613 resultados para zebra finch


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Access to the Internet has grown exponentially in Latin America over the past decade. The International Telecommunications Union (ITU) estimates that in 2009 there were 144.5 million Internet users in South America, 6.4 million in Central America, and 8.2 million in the Caribbean, or a total 159.2 million users in all of Latin America.1 At that time, ITU reported an estimated 31 million Internet users in Mexico, which would bring the overall number of users in Latin America to 190.2 million people. More recent estimates published by Internet World Stats place Internet access currently at an estimated 204.6 million out of a total population of 592.5 million in the region (this figure includes Mexico).2 According to those figures, 34.5 per cent of the Latin American population now enjoys Internet access. In recent years, universal access policies contributed to the vast increase in digital literacy and Internet use in Argentina, Brazil, Chile, Colombia, and Costa Rica. Whereas the latter was the first country in the region to adopt a policy of universal access, the most expansive and successful digital inclusion programs in the region have taken hold in Brazil and Chile. These two countries have allocated considerable resources to the promotion of digital literacy and Internet access among low income and poor populations; in both cases, civil society groups significantly assisted in the promotion of inclusion at the grassroots level. Digital literacy and Internet access have come to represent, particularly in the area of education, a welcome complementary resource for populations chronically underserved in nations with a long-standing record of inadequate public social services. Digital inclusion is vastly expanding throughout the region, thanks to stabilizing economies, increasingly affordable technology, and the rapid growth in the supply of cellular mobile telephony. A recent study by the global advertising agency Razorfish revealed significant shifts in the demographics of digital inclusion in the major economies of South America, where Web access is rapidly increasing amid the lower middle class and the working poor.3 Several researchers have suggested that Internet access will bring about greater civic participation and engagement, although skeptics remain unsure this could happen in Latin America. Yet, there have been some recent instances of political mobilization facilitated through the use of the Web and social media applications, starting in Chile when “smart mobs” nationwide demonstrated against former Chilean President Michelle Bachelet when she failed to enact education reforms in May 2006. The Internet has also been used by marginalized groups and by guerrillas groups to highlight their stories. In sum, Internet access in Latin is no longer a medium restricted to the elite. It is rather a public sphere upon which civil society has staked its claim. Some of the examples noted in this study point toward a developing trend whereby civil society, through online grassroots movements, is able to effectively pressure public officials, instill transparency and demand accountability in government. Access to the Internet has also made it possible for voices on the margins to participate in the conversation in a way that was never previously feasible. 1 International Telecommunications Union [ITU], “Information Technology Public & Report,” accessed May 15, 2011, http://www.itu.int/. 2 Internet World Stats, “Internet Usage Statistics for the Americas,” accessed March 24, 2011, http://www.internetworldstats.com/stats2.htm 3 J. Crump, “The finch and the fox,” London, UK (2010), http://www.slideshare.net/razorfishmarketing/the-finch-and-the-fox.

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The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

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Sono dette “challenged networks” quelle reti in cui lunghi ritardi, frequenti partizionamenti e interruzioni, elevati tassi di errore e di perdita non consentono l’impiego dei classici protocolli di comunicazione di Internet, in particolare il TCP/IP. Il Delay-/Disruption-Tolerant Networking (DTN) è una soluzione per il trasferimento di dati attraverso queste reti. L’architettura DTN prevede l’introduzione, sopra il livello di trasporto, del cosiddetto “bundle layer”, che si occupa di veicolare messaggi, o bundle, secondo l’approccio store-and-forward: ogni nodo DTN conserva persistentemente un bundle finché non si presenta l’opportunità di inoltrarlo al nodo successivo verso la destinazione. Il protocollo impiegato nel bundle layer è il Bundle Protocol, le cui principali implementazioni sono tre: DTN2, l’implementazione di riferimento; ION, sviluppata da NASA-JPL e più orientata alle comunicazioni spaziali; IBR-DTN, rivolta soprattutto a dispositivi embedded. Ciascuna di esse offre API che consentono la scrittura di applicazioni in grado di inviare e ricevere bundle. DTNperf è uno strumento progettato per la valutazione delle prestazioni in ambito DTN. La più recente iterazione, DTNperf_3, è compatibile sia con DTN2 che con ION nella stessa versione del programma, grazie all’introduzione di un “Abstraction Layer” che fornisce un’unica interfaccia per l’interazione con le diverse implementazioni del Bundle Protocol e che solo internamente si occupa di invocare le API specifiche dell’implementazione attiva. Obiettivo della tesi è estendere l’Abstraction Layer affinché supporti anche IBR-DTN, cosicché DTNperf_3 possa essere impiegato indifferentemente su DTN2, ION e IBR DTN. Il lavoro sarà ripartito su tre fasi: nella prima esploreremo IBR DTN e le sue API; nella seconda procederemo all’effettiva estensione dell’Abstraction Layer; nella terza verificheremo il funzionamento di DTNperf a seguito delle modifiche, sia in ambiente esclusivamente IBR-DTN, sia ibrido.

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This work contributes to the ELUM (Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial) project, which was commissioned and funded by the Energy Technologies Institute (ETI). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu).

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The Sr/Ca of aragonitic coral skeletons is a commonly used palaeothermometer. However skeletal Sr/Ca is typically dominated by weekly-monthly oscillations which do not reflect temperature or seawater composition and the origins of which are currently unknown. To test the impact of transcellular Ca2+ transport processes on skeletal Sr/Ca, colonies of the branching coral, Pocillopora damicornis, were cultured in the presence of inhibitors of Ca-ATPase (ruthenium red) and Ca channels (verapamil hydrochloride). The photosynthesis, respiration and calcification rates of the colonies were monitored throughout the experiment. The skeleton deposited in the presence of the inhibitors was identified (by 42Ca spike) and analysed for Sr/Ca and Mg/Ca by secondary ion mass spectrometry. The Sr/Ca of the aragonite deposited in the presence of either of the inhibitors was not significantly different from that of the solvent (dimethyl sulfoxide) control, although the coral calcification rate was reduced by up to 66% and 73% in the ruthenium red and verapamil treatments, respectively. The typical precision (95% confidence limits) of mean Sr/Ca determinations within any treatment was <±1% and differences in skeletal Sr/Ca between treatments were correspondingly small. Either Ca-ATPase and Ca channels transport Sr2+ and Ca2+ in virtually the same ratio in which they are present in seawater or transcellular processes contribute little Ca2+ to the skeleton and most Ca is derived from seawater transported directly to the calcification site. Variations in the activities of Ca-ATPase and Ca-channels are not responsible for the weekly-monthly Sr/Ca oscillations observed in skeletal chronologies, assuming that the specificities of Ca transcellular transport processes are similar between coral genera.

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In Canada, increases in rural development has led to a growing need to effectively manage the resulting municipal and city sewage without the addition of significant cost- and energy- expending infrastructure. Storring Septic Service Limited is a family-owned, licensed wastewater treatment facility located in eastern Ontario. It makes use of a passive waste stabilization pond system to treat and dispose of waste and wastewater in an environmentally responsible manner. Storring Septic, like many other similar small-scale wastewater treatment facilities across Canada, has the potential to act as a sustainable eco-engineered facility that municipalities and service providers could utilize to manage and dispose of their wastewater. However, it is of concern that the substantial inclusion of third party material could be detrimental to the stability and robustness of the pond system. In order to augment the capacity of the current facility, and ensure it remains a self-sustaining system with the capacity to safely accept septage from other sewage haulers, it was hypothesized that pond effluent treatment could be further enhanced through the incorporation of one of three different technology solutions, which would allow the reduction of wastewater quality parameters below existing regulatory effluent discharge limits put in place by Ontario’s Ministry of the Environment and Climate Change (MOECC). Two of these solutions make use of biofilm technologies in order to enhance the removal of wastewater parameters of interest, and the third utilizes the natural water filtration capabilities of zebra mussels. Pilot-scale testing investigated the effects of each of these technologies on treatment performance under both cold and warm weather operation. This research aimed to understand the important mechanisms behind biological filtration methods in order to choose and optimize the best treatment strategy for full-scale testing and implementation. In doing so, a recommendation matrix was elaborated provided with the potential to be used as a universal operational strategy for wastewater treatment facilities located in environments of similar climate and ecology.

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El objetivo del artículo es realizar un diagnóstico sobre la percepción de los factores que intervienen en el rendimiento académico de los estudiantes de cinco carreras universitarias en una escuela de educación superior en México, para así reconocer las áreas de oportunidad que permitan sugerir políticas y estrategias para elevar su rendimiento. Se utilizó una muestra de 1651 estudiantes, se obtuvieron los datos a partir de un cuestionario con treinta preguntas que estudian la percepción del rendimiento académico en escala tipo Likert. Se realizó un análisis factorial exploratorio que permitiera reducir los datos, facilitar la interpretación y validar el instrumento. Se identificaron tres factores: a) el rol de los profesores, b) la evaluación y c) la motivación de los estudiantes. Se llevó a cabo un análisis comparativo por carrera. Se encontró que los estudiantes perciben que la mayoría de los maestros no se preocupan por la condición de los jóvenes en situación de reprobación. Además, casi no motivan y carecen de expresiones de sentimientos de orgullo por los logros académicos de los estudiantes. La mitad de los participantes piensa que los docentes no cubren el temario en su totalidad. Se detectó que los estudiantes poseen una alta motivación siendo esto positivo porque son alumnos dedicados y responsables. Se concluye realizando una serie de sugerencias y explicando las implicaciones que tiene este trabajo para las instituciones de educación superior.

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This paper reports the progress achieved in an anthropological investigation based on which there is now a more in depth understanding of some dimensions of the “kinship work” carried out by families in Chile. The main objective is to analyze the work of maintaining family links performed primarily by women within families and show how this work reproduces gender inequalities within them. On the basis of a longitudinal methodology based on semi-structured interviews, it is concluded that the work of maintaining family links performed by women is crucial but goes unnoticed because kinship obligations are seen as a naturally being part of women’s role in the family.

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Body size is a key determinant of metabolic rate, but logistical constraints have led to a paucity of energetics measurements from large water-breathing animals. As a result, estimating energy requirements of large fish generally relies on extrapolation of metabolic rate from individuals of lower body mass using allometric relationships that are notoriously variable. Swim-tunnel respirometry is the ‘gold standard’ for measuring active metabolic rates in water-breathing animals, yet previous data are entirely derived from body masses <10 kg – at least one order of magnitude lower than the body masses of many top-order marine predators. Here, we describe the design and testing of a new method for measuring metabolic rates of large water-breathing animals: a c. 26 000 L seagoing ‘mega-flume’ swim-tunnel respirometer. We measured the swimming metabolic rate of a 2·1-m, 36-kg zebra shark Stegostoma fasciatum within this new mega-flume and compared the results to data we collected from other S. fasciatum (3·8–47·7 kg body mass) swimming in static respirometers and previously published measurements of active metabolic rate measurements from other shark species. The mega-flume performed well during initial tests, with intra- and interspecific comparisons suggesting accurate metabolic rate measurements can be obtained with this new tool. Inclusion of our data showed that the scaling exponent of active metabolic rate with mass for sharks ranging from 0·13 to 47·7 kg was 0·79; a similar value to previous estimates for resting metabolic rates in smaller fishes. We describe the operation and usefulness of this new method in the context of our current uncertainties surrounding energy requirements of large water-breathing animals. We also highlight the sensitivity of mass-extrapolated energetic estimates in large aquatic animals and discuss the consequences for predicting ecosystem impacts such as trophic cascades.

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Body size is a key determinant of metabolic rate, but logistical constraints have led to a paucity of energetics measurements from large water-breathing animals. As a result, estimating energy requirements of large fish generally relies on extrapolation of metabolic rate from individuals of lower body mass using allometric relationships that are notoriously variable. Swim-tunnel respirometry is the ‘gold standard’ for measuring active metabolic rates in water-breathing animals, yet previous data are entirely derived from body masses <10 kg – at least one order of magnitude lower than the body masses of many top-order marine predators. Here, we describe the design and testing of a new method for measuring metabolic rates of large water-breathing animals: a c. 26 000 L seagoing ‘mega-flume’ swim-tunnel respirometer. We measured the swimming metabolic rate of a 2·1-m, 36-kg zebra shark Stegostoma fasciatum within this new mega-flume and compared the results to data we collected from other S. fasciatum (3·8–47·7 kg body mass) swimming in static respirometers and previously published measurements of active metabolic rate measurements from other shark species. The mega-flume performed well during initial tests, with intra- and interspecific comparisons suggesting accurate metabolic rate measurements can be obtained with this new tool. Inclusion of our data showed that the scaling exponent of active metabolic rate with mass for sharks ranging from 0·13 to 47·7 kg was 0·79; a similar value to previous estimates for resting metabolic rates in smaller fishes. We describe the operation and usefulness of this new method in the context of our current uncertainties surrounding energy requirements of large water-breathing animals. We also highlight the sensitivity of mass-extrapolated energetic estimates in large aquatic animals and discuss the consequences for predicting ecosystem impacts such as trophic cascades.

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Following and contributing to the ongoing shift from more structuralist, system-oriented to more pragmatic, socio-cultural oriented anglicism research, this paper verifies to what extent the global spread of English affects naming patterns in Flanders. To this end, a diachronic database of first names is constructed, containing the top 75 most popular boy and girl names from 2005 until 2014. In a first step, the etymological background of these names is documented and the evolution in popularity of the English names in the database is tracked. Results reveal no notable surge in the preference for English names. This paper complements these database-driven results with an experimental study, aiming to show how associations through referents are in this case more telling than associations through phonological form (here based on etymology). Focusing on the socio-cultural background of first names in general and of Anglo-American pop culture in particular, the second part of the study specifically reports on results from a survey where participants are asked to name the first three celebrities that leap to mind when hearing a certain first name (e.g. Lana, triggering the response Del Rey). Very clear associations are found between certain first names and specific celebrities from Anglo-American pop culture. Linking back to marketing research and the social turn in onomastics, we will discuss how these celebrities might function as referees, and how social stereotypes surrounding these referees are metonymically attached to their first names. Similar to the country-of-origin-effect in marketing, these metonymical links could very well be the reason why parents select specific “celebrity names”. Although further attitudinal research is needed, this paper supports the importance of including socio-cultural parameters when conducting onomastic research.

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Highly swellable polymer films doped with Ag nanoparticle aggregates (poly-SERS films) have been used to record very high signal:noise ratio, reproducible surface-enhanced (resonance) Raman (SER(R)S) spectra of in situ dried ink lines and their constituent dyes using both 633 and 785 nm excitation. These allowed the chemical origins of differences in the SERRS spectra of different inks to be determined. Initial investigation of pure samples of the 10 most common blue dyes showed that the dyes which had very similar chemical structures such as Patent Blue V and Patent Blue VF (which differ only by a single OH group) gave SERRS spectra in which the only indications that the dye structure had been changed were small differences in peak positions or relative intensities of the bands. SERRS studies of 13 gel pen inks were consistent with this observation. In some cases inks from different types of pens could be distinguished even though they were dominated by a single dye such as Victoria Blue B (Zebra Surari) or Victoria Blue BO (Pilot Acroball) because their predominant dye did not appear in other inks. Conversely, identical spectra were also recorded from different types of pens (Pilot G7, Zebra Z-grip) because they all had the same dominant Brilliant Blue G dye. Finally, some of the inks contained mixtures of dyes which could be separated by TLC and removed from the plate before being analysed with the same poly-SERS films. For example, the Pentel EnerGel ink pen was found to give TLC spots corresponding to Erioglaucine and Brilliant Blue G. Overall, this study has shown that the spectral differences between different inks which are based on chemically similar, but nonetheless distinct dyes, are extremely small, so very close matches between SERRS spectra are required for confident identification. Poly-SERS substrates can routinely provide the very stringent reproducibility and sensitivity levels required. This, coupled with the awareness of the reasons underlying the observed differences between similarly coloured inks allows a more confident assessment of the evidential value of inks SERS and should underpin adoption of this approach as a routine method for the forensic examination of inks.

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In the Western Sudetes (Mts.) in SW Poland carbonate rocks occur which are well known in the older German literature as ’’Kauffung Limestone” or ’’Wojcieszow Limestone” in recent publications, respectively. They are intercalated in sedimentary (shales) and volcanic (greenstone) successions and are, presumed - due to the lack of index fossils - to be Cambrian in age. These deposits occur in a variety of isolated massifs in the Bober-Katzbach Mts. where they have been mined in many quarries in the past. In a single location (Polom quarry near Wojcieszow) they are exploited up until today. The predominantly calcitic rocks display a wide variety of different lithologies and are, consequently, subdivided into the following lithological units which differ in textural characteristics, mineral constituents, and different grades of diagenetic and metamorphic alteration: 1. Calcite Marble: massive, calcitic, chiefly metamorphic recrystallized. 2. Zebra Limestone: dolomitic-calcitic, certain content of metasomatic silica, fine bedding as a result of microbial calcite precipitation or of diagenetic to metamorphic separation of carbonate and silica constituents. 3. Massive matrix Dolomite: compact, of diagenetic to metamorphic origin. 4. Dolomite Marble: metamorphic. 5. Hydrothermal Dolomite: hydrothermal alteration of limestone, postdating the tectonic deformation. The recent appearance of ’’Kauffung Limestone” is mainly a result of regional metamorphosis at low temperature up to about 300°C and locally high pressure. The typical textural features are stress induced, mostly protomylonitic calcite recrystallisation and generally slowly or not infected dolomite crystals. The different reactions of the two carbonate phases are attributed to their mineral properties. Rhyolitic and dacitic dykes penetrating the carbonate rocks are interpreted as a result of post- orogenic, probably Carboniferous or Permian volcanism. Microprobe investigation on the carbonates revealed a stochiometric composition of dolomite and calcite. The stable isotope content (8 c 0,8* ^C) reflects increased crystallisation temperature of the carbonate minerals (8 O von -7,75 bis -15,78). A variety of fossil remains have been extracted from bulk samples, consisting of sponge needles, floral components, foramini- fera, and vertebrate remains the latter two of which indicate a depositional age younger than Ordovician. Due to the stratigraphic re-attribution of the Kauffung Limestone, the hypothesis of a Cambrian/Ordovician rifting in the Western Sudetes should be abandoned.

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Chains of interacting non-Abelian anyons with local interactions invariant under the action of the Drinfeld double of the dihedral group D-3 are constructed. Formulated as a spin chain the Hamiltonians are generated from commuting transfer matrices of an integrable vertex model for periodic and braided as well as open boundaries. A different anyonic model with the same local Hamiltonian is obtained within the fusion path formulation. This model is shown to be related to an integrable fusion interaction round the face model. Bulk and surface properties of the anyon chain are computed from the Bethe equations for the spin chain. The low-energy effective theories and operator content of the models (in both the spin chain and fusion path formulation) are identified from analytical and numerical studies of the finite-size spectra. For all boundary conditions considered the continuum theory is found to be a product of two conformal field theories. Depending on the coupling constants the factors can be a Z(4) parafermion or a M-(5,M-6) minimal model.