2,079 research outputs found
The Midgut Of Cephalotes Ants (formicidae: Myrmicinae): Ultrastructure Of The Epithelium And Symbiotic Bacteria
No full textThe ultrastructural analysis of the midgut of Cephalotes atratus, C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined. © 2010 Elsevier Ltd.415448454Arab, A., Caetano, F.H., Functional ultrastructure of the midgut of the fire ant Solenopsis saevissima Forel 1904 (Formicidae: Myrmicinae) Cytobios (2001) Cambridge, 105, pp. 45-53Baumann, P., Baumann, L., Lai, C.Y., Rouhbahsh, D., Moran, N.A., Clark, M.A., Genetics, physiology, and evolutionary relationship of the genus Buchnera: intracellular symbionts of the Aphides (1995) Annu. Rev. Microbiol., 49, pp. 55-94Blochmann, F., Uber das Vorkommen bakterienahnlicher Gebilde in den Geweben und Eiern verschiedener Insekten (1882) Zbl. Bakt. II., pp. 234-240Bution, M.L., Caetano, F.H., Ileum of the Cephalotes ants: a specialized structure to harbor symbionts microorganisms (2008) Micron, 39, pp. 897-909Bution, M.L., Caetano, F.H., Fabio, B., Britto, Giovana, A., Tomaino-Gomes, Zara, F.J., Histology and histochemistry of the ventriculus Dolichoderus (=Monacis) bispinosus (Olivier, 1792) (Hymenoptera: Formicidae) (2006) Micron, 37, pp. 249-254Caetano, F.H., Anatomia, histologia e histoquímica do sistema digestivo e excretor de operárias de formigas (Hymenoptera, Formicidae) (1988) Naturalia, São Paulo, 13, pp. 129-174Caetano, F.H., Endosymbiosis of ants with intestinal and salivary gland bactéria (1989) Insect Endocytobiosis: Morphology, Physiology, Genetic, Evolution, pp. 57-75. , C.R.C. Press, Inc., USACaetano, F.H., Cruz-Landim, C., Ultra-estrutura das células colunares do ventrículo de Camponotus arboreus (Hymenoptera, Formicidae) (1983) Naturalia, São Paulo, 8, pp. 91-100Caetano, F.H., Cruz-Landim, Presence of microorganisms in the alimentary canal of ants of the Cephalotini tribe (Myrmicinae): location and relationship with intestinal structures (1985) Naturalia, São Paulo, 10, pp. 37-47Caetano, F.H., Jaffé, K., Crewe, R.W., The digestive tract of the Cataulacus ants: presence of the microorganisms in the ileum (1994) 12TH World Congress on Social Insects, pp. 391-392Caetano, F.H., Torres, A.H., Camargo-Mathias, M.I., Tomotake, M.E.M., (1994) Apocrine secretion in the ant, Pachycondyla striata, ventriculus (Formicidae: Ponerinae), pp. 235-242. , Cytobios, CambridgeCaetano, F.H., Bution, M.L., Zara, F.J., First report of endocytobionts in the digestive tract of ponerine ants (2009) Micron, 40, pp. 194-197Caldwell, D.R., (1995) Microbial Physiology and Metabolism, p. 353. , Wm. C. Brown Communications, IncChapman, R.F., (1975) The Insects: structure and function, p. 819. , American Elsevier, New YorkChen, X., Li, S., Aksoy, S., Concordant evolution of a symbiont with its host insect species: molecular physiology of genus Glossina and its bacteriome-associated endosymbiont, Wigglesworthia glossinidia (1999) J. Mol. Evol., 48, pp. 49-58Jeantet, A.Y., Recherches histophisiologiques sur le developpement postembryonnaire, et le cycle annuel de Formica (Hyménoptère) (1971) Z. Zellforsch., 116, pp. 24-405Jones, C.G., Microorganisms as mediators of plant resource exploitation by insect herbivores (1983) A New Ecology: Novel Approach to Interactive Systems, pp. 53-99. , P.W. Price, C.N. Slobodchikoff, W.S. Gand (Eds.)King, R.C., Akai, H., (1984) Insect Ultrastructure, 2, p. 624. , Plenum Press, New YorkLehane, M.J., Billingsley, P.F., (1996) Biology of the Insect Midgut, p. 486. , Chapman and HallMartoja, R., Ballan-Dufarnçais, C., The ultra-structure of the digestive and excretory organs (1984) Insect Ultrastructure, 2, pp. 199-268. , Plenum Press, New YorkRoche, R.K., Wheeler, D.E., Morphological specializations of the digestive tract of Zacryptocerus rohweri (Hymenoptera, Formicidae) (1997) Journal of Morphology, Tucson, 234, pp. 253-262Schroder, D., Deppsch, H., Obermayer, M., Krohne, G., Stackebrandt, E., Holldobler, B., Goebel, W., Gross, R., Intracellular endosymbiotic bacteria of Camponotus species (carpenter ants): systematics, evolution and ultrastructural characterization (1996) Mol. Microbiol., 21 (3), pp. 479-489Snodgrass, R.E., (1935) Principles of Insect Morphology, p. 667. , Mcgraw-hill Book CompanyTerra, W.R., The origin and functions of the insect peritrophic membrane and peritrophic gel (2001) Arch. Insect Biochem. Physiol., 47, pp. 47-61Terra, W.R., Ferreira, C., Insect digestive enzymes: properties, compartmentalization and function (1994) Comp. Biochem. Physiol., pp. 1-62Terra, W.R., Ferreira, C., Baker, J.E., (1996) Biology of the Insect Midgut, pp. 206-231. , Lehane and Billingsley/Chapman and HallWigglesworth, V.B., (1974) The Principles of Insect Physiology, p. 827. , Chapman and Hall, Londo
Symbiotic Bacteria And The Structural Specializations In The Ileum Of Cephalotes Ants
No full textLight, scanning, and transmission electron microscopy were used to examine the ultramorphology and ultrastructure of the ileum of Cephalotes atratus, Cephalotes clypeatus, and Cephalotes pusillus. Sections along the ileum revealed differences among the three main regions: proximal (or pylorus), medial, and distal. The structural specializations present in the ileum of these three ants have implications especially to the symbiotic bacteria harbored in this region of the digestive tract. The structural similarities are conspicuous for the three species examined, suggesting that this is the pattern adopted by the genus Cephalotes. © 2010 Elsevier Ltd. All rights reserved.414373381Billen, J., Buscinger, A., Morphology and ultrastructure of a specialized bacterial pouch in the digestive tract of Tetraponera ants (Formicidae, Pseudomyrmecinae) (2000) Arthropod Struct. Dev., 29, pp. 259-266Bution, M.L., Caetano, F.H., Fabio, B.B., Giovana, A.T.G., Zara, F.J., Histology and histochemistry of the ventriculus Dolichoderus (=Monacis) bispinosus (Olivier, 1792) (Hymenoptera: Formicidae) (2006) Micron, 37, pp. 249-254Bution, M.L., Caetano, F.H., Ileum of the Cephalotes ants: a specialized structure to harbor symbionts microorganisms (2008) Micron, 39, pp. 897-909Caetano, F.H., Lage Filho, A.L., Anatomia e histologia do trato digestivo de formigas do gênero Odontomachus (Hymenoptera, Ponerinae) (1982) Naturalia São Paulo, 7, pp. 125-134Caetano, F.H., Morfologia comparada do trato digestivo de formigas da subfamília Myrmicinae (Hymenoptera, Formicidae) (1984) Pap. Avulsos Zool. (São Paulo), 35, pp. 257-305Caetano, F.H., Cruz-Landim, C., Presence of microorganisms in the alimentary canal of ants of the tribe Cephalotini (Myrmicinae): location and relationship with intestinal structures (1985) Naturalia (São Paulo), 10, pp. 37-47Caetano, F.H., Camargo-Mathias, M.I., Overal, W.L., Anatomia e histologia do trato digestivo de Dinoponera gigantea e Panaponera clavata (Formicidae: Ponerinae) (1986) Naturalia, 11-12, pp. 125-134Caetano, F.H., Anatomia, histologia e histoquímica do sistema digestivo e excretor de operárias de formigas (Hymenoptera, Formicidae) (1988) Naturalia (São Paulo), 13, pp. 129-174Caetano, F.H., (1989) Endosymbiosis of Ants with Intestinal and Salivary Gland Bactéria. Insect Endocytobiosis: Morphology, Physiology, Genetic, Evolution, , CRC Press Inc., USA pp. 57-75Caetano, F.H., Tomotake, M.E., Pimentel, M.A.L., Camargo-Mathias, M.I., Morfologia interna de operárias de Dolichoderus attelaboides (FABRICIUS, 1775) (FORMICIDAE: DOLICHODERINAE). Trato digestivo e sistema excretor anexo (1990) Naturália, São Paulo, 15, pp. 57-65Caetano, F.H., Jaffé, K., Crewe, R.W., The digestive tract of the Cataulacus ants: presence of the microorganisms in the ileum (1994) Proceedings of the 12th World Congress on Social Insects (IUSSI), pp. 391-392. , ParisChapman, R.F., (1975) The Insects: Structure and Function, , American Elsevier, New York p. 819Dillon, R.J., Dillon, V.M., The gut bacteria of insects: nonpathogenic Interactions (2004) Annu. Rev. Entomol., 49, pp. 71-92Holldobler, B., Wilson, E.O., (1990) The Ants, , Springer, London pp. 436-467Lemos, F.J.A., Terra, W.R., Digestion of bacteria and the role of midgut lysozyme in some insect larvae (1991) Comp. Biochem. Physiol., 100 B, pp. 265-268Roche, R.K., Wheeler, D.E., Morphological Specializations of the Digestive Tract of Zacryptocerus rohweri (Hymenoptera, Formicidae) (1997) J. Morphol. (Tucson), 234, pp. 253-262Wigglesworth, V.B., (1974) The Principles of Insect Physiology. 7th ed., , Chapman and Hall, London p. 827van Borm, S., Buschinger, A., Boomsma, J.J., Billen, J., Tetraponera ants heve gut symbionts related to nitrogen-fixing root-nodule bacteria (2002) Proc. R. Soc. Lond., 296, pp. 2023-202
Realtà, realismo, straniamento : Auerbach e il romanzo cavalleresco fino a Cervantes
No full textAuerbach’s research, besides exploring the three main fields the author explicitly names (i.e. the succession of different and differently grounded forms of realism in literary fiction, the alternate splitting and melting of styles, the link between literary work and a Christian vision of the world), in various chapters of Mimesis, and particularly in chs. 2, 6, 12, 14 and 20, is also focused, albeit only implicitly, on the developments of a further distinctive feature in Western literature, which is the emergence of subjectivity in the representation of reality. Focusing mainly on the chapter on courtly romance (ch. 6) and on the Quijote (ch. 14), this essay will examine Auerbach’s interpreting work on texts that adopt, in different ways, a ‘subjective point of view’; this kind of interpretation is, in part, unexpectedly similar to the approach of other critics and theorists of literature contemporary to Auerbach, like Bachtin, Américo Castro and Viktor Šklovskij
Shedding light on the black hole: The roll-out of broadband access networks by private operators
No full textSeveral market studies have indicated that the roll-out of broadband has significant economic and social relevance. The investments in broadband infrastructures needed to realise these economic and social benefits are, however, high-risk. This is firstly caused by the fact that the roll-out of access networks is extremely costly and requires high initial investments. Moreover, the multidisciplinary environment and involvement of many actors with diverging objectives and interests cause high complexity. Moreover, the market for broadband is changing fast and continuously. Although broadband has been on the academic research agenda for quite some time, this has as yet not resulted in a structured insight into the decision-making process around the upgrading of broadband networks, seen from the perspective of private operators and taking into account the vast complexity of the surroundings in which this decision-making process takes place in. The objective of this research was to provide a unifying theory combining technical, economic, market-related and regulatory factors with regard to an evolutionary, flexible approach of network upgrading from a decision-maker perspective. The result of this research is a robust, explanatory, parsimonious model for the impact and outcomes of broadband roll-out. This model provides a certain degree of stability in this multidisciplinary, unpredictable and highly dynamic research field.Technology, Policy and Managemen
“Maistre (certa)”. Niveaux de savoir et conception du monde chez Guillaume IX d’Aquitaine
No full textStarting with a study by M. Black (Models and Archetypes, 1958), the author examines the possibility of broadening this heuristic perspective to include literature. In particular, she analyses a text by William IX, in which the troubadour seems identify himself with God
Oltre lo specchio: il Joufroi de Poitiers e la cultura lirica del suo autore
No full textCome è stato a più riprese osservato, il Joufroi de Poitiers, romanzo d’autore borgognone collocabile verso la metà del XIII secolo, si ispira molto da vicino alla figura di Guglielmo IX d’Aquitania, grande signore e primo trovatore di cui ci siano giunti i componimenti. Ma a quali materiali si ispira veramente l’autore del Joufroi? Alla vida provenzale conservata, o piuttosto a una più ampia biografia latina perduta, o ad altri testi ancora? La presente ricerca cercherà di mettere in luce quali siano state le effettive fonti del romanzo e di abbozzare un’ipotesi che spieghi le motivazioni di questi recuperi.As has been repeatedly noted, Joufroi de Poitiers, a novel written by a Burgundian author and composed around the middle of the thirteenth century, is based very closely on the figure of William IX of Aquitaine, great lord and first troubadour whose poems have been compiled. But what materials did truly inspire the author of Joufroi? The extant Provençal vida, or rather a lost broader Latin biography, or still other texts? This research will try to shed light on what were the actual sources of the novel and to outline a hypothesis that explains the motivations of these works
Proceedings of the Per Bruun Symposium
No full textHolocene sea level rise, shoreline erosion and the Bruun Rule-overview (J.J. Fisher) The Bruun Rule: A historical perspective (M.L. Schwartz and V. Milicic) Hypothetical shore profiles in response to rising water level (R.N. Dubois) Shoreline erosion, Rhode Island and North Carolina coasts-test of Bruun Rule (J. J. Fisher) An application of the Bruun Rule in the Chesapeake Bay (P.S. Rosen) Bruun's Concept applied to the Great Lakes (E.B. Hands) Enigma of the Bruun's formula in shore erosion (H. Allison) The 11 Bruun Rule", Discussion on boundary conditions (P. Bruun)KWP-collectio
Realtà, realismo, straniamento: Auerbach e il romanzo cavalleresco fino a Cervantes
No full textAuerbach’s research, besides exploring the three main fields the author explicitly names (i.e. the succession of different and differently grounded forms of realism in literary fiction, the alternate splitting and melting of styles, the link between literary work and a Christian vision of the world), in various chapters of Mimesis, and particularly in chs. 2, 6, 12, 14 and 20, is also focused, albeit only implicitly, on the developments of a further distinctive feature in Western literature, which is the emergence of subjectivity in the representation of reality. Focusing mainly on the chapter on courtly romance (ch. 6) and on the Quijote (ch. 14), this essay will examine Auerbach’s interpreting work on texts that adopt, in different ways, a ‘subjective point of view’; this kind of interpretation is, in part, unexpectedly similar to the approach of other critics and theorists of literature contemporary to Auerbach, like Bachtin, Américo Castro and Viktor Šklovskij
La guerra interdetta : "Il campo 29" di Sergio Antonielli
No full textIl campo 29 is the debut as novelist of Sergio Antonielli. It was
published in Milan in 1949 by “Edizioni Europee” and in 1976
by “Editori Riuniti”. The novel tells the personal experience of
imprisonment in British Raj during the Second World War with other
ten thousand Italian officers.
Through the analysis of the text and documents from the archives
of the author, stored in the Centro Apice, I would like to discuss the
techniques of composition that make this work a peculiar case in the
post-world war literary system. Antonielli, forcing himself to overcome
the tragedy suffered, commits to the writing a dual purpose: to avoid
mere “documentarismo” without overindulging in the romance, and
to take the advantage of the exceptional nature of his experience to
create a work that exceed all individual and historical contingencies.
In respect of these moral and stylistic imperatives, the writer refuses
the autobiography and choices a choral intonation, different from
sentimental style, typical of other writers involved in the literature
of war. His critic studies and the introductions, written by author for
two editions, show distinct interpretations about his work and about
typical methods and category of neorealist literature: document,
diary, autobiographical novel.
The story does not give way to political disquisitions or to sentimental
parenthesis, but it consists of representation of the life in prison
camps. A “city of prisoners” comes alive, where coexist vices and
virtues of the normal society, and where the war is banned
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