na metamorfose destes insetos, o trato gastrointestinal é completamente remodelado. Poucos estudos enfatizam os aspectos que envolvem a reconstituição do epitélio do intestino médio de abelhas durante a metamorfose. Os trabalhos que destacam a proliferação das células digestivas durante a metamorfose carecem de documentação das figuras de mitose. O presente trabalho contribui para o conhecimento da biologia dos Hymenoptera, gerando dados que possam esclarecer aspectos da fisiologia digestiva durante a metamorfose dos insetos sociais. Comprovamos a necessidade de aumento do número de células digestivas do intestino médio de Melipona quadrifasciata anthidioides ao final da metamorfose sem, contudo, observar figuras de mitose que comprovassem a proliferação destas células, como notado em Nasutitermes rotundatus (Holmgren) (Isoptera). É possível que as células regenerativas tenham origem externa ao intestino médio e migrem através da membrana basal para se estabelecerem no epitélio. Além disso, nesse trabalho descrevemos a morfologia do epitélio do intestino médio com auxílio da microscopia eletrônica de varredura, demonstrando que somente a membrana peritrófica diferiu entre as castas
Abstract: Bees are holometabolus insects, since they present complete metamorphosis. During the metamorphosis of the insects the gut is completely remodeled. Few studies emphasize aspects of the renewal of the epithelium of bee¿s midgut during metamorphosis. Studies that describe digestive cell proliferation are lacking in images of mitosis. This research is a contribution to the understanding of Hymenoptera biology in relation to some aspects of digestive physiology during metamorphosis of social insects. We have established the necessity of increasing the number of cells in the median intestine of Melipona quadrifasciata anthidioides at the end of metamorfosis without having, however, observed mitosis, as was found for Nasutitermes rotundatus (Holmgren) (Isoptera). Possibly the regenerative cells arisen outside the midgut migrated through the basal membrane, to establish themselves in the epithelium. Also, in this study we describe the morphology of the median intestine epithelium, using scanning electron microscopy, showing that only the peritrophic membrane presented differences in the casts studied.
Mestrado
Biologia Celular
Mestre em Biologia Celular e Estrutural

This work addresses torture with the ambition to strengthen a properly sociological approach to it by bringing to the fore the social history of the tortured, also through the fundamental contribution of the political economy. This category is not utilised in an abstract way, it is brought into the picture through the social history of the bodies of those tortured. These bodies are not considered mere biological bodies subjugated by ‘power’, but rather bodies with a voice, bodies capable of revealing their social standing. Placing the bodies’ class at the centre of the analysis allows us to fully grasp the sociological substance of torture, to understand the underlying reasons for its historical persistence and constant diffusion. The book explores torture in a threefold way: firstly by analysing the image of torture as an effective hermeneutic tool of late modernity; secondly by adopting a historical perspective to identify structural elements and metamorphoses; thirdly by examining the concrete practices of torture to enable the establishment of a mutual relationship between history and biography.

<em>Abstract</em>.—In most lamprey genera, “paired” species exist in which the larvae (which are microphagous filter feeders) are morphologically similar but the adults differ dramatically, becoming parasitic on teleost fishes or nonparasitic (i.e., do not feed at all) following metamorphosis. Parasitic lampreys feed for several months to several years (either in their natal stream or after migrating to larger fresh or marine water bodies) before embarking on a nontrophic upstream migration, sexual maturation, and spawning (followed by death); nonparasitic lampreys eliminate the parasitic phase, begin sexual maturation toward the end of metamorphosis, and spawn and die within 6–10 months of metamorphosis. In each species pair, the reduction in the length of postlarval life in nonparasitic lampreys is generally accompanied by an increase in the length of the larval period (and size at metamorphosis) so that the evolution of nonparasitism appears to have occurred without a change in the overall life span. Rather, nonparasitism appears to have evolved as a result of a change in the timing of metamorphosis relative to the timing of sexual maturation. Conspicuous morphological (e.g., adult body size, relative eye and oral disk size) and histological (e.g., lack of a functional digestive tract) differences distinguish nonparasitic adults from parasitic forms, and most lamprey taxonomists recognize life history type as a species-specific characteristic. However, plasticity of feeding type (e.g., facultative parasitism) has been observed in some lamprey populations, and molecular data on a number of paired species show no genetic differentiation between sympatric species pairs and suggest a polyphyletic origin for several nonparasitic species. This paper reviews the paired species concept, the repeated and independent evolution of nonparasitism in different genera and even within species, the evidence for facultative parasitism or facultative nonparasitism in some lamprey species, and the potential for hybridization between paired species and attempts to answer the question, are brook lampreys “real” species? The tentative answer is that there likely is not a single answer for all lamprey species pairs; different species pairs represent speciation at different stages. Some pairs appear to be distinct species according to both the biological and phylogenetic species concepts (i.e., they are reproductively isolated and show reciprocal monophyly), although each is not necessarily fixed for feeding type. In contrast, other pairs may represent incipient speciation and others yet may be experiencing ongoing gene flow. Parallels are therefore drawn between different lamprey species pairs and the divergent life history types found in other animal taxa (e.g., echinoderms and amphibians) and other temperate fish species (e.g., anadromous and freshwater-resident salmonids).

Abstract Trophic interactions are at the core of several key ecological processes and theories as they determine the flow of material and energy within and across communities and habitats. Odonates provide a rich and diverse taxonomic group with several features (e.g. trophic position, hunting behavior, olfaction) that make them a very interesting biological model for the study of trophic interactions in aquatic and terrestrial habitats. Moreover, odonates undergo incomplete metamorphosis with aquatic larvae and terrestrial adults, which provides opportunities to investigate ontogenetic diet variation and trophic links between aquatic and terrestrial systems. They are also important predators regulating prey populations and mediating community processes such as trophic cascades. Finally, recent studies on odonates have pioneered whether local adaptation and phenotypic plasticity can counterbalance the negative impacts of global change on resource acquisition and fitness. This chapter reviews recent studies investigating the trophic features and role of odonates in aquatic and terrestrial ecosystems as well as their importance for investigating the impact of global change on trophic ecology, local adaption, and community processes. Many of the insights highlighted in this chapter go beyond odonates and have helped to advance key concepts in trophic ecology.

This chapter discusses Johann Wolfgang von Goethe and the metamorphoses of form. Goethe's biological and literary writings of the 1790s radicalize Kant's insights. On the one hand, he emphasizes the “metamorphic” fluidity of both natural forms and human cognition; on the other, he stresses the erotic and social dimension of subjectivity. For Goethe, human life is singularly precarious because it is subject to libidinal investments and the unruliness of the imagination. To develop properly, human life must therefore be regularized by social forms that (re)direct its innate vitality — it must assume a second-order, socialized naturalness. Goethe's novel Wilhelm Meister's Apprenticeship associates the creation of this second nature with liberal forms of governing, depicting liberalism's normative force as a necessary, if at times violent, supplement to human life. With Goethe, vitalism opens itself to biopower.

histological and electron microscopic investigations were performed of the development of generative elements of Schistosoma mansoni mother sporocysts (MS). On average 20 germinal cells (GC) are found in miracidium. After metamorphosis of miracidium into sporocysts GC grow and on the 3d day start to divide thus forming first embryos of daughter sporocysts. During the same time germinal masses start to form in the subtegumental body area of MS. At this point proliferation of undifferentiated cells (UC) occurs only in the germinal masses. Here also a part of UC differentiates into GC. These cells form sporocystoid embryos. Therefore, the formation of generative elements into S. mansoni MS occurs in two stages. The primaries GC are formed in the process of the miracidium development into the egg, but secondary GC forming into germinal masses of MS.