51 research outputs found
The trophic role of the squid Loligo plei as a keystone species in the South Brazil Bight ecosystem
No full textAbstract
Gasalla, M. A., Rodrigues, A. R., and Postuma, F. A. 2010. The trophic role of the squid Loligo plei as a keystone species in the South Brazil Bight ecosystem. – ICES Journal of Marine Science, 67: 1413–1424. The issue of whether loliginid squid can influence the average structure of marine ecosystems in a keystone role, i.e. a strong effect with relatively low biomass, has not yet been examined. Here, the diet of Loligo plei in inner shelf waters of the South Brazil Bight was examined, as a first step, based on the stomach contents of 2200 squid hand-jigged in shallow water (<30 m) and taken as bycatch of shrimp trawlers in deeper water (30–100 m). Diet varied by size, season, and fishing zone. Stomachs were not empty in ∼12%, with more empty during winter. The range of mantle lengths of squid caught by jigging (101–356 mm) appeared to differ from the squid trawled (30–236 mm), and the diet also differed. Food categories recorded in deeper water did not include amphipods or polychaetes, but in both fishing areas, fish were the most common prey. The fish prey identified included Trachurus lathami, small pelagic species, trichiurids, and Merluccius hubbsi. Demersal species, such as Ctenosciaena gracilicirrhus, and flatfish were also present. An ecosystem network model is updated through which a mixed-trophic impact matrix and “keystoneness” indicators were calculated. Loligo plei represents an important link between pelagic and demersal energy pathways, with high indices of keystoneness.</jats:p
Biologia populacional e aspectos comportamentais da lula Doryteuthis plei (Blainville, 1823) no litoral norte de São Paulo, com ênfase na reprodução e alimentação
No full textThis PhD thesis addresses several aspects of the biology and ecology of the squid Doryteuthis plei in the coast of São Paulo, SE Brazil, at both the population and individual levels. On the population structure of the exploited stock, it includes the patterns of reproductive activity, size-at-maturity, and biometrics of reproductive organs associated with squid size, as well as feeding habits and ontogenetic, sexual, and spatial-temporal shifts. Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to identify such population patterns and spatial and temporal factors based on the particular small-scale fishery that targets the species around the São Sebastião Island. At the individual level, the study focused on behavioural traits in two periods of the life-cycle: (1) the reproductive phase, where the body patterns were described, generating a comprehensive ethogram for the species, and (2) the paralarval phase, where the development of swimming and predatory behaviours was detailed. Size-at-maturity was found to be 151-175 mm of mantle length (ML) for females, and 187-190 mm ML for males, that also showed the co-occurrence of two distinct maturation groups (Chapter 1). A significant peak of females gonad weight occurs in February and March especially in the island\'s South and Southeastern areas, and of males in March. An ethogram analysis showed 19 chromatic, 5 locomotor, and 12 postural components and behavioural sequences for the species, including agonistic, courtship, and mating behaviour (Chapter 2). Light chromatic components (clear and iridophore splotches) showed a longer duration than dark chromatic components, especially those associated with calm behaviour, more frequent in females. Males appeared more dedicated to disputes over resources and used fast miscellaneous visual signalling. In respect to feeding habits (Chapter 3), prey composition differed among sexes, size, maturity, and spatio-temporal pattern. Females do not stop feeding during sexual maturation and the amount of food increases with size. Cephalopods were significant preys for mature females, as well as fish and crustaceans to the largest females, while pelagic polychaetes were dominant prey for largest males. Observations and filming of D. plei paralarvae (Chapter 4) show a complex predatory behaviour on live preys, with different hunting types differing in speed and position. Aggressive intra-specific behaviour was found in the absence of prey when paralarvae show both a pursuit strategy and a rapid backward escape after attack. These findings contribute to better understand the population biology and behavior of the species and also in the future definition and guidance of fisheries management plans.A presente tese aborda diferentes aspectos da biologia e ecologia da lula Doryteuthis plei na costa de São Paulo, SE do Brasil, tanto em nível individual quanto populacional. Com relação à estrutura populacional do estoque explorado, foram analisados padrões da atividade reprodutiva, tamanho de primeira maturação, morfometria dos órgãos reprodutivos associados às fases de desenvolvimento e também hábitos alimentares e mudanças ontogenéticas, sexuais e espaço-temporais. Modelos aditivos generalizados para localização, escala e forma (Generalized Additive Models for Location, Scale, and Shape - GAMLSS) foram utilizados com intuito de identificar padrões populacionais, espaciais e temporais baseados em desembarques da pesca de pequena escala em torno da Ilha de São Sebastiao. Em nível individual, o estudo abordou padrões comportamentais em 2 diferentes períodos do ciclo de vida: (1) fase de reprodução, onde padrões corporais foram descritos, tendo como resultado um abrangente etograma (2) fase paralarval, onde o desenvolvimento de comportamento natatório e predatório foram detalhados. O tamanho de primeira maturação foi estimado entre 151 e 175 mm de comprimento do manto (ML) para as fêmeas e entre 187 e 190 mm ML para os machos, também foi identificada a co-ocorrência de 2 grupos de maturação para os machos. (Capitulo 1). Um pico significativo com relação ao peso das gônadas foi identificado entre os meses de Fevereiro e Março para as fêmeas e em Março para os machos, especialmente nas áreas Sul e Sudeste da ilha. Uma análise dos comportamentos reprodutivos e dos padrões corporais, resultando em um amplo etograma, revelou 19 componentes cromáticos, 5 locomotores e 12 posturais, como também, sequências comportamentais para a espécie, incluindo comportamentos agonístico, de corte e acasalamento (Capitulo 2). Componentes cromáticos claros (manchas claras e irridóforos) apresentaram maior duração do que os componentes cromáticos escuros, particularmente aqueles relacionados ao comportamento calmo, mais frequente nas fêmeas. Machos aparentemente foram mais propensos a disputas por recursos usando sinalizações visuais rápidas e variadas. Em relação aos hábitos alimentares (Capítulo 3), a composição de presas diferiu entre sexos, tamanhos, maturidade e padrões espaço-temporais. As fêmeas não deixaram de se alimentar durante a maturação e foi observada uma relação positiva entre a quantidade de alimentos e o tamanho dos indivíduos. Pequenos cefalópodes, assim como peixes e crustáceos foram às presas mais significativas entre as fêmeas maduras, enquanto que para os machos foram os poliquetas. Através de observações e filmagens de paralarvas de D. plei (Capitulo 4), identificou-se um comportamento predatório complexo sobre presas vivas, com diferentes tipos de caça que diferem em velocidade e posição. Comportamentos agressivos entre indivíduos da mesma espécie (estratégias de ataque e fuga) foram identificados quando na ausência de presas. Estes achados contribuem para melhor compreender a biologia populacional, comportamento da espécie, e também na futura definição e orientação nos planos do manejo pesqueiro
On the relationship between squid and the environment: artisanal jigging for Loligo plei at São Sebastião Island (24°S), southeastern Brazil
No full textAbstractPostuma, F. A., and Gasalla, M. A. 2010. On the relationship between squid and the environment: artisanal jigging for Loligo plei at São Sebastião Island (24°S), southeastern Brazil. – ICES Journal of Marine Science, 67: 1353–1362. The squid Loligo plei concentrates in the southeastern Brazil Bight, where it has traditionally supported small-scale fisheries around São Sebastião Island (SSI). Sea surface temperature (SST), chlorophyll-a (Chl a), windspeed, wave height, rainfall, and lunar phase are related to fishing records and to the results of a survey of local fishers to investigate how they believe environmental variables might affect catches of L. plei. Daily fishery-dependent data over the years 2005–2009 were obtained from a fishing cooperative and were matched with satellite and meteorological forecast data. Generalized linear models were used to explore the significance of environmental variables in relation to variability in catch and catch per unit effort (cpue). Squid are fished with jigs in water shallower than 20 m, generally where SST is warmer and Chl a and windspeed are lower. Cpue and monthly catches decreased from 2005 to 2008, followed by a slight increase in 2009. The correlations between fishery and environmental data relate well to fishers' oceanological knowledge, underscoring the potential of incorporating such knowledge into evaluations of the fishery.</jats:p
Rapport evaluatie nautisch onderzoek havenmond van Hoek van Holland
No full textTen behoeve van de bouw van de nieuwe havenmond nabij Hoek van Holland, de definitieve toegang naar Europoort en de aanleg van de naderingsgeul voor diepstekende schepen, is in de periode van 1960 tot heden veel onderzoek verricht. Als onderdeel van de afsluiting van de werkzaamheden wordt een samenvattende rapportage én evaluatie gemaakt van alle "hiertoe verrichte nautische onderzoekingen. Het onderhavige rapport behandelt daartoe dat gedeelte van de uitgevoerde onderzoeken, dat verricht werd door/bij het Nederlands Scheepsbouwkundig Proefstation te Wageningen. Het onderzoek dat door het N.S.P. in de verschillende fasen van de realisatie van de nieuwe havenmonden werd uitgevoerd kan naar de aard van de toegepaste methodieken in twee groepen worden onderverdeeld. Eén groep bevat het onderzoek waarbij gekozen is voor metingen aan schaalmodellen van schepen in een fysisch model van de vaarsituatie. Een tweede groep omvat onderzoeken welke meer gericht zijn op de bestudering van het integrale gedrag van het "mens-schip-omgevings syteem", waarbij inschakeling van een scheepsmanoeuvreersimulator werd geprefereerd
Giuseppe Valadier, 1964. Una recensione postuma
No full textIl contributo è pubblicato in un fascicolo dedicato alla memoria del prof. Paolo Marconi (1933-2013).Paolo Marconi wrote a seminal book on the neoclassic architect Giuseppe Valadier in 1963: invited to commemorate Marconi, deceased in 2013, the author try to assess his legacy as historian of architecture
La cappella dei Gavotti: struttura e colore nell'ultimo Cortona
No full textOpera tarda di Pietro da Cortona, in buona parte postuma e quasi del tutto ignorata negli studi, la cappella si rivela un monumento di estrema ricchezza e per l'uso dei materiali e per la complessità dell'articolazione. Le ricerche documentarie condotte a Roma e a Savona, nell'archivio privato della famiglia Gavotti, e un'apposita campagna di rilevamento hanno dimostrato che il progetto venne eseguito in modo sostanzialmente fedele a quanto stabilito dall’autore, nonostante il protrarsi dei lavori. La raddensata articolazione permette poi di considerare in modo più completo gli esiti ultimi delle ricerche architettoniche di Cortona.Late work of Pietro da Cortona, mostly posthumous, and almost completely ignored in the studies, the chapel reveals a monument of extreme wealth and the use of materials and the complexity of the joint. The desk research conducted in Rome and Savona, in the private family Gavotti, and a special survey campaign have shown that the project was carried out in an essentially faithful to what established by the author, despite the ongoing work. The raddensata articulation allows then to consider more fully the results of recent architectural research of Cortona
Past, present, and future of Parkinson's disease: A special essay on the 200th Anniversary of the Shaking Palsy.
No full textThis article reviews and summarizes 200 years of Parkinson's disease. It comprises a relevant history of Dr. James Parkinson's himself and what he described accurately and what he missed from today's perspective. Parkinson's disease today is understood as a multietiological condition with uncertain etiopathogenesis. Many advances have occurred regarding pathophysiology and symptomatic treatments, but critically important issues are still pending resolution. Among the latter, the need to modify disease progression is undoubtedly a priority. In sum, this multiple-author article, prepared to commemorate the bicentenary of the shaking palsy, provides a historical state-of-the-art account of what has been achieved, the current situation, and how to progress toward resolving Parkinson's disease. © 2017 International Parkinson and Movement Disorder Society
Appunti per una inedita epistemologia dell’ingegneria strutturale = Suggestions for a New Epistemology of Structural Engineering
No full textIl criterio che maggiormente caratterizza la scienza moderna è la probabilità, ampiamente introdotto con mirabile chiarezza da Jakob Bernoulli e Pierre-Simon Laplace attorno al 1712, colpendo e contraddicendo l’ordine rigidamente deterministico della fisica e meccanica classiche. La probabilità ha introdotto l’incertezza: anche ammettendo l’esistenza della causalità naturale non si può parlare di certezza di un evento ma soltanto di una più o meno grande probabilità del suo verificarsi. Tale osservazione è sintetizzata dalla lapidaria affermazione di Bernoulli nella sua storica opera Ars Conjectandi del 1713 (postuma): “La probabilità è un grado della certezza” (“probabilitas enim est gradus certitudinis”).---The tutorial makes a parallelism between structural engineering of today and in the past. First, the article analyz-es how the most important principles that have characterized modern physics affect structural engineering. Then, the author questions how the great structural engineers would be if they lived and worked now and attempts at offering an answer. Finally, the author gives his suggestion about what changes must be made in the relationship between society and engineers of today in order for the latter to have the same tremendous impact on the world as they did in the past
La traduzione del ritmo ne Il vento nei salici di Beppe Fenoglio
No full textThe essay aims to underline a set of stylistic features that characterise Beppe Fenoglio\u27s "Il vento nei salici", a posthumously published (1982) translation of Kenneth Grahame\u27s children\u27s novel "The Wind in the Willows". The analysis will point out some widespread tendencies in the author\u27s translation choices in the area of syntax and especially in the rhythm of language, which will be interpreted by referring to Henri Meschonnic\u27s critical proposals.Questo saggio intende evidenziare un insieme di fenomeni stilistici che caratterizzano il testo «Il vento nei salici» di Beppe Fenoglio, una traduzione pubblicata postuma (1982) del romanzo per l’infanzia «The Wind in the Willows» di Kenneth Grahame. L’analisi individuerà alcune costanti nelle scelte traduttive operate dall’autore nell’ambito della sintassi e specialmente del ritmo della lingua, che verranno interpretate facendo riferimento alle proposte critiche di Henri Meschonnic
Il concetto di immortalità culturale e gli artefici della presenza postuma nella cultura
No full textEnIn Nowicki's philosophical system there is no place for the immortality of the soul. Rather, he believes in the immortality of the individual through his works. They continue to live after the death of those who made them and have active lives in the "encounters" with works by other authors. Sometimes a fragment, a thought, is enough to make a work perpetuate itself together with its author. This is how "man is eternal".ItNel sistema filosofico di Nowicki non c'è posto per l'immortalità dell'anima. Egli crede piuttosto nell'immortalità dell'individuo attraverso le sue opere. Esse continuano a vivere dopo la morte di chi le ha compiute ed hanno vita attiva negli "incontri" con opere di altri autori. A volte basta un frammento, un pensiero per far sì che un'opera si perpetui insieme col suo autore. È così che "l'uom s'eterna"
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