908 resultados para Restricted Lie algebras


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The hallmark of oceanic anoxic event 1a (OAE1a) (early Aptian ~125 Ma) corresponds to worldwide deposition of black shales with total organic carbon (TOC) content > 2% and a d13C positive excursion up to ~5‰. OAE1a has been related to large igneous province volcanism and dissociation of methane hydrates during the Lower Cretaceous. However, the occurrence of atypical, coeval and diachronous organic-rich deposits associated with OAE1a, which are also characterized by positive spikes of the d13C in epicontinental to restricted marine environments of the Tethys Ocean, indicates localized responses decoupled from complex global forcing factors. The present research is a high-resolution, multiproxy approach to assess the paleoenvironmental conditions that led to enhanced carbon sequestration from the late Barremian to the middle Aptian in a restricted, Tethyan marginal basin prior to and during OAE1a. I studied the lower 240 m of the El Pui section, Organyà Basin, Spanish Pyrenees. The basin developed as the result of extensional tectonism linked to the opening of the Atlantic Ocean. At the field scale the section consists of a sequence of alternating beds of cm – m-scale, medium-gray to grayish-black limestones and marlstones with TOC up to ~4%. The results indicate that the lowest 85 m of the section, from latest Barremian –earliest Aptian, characterize a deepening phase of the basin concomitant with sustained riverine flux and intensified primary productivity. These changes induced a shift in the sedimentation pattern and decreased the oxygen levels in the water column through organic matter respiration and limited ventilation of the basin. The upper 155 m comprising the earliest – late-early Aptian document the occurrence of OAE1a and its associated geochemical signatures (TOC up to 3% and a positive shift in d13C of ~5‰). However, a low enrichment of redox-sensitive trace elements indicates that the basin did not achieve anoxic conditions. The results also suggest that a shallower-phase of the basin, coeval with platform progradation, may have increased ventilation of the basin at the same time that heightened sedimentation rates and additional input of organic matter from terrestrial sources increased the burial and preservation rate of TOC in the sediment.

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From Hidoep Baroe Series, Taon ka 2, No. 13.

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The reproductive efficiency is directly related to the nutritional management. The diet lipid inclusion, especially with enhanced sources of omega 6 and omega 3 fatty acids, is positively associated to the ovarian follicular development of ruminants. The objective of this study was to evaluate the effects of toasted soybean grain addition on restricted or ad libitum feeding on ovarian follicular development of Santa Inês ewe lambs In conclusion, the diameter of the largest follicle and the number of >5 mm follicles were not influenced by the restricted intake diet nor the lipid inclusion; however, they increased in a direct relationship with the age of the animals.

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The age at first ovulation is influenced by several factors, and nutrition has an essential role on it. Lipids provide essential fatty acids that are positively associated to reproductive aspects. The aims of this study were to evaluate the effects of lipid inclusion and restricted intake on age and weight at the first ovulation and the serum progesterone (P4) concentration at the sixth day after first ovulation. The restricted intake imposed in this study did not delay the age at fist ovulation. The greater lipid intake did not favor reproductive parameters. Serum P4 did not increase with the soybean inclusion in the die.

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Examines how society allocates support for species’ conservation when numbers involved are large and resources are limited. Rational behaviour suggests that species in urgent need of conservation will receive more support than those species that are common. However, we demonstrate that in the absence of balanced knowledge common species will receive support more than they would otherwise receive despite society placing high existence values on all species. Twenty four species, both common and endangered and some with a restricted distribution, are examined. We demonstrate that balanced information is vital in order to direct more support for species that are endangered than those that are not. Implications for conservation stemming from the findings are discussed.

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For robots to operate in human environments they must be able to make their own maps because it is unrealistic to expect a user to enter a map into the robot’s memory; existing floorplans are often incorrect; and human environments tend to change. Traditionally robots have used sonar, infra-red or laser range finders to perform the mapping task. Digital cameras have become very cheap in recent years and they have opened up new possibilities as a sensor for robot perception. Any robot that must interact with humans can reasonably be expected to have a camera for tasks such as face recognition, so it makes sense to also use the camera for navigation. Cameras have advantages over other sensors such as colour information (not available with any other sensor), better immunity to noise (compared to sonar), and not being restricted to operating in a plane (like laser range finders). However, there are disadvantages too, with the principal one being the effect of perspective. This research investigated ways to use a single colour camera as a range sensor to guide an autonomous robot and allow it to build a map of its environment, a process referred to as Simultaneous Localization and Mapping (SLAM). An experimental system was built using a robot controlled via a wireless network connection. Using the on-board camera as the only sensor, the robot successfully explored and mapped indoor office environments. The quality of the resulting maps is comparable to those that have been reported in the literature for sonar or infra-red sensors. Although the maps are not as accurate as ones created with a laser range finder, the solution using a camera is significantly cheaper and is more appropriate for toys and early domestic robots.

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The world of work in the 21st century has been described by many as globalised (Peiperl & Jonsen, 2007; Levy, 2007; Bhagat, 2006; Czinkota & Ronkainen, 2005). Globalisation is generally understood as a greater awareness of the world as a whole; an integrated stage where the countries of the world are seen to be players on the one playing field. This notion is driven by a perception of the world as being occupied by global citizens who are affiliated not with the country in which they are born but whose loyalties lie with planet Earth. They strive to live and work with this focus foremost in their consciousness. Indeed, many of these global citizens will enjoy global careers during their lifetime whereby they work in more than one region of the world during the course of their employment. The present chapter will present a discussion on globalisation and its impact on the world of work, in particular the changes on particular demographic groups in both developed and developing economies. It will then discuss implications for workers and their careers, specifically focusing on changing relationships between workers and organisations and the need for individuals to maintain their competitive edge in the market place through an ongoing focus on relevant career management competencies.

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Habitat fragmentation can have an impact on a wide variety of biological processes including abundance, life history strategies, mating system, inbreeding and genetic diversity levels of individual species. Although fragmented populations have received much attention, ecological and genetic responses of species to fragmentation have still not been fully resolved. The current study investigated the ecological factors that may influence the demographic and genetic structure of the giant white-tailed rat (Uromys caudimaculatus) within fragmented tropical rainforests. It is the first study to examine relationships between food resources, vegetation attributes and Uromys demography in a quantitative manner. Giant white-tailed rat densities were strongly correlated with specific suites of food resources rather than forest structure or other factors linked to fragmentation (i.e. fragment size). Several demographic parameters including the density of resident adults and juvenile recruitment showed similar patterns. Although data were limited, high quality food resources appear to initiate breeding in female Uromys. Where data were sufficient, influx of juveniles was significantly related to the density of high quality food resources that had fallen in the previous three months. Thus, availability of high quality food resources appear to be more important than either vegetation structure or fragment size in influencing giant white-tailed rat demography. These results support the suggestion that a species’ response to fragmentation can be related to their specific habitat requirements and can vary in response to local ecological conditions. In contrast to demographic data, genetic data revealed a significant negative effect of habitat fragmentation on genetic diversity and effective population size in U. caudimaculatus. All three fragments showed lower levels of allelic richness, number of private alleles and expected heterozygosity compared with the unfragmented continuous rainforest site. Populations at all sites were significantly differentiated, suggesting restricted among population gene flow. The combined effects of reduced genetic diversity, lower effective population size and restricted gene flow suggest that long-term viability of small fragmented populations may be at risk, unless effective management is employed in the future. A diverse range of genetic reproductive behaviours and sex-biased dispersal patterns were evident within U. caudimaculatus populations. Genetic paternity analyses revealed that the major mating system in U. caudimaculatus appeared to be polygyny at sites P1, P3 and C1. Evidence of genetic monogamy, however, was also found in the three fragmented sites, and was the dominant mating system in the remaining low density, small fragment (P2). High variability in reproductive skew and reproductive success was also found but was less pronounced when only resident Uromys were considered. Male body condition predicted which males sired offspring, however, neither body condition nor heterozygosity levels were accurate predictors of the number of offspring assigned to individual males or females. Genetic spatial autocorrelation analyses provided evidence for increased philopatry among females at site P1, but increased philopatry among males at site P3. This suggests that male-biased dispersal occurs at site P1 and female-biased dispersal at site P3, implying that in addition to mating systems, Uromys may also be able to adjust their dispersal behaviour to suit local ecological conditions. This study highlights the importance of examining the mechanisms that underlie population-level responses to habitat fragmentation using a combined ecological and genetic approach. The ecological data suggested that habitat quality (i.e. high quality food resources) rather than habitat quantity (i.e. fragment size) was relatively more important in influencing giant white-tailed rat demographics, at least for the populations studied here . Conversely, genetic data showed strong evidence that Uromys populations were affected adversely by habitat fragmentation and that management of isolated populations may be required for long-term viability of populations within isolated rainforest fragments.

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Despite the numerous observations that dynamic capabilities lie at the source of competitive advantage, we still have limited knowledge as to how access to firm-based resources and changes to these affect the development of dynamic capabilities. In this paper, we examine founder human capital, access to employee human capital, access to technological expertise, access to other specific expertise, and access to two types of tangible resources in a sample of new firms in Sweden. We empirically measure four dynamic capabilities and find that the nature and effect of resources employed in the development of these capabilities vary greatly. For the most part, there are positive effects stemming from access to particular resources. However, for some resources, such as access to employee human capital and access to financial capital, unexpected negative effects also appear. This study therefore provides statistical evidence as to the varying role of resources in capability development. Importantly, we also find that changes in resource bases have more influential roles in the development of dynamic capabilities than the resource stock variables that were measured at an earlier stage of firm development. This provides empirical support for the notion of treating the firm as a dynamic flow of resources as opposed to a static stock. This finding also highlights the importance of longitudinal designs in studies of dynamic capability development. Further recommendations for future empirical studies of dynamic capabilities are presented.

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Two recent and related social developments of note for libraries are an upsurge in cultural participation enabled by Web 2.0 media and calls in government policy for enhanced innovation through education. Ironically, these have occurred at the same time that increasingly stringent copyright laws have restricted access to cultural content. Concepts of governmentality are used here to examine these tensions and contradictions. In particular, Foucault’s critique of the author figure and of freedom as part of the will to govern within liberal democratic societies is used to argue for better quality copyright education programs in school libraries and library information science education programs. For purposes of teaching and research, copyrights are defined as agglomerations of legal, economic, and educational discourses that enable and constrain what can and cannot be done with text in homes, schools, and library media centers. The article presents some possibilities for renewal of school libraries around copyright education and Creative Commons licensing.

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The building life cycle process is complex and prone to fragmentation as it moves through its various stages. The number of participants, and the diversity, specialisation and isolation both in space and time of their activities, have dramatically increased over time. The data generated within the construction industry has become increasingly overwhelming. Most currently available computer tools for the building industry have offered productivity improvement in the transmission of graphical drawings and textual specifications, without addressing more fundamental changes in building life cycle management. Facility managers and building owners are primarily concerned with highlighting areas of existing or potential maintenance problems in order to be able to improve the building performance, satisfying occupants and minimising turnover especially the operational cost of maintenance. In doing so, they collect large amounts of data that is stored in the building’s maintenance database. The work described in this paper is targeted at adding value to the design and maintenance of buildings by turning maintenance data into information and knowledge. Data mining technology presents an opportunity to increase significantly the rate at which the volumes of data generated through the maintenance process can be turned into useful information. This can be done using classification algorithms to discover patterns and correlations within a large volume of data. This paper presents how and what data mining techniques can be applied on maintenance data of buildings to identify the impediments to better performance of building assets. It demonstrates what sorts of knowledge can be found in maintenance records. The benefits to the construction industry lie in turning passive data in databases into knowledge that can improve the efficiency of the maintenance process and of future designs that incorporate that maintenance knowledge.

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Much recent research into citizen journalism has focussed on its role in political debate and deliberation. Such research examines important questions about citizen participation in democratic processes – however, it perhaps places undue focus on only one area of journalistic coverage, and presents a challenge which only a small number of citizen journalism projects can realistically hope to meet. A greater opportunity for broad-based citizen involvement in journalistic activities may lie outside of politics, in the coverage of everyday community life. A leading exponent of this approach is the German-based citizen journalism Website myHeimat.de, which provides a nationwide platform for participants to contribute reports about events in their community. myHeimat takes a hyperlocal approach but also allows for content aggregation on specific topics across multiple local communities; Hannover-based newspaper publishing house Madsack has recently acquired a stake in the project. Drawing on extensive interviews with myHeimat CEO Martin Huber and Madsack newspaper editors Peter Taubald and Clemens Wlokas during October 2008, this paper analyses the myHeimat project and examines its applicability beyond rural and regional areas in Germany; it investigates the question of what role citizen journalism may play beyond the political realm.

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Supply chain management and knowledge management have emerged as two distinct business philosophies in the last decade. Both are making rapid inroads into the construction industry. The premise of this paper is that knowledge management would make it possible for all the trading partners in a supply chain to reap benefits. Current research in knowledge management in the construction industry is generally targeting those big organisations that are main contractors. This has restricted the scope of knowledge management, and limits the benefits to a few, rather than the whole industry. If the construction industry as a whole is to prosper and improve its productivity, strategies for knowledge management strategy at the industry level must be established. This paper argues the case for extending the scope of knowledge management across the full extent of the supply chain, and attempts to identify the benefits that may arise out of sharing knowledge across the supply chain.

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The following article arises from the projects submitted for the 2004 Awards fo the Western Australian Chapter of the Australian Institute of Landscape Architects, for which we were judges, together with Craig Burton of CAB Consulting and Natalie palleros of Tierra Design. This article is an attempt to understand some dominant trends that emerged from viewing a range of new suburban developments. Suburban developments dominated the awards and seemed to characterise much of the work being done by landscape architects in the west. It is easy to be critical of contemporary landscape architecture in Perth, as the projects presented were mostly the same in that their scope of design activity was restricted to the decorative rather than the structural. However, as critics, we feel it is important to initate a conversation about what has been presented as the best of the profession, in order to begin to understand the current state of the profession.