Página 1 dos resultados de 164 itens digitais encontrados em 0.205 segundos

## ‣ “Autonomic Networking” – tendencies and evolution of network management technologies and computer communication protocols

Fernandes, Vitor Celso de Pinho Leal
Português
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## ‣ A brief overview of the evolution and main features of the biotechnology industry

Fontes, M.; Videira, P.
Fonte: Instituto Universitário de Lisboa Publicador: Instituto Universitário de Lisboa
Tipo: Trabalho em Andamento
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This paper offers an overview of the origin, evolution and main features of the biotechnology industry, putting particular emphasis on the behaviour of one key actor – the dedicated biotechnology firm. It starts with a brief historical background detailing the origin and dynamics of the industry, which is followed by a more detailed examination of the firms’ strategies, business models and networking behaviour. It concludes with a discussion on the constraints and opportunities faced by firms operating outside the main centres of knowledge production and business in biotechnology, as is the case of dedicated biotechnology firms located in Portugal.

## ‣ Mobilized to access key resources at early stages of biotech firms: a comparative analysis in two moderately innovative countries

Capaldo, Guido; Fontes, Margarida; Cannavacciuolo, Lorella; Rippa, Pierluigi; Sousa, Cristina
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
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This paper investigates the networking behaviour of biotechnology start-ups in peripheral locations. The aim is to understand whether the conditions found in this type of environment introduce some specificities in the networking process, namely in network building and early mobilization to access key resources. The paper compares biotechnology start-ups in Portugal and in Southern Italy, focusing on relationships with research organizations and on the relevance assumed by international connections, and investigating the role played by entrepreneurs’ personal networks. The research identified some common features that diverge from the typical biotechnology start-up behaviour and can be regarded as firms’ adaptive responses to the conditions faced. Notwithstanding the frequent presence of close connections with local research organizations—that often play functions that go much beyond that of a knowledge source—the local environment is a lesser determinant for a substantial proportion of firms than would be expected in start-ups. A distinctive feature of these firms is an extensive reliance on foreign sources, for different purposes and from the very early stages. Entrepreneurs’ personal networks are found to be instrumental...

## ‣ Behaviour of osteoclasts in vitro: contact behaviour of osteoclasts with osteoblast-like cells and networking of osteoclasts for 3D orientation.

Vesely, P; Boyde, A; Jones, S J
Tipo: Artigo de Revista Científica
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The cell-cell contact-induced behaviour of osteoclasts and osteoblasts in vitro was investigated by time-lapse videomicroscopy. Contact interactions of osteoclasts with autologous cells, derived mostly from chick but also from rat bones, included contact inhibition, failure of contact inhibition, contact guidance along stabilised edges of other cells, and underlapping of other cells. Message-mediated contact behaviour (MMCB) between osteoclasts and autologous osteoblastic cells resulted, after a time delay, in zeiosis of the osteoblast-like cell which could continue, or even begin, after the osteoclast broke contact, leading to retraction of the cell and occupation of its position by the osteoclast. MMCB may play a part in the breaching of the osteoblastic sheet by osteoclasts and, in general, in the malignant spread of neoplastic cells. Two or more osteoclasts were often joined by connecting and coordinating tubules (CCTs) of varied, and varying, lengths and widths. Osteoclasts could travel along the CCTs in both directions, or send nuclei through them. The CCTs became temporarily attached to the surface of other cells, or to the substrate, then acting as a temporary anchorage for orientation and for the return of the cell to the same spot. The dynamics of osteoclastic behaviour suggest that such a networking of osteoclasts is valuable for the 3D coordination of their role in bone turnover.

## ‣ Cooperation Improves Success during Intergroup Competition: An Analysis Using Data from Professional Soccer Tournaments

David, Gwendolyn Kim; Wilson, Robbie Stuart
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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The benefit mutually gained by cooperators is considered the ultimate explanation for why cooperation evolved among non-relatives. During intergroup competition, cooperative behaviours within groups that provide a competitive edge over their opposition should be favoured by selection, particularly in lethal human warfare. Aside from forming larger groups, three other ways that individuals within a group can cooperate to improve their chances of gaining a mutual benefit are: (i) greater networking, (ii) contributing more effort, and (iii) dividing labour. Greater cooperation is expected to increase the chances of gaining a group benefit by improving proficiency in the tasks critical to success—yet empirical tests of this prediction using real-world cases are absent. In this study, we used data derived from 12 international and professional soccer competitions to test the predictions that: 1) greater levels of cooperative behaviour are associated with winning group contests, 2) the three forms of cooperation differ in relative importance for winning matches, 3) competition and tournament-type affect the levels of cooperation and shooting proficiency in matches, and 4) greater levels of networking behaviour are associated with increased proficiency in the most critical task linked with winning success in soccer—shooting at goal. Winners were best predicted by higher shooting proficiency...

## ‣ Sexual networking among market women in Benin City, Bendel State, Nigeria

Omorodion, Francisca Isi
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 31747 bytes; application/pdf
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A survey of market women was conducted in Benin City. These women are vulnerable to HIV/AIDS and STD infections since their trading activities involve long-distance travelling away from families and sexual exposure to strangers. The questionnaire included questions on socioeconomic background, sexual and health behaviour. Results indicate that there is a high level of sexual networking, especially extramarital: 26 per cent of the women have sexual intercourse with strangers, and 70 per cent have extramarital sexual relationships. A high proportion of the market women and those in close contact have contracted STDs. It is evident, therefore, that public-health education concerning AIDS and STDs is urgently needed.; no

## ‣ Sexual networking among some Lagos State adolescent Yoruba students

Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 23514 bytes; application/pdf
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Adolescent sexual behaviour was studied in order to provide more valid data on the onset of sexual experience and aspects of premarital sexual networking which may influence sexuality in later life. Yoruba students from five secondary schools were surveyed. Almost half the respondents were sexually active and most had more than two sexual partners. Despite this, most respondents favoured premarital chastity for girls. More students had heard of AIDS than STDs but, even so, knowledge of transmission was limited. Yet nearly one-third indicated that they knew of someone with AIDS. The evaluation, however, of premarital chastity as desirable suggests that subsequent sexual behaviour may be amenable to shaping through family-life education, a possible route for AIDS control campaigns.; no

## ‣ Sexual networking in Freetown against the background of the AIDS epidemic

Adegbola, O; Babatola, O; Oni, Jacob Bamidele
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 97710 bytes; application/pdf
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West Africa, since the discovery of the HIV virus, has remained relatively unperturbed by the attendant AIDS epidemic sweeping through the other portions of the continent south of Sahara. The low level, of both the reported and the diagnosed cases of the epidemic at the onset, seem to explain the initial lukewarm and sometimes cynical attitude on the part of both the government and the populace. In recent times, however, emerging revelations from research on sexual behaviour in the region seem to be generating greater concerns about the possibility of continued containment of this scourge. So in many West African countries efforts are being made to generate baseline data to help in assessing the risk of this epidemic, given the background knowledge of the sexual behavioural correlates of AIDS gained elsewhere. However, not all the strategic points in this region have had such an inventory carried out or reported. Not only does Freetown, the capital of Sierra Leone, fall into this category, it is also confronted with certain challenges at the regional level, as well as some internal peculiarities which underscore the need for the present inventory.; no

## ‣ Sexuality, migration and AIDS in Ghana

Anarfi, John Kwasi
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 68352 bytes; application/pdf
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Sexual behaviour in Ghana characterizes a society in transition. Although cultural restrictions against sexuality are no longer strictly enforced, the very nature of the social organization puts a brake on some excesses. Migration removes people from these restrictions into a situation where sexual fulfilment is enhanced. This paper explores the risk factors associated with migration. Results of a large survey across Ghana indicate widespread sexual networking. There is, however, an apparent decline in the number of sexual partners in recent periods which may be related to the AIDS campaign. Yet migration acts to increase the extent of sexual networking. While many migrants have regular sexual partners, there are a substantial number of encounters with casual partners. The circular nature of migration and the maintenance of links with home through frequent visits puts people at risk at both ends of the migratory movement. This risk is increased with international migration, associated with higher than average numbers of sexual partners. An appropriate policy for the control of the spread of AIDS in Ghana, therefore, would be one which combines educational programs with strategies for removing the factors which compel young people to migrate.; no

## ‣ Experimental research on sexual networking in some selected areas of Ghana

Anarfi, John Kwasi; Awusabo-Asare, Kofi
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 45817 bytes; application/pdf
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Despite increasing evidence that West Africa is at a critical stage in its experience of the AIDS pandemic, there is a lack of specific information about the sexual behaviour of people in the society. To provide such information, 360 individuals were surveyed. Results indicate that the nature of sexual contacts within Ghanaian society has the potential to promote the spread of STDs and AIDS. Polygyny, central in Ghanaian socio-cultural organization, underlies the male tendency to seek multiple sexual partners. Early widowhood, the general instability of marriage and the high level of remarriage, also suggest that there is a high level of sexual networking within the society. Although Ghanaian society accepts sexual networking, and some people are even casual about the AIDS scare, it appears that people are changing their sexual habits in response to the campaign on AIDS, which seems to have succeeded in instilling fear.; no

## ‣ The cultural, social and attitudinal context of male sexual behaviour in urban south-west Nigeria

Orubuloye, I. O; Caldwell, John C; Caldwell, Pat
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 47765 bytes; application/pdf
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From 1989 onward a research program based at Ondo State University, Nigeria, investigated the social and behavioural context of the sexually transmitted disease and AIDS epidemics (Orubuloye et al. 1994). Between 1989 and 1993 the researchers reached the conclusion that premarital and extramarital sexual activities were on a sufficient scale in Ondo State to maintain an STD epidemic and possibly to maintain an AIDS epidemic. The reason for caution with regard to AIDS arose from an awareness of the current relatively low seroprevalence levels in Nigeria and the demonstration by the program that much of the premarital and extramarital sexual activity was not with prostitutes but diffused more widely. The researchers also concluded that the economic returns to young women from commercial sex were so substantial and the current and later social sanctions so weak that no government intervention was likely to reduce the inflow of recruits to the occupation sufficiently to stem the STD epidemic or reduce the risk of a major AIDS epidemic. Clearly something would be achieved by a program aimed at increasing the practice of safe sex, especially the use of condoms, by everyone participating in sexual networking, particularly prostitution. There was little evidence that specific planned intervention was already achieving much...

## ‣ HIV/AIDS and sexual behaviour among youth in Zambia

Kalunde, Wendy Kabwe
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 23476 bytes; application/pdf
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This study was carried out in selected urban areas in Zambia in the area along the major rail links between the urban areas of Lusaka, Kabwe, Kitwe and Ndola. The objective of the study was to ascertain the influence of socio-economic, demographic and cultural correlates on the sexual networking and activities of the youth in selected towns of Zambia: specifically to determine how sexual behaviour among young people might influence the course of the AIDS epidemic and also to suggest policy interventions. Sexual behaviour among young people both in-school and out-ofschool, aged between 12 and 25, may be vital in influencing the spread of AIDS in Zambia. The results indicate that sexual matters are discussed with close friends of the same sex and peer group, or with cousins who are of the same age. Sometimes grandmothers are consulted for advice by co-resident grand-daughters. Girls and boys engaged in sex or thought about engaging in sex at quite an early age. Girls discussed their intentions about sex with their close friends, many of whom appeared poorly informed about sex themselves. The general views of both sexes about STDs should be a source of concern. The youth do not seem to take STDs seriously basically because most of them...

## ‣ The role of individual-media relationship and consumer personal factors on spanish teenagers´ mobile social networking sites usage

Ruiz Mafé, Carla; Sanz Blas, Silvia; Martí Parreño, José
Tipo: Artigo de Revista Científica
Português
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Social Networking Sites (SNS) are gaining momentum as powerful tools of marketing communications. Mobile phones are becoming one of the most popular devices for accessing Social Networking Sites. In Spain, 44% of Social Networking Sites users access these sites on a daily basis while 79% of them access these sites on a weekly basis. Furthermore, it is notable that over 70% of Social Networking Sites users talk about and recommend commercial brands. This justifies the interest of the study of Social Networking Sites users from a marketing perspective. The aim of this research is to assess the influence of consumers` personal factors (attitude, innovativeness and gender) and individual-media relationships (media affinity and individual-media dependency) on mobile SNSs usage behaviour. Managerial implications improving marketers´ advertising effectiveness are also provided.

## ‣ The Social, Less Social and the Fecund Aspects of Social Networking Sites

CACHIA Romina
Fonte: European Cooperation in Science and Technology - COST Publicador: European Cooperation in Science and Technology - COST
Tipo: Contributions to Conferences Formato: Online
Português
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This work attempts to highlight the unique characteristics of SNS and explore some of the social externalities of SNS and how these sites are influencing the dynamics of social networking and everyday communication practices. Social networking sites (SNS) have been with us for a few years. Throughout this time, these sites have evolved and are having significant social implications especially, amongst young people. This work analyses these application against social and media theory, mainly in the field of identity, self-exploration, exhibitionist behaviour, network effects and community. While the main data gathering is based on analysis of secondary data, the major issues and conclusions are based on in-depth interviews and a validation workshop with experts in the field. Findings suggest that SNS provide more room for self-expression, another means for socializing, as well as innovative ways of creating and maintaining personal networks. However, these sites are also changing the dynamics of privacy, mainly as a result of public disclosure of social ties and the different levels of play with identity and self-exploration. This work also observes how the technical affordances (for instance, status update on Facebook) of these sites are reinforcing different levels of technology addiction and exhibitionist behavior. Based on these results...

## ‣ Sexual networking in southwestern Nigeria

Owuamanam, Donatus O
Fonte: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University Publicador: Health Transition Centre, National Centre for Epidemiology and Population Health, The Australian National University
Tipo: Artigo de Revista Científica Formato: 31989 bytes; application/pdf
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Freud's discussion of infantile sexuality triggered considerable interest in sexual attitudes of boys and girls, particularly those at the age of adolescence. Prominent in the development of knowledge of sexual behaviour and in the attempt to make sexuality a scholarly topic for academic and public discussion are the works of Kinsey (Kinsey, Pomeroy and Martin 1948, 1953). Before Kinsey's research, sexuality was an indecent subject that should be discussed only in private. There is today, however, marked concentration of research efforts on sexuality, made from different perspectives. In Nigeria, such attempts are not lacking, not even in the southwestern part where the present study was conducted...... Today, the cultural regulations regarding premarital sex are no longer adhered to; the ideal virginal marriage or virginity at marriage no longer exists. Renne (1993) has observed that not only is virginity at marriage no longer perceived as socially desirable in southwestern Nigeria but it is now perceived as 'socially backward', 'antisocial' or even associated with infertility-related diseases such as gonorrhoea and 'epilepsy'. The purpose of the present study was to investigate the sexual networking and contraceptive behaviour of students in southwestern Nigeria...

## ‣ Energy Saving in IP over WDM Backbone Networks

COIRO, ANGELO
Português
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The energy consumption of the Internet is exploding due to the increase of the number of devices connected to it as well as the increase of traffic volume that is estimated in about 50% per year fuelled by mobile data and video applications; consequently, it is crucial to improve network efficiency to prevent the Internet from being throttled by an energy bottleneck. This PhD dissertation deals with the energy efficiency of telecommunication networks and specifically faces the problem of saving energy in the backbone section of the network. The main contributions concern the definition of algorithms and mechanisms that integrate and exploit the knowledge of the network topology, the carried traffic and the power behaviour of network devices to achieve energy efficiency in the network. Three novel contributions are presented which are related to three different saving strategies. The first faced problem concerns the design of energy efficient virtual topologies in two-layers IP over WDM networks. The problem is formalized as a Mixed Integer Linear Programming (MILP) problem and a novel heuristic algorithm, named Start-Single Hop and ReRoute, is proposed and compared with the optimal solution and another heuristic solution proposed in the literature. Results obtained through extended simulations demonstrate that the proposed solution is able to reduce the network energy consumption with respect to other solutions and to perform close to the optimal solution. Another key aspect faced in the dissertation is related to the possibility of saving energy in presence of variable traffic exploiting traffic engineering strategies that aim at aggregating the traffic on a subset of network elements in order to put in sleeping unused devices. Concerning this point...

## ‣ Measuring Co-Authorship and Networking-Adjusted Scientific Impact

Ioannidis, John P. A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. In this competitive environment, the number of authors per paper is increasing and apparently some co-authors don't satisfy authorship criteria. Listing of individual contributions is still sporadic and also open to manipulation. Metrics are needed to measure the networking intensity for a single scientist or group of scientists accounting for patterns of co-authorship. Here, I define I1 for a single scientist as the number of authors who appear in at least I1 papers of the specific scientist. For a group of scientists or institution, In is defined as the number of authors who appear in at least In papers that bear the affiliation of the group or institution. I1 depends on the number of papers authored Np. The power exponent R of the relationship between I1 and Np categorizes scientists as solitary (R>2.5), nuclear (R = 2.25–2.5), networked (R = 2–2.25), extensively networked (R = 1.75–2) or collaborators (R<1.75). R may be used to adjust for co-authorship networking the citation impact of a scientist. In similarly provides a simple measure of the effective networking size to adjust the citation impact of groups or institutions. Empirical data are provided for single scientists and institutions for the proposed metrics. Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles.

## ‣ On client interactive behaviour to design peer selection policies for BitTorrent-like protocols

Rocha, Marcus V. M.; Rodrigues, Carlo Kleber da S.
Tipo: Artigo de Revista Científica
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Peer-to-peer swarming protocols have been proven to be very efficient for content replication over Internet. This fact has certainly motivated proposals to adapt these protocols to meet the requirements of on-demand streaming system. The vast majority of these proposals focus on modifying the piece and peer selection policies, respectively, of the original protocols. Nonetheless, it is true that more attention has often been given to the piece selection policy rather than to the peer selection policy. Within this context, this article proposes a simple algorithm to be used as basis for peer selection policies of BitTorrent-like protocols, considering interactive scenarios. To this end, we analyze the client interactive behaviour when accessing real multimedia systems. This analysis consists of looking into workloads of real content providers and assessing three important metrics, namely temporal dispersion, spatial dispersion and object position popularity. These metrics are then used as the main guidelines for writing the algorithm. To the best of our knowledge, this is the first time that the client interactive behaviour is specially considered to derive an algorithm for peer selection policies. Finally, the conclusion of this article is drawn with key challenges and possible future work in this research field.

## ‣ On The Linear Behaviour of the Throughput of IEEE 802.11 DCF in Non-Saturated Conditions

Tipo: Artigo de Revista Científica
We propose a linear model of the throughput of the IEEE 802.11 Distributed Coordination Function (DCF) protocol at the data link layer in non-saturated traffic conditions. We show that the throughput is a linear function of the packet arrival rate (PAR) $\lambda$ with a slope depending on both the number of contending stations and the average payload length. We also derive the interval of validity of the proposed model by showing the presence of a critical $\lambda$, above which the station begins operating in saturated traffic conditions. The analysis is based on the multi-dimensional Markovian state transition model proposed by Liaw \textit{et al.} with the aim of describing the behaviour of the MAC layer in unsaturated traffic conditions. Simulation results closely match the theoretical derivations, confirming the effectiveness of the proposed linear model.; Comment: To appear on IEEE Communications Letters, November 2007