Pre-Columbian landscape impact and agriculture in the Monumental Mound region of the Llanos de Moxos, lowland Bolivia

We present a multiproxy study of land use by a pre-Columbian earth mounds culture in the Bolivian Amazon. The Monumental Mounds Region (MMR) is an archaeological sub-region characterized by hundreds of pre-Columbian habitation mounds associated with a complex network of canals and causeways, and situated in the forest–savanna mosaic of the Llanos de Moxos. Pollen, phytolith, and charcoal analyses were performed on a sediment core from a large lake (14 km2), Laguna San José (14°56.97′S, 64°29.70′W).We found evidence of high levels of anthropogenic burning from AD 400 to AD 1280, corroborating dated occupation layers in two nearby excavated habitation mounds. The charcoal decline pre-dates the arrival of Europeans by at least 100 yr, and challenges the notion that the mounds culture declined because of European colonization. We show that the surrounding savanna soils were sufficiently fertile to support crops, and the presence of maize throughout the record shows that the area was continuously cultivated despite land-use change at the end of the earthmounds culture. We suggest that burning was largely confined to the savannas, rather than forests, and that pre-Columbian deforestation was localized to the vicinity of individual habitation mounds, whereas the inter-mound areas remained largely forested.

Pasolini and Third World hunger: an approach to Cinema Novo through 'La ricotta'

Among the links between Pier Paolo Pasolini and Brazilian Cinema Novo, one of the most inspiring is the political approach to hunger and consumption. In this text, I analyse this topic to look at how some of the aesthetic ideas in Pasolini’s La ricotta (1963) can also be found in some of the most important films of Cinema Novo. In 'La ricotta' (1963), the irresistible need to eat of a subproletarian interacts and clashes with his responsibilities as an actor in a movie version of the Passion of Christ, so that the film creates a complex network of relations between film shooting, social differences, art, hunger, consumption, time and light, which turns the film set into a space for displaying political relations, differences, exploitation and revolution. The correspondences between these concepts and some aggression techniques of Cinema Novo are numerous and confirm the capacity of Pasolini’s film to project ideas on cinema and politics beyond its particular production context.

SEM and Neurohistological Observations of Nerve Endings in the Middle Region of the Tongue of the Collared Peccary (Tayassu tajacu): A Silver Impregnation Method

The presence of lingual papillae and the nerve endings in the middle region of the tongue mucosa of collared peccary (Tayassu tajacu) were studied using scanning electron microscopy and light microscopy, based upon the silver impregnation method. The middle region of tongue mucosa revealed numerous filiform and fungiform papillae. The thick epithelial layer showed epithelial cells and a dense connective tissue layer containing nerve fibre bundles and capillaries. The sensory nerve endings, intensely stained by silver impregnation, were usually non-encapsulated and extended into the connective tissue of the filiform and fungiform papillae very close to the epithelial cells. In some regions, the sensory nerves fibres formed a dense and complex network of fine fibrils. The presence of these nerve fibrils may characterize the mechanisms of transmission of sensitive impulses to the tongue mucosa.

The web of connections between tourism companies: Structure and dynamics

Tourism destination networks are amongst the most complex dynamical systems, involving a myriad of human-made and natural resources. In this work we report a complex network-based systematic analysis of the Elba (Italy) tourism destination network, including the characterization of its structure in terms of several traditional measurements, the investigation of its modularity, as well as its comprehensive study in terms of the recently reported superedges approach. In particular, structural (the number of paths of distinct lengths between pairs of nodes, as well as the number of reachable companies) and dynamical features (transition probabilities and the inward/outward activations and accessibilities) are measured and analyzed, leading to a series of important findings related to the interactions between tourism companies. Among the several reported results, it is shown that the type and size of the Companies influence strongly their respective activations and accessibilities, while their geographical position does not seem to matter. It is also shown that the Elba tourism network is largely fragmented and heterogeneous, so that it could benefit from increased integration. (C) 2009 Elsevier B.V. All rights reserved.

Investigating relationships within and between category networks in Wikipedia

This work maps and analyses cross-citations in the areas of Biology, Mathematics, Physics and Medicine in the English version of Wikipedia, which are represented as an undirected complex network where the entries correspond to nodes and the citations among the entries are mapped as edges. We found a high value of clustering coefficient for the areas of Biology and Medicine, and a small value for Mathematics and Physics. The topological organization is also different for each network, including a modular structure for Biology and Medicine, a sparse structure for Mathematics and a dense core for Physics. The networks have degree distributions that can be approximated by a power-law with a cut-off. The assortativity of the isolated networks has also been investigated and the results indicate distinct patterns for each subject. We estimated the betweenness centrality of each node considering the full Wikipedia network, which contains the nodes of the four subjects and the edges between them. In addition, the average shortest path length between the subjects revealed a close relationship between the subjects of Biology and Physics, and also between Medicine and Physics. Our results indicate that the analysis of the full Wikipedia network cannot predict the behavior of the isolated categories since their properties can be very different from those observed in the full network. (C) 2011 Elsevier Ltd. All rights reserved.

Modularity and robustness of bone networks

Cortical bones, essential for mechanical support and structure in many animals, involve a large number of canals organized in intricate fashion. By using state-of-the art image analysis and computer graphics, the 3D reconstruction of a whole bone (phalange) of a young chicken was obtained and represented in terms of a complex network where each canal was associated to an edge and every confluence of three or more canals yielded a respective node. The representation of the bone canal structure as a complex network has allowed several methods to be applied in order to characterize and analyze the canal system organization and the robustness. First, the distribution of the node degrees (i.e. the number of canals connected to each node) confirmed previous indications that bone canal networks follow a power law, and therefore present some highly connected nodes (hubs). The bone network was also found to be partitioned into communities or modules, i.e. groups of nodes which are more intensely connected to one another than with the rest of the network. We verified that each community exhibited distinct topological properties that are possibly linked with their specific function. In order to better understand the organization of the bone network, its resilience to two types of failures (random attack and cascaded failures) was also quantified comparatively to randomized and regular counterparts. The results indicate that the modular structure improves the robustness of the bone network when compared to a regular network with the same average degree and number of nodes. The effects of disease processes (e. g., osteoporosis) and mutations in genes (e.g., BMP4) that occur at the molecular level can now be investigated at the mesoscopic level by using network based approaches.

Applying supply chain management models in the banking industry: a brazilian case analysis

The study presents the results and recommendations deriving from the application of two supply chain management analysis models as proposed by the Supply Chain Council (SCOR, version 10.0) and by Lambert (1997, Framework for Supply Chain Management) on the logistics of cash transfers in Brazil. Cash transfers consist of the transportation of notes to and from each node of the complex network formed by the bank branches, ATMs, armored transportation providers, the government custodian, Brazilian Central Bank and financial institutions. Although the logistic to sustain these operations is so wide-ranged (country-size), complex and subject to a lot of financial regulations and security procedures, it has been detected that it was probably not fully integrated. Through the use of a primary and a secondary data research and analysis, using the above mentioned models, the study ends up with propositions to strongly improve the operations efficiency

Caracterização funcional de dois cDNAs de cana-de- açúcar : PKCI e SHAGGY

Flowering is controlled by several environmental and endogenous factors, usually associated with a complex network of metabolic mechanisms. The gene characterization in Arabidopsis model has provided much information about the genetic and molecular mechanisms that control flowering process. Some of these genes had been found in rice and maize. However, in sugarcane this processe is not well known. It is known that early flowering may reduce its production up to 60% at northeast conditions. Considering the impact of early flowering in sugarcane production, the aim of this work was to make the gene characterization of two cDNAs previously identified in subtractive cDNA libraries: scPKCI and scSHAGGY. The in silico analysis showed that these two cDNAs presented both their sequence and functional catalytic domains conserved. The results of transgenic plants containing the overexpression of the gene cassette scPKCI in sense orientation showed that this construction had a negative influence on the plant development as it was observed a decrease in plant height and leaf size. For the scPKCI overexpression in antisense orientation it was observed change in the number of branches from T1 transgenic plants, whereas transgenic T2 plants showed slow development during germination and initial stages of development. The other cDNA analyzed had homology to SHAGGY protein. The overexpression construct in sense orientation did not shown any effect on development. The only difference observed it was an increase in stigma structure. These results allowed us to propose a model how these two genes may be interact and affect floweringdevelopment.

Effects of Aspergillus spp. exogenous fibrolytic enzymes on in vitro fermentation of tropical forages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da topologia de redes de conexão funcional no córtex sensorial primário e hipocampo durante o sono de ondas lentas

Complex network analysis is a powerful tool into research of complex systems like brain networks. This work aims to describe the topological changes in neural functional connectivity networks of neocortex and hippocampus during slow-wave sleep (SWS) in animals submited to a novel experience exposure. Slow-wave sleep is an important sleep stage where occurs reverberations of electrical activities patterns of wakeness, playing a fundamental role in memory consolidation. Although its importance there s a lack of studies that characterize the topological dynamical of functional connectivity networks during that sleep stage. There s no studies that describe the topological modifications that novel exposure leads to this networks. We have observed that several topological properties have been modified after novel exposure and this modification remains for a long time. Major part of this changes in topological properties by novel exposure are related to fault tolerance

Fraturas e caminhos ótimos na rede de Barabasi-Albert

Following the study of Andrade et al. (2009) on regular square lattices, here we investigate the problem of optimal path cracks (OPC) in Complex Networks. In this problem we associate to each site a determined energy. The optimum path is defined as the one among all possible paths that crosses the system which has the minimum cost, namely the sum of the energies along the path. Once the optimum path is determined, at each step, one blocks its site with highest energy, and then a new optimal path is calculated. This procedure is repeated until there is a set of blocked sites forming a macroscopic fracture which connects the opposite sides of the system. The method is applied to a lattice of size L and the density of removed sites is computed. As observed in the work by Andrade et al. (2009), the fractured system studied here also presents different behaviors depending on the level of disorder, namely weak, moderated and strong disorder intensities. In the regime of weak and moderated disorder, while the density of removed sites in the system does not depend of the size L in the case of regular lattices, in the regime of high disorder the density becomes substantially dependent on L. We did the same type of study for Complex Networks. In this case, each new site is connected with m previous ones. As in the previous work, we observe that the density of removed sites presents a similar behavior. Moreover, a new result is obtained, i.e., we analyze the dependency of the disorder with the attachment parameter m

Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia

Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusions

Análise da rede política do turismo brasileiro.

The dissertation examines the influence of relationships among actors from Brazilian Tourism Political Network who compose the National Council of Tourism in the drafting of the National Tourism Plans (PNT) - PNTs 2003/2007 and 2007/2010, focusing on two main types of interaction: cooperation and information exchange. Therefore, the study departed from the understanding that the concept of tourism as a human phenomenon is configured as an essential conceptual basis for the development, implementation and analysis of public policies. The application of Network Theory and Social Network Analysis serves as an analytical tool, in addition, the use of concepts of Policy Networks enabled to interpret, in distinct aspects, the social reality of tourism in a more precise and detailed way. The study had a cross-sectional with a longitudinal perspective and case study was adopted, thus enabling to apply the model of social network analysis and qualitative approach. Through the survey conducted, it was found that the drafting process of National Tourism Plans was the result of the interaction of a complex network of actors from public and private initiatives, who compose the National Council of Tourism, and that their power of influence came out simultaneously, but not symmetrically, for both their performance/intervention in the meetings, and the possession of economic and organizational resources. Hence, the establishment of partnerships and information exchanges among the actors were underlying to the PNT drafting process, both in problems perception and insertion in the government agenda, as in making proposals to solve them, thus guiding the construction of large programs and programs contained in both investigated plans.

Dinâmica e estrutura de redes complexas no modelo de afinidade

In this work we elaborate and discuss a Complex Network model which presents connectivity scale free probability distribution (power-law degree distribution). In order to do that, we modify the rule of the preferential attachment of the Bianconi-Barabasi model, including a factor which represents the similarity of the sites. The term that corresponds to this similarity is called the affinity, and is obtained by the modulus of the difference between the fitness (or quality) of the sites. This variation in the preferential attachment generates very interesting results, by instance the time evolution of the connectivity, which follows a power-law distribution ki / ( t t0 )fi, where fi indicates the rate to the site gain connections. Certainly this depends on the affinity with other sites. Besides, we will show by numerical simulations results for the average path length and for the clustering coefficient

Física estatística aplicada a sistemas sociais através do estudo de redes complexas

In this work a study of social networks based on analysis of family names is presented. A basic approach to the mathematical formalism of graphs is developed and then main theoretical models for complex networks are presented aiming to support the analysis of surnames networks models. These, in turn, are worked so as to be drawn leading quantities, such as aggregation coefficient, minimum average path length and connectivity distribution. Based on these quantities, it can be stated that surnames networks are an example of complex network, showing important features such as preferential attachment and small-world character