Genetic algorithm inversion of the average 1D crustal structure using local and regional earthquakes

Knowing the best 1D model of the crustal and upper mantle structure is useful not only for routine hypocenter determination, but also for linearized joint inversions of hypocenters and 3D crustal structure, where a good choice of the initial model can be very important. Here, we tested the combination of a simple GA inversion with the widely used HYPO71 program to find the best three-layer model (upper crust, lower crust, and upper mantle) by minimizing the overall P- and S-arrival residuals, using local and regional earthquakes in two areas of the Brazilian shield. Results from the Tocantins Province (Central Brazil) and the southern border of the Sao Francisco craton (SE Brazil) indicated an average crustal thickness of 38 and 43 km, respectively, consistent with previous estimates from receiver functions and seismic refraction lines. The GA + HYPO71 inversion produced correct Vp/Vs ratios (1.73 and 1.71, respectively), as expected from Wadati diagrams. Tests with synthetic data showed that the method is robust for the crustal thickness, Pn velocity, and Vp/Vs ratio when using events with distance up to about 400 km, despite the small number of events available (7 and 22, respectively). The velocities of the upper and lower crusts, however, are less well constrained. Interestingly, in the Tocantins Province, the GA + HYPO71 inversion showed a secondary solution (local minimum) for the average crustal thickness, besides the global minimum solution, which was caused by the existence of two distinct domains in the Central Brazil with very different crustal thicknesses. (C) 2010 Elsevier Ltd. All rights reserved.

Germination rate and sporeling development of Chondracanthus chamissoi (Rhodophyta, Gigartinales) varies along a latitudinal gradient on the coast of Chile

Chondracanthus chamissoi (C. Agardh) Kutzing is an economically important red seaweed with an extended latitudinal distribution along the south-east Pacific. Here we report on the seasonal in vitro germination of carpospores and tetraspores from four populations distributed from 27 to 41 degrees S on the Chilean coast. Our results show that both types of spores exhibited a different physiological behavior related to the geographic origin of the specimens. Germination occurred throughout the year for both spore types in the four populations. However, for the northern locations (Calderilla, La Herradura and Puerto Aldea) germination was higher in spring, while for the southern location (Lechagua), germination was higher in summer. The growth rate of carposporelings and tetrasporelings varied seasonally in ail locations studied, with higher growth in spring. Among all, carposporelings from Lechagua specimens reached the highest growth rates (9.3 +/- 0.2% d(-1)). However, spores from Herradura and P. Aldea had a good germination and SGR in all seasons and would be good candidates to start spores-based cultivation of this valuable resource in Chile. (C) 2009 Elsevier B.V. All rights reserved

Role of SOCS-1 Gene on Melanoma Cell Growth and Tumor Development

Melanoma is the most aggressive form of skin cancer, and its incidence has increased dramatically over the years. The murine B16F10 melanoma in syngeneic C57Bl/6 mice has been used as a highly aggressive model to investigate tumor development. Presently, we demonstrate in the B16F10-Nex2 subclone that silencing of SOCS-1, a negative regulator of Jak/Stat pathway, leads to reversal of the tumorigenic phenotype and inhibition of melanoma cell metastasis. SOCS-1 silencing with short hairpin RNA affected tumor growth and cell cycle regulation with arrest at the S phase with large-sized nuclei, reduced cell motility, and decreased melanoma cell invasion through Matrigel. A clonogenic assay showed that SOCS-1 acted as a modulator of resistance to anoikis. In addition, down-regulation of SOCS-1 decreased the expression of epidermal growth factor receptor ( mainly the phosphorylated-R), Ins-R alpha, and fibroblast growth factor receptor. In vivo, silencing of SOCS-1 inhibited subcutaneous tumor growth and metastatic development in the lungs. Because SOCS-1 is expressed in most melanoma cell lines and bears a relation with tumor invasion, thickness, and stage of disease, the present results on the effects of SOCS-1 silencing in melanoma suggest that this regulating protein can be a target of cancer therapy.

Hyperfine and magnetic properties of Fe-Cu clusters and Fe precipitates embedded in a Cu matrix

Using the first-principles real-space linear muffin-tin orbital method within the atomic sphere approximation (RS-LMTO-ASA) we study hyperfine and local magnetic properties of substituted pure Fe and Fe-Cu clusters in an fcc Cu matrix. Spin and orbital contributions to magnetic moments, hyperfine fields and the Mossbauer isomer shifts at the Fe sites in Fe precipitates and Fe-Cu alloy clusters of sizes up to 60 Fe atoms embedded in the Cu matrix are calculated and the influence of the local environment on these properties is discussed.

The link between partial melting, granitization and granulite development in central Ribeira Fold Belt, SE Brazil: New evidence from elemental and Sr-Nd isotopic geochemistry

Elemental and Sr-Nd isotopic data on metatexites, diatexites, orthogneisses and charnockites from the central Ribeira Fold Belt indicate that they are LILE-enriched weakly peraluminous granodiorites. Harker and Th-Hf-La correlation trends suggest that these rocks represent a co-genetic sequence, whereas variations on CaO, MnO, Y and HREE for charnockites can be explained by garnet consumption during granulitic metamorphism. Similar REE patterns and isotopic results of epsilon(565)(Nd) = -5.4 to -7.3 and (87)Sr/(86)Sr(565) = 0.706-0.711 for metatexites, diatexites, orthogneisses and charnockites, as well as similar T(DM) ages between 2.0 and 1.5 Ga are consistent with evolution from a relatively homogeneous and enriched common crustal (metasedimentary) protolith. Results suggest a genetic link between metatexites, diatexites, orthogneisses and charnockites and a two-step process for charnockite development: (a) generation of the hydrated igneous protoliths by anatexis of metasedimentary rocks; (b) continuous high-grade metamorphism that transformed the ""S-type granitoids"" (leucosomes and diatexites) into orthogneisses and, as metamorphism and dehydration progressed, into charnockites. (C) 2011 Elsevier Ltd. All rights reserved.

Exports, Inward Foreign Direct Investment (FDI) and Regional Economic Growth in China

The relationship between exports and economic growth is strong in developing economies. Both externality effects of exports on the non-exports sector and higher marginal productivity in the exports sector in relation to the non-exports sector play an important role in promoting exports and GDP growth. The underlying theoretical model of FEDER, 1982, is used with the data on the Chinese provinces and it is shown that the economic structure, degree of openness and policy environment have a significant role in the relationship between exports and economic growth.

Foreign Direct Investment and Regional Export Performance in China

This paper investigates the impact of foreign direct investment (FDI) on the export performance of China at the provincial level. First, it presents a theoretical discussion of the impact of FDI on foreign trade, and then an empirical study of the impact of FDI on the export performance of regions in Chin. It has been found that the impact of FDI on exports differs across three macro-regions in China. The effect is stronger in the coastal region than in the inland regions. Although FDI shows a positive and significant impact on exports from the central region, its impact on the western region is found to be insignificant.

Tourism and regional immiserization

This paper analyzes the consequences of tourism in rural and urban areas on regional incomes, welfare and urban unemployment using a generalized Harris Todaro model. In this model two urban and two rural goods are produced. A distinguishing characteristic of this model is that the urban non-traded good is not consumed in the rural region and, similarly, the rural non-traded good is not consumed in the urban region. The most important result we obtain is that a tourist boom in the urban region may immiserize the rural area. Hence the welfare interests of rural and urban consumers may be in conflict as a result of tourist expansion in the urban region.

Communication dynamics : discussion boards, weblogs and the development of communities of inquiry in online learning environments

Online learning environments (OLEs) are now critical to teaching and learning across Australian higher education. Their influence impacts on the availability of content, the design of courses and, perhaps most pedagogically significantly, the nature of communication. The discussion board is the ubiquitous communication tool within these OLEs and hence significantly shapes the kind of communication that takes place. In light of this, the degree to which a successful community of inquiry can be facilitated through the use of discussion boards is examined and compared to the possibilities afforded by weblogs in the same role. Weblogs, it is argued, offer new opportunities in the development of social, cognitive and teacher presence online and should be considered in the development of or alongside established OLEs.

The media and the development of the tourism industry during the 20th and 21st centuries: an analysis of four noteworthy cases

The aim of this paper was to explore the role of the media within the context of tourism, specifically with regard to how the media has influenced the activities and perceptions of the tourism sector. In this paper, the term ‘media’ is referred to as mass communication, specifically with regard to newspapers, magazines and broadcasting. It is important to gain a better understanding of the ways in which the media has interacted with the tourism sector, as this information can provide practitioners and academics with insights as to how the media can best be employed to benefit stakeholders of the tourism industry. Lessons can be learned from the past so that the experience gained from it can contribute to best practice in the future. In this way, strategies can be developed to minimise the vulnerability of the tourism sector to damaging or erroneous portrayals of it and its activities in the media.
The case study method was used to explore the role of the media within the context of tourism. Four case studies provided insights on this topic. The four case studies were selected based on their diversity, within the context of the tourism sector, and because they covered a considerable period of time. These variables provided the researchers with a wide-ranging perspective on the topic.
The paper firstly focuses on the 1920’s Waiters’ Strike in the resort town of San Sebastián, Spain, and discusses the role of the media in relation to this event. The second case investigates the use of the media as a destination-marketing tool and reflects on an early manipulation of this process by the German authorities in the documentary Olympia, a film produced for the summer Olympics in 1936. The third case study reports on the manner in which the media has created tensions between connoisseurs of fine food and drink and hospitality industry professionals, and its subsequent implications on service quality. The final case investigates the role of the media in reducing demand for hospitality services in Melbourne on New Year’s Eve 2000.
Through an analysis of these diverse, but important case studies, it can be seen that the media has had, and continues to have, an impact on the development of the tourism industry in both positive and negative ways. The limitations of this research are discussed and recommendations are made for further research that will assist in developing a more comprehensive typology of the media’s role in tourism.