956 resultados para mutualism disruption
Resumo:
We studied the potential role as seed disperser of the pacu fish (Piaracrus mesopotamicus, Characidae) in the Pantanal of Brazil. The most important food item in the diet of the pacu in the wet season was fruits of the palm Bactris glaucescens found in the guts of 73 percent of all fishes collected (N = 70). We found a positive relationship between fish length, weight, and gape size and the number of intact seeds in their gut. Therefore, large pacus are especially important in dispersing B. glaucescens seeds within the studied system. Since the best seed dispersers are the largest fishes, which are preferred by commercial fisheries, we predict that the ongoing over fishing in freshwater ecosystems will have major impacts on the dispersal system of fish-dependent plants. We suggest that it is paramount to change the attitudes in fisheries management of fruit-eating fishes and urgent to evaluate the impact of fishing on forest regeneration.
Resumo:
The rise of videosharing and self-(re)broadcasting Web services is posing new threats to a television industry already struggling with the impact of filesharing networks. This paper outlines these threats, focussing especially on the DIY re-broadcasting of live sports using Websites such as Justin.tv and a range of streaming media networks built on peer-to-peer filesharing technology.
Disruption of androgen regulation in the prostate by the environmental contaminant hexachlorobenzene
Resumo:
Hexachlorobenzene (HCB) is a persistent environmental contaminant that has the potential to interfere with steroid hormone regulation. The prostate requires precise control by androgens to regulate its growth and function. To determine if HCB impacts androgen action in the prostate, we used a number of methods. Our in vitro cell-culture-based assay used a firefly luciferase reporter gene driven by an androgen-responsive promoter. In the presence of dihydrotestosterone, low concentrations (0.5-5 nM) of HCB increased the androgen-responsive production of firefly luciferase and high concentrations of HCB (> 10 microM) suppressed this transcriptional activity. Results from a binding assay showed no evidence of affinity between HCB and the androgen receptor. We also tested HCB for in vivo effects using transgenic mice in which the transgene was a prostate-specific, androgen-responsive promoter upstream of a chloramphenicol acetyl transferase (CAT) reporter gene. In 4-week-old mice, the proportion of dilated prostate acini, a marker of sexual maturity, increased in the low HCB dose group and decreased in the high HCB dose mice. In the 8-week-old mice, there was a significant decrease in both CAT activity and prostate weight upon exposure to 20 mg/kg/day HCB. Therefore, in vitro and in vivo data suggest that HCB weakly agonizes androgen action, and consequently, low levels of HCB enhanced androgen action but high levels of HCB interfered. Environmental contaminants have been implicated in the rising incidence of prostate cancer, and insight into the mechanisms of endocrine disruption will help to clarify their role.
Resumo:
Agricultural adoption of innovation has traditionally been described as slow to diffuse. This paper therefore describes a case study grounded in PD to address a disruptive technology/system within the livestock industry. Results of the process were positive, as active engagement of stakeholders returned rich data. The contribution of the work is also presented as grounds for further design research in the livestock industry.
Resumo:
A vast proportion of companies nowadays are looking to design and are focusing on the end users as a means of driving new projects. However still many companies are drawn to technological improvements which drive innovation within their industry context. The Australian livestock industry is no different. To date the adoption of new products and services within the livestock industry has been documented as being quite slow. This paper investigates how disruptive innovation should be a priority for these technologically focused companies and demonstrates how the use of design led innovation can bring about a higher quality engagement between end user and company alike. A case study linking participatory design and design thinking is presented. Within this, a conceptual model of presenting future scenarios to internal and external stakeholders is applied to the livestock industry; assisting companies to apply strategy, culture and advancement in meaningful product offerings to consumers.
Resumo:
TESOL teachers, like mainstream teachers, often experience key incidents in their professional development. In expatriate TESOL however, unfamiliar cultural and linguistic contexts may disrupt teachers’ sense of both professional and personal identity. In this paper, narratives constructed from interviews of teacher experiences document a selection of critical events and discuss their implications for professional development in TESOL. Teachers reported that deep reflection on their experiences led to a re-conceptualisation of their professional and cultural identities. The analysis of their reflections may have significant implications for TESOL work in the context of the global and the local.
Resumo:
Digital Disruption: Cinema Moves On-line helps to make sense of what has happened in the short but turbulent history of on-line moving image distribution. It provides a realistic assessment of both the genuine and the not-so-promising methods that have been experimented in response to the disruptions that moving from ‘analogue dollars’ to ‘digital cents’ have provoked in the film industry. Paying close attention to how the Majors have dealt – often unsuccessfully – with the challenges it poses, it also focuses closely on the innovations and practices that have taken place beyond the mainstream, showcasing important entrepreneurial innovations such as Mubi, Jaman, Withoutabox and IMDb. Written by leading academic commentators and experts close to the fluctuating fortunes of the industry, Digital Disruption: Cinema Moves On-line is an indispensable guide to the changes currently facing film and its audiences.
Resumo:
This paper reviews the diversity in parenting values and practices amongst Aboriginal peoples and Torres Strait Islanders. Firstly, issues arising from the historical traumatic disruption of families’ attachments are discussed, Then the contribution Indigenous parenting makes to the development of healthy and vulnerable individuals becomes the central focus. Family therapists can draw from a broad understanding of the diversity of parenting values and practices in the context of a strength-based approach.
Resumo:
Actin is the most abundantly distributed protein in living cells which plays critical roles in the cell interior force generation and transmission. The fracture mechanism of microfilament networks, whose principle component is actin, would provide insights which can contribute to the understandings of self-protective characters of cytoskeleton. In this study, molecular simulations are conducted to investigate the molecular mechanisms of disruption of microfilament networks from the viewpoint of biophysics. By employing a coarse-grained (CG) model of actin filament networks, we focused on the ultimate strength and crack growth mode of microfilament networks that have dependency on the crack length. It can be found that, the fracture mechanism of microfilament network has dependency on the structural properties of microfilament networks. The structure flaws marginally change the strength of microfilament networks which would explain the self-protective characters of cytoskeleton.
Resumo:
This is the first volume in a book series examining how organizations in the creative industries respond to disruptive change and how they themselves generate business innovations. The aspiration of this book series is to understand some of the common forces behind the disruptions occurring in so many creative industries today and identifying the most promising strategies and responses by organizations to create new value propositions, business models and business practices that can enable these industry participants to cope with and eventually thrive as their industries and sectors are transformed. The chapters included in the volume examine the processes of disruption and transformation due to the technology of the Internet, social forces driven by social media, the development of new portable digital devices with greater capabilities and smaller size, the decreasing costs of new information, and the creation of new business models and forms of intellectual property ownership rights for a digitized industry. The context for this volume is the publishing industries, understood as the industries for the publishing of fiction and non-fiction books, academic literature, consumer as well as trade magazines, and daily newspapers. This volume includes chapters by an internationally diverse array of media scholars whose chapters provide insights into these phenomena in Eastern Europe, Finland, France, Germany, Norway, Portugal, Russia, and the United States, using different methodological frameworks including, but not limited to, surveys, in-depth interviews and multiple-case studies. One gap that this book series seeks to fill is that between the study of business innovation and disruption by innovation scholars largely based in business school settings and similar studies by scholarly experts from non-business school disciplines, including the broader social sciences (e.g. sociology, political science, economic geography) and creative industry based professional school disciplines (e.g. architecture, communications, design, film making, journalism, media studies, performing arts, photography and television). Future volumes of this book series will examine disruption and business innovation in the film, video and photography sectors (volume two), the music sector (volume three) and interactive entertainment (volume four), with subsequent volumes focusing on the most relevant developments in creative industry business innovation and disruption that emerge.
Resumo:
SPARC (secreted protein acidic and rich in cysteine)/ osteonectin/BM-40 is a matricellular protein implicated in development, cell transformation and tumorigenesis. We have examined the role of SPARC in cell transformation induced chemically with 7,12-dimethylbenz[a]anthracene (DMBA) and 12- tetradecanoylphorbol-13-acetate (TPA) in embryonic fibroblasts and in the skin of mice. Embryonic fibroblasts from SPARCnull mice showed increases in cell proliferation, enhanced sensitivity to DMBA and a higher number of DMBA/TPA-induced transformation foci. The number of DMBA-DNA adducts was 9 times higher in SPARCnull fibroblasts and their stability was lower than wild-type fibroblasts, consistent with a reduction in excision repair cross-complementing 1 the nucleotide excision repair enzyme in these cells. The SPARCnull mice showed an increase in both the speed and number of papillomas forming after topical administration of DMBA/TPA to the skin. These papillomas showed reduced growth and reduced progression to a more malignant phenotype, indicating that the effect of SPARC on tumorigenesis depends upon the transformation stage and/or tissue context. These data reinforce a growing number of observations in which SPARC has shown opposite effects on different tumor types/stages.