WorldWideScience

Sample records for niche market phenomenon

  1. The United States pork niche market phenomenon.

    Science.gov (United States)

    Honeyman, M S; Pirog, R S; Huber, G H; Lammers, P J; Hermann, J R

    2006-08-01

    After the broad industrialization of the US pork industry, there has been a development of niche markets for export and domestic pork; that is, there is a pork niche market phenomenon. The US pork niche market phenomenon is characterized, and 2 of the major markets are explained in detail. With the Midwest's tradition of a diversified family-based agriculture and record low hog prices of the late 1990s, the conditions were conducive for this phenomenon to develop. Pork niche markets utilize various sales methods including Internet sales, local abattoir sales, direct marketing, farmer networks, and targeting to organized groups. In 2003, there were approximately 35 to 40 active pork niche marketing efforts in Iowa. The Berkshire breed is an example of a swine breed that has had a recent resurgence because of niche markets. Berkshire pork is known for tenderness and excellent quality. Berkshire registrations have increased 4-fold in the last 10 yr. One of the larger niche marketers of "natural pork" is Niman Ranch Pork, which has more than 400 farmer-producers and processes about 2,500 pigs weekly. Many US consumers of pork are interested in issues concerning the environment, food safety, pig welfare, and pig farm ownership and structure. These consumers may be willing to pay more for pork from farmers who are also concerned about these issues. Small- and medium-sized swine farmers are active in pork niche markets. Niche markets claim product differentiation by superior or unique product quality and social attributes. Quality attributes include certain swine breeds, and meat quality, freshness, taste or flavor, and tenderness. Social or credence attributes often are claimed and include freedom from antibiotics and growth promotants; local family farm production; natural, organic, outdoor, or bedded rearing; humane rearing; known origin; environmentally friendly production; and the absence of animal by-products in the feed. Niche pork markets and alternative swine

  2. Niche energy markets in rural areas

    International Nuclear Information System (INIS)

    Walsh, M.; McCarthy, S.

    1996-01-01

    The objective of this project is the development of a standard methodology for integrating non-food crops in rural areas with niche energy markets. This has involved a number of steps including (i) identification of 3 niche markets for energy crops which are of common interest to the partners, (ii) application of the standard costing methodology to investigate these three niche markets and (iii) comparison of the results from this work in three workshops (one for each market). Three tightly defined niche markets were identified; these were chosen following an examination of the national energy marekts in each of the partners countries (Ireland, Germany, Netherlands, UK, Greece and Portugal). This paper gives an overview of the national energy markets which were examined. The three niche markets are introduced and the reasons for their selection given. The application of the methodology to each of the niche markets is presented along with the conclusions of the partners regarding the niche markets. (Author)

  3. A niche marketing guide for lamb cooperatives

    OpenAIRE

    Kazmierczak, Tamra Kirkpatrick; Bell, James B.

    1995-01-01

    The two types of niche markets targeted by lamb marketing cooperatives are described in this guide. The first type includes specialty middlemen outlets that cooperatives used to market lamb to specialized niches within the traditional meat marketing system of retail food stores, restaurants, food service outlets, and specialty distributors. The second type includes those outlets that cooperatives used to market lamb directly to the consumer, such as freezer markets, farmers' markets, mobile m...

  4. Market niche analysis in the casino gaming industry.

    Science.gov (United States)

    Dandurand, L

    1990-03-01

    This article discusses the nature of market niche analysis in the casino gaming industry. It presents four approaches for conducting market niche analysis. An an example of one approach, the Las Vegas Visitor Profile Study is used to identify a premium niche in the Las Vegas Slot Target Market. A detailed examination of the premium niche profile provides a description of the typical premium slot player. The description of the typical premium player leads to hypotheses regarding needs (the unique preference set) of the premium player. An analysis of the unique preference set suggests an appropriate enhanced marketing program.

  5. Green Power Marketing - from Niches to Mass Markets

    International Nuclear Information System (INIS)

    Wuestenhagen, Rolf

    2000-01-01

    In the process of liberalization of the electricity market the customers are now in a position to participate in the decision on how their electricity is produced. In particular, many consumers have a preference for renewable energies. For the producers, marketing of 'eco-power' is an opportunity to achieve sustainable competitive advantage. However, the market share of these products is still quite small today, and 'eco-power' is usually marketed as an expensive niche product. From the perspective of sustainable development these niches are a necessary but not sufficient step. In this book, ways are discussed which could lead to a mass-market penetration of eco-power products. A theoretical analysis is combined with empirical evidence derived from the eco-power market in Germany, Switzerland, Great Britain and the U.S. as well as with a comparison with other market segments [de

  6. Niche Marketing Potentials for Farm Entrepreneurs in Nigeria https ...

    African Journals Online (AJOL)

    User

    . Niche marketing involves targetting a product or service to a small but specific well ... Table 1: Examples of possible niche markets for entrepreneurs in Nigeria. Farm Business .... Concepts, Principles and Decisions, 2nd Edition. Afritowers ...

  7. Fuel cells niche market applications and design studies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Mainstream fuel cell markets such as stationary power and transport propulsion have already received considerable attention. However, the niche areas considered in this report also offer considerable markets that are considered potentially ready for exploitation. This report examines those markets and considers the broad issues for exploitation. This programme of work has been funded under the DTI's Advanced Fuel Cell Programme. The overall aim of this project was to identify and evaluate niche market applications that have the potential to provide early commercially competitive market opportunities for fuel cell systems. Battery replacement, portable, mobile auxiliary power and stationary applications for non-standard generation are covered. (author)

  8. The exploitation of the niche market through innovation and marketing : the case of Japanese small businesses

    OpenAIRE

    Sato, Yoshio

    1992-01-01

    Japan's economic growth brought many business oportunities and niche markets for small business, where new entrepreneurs entered. Competition and self-revolutionalizing efforts made the level of their technology and management highly specialized. Various examples of niche marketing strategies in Japan by several types of smaller businesses are followed. Recent new ventures' strategies, typical "venture businesses" activities, niche marketing by diversification strategies and self revolutional...

  9. Creating markets for efficient technologies by establishment of strategic niche markets

    International Nuclear Information System (INIS)

    Wene, Clas-Otto; Nilsson, Hans

    2003-01-01

    Creation of markets for more efficient technologies requires careful targeting of actors that have an interest in driving the process further. Such will both reduce the resources needed and make use of the actors self-interest for development and thus uphold the learning process. This is done by identification of strategic niche markets (SNM) where those suppliers and users, that have the biggest interest and benefit of the change will act. Both the identification and the development is a dynamic process that is better designed and operated by use of a triangulation method introduced by the IEA in its recent work

  10. From an info-brochure to the Green Power Festival: Eco-current marketing between niche market and mass market. Comparative analysis of marketing strategies and trends in the USA and Switzerland

    International Nuclear Information System (INIS)

    Wuestenhagen, R.

    1999-01-01

    Liberalisation and sustainability pose a dual challenge to the electric power industry. In some countries, public utilities and other suppliers are relying on eco-current as an adequate answer to the challenge. Availabilities and marketing strategies in Switzerland and the USA are compared. It is found that eco-current is still a high-priced niche market commodity in Switzerland. In the USA, on the other hand, professional eco-current suppliers are aiming at mass market introduction in California and Pennsylvania. The author compares marketing concepts and attempts to identify the factors that can make eco-current more than just a niche market commodity also in Switzerland [de

  11. NICHE MARKETS FOR TRADITIONAL TRAVEL AGENCIES IN CHINA

    OpenAIRE

    Chen, Min

    2014-01-01

    Social media is becoming more and more important in our daily life as it influences the ways people live and how they think. For example, people no longer just rely on traditional travel agencies for travelling. Thus, how traditional travel agencies survive in such transformation is crucial. In order to find connections between social media and travel agencies marketing strategies, quantitative research was introduced to encourage and help the traditional travel agencies to find their niche m...

  12. Fairy-Tale Niche Marketing: Neoliberal Appropriation of Pre-School Education

    Directory of Open Access Journals (Sweden)

    Urszula Dzikiewicz-Gazda

    2013-12-01

    Full Text Available In the article the author describes specfic mechanisms of neoliberalization at work in pre-school education in Poland. The argument is based on an ethnographic analysis of a theatre performance which crowned one of Wrocław’s educational projects called “Enterprising Pre-school Student”. It demonstrates the workings of neoliberal ideology, which—based on the niche marketing strategy—targets specific needs of particular consumer groups. Addressing children with a specialised marketing message, the strategy uses fairy tales as a tool and cover for instilling desired behaviour patterns in them.

  13. Energy efficiency programs for niche markets: The Labs21 program as an exemplar

    Energy Technology Data Exchange (ETDEWEB)

    Wirdzek, Phillip; Lintner, William; Mathew, Paul; Carlisle, Nancy

    2004-06-01

    Most federal programs that promote energy efficiency and environmental sustainability in the building industry focus on the larger market segments such as offices, residential buildings, etc. Niche markets such as laboratories are often overlooked and beyond the scope of such programs, for at least two reasons: (a) by definition, niche markets are a relatively small ''wedge'' of the overall energy consumption ''pie''; and (b) laboratories have health and safety concerns, complex flexibility requirements and are perceived to be less amenable to broadly applicable strategies. Nevertheless, laboratories and other ''high-tech'' buildings demand the attention of the energy efficiency and sustainable design community for several reasons: (1) They are a growing segment of the building sector. (2) They are very energy and resource intensive laboratories on average are four to six times as energy intensive as office buildings, and five to ten times as expensive to build. (3) There are significant opportunities for efficiency and conservation, especially when compared to other buildings. In this paper, we describe how the Labs21 program, a joint program of the US EPA and US DOE, is structured to meet these needs recognizing that laboratories require very specialized engineering and design knowledge not addressed in academia or industry, and not readily shared to a level commensurate with the needs of this building sector. While Labs21 is focused on one niche market, we also highlight some experiences from this program applicable to other specialized building types.

  14. The Phenomenon of Youtubers and their Utilisation in Marketing

    OpenAIRE

    Tauchenová, Kateřina

    2014-01-01

    This master´s thesis is called The Phenomenon of Youtubers and their Utilisation in Marketing. It presents Youtubers as idols of today´s young people and introduces options of utilization of their power for marketing purposes. The first chapter introduces the reader to the general matters of online marketing and offers basic knowledge about this area. The second chapter is dedicated to social networks and their utilisation in marketing field. The third chapter introduces the topic YouTube. It...

  15. Impacts of CO2 taxes in an Economy with Niche Markets and Learning-by-doing

    International Nuclear Information System (INIS)

    Van der Zwaan, B.C.C.; Gerlagh, R.; Hofkes, M.W.; Klaassen, G.

    2003-09-01

    In this paper, we analyse the impact of carbon taxes on emission levels, when niche markets exist for new carbon-free technologies, and when these technologies experience 'learning-by-doing' effects. For this purpose, a general equilibrium model has been developed, DEMETER, which specifies two energy technologies: one based on fossil fuels and one on a composite of carbon-free energy technologies. Initially, the carbon-free technology has relatively high production costs, but niche markets ensure positive demand. Learning-by-doing decreases production costs, which increases the market share, which in turn accelerates learning-by-doing, and so forth. This mechanism allows a relatively modest carbon tax, of about 50 US$/tC, to almost stabilise carbon emissions at their 2000 levels throughout the entire 21st century. Sensitivity analysis shows that the required carbon tax for emission stabilisation crucially depends on the elasticity of substitution between the fossil fuel and carbon-free technology

  16. SERVICING THE MARKET NICHE – A POSSIBLE SOLUTION FOR THE MAINTENANCE AND/OR SUCCESS OF THE FIRM ON THE MARKET IN THE CONTEXT OF THE GLOBAL ECONOMIC CRISIS

    OpenAIRE

    Doina I. POPESCU

    2013-01-01

    This work shows the importance of servicing the market niche by firms operating in the garment industry in the context of the world economic crisis. The paper presents the necessity of adapting companies’ strategies based on the main trends set out by the global economic crisis. Within this work is presented a study that aims to highlight the degree in which Romanian firms acting in the clothing industry service the market niche, their identification, the measure in which these firms’ managem...

  17. Development of a standard methodology for integrating non-food crop production in rural areas with niche energy markets. Proceedings

    International Nuclear Information System (INIS)

    1996-09-01

    This project was supported as a Concerted Action under the EC DGVI AIR programme from 1993-1996. It has successfully developed a standard methodology to help integrate non-food crop production in rural areas with niche energy markets. The methodology was used to compare the costs of different energy crop production and conversion options across the six participating nations. The partners provide a representative cross-section of European agriculture and energy expertise. All partners agreed on three niche markets favourable for biomass and biofuels: small-scale heat markets (less than 1 MW th ) for agro-industry, domestic and commercial buildings, medium-scale heat markets (1-10MW th ), including cogeneration for light industry and district heating, and liquid biofuels as substitutes for fossil fuels in transport, heat and power applications. (Author)

  18. Socio-technical transition as a co-evolutionary process: Innovation and the role of niche markets in the transition to motor vehicles

    Science.gov (United States)

    Birky, Alicia K.

    2008-10-01

    Significant reductions in greenhouse emissions from personal transportation will require a transition to an alternative technology regime based on renewable energy sources. Two bodies of research, the quasi-evolutionary (QE) model and the multi-level perspective (MLP) assert that processes within niches play a fundamental role in such transitions. This research asks whether the description of transitions based on this niche hypothesis and its underlying assumptions is consistent with the historical U.S. transition to motor vehicles at the beginning of the 20th century. Unique to this dissertation is the combination of the perspective of the entrepreneur with co-evolutionary approaches to socio-technical transitions. This approach is augmented with concepts from the industry life-cycle model and with a taxonomy of mechanisms of learning. Using this analytic framework, I examine specifically the role of entrepreneurial behavior and processes within and among firms in the co-evolution of technologies and institutions during the transition to motor vehicles. I find that niche markets played an important role in the development of the technology, institutions, and the industry. However, I also find that the diffusion of the automobile is not consistent with the niche hypothesis in the following ways: (1) product improvements and cost reductions were not realized in niche markets, but were achieved simultaneously with diffusion into mass markets; (2) in addition to learning-by-doing and learning-by-interacting with users, knowledge spillovers and interacting with suppliers were critical in this process; (3) cost reductions were not automatic results of expanding markets, but rather arose from the strategies of entrepreneurs based on personal perspectives and values. This finding supports the use of a behavioral approach with a micro-focus in the analysis of socio-technical change. I also find that the emergence and diffusion of the motor vehicle can only be understood by

  19. Earnings Management: Obvious Phenomenon in Albanian Market

    Directory of Open Access Journals (Sweden)

    Teuta Llukani

    2013-07-01

    This paper is focused on reviewing the existing literature with regard to the Earnings Management in response to the growing pressure of investors, policy makers, and companies’ governance reform mechanisms to curb opportunistic behavior of the managers of these companies. It also examines the existence of this phenomenon in Albanian context as well as tests the importance of Modified Jones Model as an efficient tool for detection of abnormal accruals, used as a proxy for earnings management. The results show that firms in the Albanian market are engaged in earnings management initiatives.

  20. The influence of different framing strategies in the social construction of a niche: ambidexterity in developing a bio resource market

    NARCIS (Netherlands)

    Loohuis, Raymond Petrus Antonius; von Raesfeld Meijer, Ariane M.; Groen, Arend J.

    2014-01-01

    Which framing strategy helps developing a regional bio resource market? Building on literature interested in the social construction of niches in the renewable energy technology, we examine how the enactment of different framing strategies (diagnostic, prognostic, and motivational) influence how a

  1. MEAT GOAT DEMOGRAPHICS AND NICHE MARKETING

    Directory of Open Access Journals (Sweden)

    Jeffrey Fisher

    2009-06-01

    religious concerns, convenience, food safety, and food quality issues. Opportunities exist to develop niche marketing opportunities for fresh goat with local ethnic or faith based populations.

  2. The Labor Market from Romania from the Perspective of Migration Phenomenon

    Directory of Open Access Journals (Sweden)

    Constantin Georgescu

    2017-12-01

    Full Text Available Population migration is a real phenomenon that has amplified over the last two decades and will continue to grow as major disparities between regions develop. There are many reasons that generate the trend of population movement. The reasons/ motive that are frequently invoked are the conflictual situation related issues that primarily affect individual security, political and social fragility, economic instability with effects in all areas of activity, degradation of living conditions, and the high risk of terrorism in certain areas. The population migration is not necessarily a bad thing if we are looking through the perspective of chances it offers to both people and the economy as a whole, being also an important factor for the growth of national and international trade. But, the lack of some decisions to control this phenomenon creates long-term imbalances. These imbalances are already extremely visible in the Romanian labor market. Numerous work field have a major staff lack and are need of solutions for doing business under normal conditions. Therefore, the present paper aims at highlighting the main features of the labor market, the country's risks, as well as identifying viable solutions for reducing economic and social imbalances.

  3. Innovation processes navigated by women groups in the Malian shea sector: How targeting of international niche markets results in fragmentation and obstructs coordination

    OpenAIRE

    Sidibe, A.; Vellema, S.; Dembele, M.M.; Traore, K.; Kuyper, T.W.

    2012-01-01

    The incorporation of women and their associations into international markets and value chains is proposed increasingly as a development pathway in Sub-Saharan Africa. The underlying assumption is that exclusion of individual women from groups specialized in supplying a single international niche market is the main obstacle to their development. Intervention under this assumption focuses on linking women groups to international business and development organizations (NGOs). To validate this pr...

  4. Innovation processes navigated by women groups in the Malian shea sector: How targeting of international niche markets results in fragmentation and obstructs coordination

    NARCIS (Netherlands)

    Sidibe, A.; Vellema, S.; Dembele, M.M.; Traore, K.; Kuyper, T.W.

    2012-01-01

    The incorporation of women and their associations into international markets and value chains is proposed increasingly as a development pathway in Sub-Saharan Africa. The underlying assumption is that exclusion of individual women from groups specialized in supplying a single international niche

  5. The malignant niche: safe spaces for toxic stem cell marketing.

    Science.gov (United States)

    Sipp, Douglas

    2017-01-01

    Many tumors are sustained by microenvironments, or niches, that support and protect malignant cells, thus conferring a competitive advantage against both healthy cells and therapeutic interventions (for a brief review, see Yao and Link (Stem Cells 35: 3-8, 2017)). The global industry engaged in the commercial promotion of unproven and scientifically implausible cell-based "regenerative" therapies has developed a number of self-protective strategies that support its survival and growth in ways that are broadly analogous to the functions of the malignant niche.

  6. Renewable energies and the poor: niche or nexus?

    International Nuclear Information System (INIS)

    Bhattacharyya, Subhes C.

    2006-01-01

    Renewable energies are considered as an essential element of any strategy for sustainable energy development. The poor in the developing world without access to modern energies are regarded as a major market for renewable energies. This short paper attempts to analyse whether such a niche is backed by any economic logic and whether renewable energy and the poor nexus could be a strategy for success. The paper suggests that contrary to the common belief, the economic logic behind the niche is unsound and that the nexus is not a recipe for success

  7. Designing a Qualitative Model of Doping Phenomenon Effect on Sport Marketing in Iran

    Directory of Open Access Journals (Sweden)

    Jasem Manouchehri

    2016-10-01

    Full Text Available There a number of factors effecting consumers' purchase behavior. It is believed that celebrities can effect selling positively by transferring their popular image to the endorsed product. But, it is heard lots about excommunicate behaviors in the sport world today. Disclosure of the recent doping affairs relating to Lance Armstrong's seven wins in Tour De France is just one among many spectacular and also negative cases. The main aim of the present paper was to explore the effect of doping phenomenon on sport marketing. Depth interviews data were analyzed in three phases: open coding, axial coding, and selective coding. 297 open codes were achieved by 18 interviews. Grouping axial codes in each case and comparing, all gained codes can be divided in five groups: brand image (athlete and endorsed product brands images, moral reasoning (moral coupling, moral decoupling, and moral rationalization, consumer behavioral consequences (word of mouth, purchasing intention, and brand loyalty, attitude change (attitudes change toward athlete and brand, and moral emotions (moral evaluation, contempt, anger, disgust, and sympathy. The proposed qualitative model for the effect of doping phenomenon on sport marketing in Iran illustrated that moral emotions and product brand image affected by the doped athlete brand image and it resulted in attitudes change toward endorser athlete and endorsed brand and negative consumer behavioral consequences, however, moral reasoning strategies emerged by cognitive dissonance might protect consumers behavior from negative effects.

  8. Marketing quality and value to the managed care market.

    Science.gov (United States)

    Kazmirski, G

    1998-11-01

    Quantifying quality and marketing care delivery have been long-term challenges in the health care market. Insurers, employers, other purchasers of care, and providers face a constant challenge in positioning their organizations in a proactive, competitive niche. Tools that measure patient's self-reported perception of health care needs and expectations have increased the ability to quantify quality of care delivery. When integrated with case management and disease management strategies, outcomes reporting and variance analysis tracking can be packaged to position a provider in a competitive niche.

  9. Spontaneous Cognition and Epistemic Agency in the Cognitive Niche

    Science.gov (United States)

    Fabry, Regina E.

    2018-01-01

    According to Thomas Metzinger, many human cognitive processes in the waking state are spontaneous and are deprived of the experience of epistemic agency. He considers mind wandering as a paradigm example of our recurring loss of epistemic agency. I will enrich this view by extending the scope of the concept of epistemic agency to include cases of depressive rumination and creative cognition, which are additional types of spontaneous cognition. Like mind wandering, they are characterized by unique phenomenal and functional properties that give rise to varying degrees of epistemic agency. The main claim of this paper will be that the experience of being an epistemic agent within a certain time frame is a relational phenomenon that emerges from the organism’s capacity to interact with its cognitive niche. To explore this relation, I develop a new framework that integrates phenomenological considerations on epistemic agency with a functional account of the reciprocal coupling of the embodied organism with its cognitive niche. This account rests upon dynamical accounts of strong embodied and embedded cognition and recent work on cognitive niche construction. Importantly, epistemic agency and organism-niche coupling are gradual phenomena ranging from weak to strong realizations. The emerging framework will be employed to analyze mind wandering, depressive rumination, and creative cognition as well as their commonalities and differences. Mind wandering and depressive rumination are cases of weak epistemic agency and organism-niche coupling. However, there are also important phenomenological, functional, and neuronal differences. In contrast, creative cognition is a case of strong epistemic agency and organism-niche coupling. By providing a phenomenological and functional analysis of these distinct types of spontaneous cognition, we can gain a better understanding of the importance of organism-niche interaction for the realization of epistemic agency.

  10. The Rise of Market-Based Job Search Institutions and Job Niches for Low-Skilled Chinese Immigrants

    Directory of Open Access Journals (Sweden)

    Zai Liang

    2018-01-01

    Full Text Available Increasingly, market-based job search institutions, such as employment agencies and ethnic media, are playing a more important role than migrant networks for low-skilled Chinese immigrants searching for jobs. We argue that two major factors are driving this trend: the diversification of Chinese immigrants’ provinces of origin, and the spatial diffusion of businesses in the United States owned by Chinese immigrants. We also identify some new niche jobs for Chinese immigrants and assess the extent to which this development is driven by China’s growing prosperity. We use data from multiple sources, including a survey of employment agencies in Manhattan’s Chinatown, job advertisements in Chinese-language newspapers, and information on Chinese immigrant hometown associations in the United States.

  11. In a niche of time: do specialty hospitals outperform general services hospitals?

    Science.gov (United States)

    Poole, LeJon; Davis, Jullet A; Gunby, Norris W

    2013-01-01

    Niche hospitals represent a growing segment in the health care industry. Niche facilities are primarily engaged in the treatment of cardiac or orthopedic conditions. The effectiveness of this strategy is of interest because niche hospitals focus on only the most profitable services. The purpose of this research was to assess the financial effectiveness of the niche strategy. We theorize that firm and market-level factors concomitantly with the strategy of the hospital-niche versus traditional-are associated with financial performance. This research used 2 data sources, the 2003 Medicare Cost Report and the 2003 Area Resource File. The sample was limited to only for-profit, urban, nongovernmental hospitals (n = 995). The data were analyzed using hierarchical least squares regression. Financial performance was operationalized using the hospital's return on assets. The principal finding of this project is that niche hospitals had significantly higher performance than traditional facilities. From the organizational perspective, the niche strategy leads to better financial performance. From a societal perspective, the niche strategy provides increased focus and efficiencies through repetition. Despite the limited focus of this strategy, patients who can access these providers may experience better outcomes than patients in more traditional hospitals.

  12. Innovative business models within niche tourist markets: shared identity, authenticity and flexibile networks. The case of three italian SMEs

    Directory of Open Access Journals (Sweden)

    Federica Montaguti

    2016-07-01

    Full Text Available Innovative business models within niche tourist markets: shared identity, authenticity and flexibile networks. The case of three italian SMEs The evolution of business models is a crucial challenge for tourism companies, which should understand how they can stimulate their creativity and introduce innovation. However for many firms, in particular for SMEs, this process is not so easy to be adopted. Even more difficult it is to understand how the business model should change to be successful in solving what appears to be one of the main problems for SMEs, especially within mature, tourist destinations, i.e. targeting new profitable segments. The paper discusses the main findings of a research project carried out by the authors about changes in the business models of Italian tourism companies, underlining in particular three case-studies of interest in terms of the innovation put in place and that relate to SMEs. The analysis, based on the business model canvas, the value constellation and the storytelling, found out that these three firms are flexible companies that have characteristics emblematic of the knowledge and information economy business models. They successfully answer the needs of specific niches, finding new opportunities within a mature tourism market and famous destinations, thanks to their ability to develop wide flexible networks, where customers are an active part, and thanks to the value proposed to the clients, centred on the idea of a shared identity between the clients and the company’s founders and of an authenticity guaranteed by the life story of the founders themselves.

  13. Integration of non-food crops in rural areas with niche energy markets

    International Nuclear Information System (INIS)

    Kwant, K.W.; Heuval, E. van der; Rijk, P.J.J.

    1996-01-01

    Integration of energy-crops in the agricultural sector is hampered by a number of factors. Within the EU AIR programme a concerted action has been initiated to contribute to a better understanding of the several aspects of introducing energy corps in the rural sector. A standard methodology to assess the economic and technical viability of energy crops for three identified niche markets was developed. Technical viability of biomass production, pretreatment and conversion to energy is a necessary condition for implementation of such a project, however, it is not a sufficient condition. Non-technical constraints can either hamper or stimulate a successful introduction. Technical issues will be dealt with in other papers. This paper will, therefore concentrate on the non-technical issues. In section 2 the major issues are described. Opportunities on how to improve biomass energy introduction are provided in section 3. As a case study, the non-technical issues of a combined heat and power plant, planned to be fired on arboricultural and short rotation willow, in the municipality of Groningen in the Netherlands will be presented. The paper ends with general conclusions. (Author)

  14. IAC Jabola and IAC Esperança: common bean cultivars for market niches

    Directory of Open Access Journals (Sweden)

    Alisson Fernando Chiorato

    2009-01-01

    Full Text Available In Brazil, the trade of common beans with specialty grains such as Jalo, Bolinha, Jabola, Vermelho, Rajado,Branco, Pintado and Canário is still considered a niche market when compared to the carioca and black grain types.However, the cultivation of these beans has proved promising as an alternative income source for farmers, since it offers adifferentiated and more valuable product. IAC-Jabola and IAC-Esperança were developed by the Instituto AgronômicoCampinas (IAC in view of their excellent grain type, plant size and higher mean yield than the standard control Jalo Precoce.The IAC had these cultivars registered in MAPA/RNC based on results of 24 VCU trials in 2005/2006/2007, in the state of SãoPaulo. The yield of IAC Jabola was 2124 kg ha-1, 2336 kg ha-1, and 2558 kg ha-1, in the rainy, dry and winter seasons,respectively. The IAC- Esperança produced 1718 kg ha-1, 1545 kg ha-1, and 2263 kg ha-1 in the rainy, dry and winter seasons,respectively.

  15. E-COMMERCE MARKET AND PERSPECTIVES FOR THE REVERSE COMMERCE

    Directory of Open Access Journals (Sweden)

    Michał Laskowski

    2015-12-01

    Full Text Available E-commerce has been evolving from being a purely niche phenomenon to owning a vital share in economies of developed countries. Growth of such distribution and sales channel has been highly correlated with technological improvements penetrating modern societies. Today we stand in front of new ideas, adoption barriers and profit opportunities. There are a few trends ready to take off in the near future, one of them is the idea of reverse e-commerce, which is engaging the consumer even more into a highly personalized buying process. Nevertheless, every new idea needs the suitable time and place to launch. The purpose of this analysis is to verify prospects for the reverse e-commerce, which has a huge market potential. Reverse e-Commerce has every chance of becoming a new, still undiscovered now, marketing channel.

  16. Innovative Marketing Strategies for National Industrial Flagships: Brand Repositioning for Accessing Upscale Markets

    NARCIS (Netherlands)

    Todiras, A.; Nijkamp, P.; Rafijeras, S.

    2011-01-01

    Product and process innovations are generally regarded as strategic competitive vehicles in industry. Identifying and conquering new market niches through focused marketing approaches - by emphasising new product qualities in mature markets - has become a very appropriate innovation strategy. This

  17. Residential customer-sited photovoltaics markets 1999

    International Nuclear Information System (INIS)

    Herig, C.; Thomas, H.; Perez, R.; Wenger, H.

    1999-01-01

    Nearly three years ago, the authors published the paper, Niche Markets for Grid Connected Photovoltaics. The paper identified target market niches for Customer-Sited Photovoltaics (CSPV), on a state-by-state basis for the US. The paper demonstrated cost-effective, grid-connected, domestic markets existed and identified those showing the most near-term promise. Many financial and policy attributes effecting the economics of CSPV have changed since the previous paper was published. Incorporating these policy changes into the analysis expands the CSPV market from a niche status to an era of significance. The number of states with break-even turnkey costs (BTC) above four dollars per watt expanded from five to fifteen. The top five state market values are now above a break-even cost of seven dollars per watt, a value at which the domestic CSPV market moves beyond a break-even status to consumer savings or industry profit, depending on system price. Emissions mitigation values were also included in the paper, but did not significantly effect the break-even market value results. The paper presents the details of the data, analysis, and results

  18. THE DYNAMICS OF THE TEXTILE MARKET. ANALYTICAL REFERENCES

    Directory of Open Access Journals (Sweden)

    Aliona CERNOVA

    2013-12-01

    Full Text Available During the transition to a market economy, the state of many countries’ economies and the international textile industry face considerable challenges. There are many uncertainties surrounding the global textile market, exacerbated by gloomy predictions that for a decade should have been eliminated, resulting in “free” trade flows. There is no doubt that manufacturers which have created niche markets will be better positioned to compete in the global marketplace and achieve higher margins for products while yielding greater profitability. This paper is an introduction of a reasearch that examines how some textile market niches have evolved. The goal of this paper is research and the role that textile niche markets will play by 2025. Specific objectives are: to give a broad overview of various trade theories, including classical, neo-classical, post-neo-classical, and modern, in order to determine what are the possibilities for development and protection. In particular, emphasis will be focused the special problems, due to the vector exchanges and commercial conjuncture, to illustrate how traditional marketing methods differ from market to market and to examine what role will play niche markets in the textiles industry and textile apparel industry in 2050. The results of this research study will help formulate a business strategy that can be used in market capitalization and will provide a framework for research for textile researchers at a global level.

  19. Gazlı İçecek Sektörü ve Gazoz Pazarındaki KOBİ’ler İçin Niş Pazarlamasına Bir Örnek(A Sample of The Applıcatıon of Niche Marketing by SMEs In The Soda and Carbonated Beverages Market

    Directory of Open Access Journals (Sweden)

    Canan AY

    2005-01-01

    Full Text Available Small and Medium-Sized Enterprises (SME rarely find themselves in distress like the ones do in carbonated beverages market. The reasons for that may be the market dominance of a few gigantic firms in terms of control and market share, and the disability of resource-limited SMEs in responding to market needs due to the competitive structure of the industry. In this paper we try to show how a local soda pop company can better deal with the challenges in its market through niche marketing.

  20. Toward a Periodic Table of Niches, or Exploring the Lizard Niche Hypervolume.

    Science.gov (United States)

    Pianka, Eric R; Vitt, Laurie J; Pelegrin, Nicolás; Fitzgerald, Daniel B; Winemiller, Kirk O

    2017-11-01

    Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and we used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal coordinates analyses were performed on niche dimensional data sets, and species scores for the first three axes were used as input for a principal components analysis to ordinate species in continuous niche space and for a regression tree analysis to separate species into discrete niche categories. Three-dimensional models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.

  1. Revisiting Ethnic Niches: A Comparative Analysis of the Labor Market Experiences of Asian and Latino Undocumented Young Adults

    Directory of Open Access Journals (Sweden)

    Esther Yoona Cho

    2017-07-01

    Full Text Available Drawing on thirty in-depth interviews with Korean- and Mexican-origin undocumented young adults in California, this comparative analysis explores how the intersection of immigration status and ethnoracial background affects social and economic incorporation. Respective locations of principal ethnic niches, and access to these labor market structures, lead to divergent pathways of employment when no legal recourse exists. Despite similar levels of academic achievement, Korean respondents were more likely to enter into a greater diversity of occupations relative to Mexican respondents. However, the experiences of Mexican respondents varied depending on their connection to pan-ethnic Latino nonprofit organizations. Illegality, therefore, is conditioned by opportunity structures that vary strongly by membership in different ethnoracial communities, leading to structured heterogeneity in experiences with undocumented status.

  2. Classification and comparison of niche services for developing strategy of medical tourism in Asian countries.

    Science.gov (United States)

    Chen, Hung-chi; Kuo, Hsin-chih; Chung, Kuo-Piao; Chang, Sophia; Su, Syi; Yang, Ming-chin

    2010-01-01

    Medical tourism is a new trend in medical service. It is booming not only in Asian countries but also in European and South American countries. Worldwide competition of medical service is expected in the future, and niche service will be a "trademark" for the promotion of global medicine. Niche service also functions for market segmentation. Niche services are usually surgical procedures. A study was carried out to compare different strategies for developing medical tourism in Asian countries. The role of a niche service is evaluated in the initiation and further development of medical tourism for individual countries. From this study, a general classification was proposed in terms of treatment procedures. It can be used as a useful guideline for additional studies in medical tourism. Niche service plays the following roles in the development of medical tourism: (1) It attracts attention in the mass media and helps in subsequent promotion of business, (2) it exerts pressure on the hospital, which must improve the quality of health care provided in treating foreign patients, especially the niche services, and (3) it is a tool for setting up the business model. E-Da Hospital is an example for developing medical tourism in Taiwan. A side effect is that niche service brings additional foreign patients, which will contribute to the benefit of the hospital, but this leaves less room for treating domestic patients. A niche service is a means of introduction for entry into the market of medical tourism. How to create a successful story is important for the development of a niche service. When a good reputation has been established, the information provided on the Internet can last for a long time and can spread internationally to form a distinguished mark for further development. Niche services can be classified into 3 categories: (1) Low-risk procedures with large price differences and long stay after retirement; (2) high-risk procedures with less of a price difference

  3. Energy Sector Market Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Arent, D.; Benioff, R.; Mosey, G.; Bird, L.; Brown, J.; Brown, E.; Vimmerstedt, L.; Aabakken, J.; Parks, K.; Lapsa, M.; Davis, S.; Olszewski, M.; Cox, D.; McElhaney, K.; Hadley, S.; Hostick, D.; Nicholls, A.; McDonald, S.; Holloman, B.

    2006-10-01

    This paper presents the results of energy market analysis sponsored by the Department of Energy's (DOE) Weatherization and International Program (WIP) within the Office of Energy Efficiency and Renewable Energy (EERE). The analysis was conducted by a team of DOE laboratory experts from the National Renewable Energy Laboratory (NREL), Oak Ridge National Laboratory (ORNL), and Pacific Northwest National Laboratory (PNNL), with additional input from Lawrence Berkeley National Laboratory (LBNL). The analysis was structured to identify those markets and niches where government can create the biggest impact by informing management decisions in the private and public sectors. The analysis identifies those markets and niches where opportunities exist for increasing energy efficiency and renewable energy use.

  4. Phase transition phenomenon: A compound measure analysis

    Science.gov (United States)

    Kang, Bo Soo; Park, Chanhi; Ryu, Doojin; Song, Wonho

    2015-06-01

    This study investigates the well-documented phenomenon of phase transition in financial markets using combined information from both return and volume changes within short time intervals. We suggest a new measure for the phase transition behaviour of markets, calculated as a return distribution conditional on local variance in volume imbalance, and show that this measure successfully captures phase transition behaviour under various conditions. We analyse the intraday trade and quote dataset from the KOSPI 200 index futures, which includes detailed information on the original order size and the type of each initiating investor. We find that among these two competing factors, the submitted order size yields more explanatory power on the phenomenon of market phase transition than the investor type.

  5. Increasing electric vehicle policy efficiency and effectiveness by reducing mainstream market bias

    International Nuclear Information System (INIS)

    Green, Erin H.; Skerlos, Steven J.; Winebrake, James J.

    2014-01-01

    Plug-in electric vehicles (PEVs) provide an opportunity for reducing energy use and emissions in the transportation sector. Currently, a number of federal policies are in place to incentivize deployment of PEVs to mainstream consumers with demographics and vehicle attribute preferences most common to today's new vehicle purchasers. This article argues that policies intending to give PEVs a foothold in the market should not focus on mainstream consumers and should instead focus on niche markets—specifically carsharing and postal fleets—and early adopters including green consumers. Two arguments can be made in support of eliminating the mainstream market bias of current policies toward a policy of cultivating niche markets. The first is efficiency: so far PEV policies featuring a mainstream market bias have proven to be inefficient and costly. The second is effectiveness: it is becoming increasingly evident that PEV policies would be more effective in achieving potential societal benefits if they focused on early adopters and niche markets using such approaches as strategic niche management, accessible loans and financing, and appropriately targeted incentives. PEV policies focused on early adopters and niche markets would create complementary system effects that will lead to increased PEV market penetration and realization of intended societal benefits. - Highlights: • We argue that U.S. electric vehicle policies are inefficient and ineffective. • We introduce “mainstream consumer bias” as an explanation for policy deficiencies. • We propose an alternative policy agenda to address some of these policy problems. • Proposed policy options include strategic niche management, targeted R and D and incentives, and loans

  6. Marketing small animal theriogenology services--one perspective.

    Science.gov (United States)

    Barber, J A

    2007-08-01

    Once a decision is made to add small animal theriogenology services to a practice, marketing strategies must be developed and implemented to attract clients to the new services. Marketing strategies for the niche market of theriogenology include start-up marketing methods, referral programs, internal marketing, and continued marketing. Marketing theriogenology services is a dynamic, ongoing process that never ends.

  7. Bestsellers dominate the market

    Energy Technology Data Exchange (ETDEWEB)

    Koenemann, Detlef

    2010-07-01

    The strong market growth of the past years has led to certain turbine types achieving very high numbers of units sold. As a result, the leading manufacturers are becoming ever more dominant, and many smaller manufacturers are beng required to seek their success in market niches. (orig.)

  8. 40 Is the New 65? Older Adults and Niche Targeting Strategies in the Online Dating Industry

    Directory of Open Access Journals (Sweden)

    Derek Blackwell

    2016-10-01

    Full Text Available Niche dating sites have become a popular trend in the online dating industry; yet, little is known about the specialization strategies these sites use to cater to their users’ needs. Moreover, previous research alludes to the idea that many of these sites may be engaging in pseudo-individualization—a deceptive technique that creates an illusion of specialization. This study focuses on niche dating sites for older adults, one of the fastest growing niches in online dating. Through a qualitative content analysis and close reading of older-adult dating sites, I seek to determine how and to what extent online dating sites that target older adults actually customize their services to benefit this population. Three key findings emerge: (1 the use of mass segmentation, a strategy that combines elements of both mass marketing and market segmentation; (2 a strategic broadening of the boundaries of the older-adult niche; and (3 the use of deceptive advertising to attract users. These findings suggest that older-adult dating sites are, in fact, engaging in pseudo-individualization. They also highlight some of the unique aspects of online media that facilitate this practice. Implications for both online daters and site producers are discussed.

  9. Why developmental niche construction is not selective niche construction: and why it matters.

    Science.gov (United States)

    Stotz, Karola

    2017-10-06

    In the last decade, niche construction has been heralded as the neglected process in evolution. But niche construction is just one way in which the organism's interaction with and construction of the environment can have potential evolutionary significance. The constructed environment does not just select for , it also produces new variation. Nearly 3 decades ago, and in parallel with Odling-Smee's article 'Niche-constructing phenotypes', West and King introduced the 'ontogenetic niche' to give the phenomena of exo genetic inheritance a formal name. Since then, a range of fields in the life sciences and medicine has amassed evidence that parents influence their offspring by means other than DNA (parental effects), and proposed mechanisms for how heritable variation can be environmentally induced and developmentally regulated. The concept of 'developmental niche construction' (DNC) elucidates how a diverse range of mechanisms contributes to the transgenerational transfer of developmental resources. My most central of claims is that whereas the selective niche of niche construction theory is primarily used to explain the active role of the organism in its selective environment, DNC is meant to indicate the active role of the organism in its developmental environment. The paper highlights the differences between the construction of the selective and the developmental niche, and explores the overall significance of DNC for evolutionary theory.

  10. Stitch the niche - a practical philosophy and visual schematic for the niche concept

    NARCIS (Netherlands)

    McInerny, Greg J.; Etienne, Rampal S.

    2012-01-01

    By over-focusing on precise definitions, ecology has produced a confused idea of the niche concept. This, our second paper, develops a practical philosophy for the niche that approaches the concept at the correct level of abstraction. We deconstruct the niche into effect and response components and

  11. Periarteriolar Glioblastoma Stem Cell Niches Express Bone Marrow Hematopoietic Stem Cell Niche Proteins

    NARCIS (Netherlands)

    Hira, Vashendriya V. V.; Wormer, Jill R.; Kakar, Hala; Breznik, Barbara; van der Swaan, Britt; Hulsbos, Renske; Tigchelaar, Wikky; Tonar, Zbynek; Khurshed, Mohammed; Molenaar, Remco J.; van Noorden, Cornelis J. F.

    2018-01-01

    In glioblastoma, a fraction of malignant cells consists of therapy-resistant glioblastoma stem cells (GSCs) residing in protective niches that recapitulate hematopoietic stem cell (HSC) niches in bone marrow. We have previously shown that HSC niche proteins stromal cell-derived factor-1α (SDF-1α),

  12. The Fluctuation Niche in Plants

    Directory of Open Access Journals (Sweden)

    Jaume Terradas

    2009-01-01

    Full Text Available Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and ecophysiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and interannual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.

  13. The Fluctuation Niche in Plants

    International Nuclear Information System (INIS)

    Terradas, J.; Penuelas, J.; Lloret, F.; Penuelas, J.

    2009-01-01

    Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and eco physiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and inter annual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.

  14. An introduction to niche construction theory.

    Science.gov (United States)

    Laland, Kevin; Matthews, Blake; Feldman, Marcus W

    Niche construction refers to the modification of selective environments by organisms. Theoretical and empirical studies of niche construction are increasing in importance as foci in evolutionary ecology. This special edition presents theoretical and empirical research that illustrates the significance of niche construction to the field. Here we set the scene for the following papers by (1) discussing the history of niche construction research, (2) providing clear definitions that distinguish niche construction from related concepts such as ecosystem engineering and the extended phenotype, (3) providing a brief summary of the findings of niche construction research, (4) discussing the contribution of niche construction and ecological inheritance to (a) expanded notions of inheritance, and (b) the extended evolutionary synthesis, and (5) briefly touching on some of the issues that underlie the controversies over niche construction.

  15. What types of investors generate the two-phase phenomenon?

    Science.gov (United States)

    Ryu, Doojin

    2013-12-01

    We examine the two-phase phenomenon described by Plerou, Gopikrishnan, and Stanley (2003) [1] in the KOSPI 200 options market, one of the most liquid options markets in the world. By analysing a unique intraday dataset that contains information about investor type for each trade and quote, we find that the two-phase phenomenon is generated primarily by domestic individual investors, who are generally considered to be uninformed and noisy traders. In contrast, our empirical results indicate that trades by foreign institutions, who are generally considered informed and sophisticated investors, do not exhibit two-phase behaviour.

  16. Technology learning in a global - local perspective: - the interplay between technology diffusion, niche markets and experience curves

    International Nuclear Information System (INIS)

    Martinsen, Thomas

    2010-01-01

    Preventing dangerous global climate change requires timely deployment of nascent energy technologies with zero or low Co2 emissions. Managing the shift to a common sustainable technology path calls for insight about the influence of global technological change on the national energy system. Moreover, national policies are required to promote the shift to the new technology path. This calls for methods to analyse the national energy system within a global perspective. The objective of the work presented in this thesis was to investigate interplay between technology diffusion, niche markets and technology learning from the perspective of a small open economy like Norway. More specifically, develop methods to include the influence of technology learning manifested in experience and learning curves into national energy-economy-environment models. Moreover, apply the methods to investigate the potential influence and sensitivity to technology learning in a small open economy. In this thesis three such methods have been developed, applied and its importance assessed using Norway as an example. In this work three models have been linked. They are the global Energy Technology Perspectives model operated by the International Energy Agency, the Norwegian Markal model at the Institute for Energy Technology and the macro economic model MSG6 at Statistics Norway. Method one and two has been developed to manage the interplay between the models. In a local perspective technology learning in the global market is perceived as spillover. Based upon a review of the characteristics of technological change and learning curves and its application to energy system modelling some criteria important for the parameterization and modelling of spillover in a small open economy are suggested. The first method incorporates spillover into the national Markal model. The second method establishes a soft-link between the national models. The soft-link served two purposes; to provide input on demand

  17. Labeling strategies to overcome the problem of niche markets for sustainable milk products: The example of pasture-raised milk.

    Science.gov (United States)

    Kühl, S; Gassler, B; Spiller, A

    2017-06-01

    Pasture-raised milk is gaining in importance in some European countries and in the United States. The production of pasture-raised milk is linked to higher costs, as the milk is normally collected and processed separately from conventional barn milk. This could hinder the production of sustainable milk products. We discuss alternative labeling strategies that allow the mixing of pasture-raised (sustainable) and conventional milk to reduce costs and break free from the current niche market. The lower price would allow for more pasture-raised milk to be produced and enter the mainstream market. The aim of this study was to analyze consumers' willingness to pay for alternative labeling types using a discrete choice experiment with 1,065 German milk buyers. The 2 alternative labels, besides the classical labeling approach, are based on the mass balance approach (at least 50% pasture-raised milk in a package) and cause-related marketing (support of farmers who keep their cows on pasture). The discrete choice experiment was combined with a cluster analysis to get a deeper understanding of the buying behavior of the diverse consumer segments for milk. We found that all consumer groups prefer the classical label where products are segregated but also understand the benefits of cause-related marketing. The average consumer was willing to pay €0.50 more for pasture-raised milk certified with the classical label and €0.38 more for pasture-raised milk labeled with a cause-related marketing claim. However, differences between the clusters are strong: The smallest cluster of ethically involved consumers (15%) is willing to pay the highest premiums, especially for the classical label. Cause-related marketing is an interesting alternative for involved buyers under price pressure (41%), whereas the mass balance approach is little understood and thus less valued by consumers. From our results we concluded that cause-related marketing (in our case, the support of pasturing of

  18. Incremental by Design? On the Role of Incumbents in Technology Niches

    DEFF Research Database (Denmark)

    Hain, Daniel S.; Jurowetzki, Roman

    for the rate and direction of technological progress as an outcome. Literature on sustainability transitions outlines the significance of niches and protected space for the development of path-breaking technologies in early stages. They are said to offer firms an environment to experiment in joint learning...... activities on emerging technologies shielded from the selection pressure on open markets. The engagement of large incumbent actors in the development of emerging technologies, and especially joint research projects together with young SME's, is generally positively perceived, since their high resource...... ability to direct the trajectory of technological development can to a large extend be explained by their position in the niche network. If path-dependent and cumulative characteristics such as reputation, age or size of actors are main drivers of change in these networks, evolutionary processes...

  19. Selling wind: Lessons in green niche marketing

    Science.gov (United States)

    Worden, Gregory Edward

    Concern about global warming, energy independence, and threats to oil supply have increased attention on wind and other forms of renewable energy. Yet after more than twenty years, the wind industry remains dependent on government interventions. This research examined the potential of renewable energy credits (RECs) to help wind energy become profitable. Messages used to promote wind and solar energy RECs were compared with those for sustainable building materials. Findings confirm a still immature approach to marketing and sales. None of those interviewed either recognized the value of or had taken action to ensure customer retention nor recognized the role socially conscious and active consumers might play in promoting and helping develop the industry. Recommended actions include continuing research on effective marketing strategies and development of a coordinated industry message.

  20. Niche Marketing: Branding Your Early Child Care and Education Business without Getting Burned

    Science.gov (United States)

    Wassom, Julie

    2004-01-01

    Branding in the early child care and education marketplace is very similar to branding on the farm. It refers to the specific image the company develops and promotes to make services unique, recognizable, and memorable in the minds of prospects and customers. This article discusses how to establish a niche in a business, develop a brand, and…

  1. Collision sensitive niche profile of the worst affected bird-groups at wind turbine structures in the Federal State of Brandenburg, Germany.

    Science.gov (United States)

    Bose, Anushika; Dürr, Tobias; Klenke, Reinhard A; Henle, Klaus

    2018-02-28

    Biodiversity-related impacts at wind energy facilities have increasingly become a cause of conservation concern, central issue being the collision of birds. Utilizing spatial information of their carcass detections at wind turbines (WTs), we quantified the detections in relation to the metric distances of the respective turbines to different land-use types. We used ecological niche factor analysis (ENFA) to identify combinations of land-use distances with respect to the spatial allocation of WTs that led to higher proportions of collisions among the worst affected bird-groups: Buntings, Crows, Larks, Pigeons and Raptors. We also assessed their respective similarities to the collision phenomenon by checking for overlaps amongst their distance combinations. Crows and Larks showed the narrowest "collision sensitive niche"; a part of ecological niche under higher risk of collisions with turbines, followed by that of Buntings and Pigeons. Raptors had the broadest niche showing significant overlaps with the collision sensitive niches of the other groups. This can probably be attributed to their larger home range combined with their hunting affinities to open landscapes. Identification of collision sensitive niches could be a powerful tool for landscape planning; helping avoid regions with higher risks of collisions for turbine allocations and thus protecting sensitive bird populations.

  2. ENOTOURISM: A NICHE TENDENCY WITHIN THE TOURISM MARKET

    Directory of Open Access Journals (Sweden)

    Sorin BIBICIOIU

    2013-01-01

    Full Text Available This paper is aimed at establishing the required actions to be taken so as to improve perception on Romanian wine and vine tourism. In the Romanian wine and vine field, the main changes over the last ten years have been the modernization of wineries by maintaining the valuable local grape varieties and replanting soil with resistant and productive varieties, introducing new technologies in wine production processes and local producers’ relocation on the market. Besides all these, technical and material facilities were developed by rehabilitating, modernizing and opening of numerous wine cellars, constructing modern accommodation units within or close to vine areas and implementing marketing programmes aimed at promoting vine areas. The tendencies of hospitality industry corroborated with the change of interest and the perceptions of the tourism products consumers make us reach the following conclusion: enotourism has to be adapted to the innovative market spirit, an efficacious brand strategy has to be defined for the final goal of attracting as many consumers as possible. Eenotourism is that form of tourism which offers great local development opportunities to vineyards areas. To conclude, the study will describe the market features and tendencies, based on a large range of resources and it will present ideas connected to the tourism management and economic policies that may positively or negatively influence this field.

  3. MEAT GOAT DEMOGRAPHICS AND NICHE MARKETING

    OpenAIRE

    Jeffrey Fisher; Richard Stock; David A. Mangione; Larry A. Nye

    2009-01-01

    Six focus groups were conducted with each having ten people who attend different Islamic Centers in Ohio. The objective of the focus groups was to understand Halal meat purchase patterns and consumption patterns of the Moslem population with special attention to goat. The Ohio State University Extension personnel are utilizing these results to work with meat goat producers to understand and meet the requirements of the Halal meat market.  Participants discussed the Zabiha approach to slaught...

  4. Niche players

    Science.gov (United States)

    Seandel, Marco; Falciatori, Ilaria; Shmelkov, Sergey V.; Kim, Jiyeon; James, Daylon; Rafii, Shahin

    2010-01-01

    The undifferentiated spermatogonia of adult mouse testes are composed of both true stem cells and committed progenitors. It is unclear what normally prevents these adult germ cells from manifesting multipotency. The critical elements of the spermatogonial stem cell niche, while poorly understood, are thought to be composed of Sertoli cells with several other somatic cell types in close proximity. We recently discovered a novel orphan G-protein coupled receptor (GPR125) that is restricted to undifferentiated spermatogonia within the testis. GPR125 expression was maintained when the progenitor cells were extracted from the in vivo niche and propagated under growth conditions that recapitulate key elements of the niche. Such conditions preserved the ability of the cells to generate multipotent derivatives, known as multipotent adult spermatogonial derived progenitor cells (MASCs). Upon differentiation, the latter produced a variety tissues including functional endothelium, illustrating the potential applications of such cells. Thus, GPR125 represents a novel target for purifying adult stem and progenitors from tissues, with the goal of developing autologous multipotent cell lines. PMID:18256534

  5. Niche construction game cancer cells play.

    Science.gov (United States)

    Bergman, Aviv; Gligorijevic, Bojana

    2015-10-01

    Niche construction concept was originally defined in evolutionary biology as the continuous interplay between natural selection via environmental conditions and the modification of these conditions by the organism itself. Processes unraveling during cancer metastasis include construction of niches, which cancer cells use towards more efficient survival, transport into new environments and preparation of the remote sites for their arrival. Many elegant experiments were done lately illustrating, for example, the premetastatic niche construction, but there is practically no mathematical modeling done which would apply the niche construction framework. To create models useful for understanding niche construction role in cancer progression, we argue that a) genetic, b) phenotypic and c) ecological levels are to be included. While the model proposed here is phenomenological in its current form, it can be converted into a predictive outcome model via experimental measurement of the model parameters. Here we give an overview of an experimentally formulated problem in cancer metastasis and propose how niche construction framework can be utilized and broadened to model it. Other life science disciplines, such as host-parasite coevolution, may also benefit from niche construction framework adaptation, to satisfy growing need for theoretical considerations of data collected by experimental biology.

  6. Niche construction game cancer cells play

    Science.gov (United States)

    Bergman, Aviv; Gligorijevic, Bojana

    2015-10-01

    Niche construction concept was originally defined in evolutionary biology as the continuous interplay between natural selection via environmental conditions and the modification of these conditions by the organism itself. Processes unraveling during cancer metastasis include construction of niches, which cancer cells use towards more efficient survival, transport into new environments and preparation of the remote sites for their arrival. Many elegant experiments were done lately illustrating, for example, the premetastatic niche construction, but there is practically no mathematical modeling done which would apply the niche construction framework. To create models useful for understanding niche construction role in cancer progression, we argue that a) genetic, b) phenotypic and c) ecological levels are to be included. While the model proposed here is phenomenological in its current form, it can be converted into a predictive outcome model via experimental measurement of the model parameters. Here we give an overview of an experimentally formulated problem in cancer metastasis and propose how niche construction framework can be utilized and broadened to model it. Other life science disciplines, such as host-parasite coevolution, may also benefit from niche construction framework adaptation, to satisfy growing need for theoretical considerations of data collected by experimental biology.

  7. Spatial distributions of niche-constructing populations

    Directory of Open Access Journals (Sweden)

    Xiaozhuo Han

    2015-12-01

    Full Text Available Niche construction theory regards organisms not only as the object of natural selection but also an active subject that can change their own selective pressure through eco-evolutionary feedbacks. Through reviewing the existing works on the theoretical models of niche construction, here we present the progress made on how niche construction influences genetic structure of spatially structured populations and the spatial-temporal dynamics of metapopulations, with special focuses on mathematical models and simulation methods. The majority of results confirmed that niche construction can significantly alter the evolutionary trajectories of structured populations. Organism-environmental interactions induced by niche construction can have profound influence on the dynamics, competition and diversity of metapopulations. It can affect fine-scale spatially distribution of species and spatial heterogeneity of the environment. We further propose a few research directions with potentials, such as applying adaptive dynamics or spatial game theory to explore the effect of niche construction on phenotypic evolution and diversification.

  8. Mobile marketing communications in consumer markets

    OpenAIRE

    Leppäniemi, M. (Matti)

    2008-01-01

    Abstract This dissertation aims to examine the theoretical and empirical foundations of the mobile marketing phenomenon. While numerous studies have yielded important insights into this topic, the existing mobile marketing literature appears to be inconsistent and somewhat fragmented. With the help of two action research projects, interviews of mobile marketing practitioners, and an online survey, this study aims to contribute to our understanding of the nature of mobile marketing communic...

  9. A variational approach to niche construction.

    Science.gov (United States)

    Constant, Axel; Ramstead, Maxwell J D; Veissière, Samuel P L; Campbell, John O; Friston, Karl J

    2018-04-01

    In evolutionary biology, niche construction is sometimes described as a genuine evolutionary process whereby organisms, through their activities and regulatory mechanisms, modify their environment such as to steer their own evolutionary trajectory, and that of other species. There is ongoing debate, however, on the extent to which niche construction ought to be considered a bona fide evolutionary force, on a par with natural selection. Recent formulations of the variational free-energy principle as applied to the life sciences describe the properties of living systems, and their selection in evolution, in terms of variational inference. We argue that niche construction can be described using a variational approach. We propose new arguments to support the niche construction perspective, and to extend the variational approach to niche construction to current perspectives in various scientific fields. © 2018 The Authors.

  10. THE NICHE CONSTRUCTION PERSPECTIVE: A CRITICAL APPRAISAL*

    Science.gov (United States)

    Scott-Phillips, Thomas C; Laland, Kevin N; Shuker, David M; Dickins, Thomas E; West, Stuart A

    2014-01-01

    Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equivalent in importance to natural selection. Here, we subject NCT to critical evaluation, in the form of a collaboration between one prominent advocate of NCT, and a team of skeptics. We discuss whether niche construction is an evolutionary process, whether NCT obscures or clarifies how natural selection leads to organismal adaptation, and whether niche construction and natural selection are of equivalent explanatory importance. We also consider whether the literature that promotes NCT overstates the significance of niche construction, whether it is internally coherent, and whether it accurately portrays standard evolutionary theory. Our disagreements reflect a wider dispute within evolutionary theory over whether the neo-Darwinian synthesis is in need of reformulation, as well as different usages of some key terms (e.g., evolutionary process). PMID:24325256

  11. The niche party concept and its measurement

    OpenAIRE

    Meyer, Thomas M; Miller, Bernhard

    2015-01-01

    The concept of the niche party has become increasingly popular in analyses of party competition. Yet, existing approaches vary in their definitions and their measurement approaches. We propose using a minimal definition that allows us to compare political parties in terms of their ?nicheness?. We argue that the conceptual core of the niche party concept is based on issue emphasis and that a niche party emphasizes policy areas neglected by its rivals. Based on this definition, we propose a con...

  12. Does niche divergence accompany allopatric divergence in Aphelocoma jays as predicted under ecological speciation? Insights from tests with niche models.

    Science.gov (United States)

    McCormack, John E; Zellmer, Amanda J; Knowles, L Lacey

    2010-05-01

    The role of ecology in the origin of species has been the subject of long-standing interest to evolutionary biologists. New sources of spatially explicit ecological data allow for large-scale tests of whether speciation is associated with niche divergence or whether closely related species tend to be similar ecologically (niche conservatism). Because of the confounding effects of spatial autocorrelation of environmental variables, we generate null expectations for niche divergence for both an ecological-niche modeling and a multivariate approach to address the question: do allopatrically distributed taxa occupy similar niches? In a classic system for the study of niche evolution--the Aphelocoma jays--we show that there is little evidence for niche divergence among Mexican Jay (A. ultramarina) lineages in the process of speciation, contrary to previous results. In contrast, Aphelocoma species that exist in partial sympatry in some regions show evidence for niche divergence. Our approach is widely applicable to the many cases of allopatric lineages in the beginning stages of speciation. These results do not support an ecological speciation model for Mexican Jay lineages because, in most cases, the allopatric environments they occupy are not significantly more divergent than expected under a null model.

  13. Plant stem cell niches.

    Science.gov (United States)

    Stahl, Yvonne; Simon, Rüdiger

    2005-01-01

    Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

  14. Bone Marrow Vascular Niche: Home for Hematopoietic Stem Cells

    Directory of Open Access Journals (Sweden)

    Ningning He

    2014-01-01

    Full Text Available Though discovered later than osteoblastic niche, vascular niche has been regarded as an alternative indispensable niche operating regulation on hematopoietic stem cells (HSCs. As significant progresses gained on this type niche, it is gradually clear that the main work of vascular niche is undertaking to support hematopoiesis. However, compared to what have been defined in the mechanisms through which the osteoblastic niche regulates hematopoiesis, we know less in vascular niche. In this review, based on research data hitherto we will focus on component foundation and various functions of vascular niche that guarantee the normal hematopoiesis process within bone marrow microenvironments. And the possible pathways raised by various research results through which this environment undergoes its function will be discussed as well.

  15. Niche Overlap and Discrediting Acts: An Empirical Analysis of Informing in Hollywood

    Directory of Open Access Journals (Sweden)

    Giacomo Negro

    2015-06-01

    Full Text Available This article examines informing on others as a discrediting act between individual agents in a labor market. We conduct an empirical analysis of artists called to testify during the 1950s Congressional hearings into Communism in Hollywood, and multi-level regression models reveal that the odds of an artist informing on another increase when their career histories are more similar. The similarity reflects levels of niche overlap in the labor market. The finding that similarity contributes to discredit in the context of resource competition is compatible with a social comparison process, whereby uncertainty about performance leads more similar people to attend to and exclude one another to a greater extent.

  16. Niche-specific cognitive strategies

    DEFF Research Database (Denmark)

    Hulgard, K.; Ratcliffe, J. M.

    2014-01-01

    Related species with different diets are predicted to rely on different cognitive strategies: those best suited for locating available and appropriate foods. Here we tested two predictions of the niche-specific cognitive strategies hypothesis in bats, which suggests that predatory species should...... the niche-specific cognitive strategies hypothesis and suggest that for gleaning and clutter-resistant aerial hawking bats, learning to associate shape with food interferes with subsequent spatial memory learning....

  17. Functional traits, convergent evolution, and periodic tables of niches.

    Science.gov (United States)

    Winemiller, Kirk O; Fitzgerald, Daniel B; Bower, Luke M; Pianka, Eric R

    2015-08-01

    Ecology is often said to lack general theories sufficiently predictive for applications. Here, we examine the concept of a periodic table of niches and feasibility of niche classification schemes from functional trait and performance data. Niche differences and their influence on ecological patterns and processes could be revealed effectively by first performing data reduction/ordination analyses separately on matrices of trait and performance data compiled according to logical associations with five basic niche 'dimensions', or aspects: habitat, life history, trophic, defence and metabolic. Resultant patterns then are integrated to produce interpretable niche gradients, ordinations and classifications. Degree of scheme periodicity would depend on degrees of niche conservatism and convergence causing species clustering across multiple niche dimensions. We analysed a sample data set containing trait and performance data to contrast two approaches for producing niche schemes: species ordination within niche gradient space, and niche categorisation according to trait-value thresholds. Creation of niche schemes useful for advancing ecological knowledge and its applications will depend on research that produces functional trait and performance datasets directly related to niche dimensions along with criteria for data standardisation and quality. As larger databases are compiled, opportunities will emerge to explore new methods for data reduction, ordination and classification. © 2015 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  18. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

  19. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

  20. The niche construction perspective: a critical appraisal.

    Science.gov (United States)

    Scott-Phillips, Thomas C; Laland, Kevin N; Shuker, David M; Dickins, Thomas E; West, Stuart A

    2014-05-01

    Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equivalent in importance to natural selection. Here, we subject NCT to critical evaluation, in the form of a collaboration between one prominent advocate of NCT, and a team of skeptics. We discuss whether niche construction is an evolutionary process, whether NCT obscures or clarifies how natural selection leads to organismal adaptation, and whether niche construction and natural selection are of equivalent explanatory importance. We also consider whether the literature that promotes NCT overstates the significance of niche construction, whether it is internally coherent, and whether it accurately portrays standard evolutionary theory. Our disagreements reflect a wider dispute within evolutionary theory over whether the neo-Darwinian synthesis is in need of reformulation, as well as different usages of some key terms (e.g., evolutionary process). © 2013 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  1. From the ecological niche to the mass market with 'Green Power Marketing' - 1st European Conference on Green Power Marketing 2001

    International Nuclear Information System (INIS)

    2001-01-01

    This report summarises the information presented at the European Conference on Green Power Marketing held in 2001 in St. Moritz, Switzerland. It takes a look at the market chances of ecologically produced electricity for use in Switzerland and for export. The opinions of experts from the areas of research, business, politics, marketing and non-governmental organisations that were presented at the meeting are summarised. European perspectives and trends in the USA are discussed and examples of green power marketing in the USA and Holland are given. Marketing issues and price policies are discussed, as are labelling strategies and customer perception of 'Green Power' issues. Also, sales issues including e-marketing, power-market rules and certificate trading are dealt with

  2. Market forces in municipal and industrial waste-to-energy

    International Nuclear Information System (INIS)

    Makansi, J.

    1991-01-01

    The market for municipal and industrial waste-to-energy can be characterized simply as currently soft with continued excellent long-term prospects. But as in all markets large and small, niche opportunities exist now which can be profitable with proper definition and strategy. Economics of several projects have proven marginal, cost overruns are common, and revenue projections are sometimes overstates. Also contributing to poorer economics of late are lower prices for the electric power produced from these plants. New environmental restrictions are adding 10-15% to the capital costs of a given project. On the industrial front, the strength of waste-fuel firing continues to be evident for independent power production. Important fuel-niche markets have sprung up over the last decade including petroleum coke, coal-mining wastes, hospital or redbag wastes, biomass, used tires, and so on. Another fuel niche is hazardous waste incineration. In the municipal arena, realism has not yet hit the recycling and source reduction enthusiasts. Only 25-35% recycling is considered practical by experts. There are also limits to how often material can be recycled. Finally, in spite of the best efforts of the population to control the amount of refuse generated and to recycle that which is, population and economic growth may overtake any new sense of environmental responsibility. And, yes, the additional refuse still has to go somewhere exclamation point The best somewhere option continues to be a waste-to-energy plant. Current market opportunities and two other market forces (international activities and the role of US utilities) are discussed

  3. The niche party concept and its measurement.

    Science.gov (United States)

    Meyer, Thomas M; Miller, Bernhard

    2015-03-01

    The concept of the niche party has become increasingly popular in analyses of party competition. Yet, existing approaches vary in their definitions and their measurement approaches. We propose using a minimal definition that allows us to compare political parties in terms of their 'nicheness'. We argue that the conceptual core of the niche party concept is based on issue emphasis and that a niche party emphasizes policy areas neglected by its rivals. Based on this definition, we propose a continuous measure that allows for more fine-grained measurement of a party's 'nicheness' than the dominant, dichotomous approaches and thereby limits the risk of measurement error. Drawing on data collected by the Comparative Manifesto Project, we show that (1) our measure has high face validity and (2) exposes differences among parties that are not captured by alternative, static or dichotomous measures.

  4. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  5. The evolution of climatic niches in squamate reptiles.

    Science.gov (United States)

    Pie, Marcio R; Campos, Leonardo L F; Meyer, Andreas L S; Duran, Andressa

    2017-07-12

    Despite the remarkable diversity found in squamate reptiles, most of their species tend to be found in warm/dry environments, suggesting that climatic requirements played a crucial role in their diversification, yet little is known about the evolution of their climatic niches. In this study, we integrate climatic information associated with the geographical distribution of 1882 squamate species and their phylogenetic relationships to investigate the tempo and mode of climatic niche evolution in squamates, both over time and among lineages. We found that changes in climatic niche dynamics were pronounced over their recent squamate evolutionary history, and we identified extensive evidence for rate heterogeneity in squamate climatic niche evolution. Most rate shifts involved accelerations, particularly over the past 50 Myr. Most squamates occupy similar regions of the climatic niche space, with only a few lineages diversifying into colder and humid climatic conditions. The changes from arid to mesic conditions in some regions of the globe may have provided opportunities for climatic niche evolution, although most lineages tended to remain near their ancestral niche. Variation in rates of climatic niche evolution seems common, particularly in response to the availability of new climatic conditions over evolutionary time. © 2017 The Author(s).

  6. The HysNiche trial: hysteroscopic resection of uterine caesarean scar defect (niche) in patients with abnormal bleeding, a randomised controlled trial.

    Science.gov (United States)

    Vervoort, A J M W; Van der Voet, L F; Witmer, M; Thurkow, A L; Radder, C M; van Kesteren, P J M; Quartero, H W P; Kuchenbecker, W K H; Bongers, M Y; Geomini, P M A J; de Vleeschouwer, L H M; van Hooff, M H A; van Vliet, H A A M; Veersema, S; Renes, W B; van Meurs, H S; Bosmans, J; Oude Rengerink, K; Brölmann, H A M; Mol, B W J; Huirne, J A F

    2015-11-12

    A caesarean section (CS) can cause a defect or disruption of the myometrium at the site of the uterine scar, called a niche. In recent years, an association between a niche and postmenstrual spotting after a CS has been demonstrated. Hysteroscopic resection of these niches is thought to reduce spotting and menstrual pain. However, there are no randomised trials assessing the effectiveness of a hysteroscopic niche resection. We planned a multicentre randomised trial comparing hysteroscopic niche resection to no intervention. We study women with postmenstrual spotting after a CS and a niche with a residual myometrium of at least 3 mm during sonohysterography. After informed consent is obtained, eligible women will be randomly allocated to hysteroscopic resection of the niche or expectant management for 6 months. The primary outcome is the number of days with postmenstrual spotting during one menstrual cycle 6 months after randomisation. Secondary outcomes are menstrual characteristics, menstruation related pain and experienced discomfort due to spotting or menstrual pain, quality of life, patient satisfaction, sexual function, urological symptoms, medical consultations, medication use, complications, lost productivity and medical costs. Measurements will be performed at baseline and at 3 and 6 months after randomisation. A cost-effectiveness analysis will be performed from a societal perspective at 6 months after randomisation. This trial will provide insight in the (cost)effectiveness of hysteroscopic resection of a niche versus expectant management in women who have postmenstrual spotting and a niche with sufficient residual myometrium to perform a hysteroscopic niche resection. Dutch Trial Register NTR3269 . Registered 1 February 2012. ZonMw Grant number 80-82305-97-12030.

  7. Understanding Market Segments and Competition in the Private Military Industry

    Science.gov (United States)

    2009-12-01

    Likert scale, and importance scale) and “open-end” (unstructured) questions ( Kotler , 2009, p.137). We applied parts of the Tailored Design Method... Kotler , 2008, p. 249). Item 2 and Items 8-10 of the questionnaire attempted to capture the market niche/s that the respondents’ reportedly... Kotler , 2009, p. 137). These questions were designed using Likert-type items to assess the participant’s level of importance or level of

  8. Segmentation of electric energy customers by specific niches; Segmentacao de clientes de energia eletrica por nichos especiais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Lucia Rodrigues da; Jannuzzi, Gilberto de Martino [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)], E-mail: jannuzzi@fen.unicamp.br

    2009-04-15

    The article presents the classic segmentation used in electric energy industry for large customers. The paper argues the limitations of this classification, as well as, the potentialities to classify customers for specific niches, the example of that already occurs in other competitive sectors of the economy. Twelve potential forms for classifying large customers in electricity industry are presented: geographic localization; value of the invoice; sector of productive activity; types of share holding composition and enterprise management; forms and characteristics of the use of the electric energy in the final units; degree of technological sophistication; client relation cost benefit; common factors in energy process of purchase; brand associated with the customer; extraordinary factors, such as, urgency, application and volume of energy; personal characteristics of the purchaser in charge of the operation; former-customers who moved from the captive market to the free market and vice versa. The article concludes proposing a new methodology to identify the specific niches of customers in the electric sector, as well as the inductive and restrictive factors of this methodology. (author)

  9. Modulating the stem cell niche for tissue regeneration

    Science.gov (United States)

    Lane, Steven W; Williams, David A; Watt, Fiona M

    2015-01-01

    The field of regenerative medicine holds considerable promise for treating diseases that are currently intractable. Although many researchers are adopting the strategy of cell transplantation for tissue repair, an alternative approach to therapy is to manipulate the stem cell microenvironment, or niche, to facilitate repair by endogenous stem cells. The niche is highly dynamic, with multiple opportunities for intervention. These include administration of small molecules, biologics or biomaterials that target specific aspects of the niche, such as cell-cell and cell–extracellular matrix interactions, to stimulate expansion or differentiation of stem cells, or to cause reversion of differentiated cells to stem cells. Nevertheless, there are several challenges in targeting the niche therapeutically, not least that of achieving specificity of delivery and responses. We envisage that successful treatments in regenerative medicine will involve different combinations of factors to target stem cells and niche cells, applied at different times to effect recovery according to the dynamics of stem cell–niche interactions. PMID:25093887

  10. [Mesenchymal stroma cells and their niche].

    Science.gov (United States)

    Schneider, R K

    2013-11-01

    Stem cells reside in a highly specialized, complex microenvironment that is known as the stem cell niche. The stem cell niche can be described as an anatomically defined space where the stem cell is localized and nourished and stem cell quiescence, proliferation and differentiation are maintained. Tissue engineering aims to imitate the stem cell niche to (I) induce a directed differentiation, (II) maintain the self-renewal capacity or (III) find a regulated balance between self-renewal and differentiation. Mesenchymal stem or stromal cells (MSC) can differentiate in three-dimensional collagen gels into functional osteoblasts when subjected to a phosphate-rich cultivation medium. Furthermore, they acquire a prosynthetic, matrix remodeling, contractile phenotype. Medial artery calcification in patients with chronic kidney disease also proceeds through intramembranous ossification resulting from osteoblast-induced calcification of the collagen extracellular matrix. Thus, the influence of uremic cultivation conditions as a pathophysiological stimulus on MSC and endothelial cells was analyzed with special regards to matrix remodeling, vascularization and calcification. The results showed that BMP-2/4 mediated MSC (mal)differentiation into osteoblasts with acquired matrix remodeling phenotype and loss of proangiogenic capacity. These studies have led to the conclusion that uremia has detrimental effects on the stem cell niche and promotes the continuous calcification by osteogenic (mal)differentiation. In summary, recent studies have shown the conducting and regulating effect of the stem cell niche under physiological conditions that can be applied and mimicked for tissue engineering applications. However, under pathological conditions the stem cell niche can have detrimental effects on stem cell function and can promote disease progression.

  11. Vascular and perivascular niches, but not the osteoblastic niche, are numerically restored following allogeneic hematopoietic stem cell transplantation in patients with aplastic anemia.

    Science.gov (United States)

    Wu, Liangliang; Mo, Wenjian; Zhang, Yuping; Zhou, Ming; Li, Yumiao; Zhou, Ruiqing; Xu, Shiling; Pan, Shiyi; Deng, Hui; Mao, Ping; Wang, Shunqing

    2017-07-01

    Bone marrow (BM) niches, including the osteoblastic, vascular, and perivascular niches, are numerically impaired in patients with aplastic anemia (AA). It remains unclear whether these niches are numerically restored in AA patients after allogenic hematopoietic stem cell transplantation (allo-HSCT). To investigate changes in BM niches, we monitored 52 patients with AA who had undergone allo-HSCT and performed immunohistochemical studies of BM niches using antibodies against CD34, CD146, and osteopontin. After allo-HSCT, patients with AA exhibited a remarkable increase in the number of cellular elements in the BM niches, including the vascular and perivascular cells. However, no significant differences in endosteal cells were detected. We explored the cause of this restoration by analyzing the origin of BM mesenchymal stem cells (BM-MSCs) and the expression of cytokines in BM plasma. STR-PCR revealed that the BM-MSCs were derived from the host, not the donor. In addition, significantly elevated levels of vascular endothelial growth factor (VEGF) were found after allo-HSCT. Our data indicates that vascular and perivascular niches are numerically restored, but the endosteal niche remains numerically impaired in patients with AA after allo-HSCT, and that levels of VEGF, but not donor-derived BM-MSCs, may correlate with the restoration of BM niches.

  12. The HysNiche trial: hysteroscopic resection of uterine caesarean scar defect (niche) in patients with abnormal bleeding, a randomised controlled trial

    NARCIS (Netherlands)

    Vervoort, A. J. M. W.; van der Voet, L. F.; Witmer, M.; Thurkow, A. L.; Radder, C. M.; van Kesteren, P. J. M.; Quartero, H. W. P.; Kuchenbecker, W. K. H.; Bongers, M. Y.; Geomini, P. M. A. J.; de Vleeschouwer, L. H. M.; van Hooff, M. H. A.; van Vliet, H. A. A. M.; Veersema, S.; Renes, W. B.; van Meurs, H. S.; Bosmans, J.; Oude Rengerink, K.; Brölmann, H. A. M.; Mol, B. W. J.; Huirne, J. A. F.

    2015-01-01

    A caesarean section (CS) can cause a defect or disruption of the myometrium at the site of the uterine scar, called a niche. In recent years, an association between a niche and postmenstrual spotting after a CS has been demonstrated. Hysteroscopic resection of these niches is thought to reduce

  13. Atmospherics, the marketing concept, and a marketing tool for hospitals.

    Science.gov (United States)

    Fugate, D L

    1991-01-01

    Researchers have demonstrated that the conscious use of atmospheric structuring can induce marketer-desired behaviors in service consumers. This may be particularly relevant to marketers of hospital care since consumer judgments often depend upon peripheral rather than core evidences of quality and satisfaction. Under these circumstances, health care marketers have an obligation to explore the phenomenon of atmospherics and its practical implications in the health care marketing mix.

  14. The Energy Markets of the APEC Countries: Opportunities for Russia

    Directory of Open Access Journals (Sweden)

    Olga Valeryevna Dyomina

    2012-09-01

    Full Text Available The article evaluates the export possibilities of Russian energy resources to the markets of the APEC countries. The analysis is made with the help of the IEA Model of short-term energy security (MOSES Primary Energy Sources and Secondary Fuels. This model addresses four dimensions of energy security. These include external and domestic factors, reflecting both risk exposure and resilience, the ability of energy systems to adapt to or withstand disruptions. In MOSES countries with similar characteristics are grouped in the energy profiles (from A to E by each energy resource. Countries with profiles from B to E present potential markets for Russian energy resources, while countries with the profile A are our competitors. The most promising market of energy resources is China, but for Russia it is likely to become a monopsony market. The authors assume that Russia will retain its position with respect to the concluded long-term contracts for energy resources supply, but expectations about the formation of a large market niche are overestimated. The study concludes that Russia can strengthen its competitive positions due to the launch of complete products on the markets of the APEC countries, especially, due to the creation of new market niches on the basis of technological leadership

  15. Diet and trophic niche of Lithobates catesbeianus (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Peterson T. Leivas

    2012-10-01

    Full Text Available Lithobates catesbeianus (Shaw, 1802 is an invasive anuran introduced in Brazil that is associated with the displacement and the decline of populations of native species worldwide. There is evidence that biological invasions are facilitated by certain attributes of the invading species, for instance niche breath, and that invasive species have a broader ecological niche with respect to native ones. We designed a study to ascertain the temporal, ontogenetic, and sex differences in the niche dynamics of the American bullfrog. We sampled monthly from June 2008 to May 2009 in the state of Paraná, southern Brazil. For each individual, we gathered biometric and stomach content data. We then estimated the niche breath of the juveniles and adults, and compared it between the sexes. A total of 104 females and 77 males were sampled. Lithobates catesbeianus has a generalist diet, preying upon invertebrates and vertebrates. Even though the diet of the studied population varied seasonally, it did not differ between the sexes nor did it respond to biometric variables. Niche breadth was more restricted in the winter than in the autumn. The trophic niche of juveniles and adults did not overlap much when compared with the trophic niche overlap between males and females. Adult males and females had a considerable niche overlap, but females had a broader trophic niche than males in the winter and in the spring. These niche characteristics point to an opportunistic predation strategy that may have facilitated the process of invasion and establishment of this species in the study area.

  16. An Exploratory Research Regarding Romanian Market for Halal Food

    Directory of Open Access Journals (Sweden)

    Valentin-Cosmin SARACIN

    2014-06-01

    Full Text Available The changes in the social structure, the economic crisis, the ageing of the population had an important role in the development of Romania. As a result, Romania must identify other segments and industries in order to rejuvenate the economy of the country. This study focuses on a market niche represented by Halal food products, which are underdeveloped in Romania at this moment. It may represent a potential catalyst for the development of other latent sectors and may consolidate the bilateral relations with the Muslim countries, in conformity with the globalization and the internalization of the global market. The research method used in this study is the thorough analysis of numerous scientific articles and a literature review. It focuses both on the past and the current state of Halal food products and how the development of this market niche can lead to the expansion of other sectors, such as tourism and education.

  17. Ecological and evolutionary consequences of niche construction for its agent.

    Science.gov (United States)

    Kylafis, Grigoris; Loreau, Michel

    2008-10-01

    Niche construction can generate ecological and evolutionary feedbacks that have been underinvestigated so far. We present an eco-evolutionary model that incorporates the process of niche construction to reveal its effects on the ecology and evolution of the niche-constructing agent. We consider a simple plant-soil nutrient ecosystem in which plants have the ability to increase the input of inorganic nutrient as an example of positive niche construction. On an ecological time scale, the model shows that niche construction allows the persistence of plants under infertile soil conditions that would otherwise lead to their extinction. This expansion of plants' niche, however, requires a high enough rate of niche construction and a high enough initial plant biomass to fuel the positive ecological feedback between plants and their soil environment. On an evolutionary time scale, we consider that the rates of niche construction and nutrient uptake coevolve in plants while a trade-off constrains their values. Different evolutionary outcomes are possible depending on the shape of the trade-off. We show that niche construction results in an evolutionary feedback between plants and their soil environment such that plants partially regulate soil nutrient content. The direct benefit accruing to plants, however, plays a crucial role in the evolutionary advantage of niche construction.

  18. THE GERMLINE STEM CELL NICHE UNIT IN MAMMALIAN TESTES

    Science.gov (United States)

    Oatley, Jon M.; Brinster, Ralph L.

    2014-01-01

    This review addresses current understanding of the germline stem cell niche unit in mammalian testes. Spermatogenesis is a classic model of tissue-specific stem cell function relying on self-renewal and differentiation of spermatogonial stem cells (SSCs). These fate decisions are influenced by a niche microenvironment composed of a growth factor milieu that is provided by several testis somatic support cell populations. Investigations over the last two decades have identified key determinants of the SSC niche including cytokines that regulate SSC functions and support cells providing these factors, adhesion molecules that influence SSC homing, and developmental heterogeneity of the niche during postnatal aging. Emerging evidence suggests that Sertoli cells are a key support cell population influencing the formation and function of niches by secreting soluble factors and possibly orchestrating contributions of other support cells. Investigations with mice have shown that niche influence on SSC proliferation differs during early postnatal development and adulthood. Moreover, there is mounting evidence of an age-related decline in niche function, which is likely influenced by systemic factors. Defining the attributes of stem cell niches is key to developing methods to utilize these cells for regenerative medicine. The SSC population and associated niche comprise a valuable model system for study that provides fundamental knowledge about the biology of tissue-specific stem cells and their capacity to sustain homeostasis of regenerating tissue lineages. While the stem cell is essential for maintenance of all self-renewing tissues and has received considerable attention, the role of niche cells is at least as important and may prove to be more receptive to modification in regenerative medicine. PMID:22535892

  19. Primer and interviews: The dynamic stem cell niche.

    Science.gov (United States)

    Kiefer, Julie C

    2011-03-01

    A stem cell niche is a microenvironment that supports self-renewal of a population of stem cells, and their production of differentiated cells. While the definition evokes images of a stem cell Shangri-La-where a serene stem cell pool nestles within a niche that shelters and sustains it-the reality is much more tumultuous. Niches are subject to an ever-changing maelstrom of environmental factors, the ravages of old age, and the sly tactics of disease. Presented here is a basic overview of the different ways in which stem cell niches respond to local and systemic environments, and their impact on stem cell behavior. The primer culminates with a discussion of the topic with stem cell and niche biologists D. Leanne Jones, Ph.D., and Tudorita Tumbar, Ph.D. Copyright © 2011 Wiley-Liss, Inc.

  20. The crosstalk between hematopoietic stem cells and their niches.

    Science.gov (United States)

    Durand, Charles; Charbord, Pierre; Jaffredo, Thierry

    2018-07-01

    Hematopoietic stem cells (HSCs) reside in specific microenvironments also called niches that regulate HSC functions. Understanding the molecular and cellular mechanisms involved in the crosstalk between HSCs and niche cells is a major issue in stem cell biology and regenerative medicine. The purpose of this review is to discuss recent advances in this field with particular emphasis on the transcriptional landscape of HSC niche cells and the roles of extracellular vesicles (EVs) in the dialog between HSCs and their microenvironments. The development of high-throughput technologies combined with computational methods has considerably improved our knowledge on the molecular identity of HSC niche cells. Accumulating evidence strongly suggest that the dialog between HSCs and their niches is bidirectional and that EVs play an important role in this process. These advances bring a unique conceptual and methodological framework for understanding the molecular complexity of the HSC niche and identifying novel HSC regulators. They are also promising for exploring the reciprocal influence of HSCs on niche cells and delivering specific molecules to HSCs in regenerative medicine.

  1. Astrocitary niches in human adult medulla oblongata.

    Science.gov (United States)

    Rusu, Mugurel Constantin; Dermengiu, Dan; Loreto, Carla; Motoc, Andrei Gheorghe Marius; Pop, Elena

    2013-04-01

    Astrocytes are considered as neuromodulators of the CNS. Whereas experimental studies on astrocitary functions are gaining importance, the anatomy of the astrocitary niches in the human CNS has been overlooked. The study was performed on the brainstem of 10 adult cadavers. We aimed to determine astrocitary niches in the human medulla oblongata using immunohistochemical labeling with vimentin and also CD34 immunostaining to accurately diagnose associated microvessels. Niches rich in astrocytes were identified as follows: (a) the superficial layer of astrocytes, ventral and ventrolateral, in the rostral medulla oblongata; (b) the median raphe; (c) medullary nuclei: arcuate nucleus, area postrema, nucleus of the solitary tract; (d) the subependymal zone (SEZ, caudal medulla) and subventricular zone (SVZ, rostral medulla). Astrocytes were scarce in the ventrolateral medulla, and mostly present within the pyramidal tract and the olivary nucleus. Apart from the SEZ and SVZ, the brainstem niches of astrocytes mostly overlap those regions known to perform roles as central respiratory chemoreceptors. The astrocytes of the SEZ and SVZ, which are known as stem cell niches, are related to an increased microvascular density. Copyright © 2012 Elsevier GmbH. All rights reserved.

  2. Glioblastoma niches: from the concept to the phenotypical reality.

    Science.gov (United States)

    Schiffer, Davide; Mellai, Marta; Bovio, Enrica; Bisogno, Ilaria; Casalone, Cristina; Annovazzi, Laura

    2018-05-08

    Recently, the concept of niches as sites of tumor progression, invasion, and angiogenesis in glioblastoma (GB) has been extensively debated. Niches, considered the sites in which glioblastoma stem cells (GSCs) reside, have been classified as perivascular, perinecrotic, and invasive. However, from a neuropathological point of view, it is not easy to establish when a tumor structure can be considered a niche. The relevant literature has been reviewed in the light of our recent experience on the subject. As for perinecrotic niches, the occurrence of GSCs around necrosis is interpreted as triggered by hypoxia through HIF-1α. Our alternative hypothesis is that, together with progenitors, they are the cell constituents of hyper-proliferative areas of GB, where perinecrotic niches have developed, and they would, therefore, represent the remnants of GSCs/progenitors spared by the developing necrosis. Perivascular structures originate from both transport vessels and exchange vessels, i.e., venules, arterioles, or the undefinable neo-formed small vessels, but only those in which a direct contact between GSCs/progenitors and endothelial cells occurs can be called niches. Both pericytes and microglia/macrophages play a role in niche function: Macrophages of blood origin invade GB only after the appearance of "mother vessels" with consequent blood-brain barrier disruption. Not all vessel/tumor cell structures can be considered niches, that is, crucial sites of tumor progression, invasion, and angiogenesis.

  3. Habitat niche breadth predicts invasiveness in solitary ascidians.

    Science.gov (United States)

    Granot, Itai; Shenkar, Noa; Belmaker, Jonathan

    2017-10-01

    A major focus of invasion biology is understanding the traits associated with introduction success. Most studies assess these traits in the invaded region, while only few compare nonindigenous species to the pool of potential invaders in their native region. We focused on the niche breadth hypothesis , commonly evoked but seldom tested, which states that generalist species are more likely to become introduced as they are capable of thriving under a wide set of conditions. Based on the massive introduction of tropical species into the Mediterranean via the Suez Canal (Lessepsian migration), we defined ascidians in the Red Sea as the pool of potential invaders. We constructed unique settlement plates, each representing six different niches, to assess ascidian niche breadth, and deployed them in similar habitats in the native and invaded regions. For each species found on plates, we evaluated its abundance, relative abundance across successional stages, and niche breadth, and then compared (1) species in the Red Sea known to have been introduced into the Mediterranean (Lessepsian species) and those not known from the Mediterranean (non-Lessepsian); and (2) nonindigenous and indigenous species in the Mediterranean. Lessepsian species identified on plates in the Red Sea demonstrated wider niche breadth than non-Lessepsian species, supporting the niche breadth hypothesis within the native region. No differences were found between Lessepsian and non-Lessepsian species in species abundance and successional stages. In the Mediterranean, nonindigenous species numerically dominated the settlement plates. This precluded robust comparisons of niche breadth between nonindigenous and indigenous species in the invaded region. In conclusion, using Red Sea ascidians as the pool of potential invaders, we found clear evidence supporting the niche breadth hypothesis in the native region. We suggest that such patterns may often be obscured when conducting trait-based studies in the

  4. Niche conservatism and the invasive potential of the wild boar.

    Science.gov (United States)

    Sales, Lilian Patrícia; Ribeiro, Bruno R; Hayward, Matt Warrington; Paglia, Adriano; Passamani, Marcelo; Loyola, Rafael

    2017-09-01

    Niche conservatism, i.e. the retention of a species' fundamental niche through evolutionary time, is cornerstone for biological invasion assessments. The fact that species tend to maintain their original climate niche allows predictive maps of invasion risk to anticipate potential invadable areas. Unravelling the mechanisms driving niche shifts can shed light on the management of invasive species. Here, we assessed niche shifts in one of the world's worst invasive species: the wild boar Sus scrofa. We also predicted potential invadable areas based on an ensemble of three ecological niche modelling methods, and evaluated the performance of models calibrated with native vs. pooled (native plus invaded) species records. By disentangling the drivers of change on the exotic wild boar population's niches, we found strong evidence for niche conservatism during biological invasion. Ecological niche models calibrated with both native and pooled range records predicted convergent areas. Also, observed niche shifts are mostly explained by niche unfilling, i.e. there are unoccupied areas in the exotic range where climate is analogous to the native range. Niche unfilling is expected as result of recent colonization and ongoing dispersal, and was potentially stronger for the Neotropics, where a recent wave of introductions for pig-farming and game-hunting has led to high wild boar population growth rates. The invasive potential of wild boar in the Neotropics is probably higher than in other regions, which has profound management implications if we are to prevent their invasion into species-rich areas, such as Amazonia, coupled with expansion of African swine fever and possibly great economic losses. Although the originally Eurasian-wide distribution suggests a pre-adaptation to a wide array of climates, the wild boar world-wide invasion does not exhibit evidence of niche evolution. The invasive potential of the wild boar therefore probably lies on the reproductive, dietary and

  5. Ecological niches of open ocean phytoplankton taxa

    DEFF Research Database (Denmark)

    Brun, Philipp Georg; Vogt, Meike; Payne, Mark

    2015-01-01

    We characterize the realized ecological niches of 133 phytoplankton taxa in the open ocean based on observations from the MAREDAT initiative and a statistical species distribution model (MaxEnt). The models find that the physical conditions (mixed layer depth, temperature, light) govern large...... conditions in the open ocean. Our estimates of the realized niches roughly match the predictions of Reynolds' C-S-R model for the global ocean, namely that taxa classified as nutrient stress tolerant have niches at lower nutrient and higher irradiance conditions than light stress tolerant taxa. Yet...

  6. Stem cell autotomy and niche interaction in different systems.

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-07-26

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  7. Stem cell autotomy and niche interaction in different systems

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-01-01

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  8. Cellular population dynamics control the robustness of the stem cell niche

    Directory of Open Access Journals (Sweden)

    Adam L. MacLean

    2015-11-01

    Full Text Available Within populations of cells, fate decisions are controlled by an indeterminate combination of cell-intrinsic and cell-extrinsic factors. In the case of stem cells, the stem cell niche is believed to maintain ‘stemness’ through communication and interactions between the stem cells and one or more other cell-types that contribute to the niche conditions. To investigate the robustness of cell fate decisions in the stem cell hierarchy and the role that the niche plays, we introduce simple mathematical models of stem and progenitor cells, their progeny and their interplay in the niche. These models capture the fundamental processes of proliferation and differentiation and allow us to consider alternative possibilities regarding how niche-mediated signalling feedback regulates the niche dynamics. Generalised stability analysis of these stem cell niche systems enables us to describe the stability properties of each model. We find that although the number of feasible states depends on the model, their probabilities of stability in general do not: stem cell–niche models are stable across a wide range of parameters. We demonstrate that niche-mediated feedback increases the number of stable steady states, and show how distinct cell states have distinct branching characteristics. The ecological feedback and interactions mediated by the stem cell niche thus lend (surprisingly high levels of robustness to the stem and progenitor cell population dynamics. Furthermore, cell–cell interactions are sufficient for populations of stem cells and their progeny to achieve stability and maintain homeostasis. We show that the robustness of the niche – and hence of the stem cell pool in the niche – depends only weakly, if at all, on the complexity of the niche make-up: simple as well as complicated niche systems are capable of supporting robust and stable stem cell dynamics.

  9. Ten Niche Strategies To Commercialize New High-Tech Products

    NARCIS (Netherlands)

    Ortt, J.R.; Langley, D.J.; Pals, N.

    2013-01-01

    There are serious gaps in the scientific literature relating to niche strategies as a means for commercializing new high-tech products. In particular, there is no clarity about what types of niche strategies can be distinguished, or how a niche strategy can be selected to suit a certain ituation. In

  10. Lambayeque Region marketing: Improving Incoming Tourism

    Directory of Open Access Journals (Sweden)

    Roger Pingo Jara

    2012-12-01

    Full Text Available Up to now, the marketing of the Lambayeque region as a tourist destination has been able to make important progress in the growth of domestic tourists flow. 40% of these tourists come from the capital, mostly they arrive in this region, mainly for business reasons. However, little progress is shown in relation to Incoming tourism, because from 100% of visitors who arrive to this touristic destination only 5% are of foreign origin.Furthermore, in 2011, from the total foreign tourists that visited the Moche Route - La Libertad region and Lambayeque region, 70% remained in the first one and only 30% visited both regions, completing the touristic circuit. The recommendations of the teachers of the Universidad del Pacífico, Universidad Esan and Centrum Católica, who have been interviewed are compared with the businessmen’s opinions in the region, showing the importance of targeting the tourism marketing strategy. Thus, it seeks to create value in different niches of the source markets, to prioritize potential tourists from brotherly countries, to link emotionally the tourist with the city, to build brands for each touristic product, to invest in highly specialized tourism and to improve significantly the clusters organization of the tourism sector in the region.We conclude that, in the region of Lambayeque, isolated efforts have been made regarding the incoming marketing, but, according to the needs, tastes and preferences of the potential tourist, this does not fulfill the international standards. This is demonstrated by the results achieved up to now—in terms of the foreign visitors’ number—. To that extent, It emphasizes the importance of the design and the implementation of a marketing plan connected with market reality.It should profit from the national brand and develop regional and local brand based on the international touristic demand-supply relation to market niches.

  11. Emergence of Cooperative Long-Term Market Loyalty in Double Auction Markets.

    Science.gov (United States)

    Alorić, Aleksandra; Sollich, Peter; McBurney, Peter; Galla, Tobias

    2016-01-01

    Loyal buyer-seller relationships can arise by design, e.g. when a seller tailors a product to a specific market niche to accomplish the best possible returns, and buyers respond to the dedicated efforts the seller makes to meet their needs. We ask whether it is possible, instead, for loyalty to arise spontaneously, and in particular as a consequence of repeated interaction and co-adaptation among the agents in a market. We devise a stylized model of double auction markets and adaptive traders that incorporates these features. Traders choose where to trade (which market) and how to trade (to buy or to sell) based on their previous experience. We find that when the typical scale of market returns (or, at fixed scale of returns, the intensity of choice) become higher than some threshold, the preferred state of the system is segregated: both buyers and sellers are segmented into subgroups that are persistently loyal to one market over another. We characterize the segregated state analytically in the limit of large markets: it is stabilized by some agents acting cooperatively to enable trade, and provides higher rewards than its unsegregated counterpart both for individual traders and the population as a whole.

  12. Niche conservatism in Gynandropaa frogs on the southeastern Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Hu, Junhua; Broennimann, Olivier; Guisan, Antoine; Wang, Bin; Huang, Yan; Jiang, Jianping

    2016-09-07

    The role of ecological niche in lineage diversification has been the subject of long-standing interest of ecologists and evolutionary biologists. Gynandropaa frogs diversified into three independent clades endemic to the southeastern Qinghai-Tibetan Plateau. Here, we address the question whether these clades kept the same niche after separation, and what it tells us about possible diversification processes. We applied predictions in geographical (G)-space and tests of niche conservatism in environmental (E)-space. Niche models in G-space indicate separate regions with high suitability for the different clades, with some potential areas of sympatry. While the pair of central and eastern clades displayed the largest niche overlap for most variables, and strict niche equivalency was rejected for all clade-pairs, we found no strong evidence for niche divergence, but rather the signature of niche conservatism compared to null models in E-space. These results suggest a common ancestral ecological niche, and as such give good support to divergence through allopatric speciation, but alternative explanations are also possible. Our findings illustrate how testing for niche conservatism in lineage diversification can provide insights into underlying speciation processes, and how this information may guide further research and conservation practices, as illustrated here for amphibians on the Qinghai-Tibetan Plateau.

  13. Exosomes as novel regulators of adult neurogenic niches

    Directory of Open Access Journals (Sweden)

    Luis Federico Batiz

    2016-01-01

    Full Text Available Adult neurogenesis has been convincingly demonstrated in two regions of the mammalian brain: the sub-granular zone (SGZ of the dentate gyrus (DG in the hippocampus, and the sub-ventricular zone (SVZ of the lateral ventricles. SGZ newborn neurons are destined to the granular cell layer of the DG, while new neurons from the SVZ neurons migrate rostrally into the olfactory bulb. The process of adult neurogenesis persists throughout life and is supported by a pool of neural stem cells (NSCs, which reside in a unique and specialized microenvironment known as neurogenic niche. Neurogenic niches are structured by a complex organization of different cell types, including the NSC-neuron lineage, glial cells and vascular cells. Thus, cell-to-cell communication plays a key role in the dynamic modulation of homeostasis and plasticity of the adult neurogenic process. Specific cell-cell contacts and extracellular signals originated locally provide the necessary support and regulate the balance between self-renewal and differentiation of NSCs. Furthermore, extracellular signals originated at distant locations, including other brain regions or systemic organs, may reach the niche through the cerebrospinal fluid or the vasculature and influence its nature. The role of several secreted molecules, such as cytokines, growth factors, neurotransmitters, and hormones, in the biology of adult NSCs, has been systematically addressed. Interestingly, in addition to these well-recognized signals, a novel type of intercellular messengers has been identified recently: the extracellular vesicles (EVs. EVs, and particularly exosomes, are implicated in the transfer of mRNAs, microRNAs (miRNAs, proteins and lipids between cells and thus are able to modify the function of recipient cells. Exosomes appear to play a significant role in different stem cell niches such as the mesenchymal stem cell niche, cancer stem cell niche and pre-metastatic niche; however, their roles in adult

  14. Building an International Student Market: Educational-Balanced Scorecard Solutions for Regional Australian Cities

    Science.gov (United States)

    Forbes, Linda; Hamilton, John

    2004-01-01

    There is an international student market suitable for regional Australia, but each region is different. Hence, each region must determine, target and niche market to its best potential international student customer base. For international education there remains scant, relevant, data for regional Australia, hence complete regional approaches to…

  15. Niche construction, sources of selection and trait coevolution.

    Science.gov (United States)

    Laland, Kevin; Odling-Smee, John; Endler, John

    2017-10-06

    Organisms modify and choose components of their local environments. This 'niche construction' can alter ecological processes, modify natural selection and contribute to inheritance through ecological legacies. Here, we propose that niche construction initiates and modifies the selection directly affecting the constructor, and on other species, in an orderly, directed and sustained manner. By dependably generating specific environmental states, niche construction co-directs adaptive evolution by imposing a consistent statistical bias on selection. We illustrate how niche construction can generate this evolutionary bias by comparing it with artificial selection. We suggest that it occupies the middle ground between artificial and natural selection. We show how the perspective leads to testable predictions related to: (i) reduced variance in measures of responses to natural selection in the wild; (ii) multiple trait coevolution, including the evolution of sequences of traits and patterns of parallel evolution; and (iii) a positive association between niche construction and biodiversity. More generally, we submit that evolutionary biology would benefit from greater attention to the diverse properties of all sources of selection.

  16. Ecological niche transferability using invasive species as a case study.

    Directory of Open Access Journals (Sweden)

    Miguel Fernández

    Full Text Available Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.

  17. Target Article with Commentaries: Developmental Niche Construction

    Science.gov (United States)

    Flynn, Emma G.; Laland, Kevin N.; Kendal, Rachel L.; Kendal, Jeremy R.

    2013-01-01

    Niche construction is the modification of components of the environment through an organism's activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this paper we aim to facilitate…

  18. College Access Marketing

    Science.gov (United States)

    Tremblay, Christopher W.

    2011-01-01

    College Access Marketing (CAM) is a relatively new phenomenon that seeks to positively influence the college-going rate. This report defines CAM, describes CAM examples, and discusses how CAM seeks to counter barriers to college. It explores four main elements of CAM: information, marketing, advocacy, and social mobilization. Further, it…

  19. Market Analysis, Opportunity Recognition and Strategy Diagnosis in Toy Industry

    DEFF Research Database (Denmark)

    Khajeheian, Datis

    2018-01-01

    According to many market researches and industrial reports Iran is one of the biggest toy markets in the Middle East and North Africa region. The Iranian toy market has been identified as a niche market with lots of unexploited opportunities. Nonetheless, the Iranian toy industry has shown...... for this misdirection were that the Iranian toy industry lacked a traditional structure, a strategic perspective and also absence of international cooperation. This research suggests that the Iranian toy industries need to move its focus from manufacturing, where the country has no competitive advantage, toward toy...

  20. Sustainable marketing communication strategies of Russian companies under the import substitution policy

    OpenAIRE

    Chernova, Veronika,; Zobov, Alexander,; Starostin, Vasily,; Butkovskaya, Galina,

    2017-01-01

    International audience; The sanction standoff between Russia and the West opened up new opportunities for Russian food manufacturers. A new import substitution policy declared by the government restricted the access of the leading foreign countries to the market and unlocked a potential for internal development. Russian producers spotted new niches in the food market. There exist numerous obstacles to assimilating new market prospects: organizational (logistics, infrastructure, etc.), investm...

  1. Market survey of fuel cells in Mexico: Niche for low power portable systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Salgado, Joel [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas No 152, 07730 D. F. (Mexico); Dominguez-Aguilar, Marco A. [Laboratorio de Sintesis Quimica y Electroquimica, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas No 152, 07730 D. F. (Mexico)

    2009-01-15

    This work provides an overview of the potential market in Mexico for portable electronic devices to be potentially powered by direct methanol fuel cells. An extrapolation method based on data published in Mexico and abroad served to complete this market survey. A review of electronics consumption set the basis for the future forecast and technology assimilation. The potential market for fuel cells for mobile phones in Mexico will be around 5.5 billion USD by 2013, considering a cost of 41 USD per cell in a market of 135 million mobile phones. Likewise, the market for notebook computers, PDAs and other electronic devices will likely grow in the future, with a combined consumption of fuel cell technology equivalent to 1.6 billion USD by 2014. (author)

  2. Market survey of fuel cells in Mexico: Niche for low power portable systems

    Science.gov (United States)

    Ramírez-Salgado, Joel; Domínguez-Aguilar, Marco A.

    This work provides an overview of the potential market in Mexico for portable electronic devices to be potentially powered by direct methanol fuel cells. An extrapolation method based on data published in Mexico and abroad served to complete this market survey. A review of electronics consumption set the basis for the future forecast and technology assimilation. The potential market for fuel cells for mobile phones in Mexico will be around 5.5 billion USD by 2013, considering a cost of 41 USD per cell in a market of 135 million mobile phones. Likewise, the market for notebook computers, PDAs and other electronic devices will likely grow in the future, with a combined consumption of fuel cell technology equivalent to 1.6 billion USD by 2014.

  3. Chironomidae larvae (Diptera) of Neotropical floodplain: overlap niche in different habitats.

    Science.gov (United States)

    Butakka, C M M; Ragonha, F H; Takeda, A M

    2014-05-01

    The niche overlap between trophic groups of Chironomidae larvae in different habitats was observed between trophic groups and between different environments in Neotropical floodplain. For the evaluation we used the index of niche overlap (CXY) and analysis of trophic networks, both from the types and amount of food items identified in the larval alimentary canal. In all environments, the larvae fed on mainly organic matter such as plants fragments and algae, but there were many omnivore larvae. Species that have high values of food items occurred in diverse environments as generalists with great overlap niche and those with a low amount of food items with less overlap niche were classified as specialists. The largest number of trophic niche overlap was observed among collector-gatherers in connected floodplain lakes. The lower values of index niche overlap were predators. The similarity in the diet of different taxa in the same niche does not necessarily imply competition between them, but coexistence when the food resource is not scarce in the environment even in partially overlapping niches.

  4. Evolution of climatic niche specialization: a phylogenetic analysis in amphibians.

    Science.gov (United States)

    Bonetti, Maria Fernanda; Wiens, John J

    2014-11-22

    The evolution of climatic niche specialization has important implications for many topics in ecology, evolution and conservation. The climatic niche reflects the set of temperature and precipitation conditions where a species can occur. Thus, specialization to a limited set of climatic conditions can be important for understanding patterns of biogeography, species richness, community structure, allopatric speciation, spread of invasive species and responses to climate change. Nevertheless, the factors that determine climatic niche width (level of specialization) remain poorly explored. Here, we test whether species that occur in more extreme climates are more highly specialized for those conditions, and whether there are trade-offs between niche widths on different climatic niche axes (e.g. do species that tolerate a broad range of temperatures tolerate only a limited range of precipitation regimes?). We test these hypotheses in amphibians, using phylogenetic comparative methods and global-scale datasets, including 2712 species with both climatic and phylogenetic data. Our results do not support either hypothesis. Rather than finding narrower niches in more extreme environments, niches tend to be narrower on one end of a climatic gradient but wider on the other. We also find that temperature and precipitation niche breadths are positively related, rather than showing trade-offs. Finally, our results suggest that most amphibian species occur in relatively warm and dry environments and have relatively narrow climatic niche widths on both of these axes. Thus, they may be especially imperilled by anthropogenic climate change. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  5. Role of Financial Information in Emerging Capital Markets ...

    African Journals Online (AJOL)

    ... "discriminate" analysis between good and bad performance companies. In a world of advance information technology (IT), use of electronic data processing naturally provides a competitive niche in the instantaneous business decision making process in stock markets. African Journal of Finance and Management Vol.7(2) ...

  6. Case management and quality: have we reached a tipping point?

    Science.gov (United States)

    Dulworth, Sherrie

    2006-01-01

    In The Tipping Point, Malcolm Gladwell describes a phenomenon in which a niche market or fad undergoes transformation into mainstream acceptability, resulting in widespread social change. He concludes that a "tipping point" occurs when a series of small events results in a critical mass of acceptance that produces sudden major changes.

  7. Market survey Hungary. Bio-energy

    International Nuclear Information System (INIS)

    2008-01-01

    Basic characteristics of the market for bioenergy (biomass, biogas and biofuels) in Hungary and consequences for business environment are summarized, based on a SWOT analysis. RES is the priority issue to which a lot of attention is paid both at governmental and private level; private investors should view RES as a new niche for their business activities. Standard approach based on a thoroughly done preparation of the project in terms of profitability and risk assessment is necessary in order to avoid potential financial losses due to changed market conditions or differences between assumptions and business reality. Some recommendations for entry on the Hungarian bio energy market are presented: (1) Generally, look for success stories in the Netherlands first and then look for places where such proved and time-tested technologies could be used in Hungary with respect to local specifics. In such way, you can find market niches where investment can be made or new products can be launched; (2) For retail selling it is appropriate to establish business contacts with existing dealers and associations and offer own products through their distribution network. This scheme has the advantage of low initial costs as well as risks involved; (3) In the case of large investments into equipment complexes using RES it seems more appropriate to refer directly either to municipal authorities on whose cadastre the investment should take place or to specialized consultancy agencies that can support the plan with additional information on legal requirements, national programmes supporting RES or available technology. Of course, direct collaboration with well-established local partner can be beneficial for both sides too; (4) If you want to receive up-to-date information on particular aspects of the biomass market in Hungary, you can refer to some governmental organisations associations referred in the key contact addresses

  8. Approaches to a marketing strategy for the development and penetration of the PV market in German speaking countries. Ansaetze einer Marketingstrategie zur Erschliessung und Durchdringung des PV-Marktes in den deutschsprachigen Laendern

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, F. (SOTEC - Ingenieurbuero fuer Sonnenenergie, Duesseldorf (Germany, F.R.))

    1990-01-01

    The photovoltaics market in Central Europe is characterized by the fact that a consolidation has been achieved in niche markets only. The main emphasis in this field of energy supply has been on technological progress; however, it needs to be supported by a serious marketing policy in the future. Based on an analysis of today's situation, both strategie and operative considerations for a marketing concept are demonstrated for a constitution of the PV market in Central Europe. (orig.).

  9. Emergence of Cooperative Long-Term Market Loyalty in Double Auction Markets

    Science.gov (United States)

    Alorić, Aleksandra; Sollich, Peter; McBurney, Peter; Galla, Tobias

    2016-01-01

    Loyal buyer-seller relationships can arise by design, e.g. when a seller tailors a product to a specific market niche to accomplish the best possible returns, and buyers respond to the dedicated efforts the seller makes to meet their needs. We ask whether it is possible, instead, for loyalty to arise spontaneously, and in particular as a consequence of repeated interaction and co-adaptation among the agents in a market. We devise a stylized model of double auction markets and adaptive traders that incorporates these features. Traders choose where to trade (which market) and how to trade (to buy or to sell) based on their previous experience. We find that when the typical scale of market returns (or, at fixed scale of returns, the intensity of choice) become higher than some threshold, the preferred state of the system is segregated: both buyers and sellers are segmented into subgroups that are persistently loyal to one market over another. We characterize the segregated state analytically in the limit of large markets: it is stabilized by some agents acting cooperatively to enable trade, and provides higher rewards than its unsegregated counterpart both for individual traders and the population as a whole. PMID:27120473

  10. Content Marketing Practices in Finland

    OpenAIRE

    Suuronen, Toni

    2016-01-01

    The purpose of this study is to draw attention to increasingly important business phenomenon of content marketing. This paper defines content marketing, identifies its key elements and phases, and explores content marketing practices. The theorethical part is based on Pam Didner's 4P model that describes the stages of content marketing cycle: plan, produce, promote and perfect. The empirical part of the study is based on semi-structured interviews of seasoned content marketing professionals t...

  11. Niche construction drives social dependence in hermit crabs.

    Science.gov (United States)

    Laidre, Mark E

    2012-10-23

    Organisms can receive not only a genetic inheritance from their ancestors but also an ecological inheritance, involving modifications their ancestors made to the environment through niche construction. Ecological inheritances may persist as a legacy, potentially generating selection pressures that favor sociality. Yet, most proposed cases of sociality being impacted by an ecological inheritance come from organisms that live among close kin and were highly social before their niche construction began. Here, I show that in terrestrial hermit crabs (Coenobita compressus)--organisms that do not live with kin and reside alone, each in its own shell--niche-construction drives social dependence, such that individuals can only survive in remodeled shells handed down from conspecifics. These results suggest that niche construction can be an important initiator of evolutionary pressures to socialize, even among unrelated and otherwise asocial organisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Stem cell dynamics in the hair follicle niche

    Science.gov (United States)

    Rompolas, Panteleimon; Greco, Valentina

    2014-01-01

    Hair follicles are skin appendages of the mammalian skin that have the ability to periodically and stereotypically regenerate in order to continuously produce new hair over our lifetime. The ability of the hair follicle to regenerate is due to the presence of stem cells that along with other cell populations and non-cellular components, including molecular signals and extracellular material, make up a niche microenvironment. Mounting evidence suggests that the niche is critical for regulating stem cell behavior and thus the process of regeneration. Here we review the literature concerning past and current studies that have utilized mouse genetic models, combined with other approaches to dissect the molecular and cellular composition of the hair follicle niche. We also discuss our current understanding of how stem cells operate within the niche during the process of tissue regeneration and the factors that regulate their behavior. PMID:24361866

  13. Synergistic selection between ecological niche and mate preference primes diversification.

    Science.gov (United States)

    Boughman, Janette W; Svanbäck, Richard

    2017-01-01

    The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution

  14. Reproductive Interference and Niche Partitioning in Aphidophagous Insects

    Directory of Open Access Journals (Sweden)

    Suzuki Noriyuki

    2016-01-01

    Full Text Available The range and quality of prey species differ greatly among closely related species of predators. However, the factors responsible for this diversified niche utilization are unclear. This is because the predation and resource competition do not always prevent species coexistence. In this paper, we present evidence in support of reproductive interference as a driver of niche partitioning, focusing on aphidophagous insect. Firstly, we present closely related generalist and specialist species pairs in aphidophagous lacewings to compare the reproductive interference hypothesis with two other hypotheses that have been proposed to explain niche partitioning in lacewings and sympatric speciation through host race formation and sexual selection. Secondly, we present a case study that shows how reproductive interference can drive niche partitioning in sibling ladybird species. Thirdly, we show that many ladybird genera include species inhabiting the same region but having different food and habitat preferences, raising the possibility that reproductive interference might occur in these groups. Finally, we show that intraguild predation cannot always explain the niche partitioning in aphidophagous insects including hoverflies and parasitoids. On the basis of the evidence presented, we urge that future studies investigating predator communities should take account of the role of reproductive interference.

  15. Are species' responses to global change predicted by past niche evolution?

    Science.gov (United States)

    Lavergne, Sébastien; Evans, Margaret E. K.; Burfield, Ian J.; Jiguet, Frederic; Thuiller, Wilfried

    2013-01-01

    Predicting how and when adaptive evolution might rescue species from global change, and integrating this process into tools of biodiversity forecasting, has now become an urgent task. Here, we explored whether recent population trends of species can be explained by their past rate of niche evolution, which can be inferred from increasingly available phylogenetic and niche data. We examined the assemblage of 409 European bird species for which estimates of demographic trends between 1970 and 2000 are available, along with a species-level phylogeny and data on climatic, habitat and trophic niches. We found that species' proneness to demographic decline is associated with slow evolution of the habitat niche in the past, in addition to certain current-day life-history and ecological traits. A similar result was found at a higher taxonomic level, where families prone to decline have had a history of slower evolution of climatic and habitat niches. Our results support the view that niche conservatism can prevent some species from coping with environmental change. Thus, linking patterns of past niche evolution and contemporary species dynamics for large species samples may provide insights into how niche evolution may rescue certain lineages in the face of global change. PMID:23209172

  16. Haematopoietic stem cell niches: new insights inspire new questions

    Science.gov (United States)

    Ugarte, Fernando; Forsberg, E Camilla

    2013-01-01

    Haematopoietic stem cell (HSC) niches provide an environment essential for life-long HSC function. Intense investigation of HSC niches both feed off and drive technology development to increase our capability to assay functionally defined cells with high resolution. A major driving force behind the desire to understand the basic biology of HSC niches is the clear implications for clinical therapies. Here, with particular emphasis on cell type-specific deletion of SCL and CXCL12, we focus on unresolved issues on HSC niches, framed around some very recent advances and novel discoveries on the extrinsic regulation of HSC maintenance. We also provide ideas for possible paths forward, some of which are clearly within reach while others will require both novel tools and vision. PMID:24022369

  17. CSU attention focuses on the Asian markets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-15

    European coal terminal operators increasingly select grab cranes over continuous ship loader (CSU) technology, but does the Far East still offer the greatest potential for growth? Siewertell, part of the Cargotec group, has developed something of a niche market with its screw-type CSUs. The article reports recent business by Siwertell and ThyssenKrupp Foerdertechnik (TFK). 2 photos.

  18. Analysis of market development for photovoltaics

    International Nuclear Information System (INIS)

    Gregory, J.A.; Bahaj, A.S.; Stainton, R.S.

    1994-01-01

    The acceptance of any product by the market is dependent upon a multitude of formal and informal mechanisms. These include, among others, the technical merit of the product, its presentation, its perceived image and the user feedback to the market-place. Further growth or diffusion of the product into the market-place is possible if the image and perception are positive. If the product is difficult to use, and/or lacks the information necessary for implementation and operation, it is unlikely that it will sell well. The result is a negative image and slow market growth. Today, photovoltaic (PV) systems are technically appropriate for many applications. However, apart from specific niche markets, the overall market penetration for PV is small when compared to other products of similar developmental history. This paper discusses the market development of PV applications, review some of the promoted scenarios and depicts past experiences with PV systems. In particular, it looks at the market development for PV in the telecommunications and health care sectors

  19. A hypothesis-testing framework for studies investigating ontogenetic niche shifts using stable isotope ratios.

    Directory of Open Access Journals (Sweden)

    Caroline M Hammerschlag-Peyer

    Full Text Available Ontogenetic niche shifts occur across diverse taxonomic groups, and can have critical implications for population dynamics, community structure, and ecosystem function. In this study, we provide a hypothesis-testing framework combining univariate and multivariate analyses to examine ontogenetic niche shifts using stable isotope ratios. This framework is based on three distinct ontogenetic niche shift scenarios, i.e., (1 no niche shift, (2 niche expansion/reduction, and (3 discrete niche shift between size classes. We developed criteria for identifying each scenario, as based on three important resource use characteristics, i.e., niche width, niche position, and niche overlap. We provide an empirical example for each ontogenetic niche shift scenario, illustrating differences in resource use characteristics among different organisms. The present framework provides a foundation for future studies on ontogenetic niche shifts, and also can be applied to examine resource variability among other population sub-groupings (e.g., by sex or phenotype.

  20. Competitor see, competitor do: Incumbent entry in new market niches

    NARCIS (Netherlands)

    Debruyne, M.; Reibstein, D.

    2005-01-01

    The ability to keep up with changing technology is critical for a company's long-term survival. However, companies have to balance the risk of rushing into new areas and potentially cannibalizing their existing business against the risk of missing the emerging market. This paper investigates when

  1. Niche evolution and diversification in a Neotropical radiation of birds (Aves: Furnariidae).

    Science.gov (United States)

    Seeholzer, Glenn F; Claramunt, Santiago; Brumfield, Robb T

    2017-03-01

    Rapid diversification may be caused by ecological adaptive radiation via niche divergence. In this model, speciation is coupled with niche divergence and lineage diversification is predicted to be correlated with rates of niche evolution. Studies of the role of niche evolution in diversification have generally focused on ecomorphological diversification but climatic-niche evolution may also be important. We tested these alternatives using a phylogeny of 298 species of ovenbirds (Aves: Furnariidae). We found that within Furnariidae, variation in species richness and diversification rates of subclades were best predicted by rate of climatic-niche evolution than ecomorphological evolution. Although both are clearly important, univariate regression and multivariate model averaging more consistently supported the climatic-niche as the best predictor of lineage diversification. Our study adds to the growing body of evidence, suggesting that climatic-niche divergence may be an important driver of rapid diversification in addition to ecomorphological evolution. However, this pattern may depend on the phylogenetic scale at which rate heterogeneity is examined. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  2. The evolutionary adoption of thorium beginning with its application in niche LWR fuels

    International Nuclear Information System (INIS)

    Drera, Saleem

    2015-01-01

    Since the inception of nuclear energy, the use of thorium as a nuclear fuel has been envisioned. Thorium boasts benefits, however, drawbacks which are both economic and technical including its the lack of a naturally occurring fissile isotope implies that its utility is inherently more difficult. The implementation of thorium as a nuclear fuel requires that it must provide sound technical advantages in combination with attractive economics as compared to standard uranium fuel. Revolutionary thorium concepts such as molten salt reactors and accelerator driven systems may provide theoretical merit, however, their exotic nature and associated technical challenges label them as long-term solutions at best. A near-to-medium term solution for thorium must be based on an evolutionary approach utilizing light/heavy water reactor platforms. While thorium does not provide a near-to-medium term complete replacement of uranium, it does provide substantial benefit within niche applications. To license and bring to market these niche fuels, Thor Energy and an international consortium of entities (including: Fortum, KAERI, Westinghouse, NNL, ITU, IFE, and a few other minor entities) have initiated a fuel development and irradiation test program to characterize the performance of these thoria-containing fuels. (author)

  3. Trophic specialization influences the rate of environmental niche evolution in damselfishes (Pomacentridae).

    Science.gov (United States)

    Litsios, Glenn; Pellissier, Loïc; Forest, Félix; Lexer, Christian; Pearman, Peter B; Zimmermann, Niklaus E; Salamin, Nicolas

    2012-09-22

    The rate of environmental niche evolution describes the capability of species to explore the available environmental space and is known to vary among species owing to lineage-specific factors. Trophic specialization is a main force driving species evolution and is responsible for classical examples of adaptive radiations in fishes. We investigate the effect of trophic specialization on the rate of environmental niche evolution in the damselfish, Pomacentridae, which is an important family of tropical reef fishes. First, phylogenetic niche conservatism is not detected in the family using a standard test of phylogenetic signal, and we demonstrate that the environmental niches of damselfishes that differ in trophic specialization are not equivalent while they still overlap at their mean values. Second, we estimate the relative rates of niche evolution on the phylogenetic tree and show the heterogeneity among rates of environmental niche evolution of the three trophic groups. We suggest that behavioural characteristics related to trophic specialization can constrain the evolution of the environmental niche and lead to conserved niches in specialist lineages. Our results show the extent of influence of several traits on the evolution of the environmental niche and shed new light on the evolution of damselfishes, which is a key lineage in current efforts to conserve biodiversity in coral reefs.

  4. Antitrust implications of utility participation in the market for remote photovoltaic systems

    International Nuclear Information System (INIS)

    Starrs, T.J.

    1994-01-01

    Remote photovoltaic systems are an important niche market in the development of a viable photovoltaics industry. Electric utilities in the US have started offering remote photovoltaic service. Utilities have the potential to use their monopoly power in regulated markets to unfair competitive advantage in competitive markets. Therefore, utility participation in remote photovoltaic markets raises potentially significant issues of antitrust law and policy. This paper describes some of the legal and factual criteria that US courts and regulatory agencies are likely to use in assessing the antitrust implications of utility participation in the market for remote photovoltaic systems

  5. Probabilistic and spatially variable niches inferred from demography

    Science.gov (United States)

    Jeffrey M. Diez; Itamar Giladi; Robert Warren; H. Ronald. Pulliam

    2014-01-01

    Summary 1. Mismatches between species distributions and habitat suitability are predicted by niche theory and have important implications for forecasting how species may respond to environmental changes. Quantifying these mismatches is challenging, however, due to the high dimensionality of species niches and the large spatial and temporal variability in population...

  6. PV Solar Electricity: From a Niche Market to One of the Most Important Mainstream Markets for Electricity

    Science.gov (United States)

    Hoffmann, W.; Waldmann, L.

    PV solar electricity is seen as one of the few booming markets, today and in the coming decades. This market has grown globally at a rate of about 40% per year over the past 10 years. Related industries have realized a two-digit, billion-dollar (U.S.) turnover worldwide. PV solar electricity is a high-tech industry with high performance potential in the coming decades, leaving even the electronics industries behind and approaching the automotive industry.

  7. Niche conservatism of Eulophia alta, a trans-Atlantic orchid species

    Directory of Open Access Journals (Sweden)

    Marta Kolanowska

    2014-03-01

    Full Text Available The genus Eulophia embraces over 230 species distributed through the tropical and subtropical Africa, Asia, Australia and the Americas. In Neotropics it is represented by a sole species – E. alta. The aim of the presented study was to evaluate the difference between ecological niches occupied by American and African populations of this species based on the ecological niche modeling. The similarity between the glacial and present niches occupied by E. alta was calculated and the factors limiting the species occurrence were identified. Areas of seasonal tropical forest, tropical savanna and woodland served as refugia for the studied species during last glacial maximum and they were more widespread in Neotropics than in Africa. No significant niche shift after last glacial maximum was observed. The distribution of E. alta in its whole range is restricted mainly by temperature seasonality. The differences in the niches occupied by African and Neotropical populations of E. alta suggest preglacial disjunction of the species range and independent adaptation of both groups. Despite the significant range disjunction of E. alta the species is characterized by relatively high degree of niche conservatism.

  8. Fair Trade in Sustainable Development. The Potential for Fair Trade Market Growth in Poland

    Directory of Open Access Journals (Sweden)

    Grażyna Śmigielska

    2015-11-01

    Full Text Available The paper presents the concept of Fair Trade, which is considered an alternative to conventional trade, and becomes increasingly popular in the Western countries. In addition, some results of empirical research, conveyed in Poland and aimed at diagnosis and assessment of Fairtrade products market, are provided. Fair trade is analysed not only in the broad theoretical context which shows its contribution to sustainable development and relation to corporate social responsibility, but also in the framework of supply chains management. The benefits from the Fairtrade label, including transaction costs reduction are indicated. The assumption is that to achieve them, consumer acceptance of the idea and willingness to buy Fairtrade products are necessary. The empirical research was focused on answering the question whether a market niche for Fairtrade goods exists in Poland and how to develop it by the means of communication tools. The market niche, although very small, has been identified and described. It is apparent that, in order to develop it, a public policy, aimed at raising the awareness of Fair Trade idea, is necessary as well as marketing activities like social marketing Internet campaigns and better and more prominently products display.

  9. Understanding complex dynamics in derivatives finance: why do options markets smile?

    NARCIS (Netherlands)

    Qiu, G.; Kandhai, D.; Johnson, N.F.; Sloot, P.M.A.

    2012-01-01

    The origin of the volatility smile phenomenon observed in options markets has eluded the financial world for more than two decades. We provide a new explanation of this phenomenon using a microscopic multi-agent description of markets. In our model individual trading behavior is explicitly included

  10. The Internet And Gray Marketing

    OpenAIRE

    Soumava Bandyopadhyay

    2010-01-01

    The purpose of this conceptual paper is to investigate the nature, extent, and outcomes of gray marketing on the Internet.  We examined the current state of Internet-based gray marketing in several product categories and found the phenomenon to be on the rise.  Next, we developed a series of propositions to address evolving trends in online gray marketing, regarding actions of intermediaries and manufacturers, response by consumers, and outcomes on marketing strategy.

  11. First steps in developing the niche market for PV in conservatories

    International Nuclear Information System (INIS)

    2002-06-01

    This report describes the findings of a project commissioned by the Department of Trade and Industry (DTI) to review and quantitatively assess the prospects and potential for the integration of photovoltaic (PV) modules and components into conservatories. This is considered one way of expanding the market for domestic PV installations in the UK. The report describes the outputs from the project's various work packages. These included: an assessment of the benefits provided by PVs in conservatories in terms of energy use, shading, simulations and aesthetics; the definition of design requirements for integrating PV; development of designs; market surveys of consumers, the conservatory industry and the house building industry; and the development of user guidelines

  12. Beating the Odds! Build theory from emerging markets phenomenon and the emergence of case study research—A “Test-Tube” typology

    Directory of Open Access Journals (Sweden)

    Kotapati Srinivasa Reddy

    2015-12-01

    Full Text Available The extant social sciences and management theoretical concepts and empirical literature have mostly determined based on western (developed economies institutional context. In the recent past, a number of researchers have argued that the western theories are inadequate to study the emerging markets phenomenon and described the problems relating to data collection, data analysis, and theory development. I also (experience confirm that major problems are relating to the research data collection, especially primary data (interview and survey methods. With this in mind, I develop a new case study research design, that is, “Test-Tube” typology, to build theory from emerging markets behavior as well as to add new knowledge to the mass of disciplines, particularly social sciences, medicine, travel, tourism and hospitality, sports, management, and information systems, and engineering. I design a typology that consists of eleven steps: case development, case selection, relatedness and pattern matching, case analysis, cross-case analysis, theoretical constructs, pre-testing and development, adjusting theoretical constructs, theory testing, building theory and testable propositions, and suggesting strategic swap model. Further, I suggest a set of few guidelines on how to measure the research quality and how to strengthen the research rigor in case study settings.

  13. THE GENERATING AND COMPLEMENTARY EFFECTS OF THE UNDERGROUND ECONOMY PHENOMENON

    Directory of Open Access Journals (Sweden)

    Corneliu Sorin BAICU

    2016-12-01

    Full Text Available For a comprehensive understanding of the informal sector, an analysis addressing the relationships and links between the morphology and etiology of the underground economy, on the one hand, and its effects on the economic, social or legal, on the other hand is required. The double identity, that of cause phenomenon and effect phenomenon, that the underground economy has, gives it a special status in explaining certain phenomena which vitiates the economic and social life. The generating and complementary effects of the underground area covered in this study are analyzed in terms of the following vectors of analysis: tax evasion, illegal work and money laundering. Tax evasion represents the central core of the underground economy and faithfully expresses the fiscal monetary policies ,the fiscal mortality and the degree of compliance of the taxpayer. Undeclared work is an indicator of the labor market in the informal economy and is a good barometer for analyzing the demand and supply of labor in the visible economy. Money laundering defines the level of economic and financial crime and reflects the level of illegal use of capital on the black market. Tax evasion, money laundering and illegal work can only develop on a framework provided by illicit markets for goods, services and labor. Beyond the, unidirectional or bidirectional relationships between phenomena, the paper consists in a plea for an interdependent, multi-causal analysis of the phenomena and operating mechanisms of the relationships within and outside the underground economy.

  14. Climatic niche conservatism and the evolutionary dynamics in species range boundaries

    DEFF Research Database (Denmark)

    Olalla-Tárraga1, Miguel Á.; McInnes, Linsey; Bini, Luis M.

    2011-01-01

    Aim Comparative evidence for phylogenetic niche conservatism – the tendency for lineages to retain their ancestral niches over long time scales – has so far been mixed, depending on spatial and taxonomic scale. We quantify and compare conservatism in the climatic factors defining range boundaries...... conservatism, as expected from their greater physiological sensitivity and lower dispersal abilities. Location Global; continental land masses excluding Antarctica. Methods We used nearly complete global distributional databases to estimate the climatic niche conservatism in extant continental mammals...... and amphibians. We characterized the climatic niche of each species by using a suite of variables and separately investigate conservatism in each variable using both taxonomic and phylogenetic approaches. Finally, we explored the spatial, taxonomic and phylogenetic patterns in recent climatic niche evolution...

  15. Development of a laboratory niche Web site.

    Science.gov (United States)

    Dimenstein, Izak B; Dimenstein, Simon I

    2013-10-01

    This technical note presents the development of a methodological laboratory niche Web site. The "Grossing Technology in Surgical Pathology" (www.grossing-technology.com) Web site is used as an example. Although common steps in creation of most Web sites are followed, there are particular requirements for structuring the template's menu on methodological laboratory Web sites. The "nested doll principle," in which one object is placed inside another, most adequately describes the methodological approach to laboratory Web site design. Fragmentation in presenting the Web site's material highlights the discrete parts of the laboratory procedure. An optimally minimal triad of components can be recommended for the creation of a laboratory niche Web site: a main set of media, a blog, and an ancillary component (host, contact, and links). The inclusion of a blog makes the Web site a dynamic forum for professional communication. By forming links and portals, cloud computing opens opportunities for connecting a niche Web site with other Web sites and professional organizations. As an additional source of information exchange, methodological laboratory niche Web sites are destined to parallel both traditional and new forms, such as books, journals, seminars, webinars, and internal educational materials. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Widespread correlations between climatic niche evolution and species diversification in birds.

    Science.gov (United States)

    Cooney, Christopher R; Seddon, Nathalie; Tobias, Joseph A

    2016-07-01

    The adaptability of species' climatic niches can influence the dynamics of colonization and gene flow across climatic gradients, potentially increasing the likelihood of speciation or reducing extinction in the face of environmental change. However, previous comparative studies have tested these ideas using geographically, taxonomically and ecologically restricted samples, yielding mixed results, and thus the processes linking climatic niche evolution with diversification remain poorly understood. Focusing on birds, the largest and most widespread class of terrestrial vertebrates, we test whether variation in species diversification among clades is correlated with rates of climatic niche evolution and the extent to which these patterns are modified by underlying gradients in biogeography and species' ecology. We quantified climatic niches, latitudinal distribution and ecological traits for 7657 (˜75%) bird species based on geographical range polygons and then used Bayesian phylogenetic analyses to test whether niche evolution was related to species richness and rates of diversification across genus- and family-level clades. We found that the rate of climatic niche evolution has a positive linear relationship with both species richness and diversification rate at two different taxonomic levels (genus and family). Furthermore, this positive association between labile climatic niches and diversification was detected regardless of variation in clade latitude or key ecological traits. Our findings suggest either that rapid adaptation to unoccupied areas of climatic niche space promotes avian diversification, or that diversification promotes adaptation. Either way, we propose that climatic niche evolution is a fundamental process regulating the link between climate and biodiversity at global scales, irrespective of the geographical and ecological context of speciation and extinction. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  17. Marketization Revisited

    DEFF Research Database (Denmark)

    Hansen, Morten Balle; Lindholst, Andrej Christian

    2016-01-01

    out; Benchmarking and yardstick competition; and Public-Private collaboration. On the basis of the review of the seven articles, it is found that all elements in all marketization models are firmly embedded but also under dynamic change within public service delivery systems. The review also......Purpose: The purpose of this introduction article to the IJPSM special issue on marketization is to clarify the conceptual foundations of marketization as a phenomenon within the public sector and to gauge current marketization trends on the basis of the seven articles in the special issue. Design....../methodology/approach: Conceptual clarification and cross-cutting review of seven articles analysing marketization in six countries in three policy areas at the level of local government. Findings: Four ideal-type models are deduced: Quasi-markets, involving both provider competition and free choice for users; Classic contracting...

  18. Geographical parthenogenesis: General purpose genotypes and frozen niche variation

    DEFF Research Database (Denmark)

    Vrijenhoek, Robert C.; Parker, Dave

    2009-01-01

    hypotheses concerning the evolution of niche breadth in asexual species - the "general-purpose genotype" (GPG) and "frozen niche-variation" (FNV) models. The two models are often portrayed as mutually exclusive, respectively viewing clonal lineages as generalists versus specialists. Nonetheless...

  19. A family business: stem cell progeny join the niche to regulate homeostasis.

    Science.gov (United States)

    Hsu, Ya-Chieh; Fuchs, Elaine

    2012-01-23

    Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.

  20. Compatible ecological niche signals between biological and archaeological datasets for late-surviving Neandertals.

    Science.gov (United States)

    Bible, Rachael C; Peterson, A Townsend

    2018-04-17

    To assess ecological niche similarity for biological and archaeological samples representing late-surviving Neandertals in Europe to evaluate the validity of combining these two types of data in ecological niche modeling analyses. Tests of niche conservatism were used to assess niche similarity and niche identity of samples of morphologically diagnostic Neandertal remains and Middle Paleolithic (MP) archaeological sites dating to the time period leading up to Neandertal extinction. Paleoenvironmental reconstructions for the Pre-H4 (43.3-40.2 ky cal BP) were used as environmental space analyses. Null hypotheses of niche similarity and identity of the two types of samples could not be rejected. As primary and secondary evidence of Neandertal occurrence during the Pre-H4 show high levels of niche similarity and identity, combining the two types of occurrence data to create larger samples for niche analyses is justified without the concern that different environmental signals could complicate future research. © 2018 Wiley Periodicals, Inc.

  1. Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black-spotted and red-spotted tokay geckoes (Gekko gecko).

    Science.gov (United States)

    Zhang, Yueyun; Chen, Chongtao; Li, Li; Zhao, Chengjian; Chen, Weicai; Huang, Yong

    2014-09-01

    The black-spotted tokay and the red-spotted tokay are morphologically distinct and have largely allopatric distributions. The black-spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red-spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point-based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black- and the red-spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values ("black" = 0.982, SD = ± 0.002, "red" = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the "black" form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the "red" form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black- and the red

  2. Behavioural manipulation of insect hosts by Baculoviridae as a process of niche construction.

    Science.gov (United States)

    Hamblin, Steven; Tanaka, Mark M

    2013-08-16

    Niche construction has received increasing attention in recent years as a vital force in evolution and examples of niche construction have been identified in a wide variety of taxa, but viruses are conspicuously absent. In this study we explore how niche construction can lead to viruses engineering their hosts (including behavioural manipulation) with feedback on selective pressures for viral transmission and virulence. To illustrate this concept we focus on Baculoviridae, a family of invertebrate viruses that have evolved to modify the feeding behaviour of their lepidopteran hosts and liquefy their cadavers as part of the course of infection. We present a mathematical model showing how niche construction leads to feedback from the behavioural manipulation to the liquefaction of the host, linking the evolution of both of these traits, and show how this association arises from the action of niche construction. Model results show that niche construction is plausible in this system and delineates the conditions under which niche construction will occur. Niche construction in this system is also shown to be sensitive to parameter values that reflect ecological forces. Our model demonstrates that niche construction can be a potent force in viral evolution and can lead to the acquisition and maintenance of the behavioural manipulation and liquefaction traits in Baculoviridae via the niche constructing effects on the host. These results show the potential for niche construction theory to provide new insights into viral evolution.

  3. HOW PINK ARE YOU? : Creating Awareness of the Gay Market

    OpenAIRE

    Orlik, Inez

    2012-01-01

    The objective of the thesis was to gather information on as well as draw attention to the Gay Market among representatives connected to the tourism business who met during the international fair Matka Expo 2012 held in the Helsinki Exposition and Convention Centre. The aim was to seek to improve the future situation on this particular niche market through increased interest and knowledge, which would lead to better understanding, cooperation and prejudice release. The thesis was aimed to make...

  4. Green power marketing in retail competition: an early assessment

    International Nuclear Information System (INIS)

    Wiser, R.; Porter, K.; Fang, J.

    1999-01-01

    With retail competition being introduced throughout the United States, green power marketing offers the promise of customer-driven markets for renewable energy. This paper summarizes early experience with green marketing under full retail competition. We conclude that (1) niche markets exist today among residential and non-residential consumers for green power; (2) green demand may ultimately offer an important strategic market for renewable technologies, but the market is currently rather small and the long-term prospects remain uncertain; (3) the success of green markets will depend critically on the regulatory rules established at the onset of restructuring; and (4) the biomass industry will be forced to better communicate the environmental benefits of its technology in order to play a strong role within the green market. This paper is based on a more detailed NREL Topical Issues Brief, which is available on the Internet. (author)

  5. Niche evolution and adaptive radiation: Testing the order of trait divergence

    Science.gov (United States)

    Ackerly, D.D.; Schwilk, D.W.; Webb, C.O.

    2006-01-01

    In the course of an adaptive radiation, the evolution of niche parameters is of particular interest for understanding modes of speciation and the consequences for coexistence of related species within communities. We pose a general question: In the course of an evolutionary radiation, do traits related to within-community niche differences (?? niche) evolve before or after differentiation of macrohabitat affinity or climatic tolerances (?? niche)? Here we introduce a new test to address this question, based on a modification of the method of independent contrasts. The divergence order test (DOT) is based on the average age of the nodes on a tree, weighted by the absolute magnitude of the contrast at each node for a particular trait. The comparison of these weighted averages reveals whether large divergences for one trait have occurred earlier or later in the course of diversification, relative to a second trait; significance is determined by bootstrapping from maximum-likelihood ancestral state reconstructions. The method is applied to the evolution of Ceanothus, a woody plant group in California, in which co-occurring species exhibit significant differences in a key leaf trait (specific leaf area) associated with contrasting physiological and life history strategies. Co-occurring species differ more for this trait than expected under a null model of community assembly. This ?? niche difference evolved early in the divergence of two major subclades within Ceanothus, whereas climatic distributions (?? niche traits) diversified later within each of the subclades. However, rapid evolution of climate parameters makes inferences of early divergence events highly uncertain, and differentiation of the ?? niche might have taken place throughout the evolution of the group, without leaving a clear phylogenetic signal. Similar patterns observed in several plant and animal groups suggest that early divergence of ?? niche traits might be a common feature of niche evolution in

  6. Microhabitat and Climatic Niche Change Explain Patterns of Diversification among Frog Families.

    Science.gov (United States)

    Moen, Daniel S; Wiens, John J

    2017-07-01

    A major goal of ecology and evolutionary biology is to explain patterns of species richness among clades. Differences in rates of net diversification (speciation minus extinction over time) may often explain these patterns, but the factors that drive variation in diversification rates remain uncertain. Three important candidates are climatic niche position (e.g., whether clades are primarily temperate or tropical), rates of climatic niche change among species within clades, and microhabitat (e.g., aquatic, terrestrial, arboreal). The first two factors have been tested separately in several studies, but the relative importance of all three is largely unknown. Here we explore the correlates of diversification among families of frogs, which collectively represent ∼88% of amphibian species. We assemble and analyze data on phylogeny, climate, and microhabitat for thousands of species. We find that the best-fitting phylogenetic multiple regression model includes all three types of variables: microhabitat, rates of climatic niche change, and climatic niche position. This model explains 67% of the variation in diversification rates among frog families, with arboreal microhabitat explaining ∼31%, niche rates ∼25%, and climatic niche position ∼11%. Surprisingly, we show that microhabitat can have a much stronger influence on diversification than climatic niche position or rates of climatic niche change.

  7. Regulatory System for Stem/Progenitor Cell Niches in the Adult Rodent Pituitary

    Science.gov (United States)

    Yoshida, Saishu; Kato, Takako; Kato, Yukio

    2016-01-01

    The anterior lobe of the pituitary gland is a master endocrine tissue composed of five types of endocrine cells. Although the turnover rate of pituitary endocrine cells is as low as about 1.6% per day, recent studies have demonstrated that Sex-determining region Y-box 2 (SOX2)+-cells exist as pituitary stem/progenitor cells in the adult anterior lobe and contribute to cell regeneration. Notably, SOX2+-pituitary stem/progenitor cells form two types of niches in this tissue: the marginal cell layer (MCL-niche) and the dense cell clusters scattering in the parenchyma (parenchymal-niche). However, little is known about the mechanisms and factors for regulating the pituitary stem/progenitor cell niches, as well as the functional differences between the two types of niches. Elucidation of the regulatory mechanisms in the niches might enable us to understand the cell regeneration system that acts in accordance with physiological demands in the adult pituitary. In this review, so as to reveal the regulatory mechanisms of the two types of niche, we summarize the regulatory factors and their roles in the adult rodent pituitary niches by focusing on three components: soluble factors, cell surface proteins and extracellular matrixes. PMID:26761002

  8. Regulatory System for Stem/Progenitor Cell Niches in the Adult Rodent Pituitary

    Directory of Open Access Journals (Sweden)

    Saishu Yoshida

    2016-01-01

    Full Text Available The anterior lobe of the pituitary gland is a master endocrine tissue composed of five types of endocrine cells. Although the turnover rate of pituitary endocrine cells is as low as about 1.6% per day, recent studies have demonstrated that Sex-determining region Y-box 2 (SOX2+-cells exist as pituitary stem/progenitor cells in the adult anterior lobe and contribute to cell regeneration. Notably, SOX2+-pituitary stem/progenitor cells form two types of niches in this tissue: the marginal cell layer (MCL-niche and the dense cell clusters scattering in the parenchyma (parenchymal-niche. However, little is known about the mechanisms and factors for regulating the pituitary stem/progenitor cell niches, as well as the functional differences between the two types of niches. Elucidation of the regulatory mechanisms in the niches might enable us to understand the cell regeneration system that acts in accordance with physiological demands in the adult pituitary. In this review, so as to reveal the regulatory mechanisms of the two types of niche, we summarize the regulatory factors and their roles in the adult rodent pituitary niches by focusing on three components: soluble factors, cell surface proteins and extracellular matrixes.

  9. The making of an immigrant niche.

    Science.gov (United States)

    Waldinger, R

    1994-01-01

    "This article speaks to the conceptual and methodological issues in research on the making of an immigrant niche through a case study of immigrant professionals in New York City government." The author argues that "the growth of this immigrant niche resulted from changes in the relative supply of native workers and in the structure of employment, which opened the bureaucracy to immigrants and reduced native/immigrant competition. These shifts opened hiring portals; given the advantages of network hiring for workers and managers, and an immigrant propensity for government employment, network recruitment led to a rapid buildup in immigrant ranks." excerpt

  10. Stem cell niche-specific Ebf3 maintains the bone marrow cavity.

    Science.gov (United States)

    Seike, Masanari; Omatsu, Yoshiki; Watanabe, Hitomi; Kondoh, Gen; Nagasawa, Takashi

    2018-03-01

    Bone marrow is the tissue filling the space between bone surfaces. Hematopoietic stem cells (HSCs) are maintained by special microenvironments known as niches within bone marrow cavities. Mesenchymal cells, termed CXC chemokine ligand 12 (CXCL12)-abundant reticular (CAR) cells or leptin receptor-positive (LepR + ) cells, are a major cellular component of HSC niches that gives rise to osteoblasts in bone marrow. However, it remains unclear how osteogenesis is prevented in most CAR/LepR + cells to maintain HSC niches and marrow cavities. Here, using lineage tracing, we found that the transcription factor early B-cell factor 3 (Ebf3) is preferentially expressed in CAR/LepR + cells and that Ebf3-expressing cells are self-renewing mesenchymal stem cells in adult marrow. When Ebf3 is deleted in CAR/LepR + cells, HSC niche function is severely impaired, and bone marrow is osteosclerotic with increased bone in aged mice. In mice lacking Ebf1 and Ebf3 , CAR/LepR + cells exhibiting a normal morphology are abundantly present, but their niche function is markedly impaired with depleted HSCs in infant marrow. Subsequently, the mutants become progressively more osteosclerotic, leading to the complete occlusion of marrow cavities in early adulthood. CAR/LepR + cells differentiate into bone-producing cells with reduced HSC niche factor expression in the absence of Ebf1/Ebf3 Thus, HSC cellular niches express Ebf3 that is required to create HSC niches, to inhibit their osteoblast differentiation, and to maintain spaces for HSCs. © 2018 Seike et al.; Published by Cold Spring Harbor Laboratory Press.

  11. Contemporary marketing practice : theoretical propositions and practical implications

    NARCIS (Netherlands)

    Lindgreen, A.; Palmer, R.; Vanhamme, J.

    2004-01-01

    Marketing has changed significantly since it first emerged as a distinct business and management phenomenon. We identify some of the major factors causing the observed change in marketing practice. We then describe a classification scheme that is based on transaction marketing and relationship

  12. Neural Crossroads in the Hematopoietic Stem Cell Niche.

    Science.gov (United States)

    Agarwala, Sobhika; Tamplin, Owen J

    2018-05-29

    The hematopoietic stem cell (HSC) niche supports steady-state hematopoiesis and responds to changing needs during stress and disease. The nervous system is an important regulator of the niche, and its influence is established early in development when stem cells are specified. Most research has focused on direct innervation of the niche, however recent findings show there are different modes of neural control, including globally by the central nervous system (CNS) and hormone release, locally by neural crest-derived mesenchymal stem cells, and intrinsically by hematopoietic cells that express neural receptors and neurotransmitters. Dysregulation between neural and hematopoietic systems can contribute to disease, however new therapeutic opportunities may be found among neuroregulator drugs repurposed to support hematopoiesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Fibrocytes and the tissue niche in lung repair

    Directory of Open Access Journals (Sweden)

    Bjermer Leif

    2011-06-01

    Full Text Available Abstract Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases.

  14. Dynamics of the youth travel market on a global level

    Directory of Open Access Journals (Sweden)

    Timea DEMETER

    2015-06-01

    Full Text Available The segment of young tourists has been considered a niche market and was treated as a branch of the tourism industry. In the past 10 years, however, its market value has began to increase significantly bringing real benefits to the companies adapting to this segment by developing appropriate strategies and policies. Therefore, the aim of this project is to analyse the dynamics of the youth travel market, on a global level, taking into consideration the international youth arrivals, youth accommodation units and the behavioural habits of young tourists, serving as a starting point in the strategy development process.

  15. Niche dimensions in fishes: an integrative view.

    Science.gov (United States)

    Pörtner, H O; Schulte, P M; Wood, C M; Schiemer, F

    2010-01-01

    Current shifts in ecosystem composition and function emphasize the need for an understanding of the links between environmental factors and organism fitness and tolerance. The examples discussed here illustrate how recent progress in the field of comparative physiology may provide a better mechanistic understanding of the ecological concepts of the fundamental and realized niches and thus provide insights into the impacts of anthropogenic disturbance. Here we argue that, as a link between physiological and ecological indicators of organismal performance, the mechanisms shaping aerobic scope and passive tolerance set the dimensions of an animal's niche, here defined as its capacity to survive, grow, behave, and interact with other species. We demonstrate how comparative studies of cod or killifish populations in a latitudinal cline have unraveled mitochondrial mechanisms involved in establishing a species' niche, performance, and energy budget. Riverine fish exemplify how the performance windows of various developmental stages follow the dynamic regimes of both seasonal temperatures and river hydrodynamics, as synergistic challenges. Finally, studies of species in extreme environments, such as the tilapia of Lake Magadi, illustrate how on evolutionary timescales functional and morphological shifts can occur, associated with new specializations. We conclude that research on the processes and time course of adaptations suitable to overcome current niche limits is urgently needed to assess the resilience of species and ecosystems to human impact, including the challenges of global climate change.

  16. Interactions between structural and chemical biomimetism in synthetic stem cell niches

    International Nuclear Information System (INIS)

    Nava, Michele M; Raimondi, Manuela T; Credi, Caterina; De Marco, Carmela; Turri, Stefano; Cerullo, Giulio; Osellame, Roberto

    2015-01-01

    Advancements in understanding stem cell functions and differentiation are of key importance for the clinical success of stem-cell-based therapies. 3D structural niches fabricated by two-photon polymerization are a powerful platform for controlling stem cell growth and differentiation. In this paper, we investigate the possibility of further controlling stem cell fate by tuning the mechanical properties of such niches through coating with thin layers of biomimetic hyaluronan-based and gelatin-based hydrogels. We first assess the biocompatibility of chemical coatings and then study the interactions between structural and chemical biomimetism on the response of MSCs in terms of proliferation and differentiation. We observed a clear effect of the hydrogel coating on otherwise identical 3D scaffolds. In particular, in gelatin-coated niches we observed a stronger metabolic activity and commitment toward the osteo-chondral lineage with respect to hyaluronan-coated niches. Conversely, a reduction in the homing effect was observed in all the coated niches, especially in gelatin-coated niches. This study demonstrates the feasibility of controlling independently different mechanical cues, in bioengineered stem cell niches, i.e. the 3D scaffold geometry and the surface stiffness. This will allow, on the one hand, understanding their specific role in stem cell proliferation and differentiation and, on the other hand, finely tuning their synergistic effect. (paper)

  17. Peculiarities of marketing communications in cultural marketing

    Directory of Open Access Journals (Sweden)

    Daniel Gardan

    2016-09-01

    Full Text Available Extending the application of marketing science specific concepts and principles in various sectors would not have been possible without their gradual evolution, in terms of customization and differentiation tailored for a specific field. This phenomenon regarding marketing evolution in terms of both extensively and intensively way, led to the emergence and consolidation of a set of concepts adapted also for cultural products and services market, or in other words for culture “consumption”. This article highlights a number of marketing communications specific elements, derived from the peculiarities of modern culture consumer and the latest technologies interference in the creation and delivery of cultural products and services. Given the high degree of consumer involvement in relation to the needs that underlie consumption of cultural products and services, as well as the dimension specific for an artistic act in some cases, marketing communications has to respond to particular challenges in the process of building customer-provider relationship.

  18. Two paths from lab to market: Product and standard

    Science.gov (United States)

    Knapp, Robert H.

    2018-01-01

    To shed light on the movement of sustainable technologies from basic science to widespread use, this chapter describes key aspects of the quite different paths followed by two important examples—photovoltaics (a product) and passive-house buildings (a standard). Discussion of photovoltaics includes the experience curve concept, the increasing significance of balance-of-system costs, and the importance of market heterogeneity (niches and sub-national markets) to the long-term trajectory of major cost reductions. Discussion of passive-houses highlights the array of technical developments needed for present-day energy efficient houses, and the relevance of "stretch" standards to the development of a market for very high-performance houses.

  19. Marketing fortification of business through crowdsourcing and social responsibility: focus on South African SMEs

    OpenAIRE

    Eunice Lebogang Sesale; Solly Matshonisa Seeletse

    2017-01-01

    This paper investigates networking and related activities for marketing performance of small and medium enterprises (SMEs) for the sustainable development and the preservation of the environment. These SMEs have limited business skills and knowledge, and don`t have any marketing funds. As a clearly growing trend aspect in business, networking approaches were blended to find approaches to help these SMEs to take their market niche. Thirty-seven (37) SMEs were used as a convenience sample to ex...

  20. Marketing, the For-Profit Way

    Science.gov (United States)

    Blumenstyk, Goldie

    2006-01-01

    This paper discusses a new marketing strategy that could yield new revenue opportunities. Internet-based marketing is not for the faint of heart. Even colleges that embrace the strategies note that they are rife with complications. Nonprofit colleges increasingly rely on Internet advertising to recruit students, and the phenomenon has caught the…

  1. Phylogenetic signals in the climatic niches of the world's amphibians

    DEFF Research Database (Denmark)

    Hof, Christian; Rahbek, Carsten; Araújo, Miguel B.

    2010-01-01

    amphibian orders and across biogeographical regions. To our knowledge, this is the first study providing a comprehensive analysis of the phylogenetic signal in species climatic niches for an entire clade across the world. Even though our results do not provide a strong test of the niche conservatism......The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species...... are also ecologically similar has often been made, although the prevalence of such a phylogenetic signal in ecological niches remains heavily debated. Here, we provide a global analysis of phylogenetic niche relatedness for the world's amphibians. In particular, we assess which proportion of the variance...

  2. Framework for analyzing ecological trait-based models in multidimensional niche spaces

    Science.gov (United States)

    Biancalani, Tommaso; DeVille, Lee; Goldenfeld, Nigel

    2015-05-01

    We develop a theoretical framework for analyzing ecological models with a multidimensional niche space. Our approach relies on the fact that ecological niches are described by sequences of symbols, which allows us to include multiple phenotypic traits. Ecological drivers, such as competitive exclusion, are modeled by introducing the Hamming distance between two sequences. We show that a suitable transform diagonalizes the community interaction matrix of these models, making it possible to predict the conditions for niche differentiation and, close to the instability onset, the asymptotically long time population distributions of niches. We exemplify our method using the Lotka-Volterra equations with an exponential competition kernel.

  3. Exploring the Types of SMEs Which Could use Blogs as a Marketing Tool: a Proposed Future Research Agenda

    OpenAIRE

    Adeline Phaik Harn Chua; Kenneth R. Deans; Craig M. Parker

    2009-01-01

    Blogs appear to be gaining momentum as a marketing tool which can be used by organisations for such strategies and processes as branding, managing reputation, developing customer trust and loyalty, niche marketing, gathering marketing intelligence and promoting their online presence. There has been limited academic research in this area, and most significantly concerning the types of small and medium enterprises (SMEs) for which blogs might have potential as a marketing tool. In an attempt to...

  4. Niche entrepreneurs in urban systems integration : On the role of individuals in niche formation

    NARCIS (Netherlands)

    Pesch, U.; Vernay, A.L.; van Bueren, E.M.; Pandis Iveroth, S

    2017-01-01

    In many sustainable urban innovation projects, the efforts, endurance and enthusiasm of individuals at key positions are considered a crucial factor for success. This article studies the role of individual agency in sociotechnical niches by using Kingdon’s agenda-setting model. Although strategic

  5. Language and other artifacts: socio-cultural dynamics of niche construction.

    Science.gov (United States)

    Sinha, Chris

    2015-01-01

    Niche construction theory is a relatively new approach in evolutionary biology that seeks to integrate an ecological dimension into the Darwinian theory of evolution by natural selection. It is regarded by many evolutionary biologists as providing a significant revision of the Neo-Darwinian modern synthesis that unified Darwin's theory of natural and sexual selection with 20th century population genetics. Niche construction theory has been invoked as a processual mediator of social cognitive evolution and of the emergence and evolution of language. I argue that language itself can be considered as a biocultural niche and evolutionary artifact. I provide both a general analysis of the cognitive and semiotic status of artifacts, and a formal analysis of language as a social and semiotic institution, based upon a distinction between the fundamental semiotic relations of "counting as" and "standing for." I explore the consequences for theories of language and language learning of viewing language as a biocultural niche. I suggest that not only do niches mediate organism-organism interactions, but also that organisms mediate niche-niche interactions in ways that affect evolutionary processes, with the evolution of human infancy and childhood as a key example. I argue that language as a social and semiotic system is not only grounded in embodied engagements with the material and social-interactional world, but also grounds a sub-class of artifacts of particular significance in the cultural history of human cognition. Symbolic cognitive artifacts materially and semiotically mediate human cognition, and are not merely informational repositories, but co-agentively constitutive of culturally and historically emergent cognitive domains. I provide examples of the constitutive cognitive role of symbolic cognitive artifacts drawn from my research with my colleagues on cultural and linguistic conceptualizations of time, and their cultural variability. I conclude by reflecting on

  6. Phylogenetic niche conservatism and the evolutionary basis of ecological speciation.

    Science.gov (United States)

    Pyron, R Alexander; Costa, Gabriel C; Patten, Michael A; Burbrink, Frank T

    2015-11-01

    Phylogenetic niche conservatism (PNC) typically refers to the tendency of closely related species to be more similar to each other in terms of niche than they are to more distant relatives. This has been implicated as a potential driving force in speciation and other species-richness patterns, such as latitudinal gradients. However, PNC has not been very well defined in most previous studies. Is it a pattern or a process? What are the underlying endogenous (e.g. genetic) and exogenous (e.g. ecological) factors that cause niches to be conserved? What degree of similarity is necessary to qualify as PNC? Is it possible for the evolutionary processes causing niches to be conserved to also result in niche divergence in different habitats? Here, we revisit these questions, codifying a theoretical and operational definition of PNC as a mechanistic evolutionary process resulting from several factors. We frame this both from a macroevolutionary and population-genetic perspective. We discuss how different axes of physical (e.g. geographic) and environmental (e.g. climatic) heterogeneity interact with the fundamental process of PNC to produce different outcomes of ecological speciation. We also review tests for PNC, and suggest ways that these could be improved or better utilized in future studies. Ultimately, PNC as a process has a well-defined mechanistic basis in organisms, and future studies investigating ecological speciation would be well served to consider this, and frame hypothesis testing in terms of the processes and expected patterns described herein. The process of PNC may lead to patterns where niches are conserved (more similar than expected), constrained (divergent within a limited subset of available niches), or divergent (less similar than expected), based on degree of phylogenetic relatedness between species. © 2014 Cambridge Philosophical Society.

  7. Language and other artifacts: socio-cultural dynamics of niche construction.

    Directory of Open Access Journals (Sweden)

    Chris eSinha

    2015-10-01

    Full Text Available Niche construction theory is a relatively new approach in evolutionary biology that seeks to integrate an ecological dimension into the Darwinian theory of evolution by natural selection. It is regarded by many evolutionary biologists as providing a significant revision of the Neo-Darwinian modern synthesis that unified Darwin’s theory of natural and sexual selection with 20th century population genetics. Niche construction theory has been invoked as a processual mediator of social cognitive evolution and of the emergence and evolution of language. I argue that language itself can be considered as a biocultural niche and evolutionary artifact. I provide both a general analysis of the cognitive and semiotic status of artifacts, and a formal analysis of language as a social and semiotic institution, based upon a distinction between the fundamental semiotic relations of counting as and standing for. I explore the consequences for theories of language and language learning of viewing language as a biocultural niche. I suggest that not only do niches mediate organism-organism interactions, but also that organisms mediate niche-niche interactions in ways that affect evolutionary processes, with the evolution of human infancy and childhood as a key example. I argue that language as a social and semiotic system is not only grounded in embodied engagements with the material and social-interactional world, but also grounds a sub-class of artifacts of particular significance in the cultural history of human cognition. Symbolic cognitive artifacts materially and semiotically mediate human cognition, and are not merely informational repositories, but co-agentively constitutive of culturally and historically emergent cognitive domains. I provide examples of the constitutive cognitive role of symbolic cognitive artifacts drawn from my research with my colleagues on cultural and linguistic conceptualizations of time, and their cultural variability. I conclude

  8. Marketing in the long-term care continuum.

    Science.gov (United States)

    Laurence, J Nathan; Kash, Bita A

    2010-04-01

    Today, long-term care facilities are composed of independent, assisted living, and skilled nursing facilities along with many variations of those themes in between. The clientele for these various types of facilities differ because of the level of care the facility provides as well as the amenities long-term care consumers are looking for. However, there many similarities and common approaches to how reaching the target audience through effective marketing activities. Knowing who the target audience is, how to reach them, and how to communicate with them will serve any facility well in this competitive market. Developing marketing strategies for long-term care settings is as important as understanding what elements of care can be marketed individually as a niche market. Determining the market base for a facility is equally crucial since the target populations differ among the three types of facilities. By reviewing current marketing articles and applying marketing practices, we have crafted some general principles for which each facility type can learn from. Finally, we will discuss the types of marketing and how they related to the spectrum of long-term care facilities.

  9. (Redefining tradition: the example of the world music phenomenon

    Directory of Open Access Journals (Sweden)

    Marija Ristivojević

    2016-02-01

    Full Text Available The paper problematizes the understanding of the concept of tradition in the context of the world music phenomenon. Marketed as a hybrid music genre, from the perspective of anthropological theory, the world music genre is a complex cultural phenomenon, the result of mixing global and local influences which are reflected not only in the creation of a specific sound, but through different perceptions of music itself (the audience, musicians, producers, creators of cultural policies etc. By analyzing the Serbian world music scene as exemplified by the work of the World Music association of Serbia, as well as the Serbia World Music Festival in Takovo, I will attempt to determine the way in which the concept of world music is perceived in local narratives, whether it is experienced as a form of musical tradition and if so, what is signified and represented as tradition in this context.

  10. Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling.

    Science.gov (United States)

    Escobar, Luis E; Craft, Meggan E

    2016-01-01

    Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks.

  11. A practical guideline for examining a uterine niche using ultrasonography in non-pregnant women

    DEFF Research Database (Denmark)

    Jordans, I P M; de Leeuw, R; Stegwee, S I

    2018-01-01

    OBJECTIVES: To generate a uniform, internationally recognized guideline for detailed uterine niche evaluation by ultrasonography in non-pregnant women using a modified Delphi method amongst international experts. METHODS: Fifteen international gynecological experts were recruited...... definitions, relevance, method of measurement and tips for visualization of the niche. All experts agreed on the proposed guideline for niche evaluation in non-pregnant women as presented in this paper. CONCLUSION: Consensus between niche experts was achieved on all items regarding ultrasonographic niche...

  12. Strategies to crack well-guarded markets.

    Science.gov (United States)

    Bryce, David J; Dyer, Jeffrey H

    2007-05-01

    How can companies break into attractive markets, where incumbents erect many barriers to entry? To answer this question, the authors studied organizations that successfully entered the most profitable industries in the United States between 1990 and 2000. When they dissected the strategies that worked best, one common theme stood out: indirect assault. Smart newcomers don't duplicate existing business models, compete for crowded distribution channels, or go after mainstream customers right away. Instead, they attack the enemy at its weakest points; then gain competitive advantage; and later, if doing so meets their objectives, go after its strongholds. Recent battles in the soft drink industry--where brands, bottling and distribution capabilities, and shelf space are incumbents' main advantages--are a case in point. When Virgin Drinks entered the U.S. cola market in 1998, it advertised heavily and immediately tried to get into the retail outlets that stock the leading brands. Virgin has never garnered more than a 1% share of the market. Red Bull, by contrast, came on the scene in 1997 with a niche product: a carbonated energy drink. The company started by selling the drink at bars and nightclubs. After gaining a loyal following through these outlets, Red Bull elbowed its way into the corner store. In 2005 it enjoyed a 65% share of the $650 million energy drink market. Successful entrants use three basic approaches in their indirect attacks. They leverage their existing assets and resources, reconfigure their value chains, and create niches. These approaches may appear to be simple, but their magic lies in their combination. By mixing and matching them, Bryce and Dyer say, enterprises can defy half a century of economic logic and make money entering highly profitable industries. The authors use Skype, Costco, Skechers, and many other companies to illustrate their argument.

  13. Correlated evolution of thermal niches and functional physiology in tropical freshwater fishes.

    Science.gov (United States)

    Culumber, Zachary W; Tobler, Michael

    2018-05-01

    The role of ecology in phenotypic and species diversification is widely documented. Nonetheless, numerous nonadaptive processes can shape realized niches and phenotypic variation in natural populations, complicating inferences about adaptive evolution at macroevolutionary scales. We tested for evolved differences in thermal tolerances and their association with the realized thermal niche (including metrics describing diurnal and seasonal patterns of temperature extremes and variability) across a genus of tropical freshwater fishes reared in a standardized environment. There was limited evolution along the thermal niche axis associated with variation in maximum temperature and in upper thermal limits. In contrast, there was considerable diversification along the first major axis of the thermal niche associated with minimum temperatures and in lower thermal limits. Across our adaptive landscape analyses, 70% of species exhibited evidence of divergence in thermal niches. Most importantly, the first two major axes of thermal niche variation were significantly correlated with variation in lower thermal limits. Our results indicate adaptation to divergent thermal niches and adaptive evolution of related functional traits, and highlight the importance of divergence in lower thermal limits for the evolution of tropical biodiversity. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  14. Ontogenetic niche shifts and evolutionary branching in size-structured populations

    NARCIS (Netherlands)

    Claessen, D.; Dieckmann, U.

    2002-01-01

    There are many examples of size-structured populations where individuals sequentially exploit several niches in the course of their life history. Efficient exploitation of such ontogenetic niches generally requires specific morphological adaptations. Here, we study the evolutionary implications of

  15. Mammalian niche conservation through deep time.

    Directory of Open Access Journals (Sweden)

    Larisa R G DeSantis

    Full Text Available Climate change alters species distributions, causing plants and animals to move north or to higher elevations with current warming. Bioclimatic models predict species distributions based on extant realized niches and assume niche conservation. Here, we evaluate if proxies for niches (i.e., range areas are conserved at the family level through deep time, from the Eocene to the Pleistocene. We analyze the occurrence of all mammalian families in the continental USA, calculating range area, percent range area occupied, range area rank, and range polygon centroids during each epoch. Percent range area occupied significantly increases from the Oligocene to the Miocene and again from the Pliocene to the Pleistocene; however, mammalian families maintain statistical concordance between rank orders across time. Families with greater taxonomic diversity occupy a greater percent of available range area during each epoch and net changes in taxonomic diversity are significantly positively related to changes in percent range area occupied from the Eocene to the Pleistocene. Furthermore, gains and losses in generic and species diversity are remarkably consistent with ~2.3 species gained per generic increase. Centroids demonstrate southeastern shifts from the Eocene through the Pleistocene that may correspond to major environmental events and/or climate changes during the Cenozoic. These results demonstrate range conservation at the family level and support the idea that niche conservation at higher taxonomic levels operates over deep time and may be controlled by life history traits. Furthermore, families containing megafauna and/or terminal Pleistocene extinction victims do not incur significantly greater declines in range area rank than families containing only smaller taxa and/or only survivors, from the Pliocene to Pleistocene. Collectively, these data evince the resilience of families to climate and/or environmental change in deep time, the absence of

  16. Biogeographic ranges do not support niche theory in radiating Canary Island plant clades

    DEFF Research Database (Denmark)

    Steinbauer, Manuel; Field, Richard; Fernández-Palacios, José María

    2016-01-01

    in allopatry. Main conclusions: The expectations from niche conservatism were frequently not met; instead our results suggest considerable climatic niche lability. All significant differences in climatic niche differentiation were opposite to the predictions from competitive displacement. These forces may...

  17. Illegal markets: Estimates of global proceeds

    Directory of Open Access Journals (Sweden)

    Marinković Darko M.

    2015-01-01

    Full Text Available Illegal markets represent a phenomenon of considerable economic, political and social significance whose annual income exceeds the value of a thousand billion USD. Illegal market participants are beyond the reach of government institutions and rule of law while social connections and personal acquaintances play an important role of functional substitute. In the last decade there was a significant increase of illegal trafficking of narcotics, people, fire arms, counterfeit products and natural resources. Both selling and purchase of these as well as other kinds of products and services at illegal markets are generally characterized by high level of organization and presence of strong criminal groups and networks. Although these activities existed in the past their present scope and geographic distribution are without precedent. Measuring unlawful financial flows at illegal markets represents quite a complex task. Various estimates are the result of inexistence of uniform and generally accepted methodology. In addition to this, the special problem is also the consensus of market actors, because of which the phenomenon of illegal markets and distribution of products and services at these markets is rather hidden. The paper defines and analyzes the key features of illegal markets, the role of organized crime at illegal markets, as well as the estimates of the values of financial flows at the markets of counterfeit products, narcotics, and people as goods, or human organs and sexual services, weapons, tobacco products and dirty money.

  18. Overlap and partitioning of the ecological and isotopic niches

    Science.gov (United States)

    Elizabeth A. Flaherty; Merav Ben-David

    2010-01-01

    Recently, it was proposed that stable isotope patterns can be used to quantify the width of the ecological niche of animals. However, the potential effects of habitat use on isotopic patterns of consumers have not been fully explored and consequently isotopic patterns may yield deceptive estimates of niche width. Here, we simulated four different scenarios of a...

  19. Human niche, human behaviour, human nature.

    Science.gov (United States)

    Fuentes, Agustin

    2017-10-06

    The concept of a 'human nature' or 'human natures' retains a central role in theorizing about the human experience. In Homo sapiens it is clear that we have a suite of capacities generated via our evolutionary past, and present, and a flexible capacity to create and sustain particular kinds of cultures and to be shaped by them. Regardless of whether we label these capacities 'human natures' or not, humans occupy a distinctive niche and an evolutionary approach to examining it is critical. At present we are faced with a few different narratives as to exactly what such an evolutionary approach entails. There is a need for a robust and dynamic theoretical toolkit in order to develop a richer, and more nuanced, understanding of the cognitively sophisticated genus Homo and the diverse sorts of niches humans constructed and occupied across the Pleistocene, Holocene, and into the Anthropocene. Here I review current evolutionary approaches to 'human nature', arguing that we benefit from re-framing our investigations via the concept of the human niche and in the context of the extended evolutionary synthesis (EES). While not a replacement of standard evolutionary approaches, this is an expansion and enhancement of our toolkit. I offer brief examples from human evolution in support of these assertions.

  20. Environmental niche conservatism explains the accumulation of species richness in Mediterranean-hotspot plant genera.

    Science.gov (United States)

    Skeels, Alexander; Cardillo, Marcel

    2017-03-01

    The causes of exceptionally high plant diversity in Mediterranean-climate biodiversity hotspots are not fully understood. We asked whether a mechanism similar to the tropical niche conservatism hypothesis could explain the diversity of four large genera (Protea, Moraea, Banksia, and Hakea) with distributions within and adjacent to the Greater Cape Floristic Region (South Africa) or the Southwest Floristic Region (Australia). Using phylogenetic and spatial data we estimated the environmental niche of each species, and reconstructed the mode and dynamics of niche evolution, and the geographic history, of each genus. For three genera, there were strong positive relationships between the diversity of clades within a region and their inferred length of occupation of that region. Within genera, there was evidence for strong evolutionary constraint on niche axes associated with climatic seasonality and aridity, with different niche optima for hotspot and nonhotspot clades. Evolutionary transitions away from hotspots were associated with increases in niche breadth and elevated rates of niche evolution. Our results point to a process of "hotspot niche conservatism" whereby the accumulation of plant diversity in Mediterranean-type ecosystems results from longer time for speciation, with dispersal away from hotspots limited by narrow and phylogenetically conserved environmental niches. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  1. STRATEGIC ENTREPRENEURSHIP: A CASE IN THE BRAZILIAN AUTOMOBILE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Afonso Carneiro Lima

    2010-07-01

    Full Text Available This work addresses an entrepreneurial phenomenon of strategic administration within the automobile industry: the creation of the automaker Troller Veículos Especiais (TVE. The case study at hand is justified by the positioning of this company around two market niches and its relative success in an industry characterized by few and powerful players. Our aim was to analyze the entrepreneurial and strategic process of discovering opportunity, the analysis used for internal and external factors, and the adoption of its strategic positioning in exploring two automobile market niches: in the B2B market, vehicles adapted to specific operational functions; and in the B2C, off-road vehicles with a strong appeal to consumers’ life styles. This case study allowed us to visualize the challenging path of a genuinely Brazilian small company in a sector dominated by large multinational groups, besides demonstrating decision-related dilemmas and aspects related to managerial creativity.Key-words: Automobile industry. Case study. Strategic entrepreneurship. Discovery theory. Strategic positioning.

  2. Follow the Leaders: competition in the Brazilian Auto Financing Sector

    Directory of Open Access Journals (Sweden)

    Rodrigo M. S. Moita

    2014-09-01

    Full Text Available This study seeks to understand the competitive pattern and strategy of the firms in the Brazilian automobile financing market. First, we analyzed the strong segmentation observed in this market, determining market niches. We then estimated reaction functions to price changes. The results indicated that the three largest companies in the sector have a strong influence on interest rate setting within the entire segment. This phenomenon characterizes the competition of this sector as the leader-follower type, rather than Bertrand competition, the latter of which is often expected in the banking sector and it demonstrates the existence of the leading firms' market power.

  3. Identifying niche-mediated regulatory factors of stem cell phenotypic state: a systems biology approach.

    Science.gov (United States)

    Ravichandran, Srikanth; Del Sol, Antonio

    2017-02-01

    Understanding how the cellular niche controls the stem cell phenotype is often hampered due to the complexity of variegated niche composition, its dynamics, and nonlinear stem cell-niche interactions. Here, we propose a systems biology view that considers stem cell-niche interactions as a many-body problem amenable to simplification by the concept of mean field approximation. This enables approximation of the niche effect on stem cells as a constant field that induces sustained activation/inhibition of specific stem cell signaling pathways in all stem cells within heterogeneous populations exhibiting the same phenotype (niche determinants). This view offers a new basis for the development of single cell-based computational approaches for identifying niche determinants, which has potential applications in regenerative medicine and tissue engineering. © 2017 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  4. Not all renal stem cell niches are the same: anatomy of an evolution

    Directory of Open Access Journals (Sweden)

    Clara Gerosa

    2016-08-01

    Full Text Available The renal stem cell niche represents the most important structure of the developing kidney, responsible for nephrogenesis. Recently, some Authors have reported, at ultrastructural level, a previously unknown complexity of the architecture of renal stem cell niche in experimental models. This study was aimed at studying, at histological level, the anatomy of renal stem cell niches in the human fetal kidney. To this end, ten fetal kidneys, whose gestational ages ranged from 11 up to 24 weeks, were studied. H&E-stained sections were observed at high power. The study of the anatomy of renal stem cell niches in the human kidney revealed a previously unreported complexity: some niches appeared as a roundish arrangement of mesenchymal cells; others showed the initial phases of induction by ureteric buds; in other niches the process of mesenchymal epithelial transition was more evident; finally, in other stem cell niches the first signs of nephron origin were detectable. These findings suggest the existence of niches with different anatomy in the same kidney, indicating different stages of evolution even in adjacent niches. All stem cell niches were in strict contact with the capsular cells, suggesting a major role of the renal capsule in nephrogenesis. Finally, our study confirms the existence of a strict contact between the bud tip cells and the surrounding mesenchyme in the human developing kidney, giving a morphological support to the theory of intercellular channels allowing the passage of transcription factors from the epithelial to the mesenchymal stem/progenitors cells.Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

  5. Range bagging: a new method for ecological niche modelling from presence-only data.

    Science.gov (United States)

    Drake, John M

    2015-06-06

    The ecological niche is the set of environments in which a population of a species can persist without introduction of individuals from other locations. A good mathematical or computational representation of the niche is a prerequisite to addressing many questions in ecology, biogeography, evolutionary biology and conservation. A particularly challenging question for ecological niche modelling is the problem of presence-only modelling. That is, can an ecological niche be identified from records drawn only from the set of niche environments without records from non-niche environments for comparison? Here, I introduce a new method for ecological niche modelling from presence-only data called range bagging. Range bagging draws on the concept of a species' environmental range, but was inspired by the empirical performance of ensemble learning algorithms in other areas of ecological research. This paper extends the concept of environmental range to multiple dimensions and shows that range bagging is computationally feasible even when the number of environmental dimensions is large. The target of the range bagging base learner is an environmental tolerance of the species in a projection of its niche and is therefore an ecologically interpretable property of a species' biological requirements. The computational complexity of range bagging is linear in the number of examples, which compares favourably with the main alternative, Qhull. In conclusion, range bagging appears to be a reasonable choice for niche modelling in applications in which a presence-only method is desired and may provide a solution to problems in other disciplines where one-class classification is required, such as outlier detection and concept learning.

  6. Biodiversity influences plant productivity through niche-efficiency.

    Science.gov (United States)

    Liang, Jingjing; Zhou, Mo; Tobin, Patrick C; McGuire, A David; Reich, Peter B

    2015-05-05

    The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.

  7. Hospital usage of marketing research over a ten year period.

    Science.gov (United States)

    Sanchez, P M

    1995-01-01

    The acceptance and use of marketing techniques and concepts in the health care area is a phenomenon well known to most marketers. Prior to 1979, marketing in the health care field was relatively unknown. Since that time, however, the growth of health care marketing has not been accompanied by commensurate growth in marketing research efforts.

  8. Integrating Sustainability Education into International Marketing Curricula

    Science.gov (United States)

    Perera, Chamila Roshani; Hewege, Chandana Rathnasiri

    2016-01-01

    Purpose: The purpose of this study is to extend the current knowledge of curriculum developments in international business and marketing curricula. Integrating sustainability into business and marketing curricula of the universities are widely debated in previous literature. Sustainability is a global phenomenon; however, curriculum development…

  9. The human and murine hematopoietic stem cell niches: are they comparable?

    Science.gov (United States)

    van Pel, Melissa; Fibbe, Willem E; Schepers, Koen

    2016-04-01

    Hematopoietic stem cells (HSCs) reside in specific niches that provide various instructive cues that regulate HSC self-renewal and their development into all mature cells of the peripheral blood. Progress in this research field has largely been guided by mouse studies. However, parallel studies with human subjects, tissues, and cells, in combination with xenotransplantation experiments in immunodeficient mice, have contributed to our increased understanding of the human HSC niche. Here, we summarize our current knowledge of the various specialized subsets of both stromal and hematopoietic cells that support HSCs through cell-cell interactions and secreted factors, and the many parallels between the murine and human HSC niches. Furthermore, we discuss recent technological advances that are likely to improve our understanding of the human HSC niche, a better understanding of which may allow further identification of unique molecular and cellular pathways in the HSC niche. This information may help to further improve the outcome of HSC transplantation and refine the treatment of hematopoietic diseases. © 2015 New York Academy of Sciences.

  10. Social media marketing : Acquiring customer loyalty and relationship management using social media as a marketing channel

    OpenAIRE

    Saqib, Muhammad

    2016-01-01

    Abstract Social media is a marketing phenomenon that is growing very fast. Social media helps creating value for customers in broadcasting the advertising among social networks. Blog posts, videos, pictures, reviews and ratings all have a significant impact on marketing. The purpose of the thesis is to investigate how companies can achieve customer loyalty and customer relationship management using social media marketing and if companies can target new customers by social media. An inductive ...

  11. EMPIRICAL REFLECTIONS ON MIGRATION PHENOMENON. MAJOR EFFECTS OF MIGRATION ON THE HUMAN CAPITAL

    Directory of Open Access Journals (Sweden)

    Simona BUTA

    2013-12-01

    Full Text Available The paper Empirical reflections on migration phenomenon. Major effects of migration on the human capital analyzes the migration flows of the workforce (as part of the human capital globally/regionally, especially the highly qualified workforce migration. The qualified manpower processes of attracting on the work market have not been always well understood and, in some cases, have generated a series of difficulties. This is the reason why we will focus on the „waste of brains” phenomenon, which appears when highly qualified individuals are neither employed in the source-country nor in the target country; and, if they are, their job is below their qualifications.

  12. Macrophytes shape trophic niche variation among generalist fishes.

    Directory of Open Access Journals (Sweden)

    Ivana Vejříková

    Full Text Available Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N and carbon (δ13C isotopic mixing models, perch (Perca fluviatilis L. and rudd (Scardinius erythrophthalmus (L. showed larger individual variation (i.e., variance in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.. Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence

  13. Macrophytes shape trophic niche variation among generalist fishes

    Science.gov (United States)

    Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, Mikko; Peterka, Jiří

    2017-01-01

    Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall

  14. The e-book phenomenon: a disruptive technology

    Directory of Open Access Journals (Sweden)

    Tom D. Wilson

    2014-03-01

    Full Text Available The emergence of the e-book as a major phenomenon in the publishing industry is of interest, world-wide. The English language market, with Amazon.com as the major player in the market may have dominated attention, but the e-book has implications for many other languages and book markets. The pre-e-book publishing world can be seen as a system in which authors delivered texts to publishers, who evaluated, edited, printed and distributed the published text to bookshops and thence to libraries and individual readers. This process has been going on since Gutenberg’s re-invention of movable type in about 1439 (following its original invention in China in the 9th century, and the use of metallic type in Korea in 1234, in other words, for about the past 550 years. The invention of movable type was an instance of a disruptive technology: eventually putting monastic scribes out of business altogether. Similarly, the e-book has the potential to disrupt the processes for the production, distribution and use of authorial texts, and is already in the process of doing so. First, the phenomenon of self-publishing has emerged as a serious contender to the more formal process; secondly, publishers may derive significant economic benefit from the reduction in printing and distribution costs, as well as the ability to sell directly to the consumer through their own Websites; thirdly, the impact on booksellers may result in a further reduction in the number of independent stores – a decline already in process as a result of online bookselling; fourthly, user demand is resulting in libraries wrestling with the problems of how to manage e-books within their collection development and management processes; and, finally, the behaviour of readers is changing as the devices available for using e-books become more numerous and cheaper. Only someone blessed with absolute certainty in forecasting the future can know exactly how things will change, but there is little

  15. A practioner's view on Strategic Niche Management

    International Nuclear Information System (INIS)

    Mourik, R.; Raven, R.P.J.M.

    2006-11-01

    Strategic Niche Management (SNM) is a tool to support the societal introduction of radical sustainable innovations. However, it has been mainly used in retrospective to analyse historical case studies. This report discusses SNM from a practioner's perspective with the main aim to articulate questions that should be addressed for translating SNM from an ex-post to an ex-ante tool. The main conclusion is that an SNM tool should focus on the level of 'niches' rather than single projects, i.e. SNM should aim to support (program) managers who aim at orchestrating the interaction between multiple experiments

  16. A study on the asymmetry of the news aspect of the stock market: Evidence from three institutional investors in the Taiwan stock market

    Directory of Open Access Journals (Sweden)

    Yang Tzu-Yi

    2015-01-01

    Full Text Available This paper uses daily data to investigate the behavior of institutional investors in Taiwan’s stock market. We adopted TGARCH and EGARCH models to test various news. We found that, for the entire sample, a significant clustering phenomenon exists in the investment behavior of three institutional investors, and the impact due to a change of news content shows significant asymmetry and leverage effects. That is, the impact of bad news from the market is stronger than that of good news. In addition, an asymmetric phenomenon can also be seen for the international news aspect as responded to by foreign institutional investors. This phenomenon is more significant than those of the dealers and institutional trust investors. Moreover, the asymmetric phenomenon as responded to by the dealers for domestic news is more significant than those of foreign investors and institutional trust investors.

  17. ONLINE MARKETING. CHALLENGES AND OPORTUNITIES FOR THE MILITARY HIGHER EDUCATION

    OpenAIRE

    Gheorghe MINCULETE; Maria -Ana CHISEGA-NEGRILA

    2013-01-01

    The impact of the Internet on marketing is a radical phenomenon whose elements are diffi cult to quantify. The explosive dynamics of the phenomenon has determined unpredictable evolutions, shaking the very foundations of modern economics, and putting to the test modern managers’ ability, intelligence, and capacity to adapt. In this situation, online marketing is a challenge to organizations, taking into account the opportunities offered by the Internet at global level. In higher education, on...

  18. Optimization of Femtosecond Laser Polymerized Structural Niches to Control Mesenchymal Stromal Cell Fate in Culture

    Directory of Open Access Journals (Sweden)

    Manuela T. Raimondi

    2014-06-01

    Full Text Available We applied two-photon polymerization to fabricate 3D synthetic niches arranged in complex patterns to study the effect of mechano-topological parameters on morphology, renewal and differentiation of rat mesenchymal stromal cells. Niches were formed in a photoresist with low auto-fluorescence, which enabled the clear visualization of the fluorescence emission of the markers used for biological diagnostics within the internal niche structure. The niches were structurally stable in culture up to three weeks. At three weeks of expansion in the niches, cell density increased by almost 10-fold and was 67% greater than in monolayer culture. Evidence of lineage commitment was observed in monolayer culture surrounding the structural niches, and within cell aggregates, but not inside the niches. Thus, structural niches were able not only to direct stem cell homing and colony formation, but also to guide aggregate formation, providing increased surface-to-volume ratios and space for stem cells to adhere and renew, respectively.

  19. Language and other artifacts: socio-cultural dynamics of niche construction

    Science.gov (United States)

    Sinha, Chris

    2015-01-01

    Niche construction theory is a relatively new approach in evolutionary biology that seeks to integrate an ecological dimension into the Darwinian theory of evolution by natural selection. It is regarded by many evolutionary biologists as providing a significant revision of the Neo-Darwinian modern synthesis that unified Darwin’s theory of natural and sexual selection with 20th century population genetics. Niche construction theory has been invoked as a processual mediator of social cognitive evolution and of the emergence and evolution of language. I argue that language itself can be considered as a biocultural niche and evolutionary artifact. I provide both a general analysis of the cognitive and semiotic status of artifacts, and a formal analysis of language as a social and semiotic institution, based upon a distinction between the fundamental semiotic relations of “counting as” and “standing for.” I explore the consequences for theories of language and language learning of viewing language as a biocultural niche. I suggest that not only do niches mediate organism-organism interactions, but also that organisms mediate niche-niche interactions in ways that affect evolutionary processes, with the evolution of human infancy and childhood as a key example. I argue that language as a social and semiotic system is not only grounded in embodied engagements with the material and social-interactional world, but also grounds a sub-class of artifacts of particular significance in the cultural history of human cognition. Symbolic cognitive artifacts materially and semiotically mediate human cognition, and are not merely informational repositories, but co-agentively constitutive of culturally and historically emergent cognitive domains. I provide examples of the constitutive cognitive role of symbolic cognitive artifacts drawn from my research with my colleagues on cultural and linguistic conceptualizations of time, and their cultural variability. I conclude by

  20. Organic food provision strategies of a niche market in Bangkok

    Directory of Open Access Journals (Sweden)

    Kantamaturapoj, K.

    2013-03-01

    Full Text Available Any increase in the level of sustainable food consumption in Bangkok requires both providers and consumers to change their behavior and strategies in a more sustainable direction. This paper focuses on provider’s side and examines the strategies that food providers in Bangkok use to reach the Thai consumers with their sustainable food offers. This paper looks at the “niche” specialized shops which are the first group of organic food provider and currently provide organic food to consumers in Bangkok. A focus group discussion was organized with representatives of the specialized shops in order to discuss and to assess a number of different strategies that could be applied when trying to sell organic food to consumers in Bangkok. The study found that the specialized shops in Bangkok are “small, specialized and beautiful”. The specialized shops in Bangkok form the “Green Market Network” to work together and empower individual shop owners. The major tasks of the network are to procure sufficient sustainable food from reliable sources for the individual shops, to improve their businesses by learning from each other’s experiences and to expand the market for their products. The specialized shops are not so much focused on certification but, instead rely on trust. The specialized shops communicate with consumers in an informal and friendly way, talking directly to them in the shop and organizing activities with them.

  1. Raynaud's phenomenon

    DEFF Research Database (Denmark)

    Nielsen, S L; Christensen, N J; Olsen, N

    1980-01-01

    . The forearm venous concentration of noradrenaline was lower and adrenaline concentration higher in the sympathectomized patients than in the other groups (p less than 0,05). Noradrenaline showed a significant increase during body cooling in normals and primary Raynaud's (p less than 0......The reaction to body and finger cooling was recorded in seven patients with relapse of primary Raynaud's phenomenon after sufficiently performed bilateral upper thoracic sympathectomy and for comparison in eight young women with primary Raynaud's phenomenon as well as in seven normal women......,05). There was no significant correlation between the vasoconstrictor response to cooling of a finger and the noradrenaline concentration probably due to the fact that skin vasoconstriction impeded release of noradrenaline from the skin. The relapse of Raynaud's phenomenon after surgically sufficient sympathectomy could...

  2. Stem Cell Plasticity and Niche Dynamics in Cancer Progression.

    Science.gov (United States)

    Picco, Noemi; Gatenby, Robert A; Anderson, Alexander R A

    2017-03-01

    Cancer stem cells (CSCs) have been hypothesized to initiate and drive tumor growth and recurrence due to their self-renewal ability. If correct, this hypothesis implies that successful therapy must focus primarily on eradication of this CSC fraction. However, recent evidence suggests stemness is niche dependent and may represent one of many phenotypic states that can be accessed by many cancer genotypes when presented with specific environmental cues. A better understanding of the relationship of stemness to niche-related phenotypic plasticity could lead to alternative treatment strategies. Here, we investigate the role of environmental context in the expression of stem-like cell properties through in-silico simulation of ductal carcinoma. We develop a two-dimensional hybrid discrete-continuum cellular automata model to describe the single-cell scale dynamics of multicellular tissue formation. Through a suite of simulations, we investigate interactions between a phenotypically heterogeneous cancer cell population and a dynamic environment. We generate homeostatic ductal structures that consist of a mixture of stem and differentiated cells governed by both intracellular and environmental dynamics. We demonstrate that a wide spectrum of tumor-like histologies can result from these structures by varying microenvironmental parameters. Niche driven phenotypic plasticity offers a simple first-principle explanation for the diverse ductal structures observed in histological sections from breast cancer. Conventional models of carcinogenesis largely focus on mutational events. We demonstrate that variations in the environmental niche can produce intraductal cancers independent of genetic changes in the resident cells. Therapies targeting the microenvironmental niche may offer an alternative cancer prevention strategy.

  3. Competition in a technological niche: the cars of the future

    NARCIS (Netherlands)

    Bakker, S.; Lente, H. van; Engels, R.

    2012-01-01

    The notion of ‘niche’has proved to be useful to account for the emergence of radical innovations. Most studies, however, deal with the development of single emerging technologies. In this paper we address the competition between multiple niche technologies.Within the niche of the ‘car of the future’

  4. Testing the niche variation hypothesis with a measure of body condition

    Science.gov (United States)

    Individual variation and fitness are cornerstones of evolution by natural selection. The niche variation hypothesis (NVH) posits that when interspecific competition is relaxed, intraspecific competition should drive niche expansion by selection favoring use of novel resources. Po...

  5. Evidence of niche shift and invasion potential of Lithobates catesbeianus in the habitat of Mexican endemic frogs.

    Directory of Open Access Journals (Sweden)

    Jorge Luis Becerra López

    Full Text Available Invasive alien species are one of most severe threats to biodiversity and natural resources. These biological invasions have been studied from the niche conservatism and niche shifts perspective. Niche differentiation may result from changes in fundamental niche or realized niche or both; in biological invasions, niche differences between native and non-native ranges can appear through niche expansion, niche unfilling and niche stability. The American bullfrog Lithobates catesbeianus is an invasive species that can have negative impacts on native amphibian populations. This research examines the climate niche shifts of this frog, its potential range of expansion in Mexico and the risk of invasion by bullfrog in the habitats of 82 frog species endemic to Mexico, that based on their climatic niche similarity were divided in four ecological groups. The results indicate that species in two ecological groups were the most vulnerable to invasion by bullfrog. However, the climate niche shifts of L. catesbeianus may allow it to adapt to new environmental conditions, so species from the two remaining groups cannot be dismissed as not vulnerable. This information is valuable for decision making in prioritizing areas for conservation of Mexican endemic frogs.

  6. Biogeochemical and Ecomorphological Niche Segregation of Mediterranean Woody Species along a Local Gradient

    Directory of Open Access Journals (Sweden)

    Enrique G. de la Riva

    2017-07-01

    Full Text Available According with niche theory the species are specialized in different ecological niches, being able to coexist as result of a differential use of resources. In this context, the biogeochemical niche hypothesis proposes that species have an optimal elemental composition which results from the link between the chemical and morphological traits for the optimum plant functioning. Thus, and attending to the limiting similarity concept, different elemental composition and plant structure among co-occurring species may reduce competition, promoting different functional niches. Different functional habits associated with leaf life-span or growth forms are associated with different strategies for resource uptake, which could promote niche partitioning. In the present study, based on the biogeochemical niche concept and the use of resources in different proportions, we have focused on leaf traits (morphological and chemical associated with resource uptake, and explored the niche partitioning among functional habits: leaf life-span (deciduous, evergreen, and semideciduous and growth (tree, shrub, and arborescent-shrub. To this end, we have quantified the hypervolume of the leaf functional trait space (both structure and chemical composition in a sample of 45 Mediterranean woody species from Sierra Morena Mountains (Spain growing along a local soil resource gradient. Our results show consistent variation in functional space for woody communities distributed along the environmental gradient. Thus, communities dominated by deciduous trees with faster growth and a predominant acquisitive strategy were characteristic of bottom forests and showed highest leaf biogeochemical space. While semideciduous shrubs and evergreen (arborescent, trees species, characterized by a conservative strategy, dominated ridge forests and showed smaller functional space. In addition, within each topographical zone or environment type, the foliar biogeochemical niche partitioning

  7. Biogeochemical and Ecomorphological Niche Segregation of Mediterranean Woody Species along a Local Gradient.

    Science.gov (United States)

    de la Riva, Enrique G; Marañón, Teodoro; Violle, Cyrille; Villar, Rafael; Pérez-Ramos, Ignacio M

    2017-01-01

    According with niche theory the species are specialized in different ecological niches, being able to coexist as result of a differential use of resources. In this context, the biogeochemical niche hypothesis proposes that species have an optimal elemental composition which results from the link between the chemical and morphological traits for the optimum plant functioning. Thus, and attending to the limiting similarity concept, different elemental composition and plant structure among co-occurring species may reduce competition, promoting different functional niches. Different functional habits associated with leaf life-span or growth forms are associated with different strategies for resource uptake, which could promote niche partitioning. In the present study, based on the biogeochemical niche concept and the use of resources in different proportions, we have focused on leaf traits (morphological and chemical) associated with resource uptake, and explored the niche partitioning among functional habits: leaf life-span (deciduous, evergreen, and semideciduous) and growth (tree, shrub, and arborescent-shrub). To this end, we have quantified the hypervolume of the leaf functional trait space (both structure and chemical composition) in a sample of 45 Mediterranean woody species from Sierra Morena Mountains (Spain) growing along a local soil resource gradient. Our results show consistent variation in functional space for woody communities distributed along the environmental gradient. Thus, communities dominated by deciduous trees with faster growth and a predominant acquisitive strategy were characteristic of bottom forests and showed highest leaf biogeochemical space. While semideciduous shrubs and evergreen (arborescent, trees) species, characterized by a conservative strategy, dominated ridge forests and showed smaller functional space. In addition, within each topographical zone or environment type, the foliar biogeochemical niche partitioning would underlie the

  8. Intersexual trophic niche partitioning in an ant-eating spider (Araneae: Zodariidae.

    Directory of Open Access Journals (Sweden)

    Stano Pekár

    2011-01-01

    Full Text Available Divergence in trophic niche between the sexes may function to reduce competition between the sexes ("intersexual niche partitioning hypothesis", or may be result from differential selection among the sexes on maximizing reproductive output ("sexual selection hypothesis". The latter may lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning.Comparative analysis of trophic morphology (the chelicerae and body size of males, females and juveniles demonstrated highly female biased SSD (Sexual Size Dimorphism in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size, and larger than ants captured by juveniles and males. Female fecundity was highly positively correlated with female body mass, which reflects foraging success during the adult stage. Females in laboratory experiments preferred the large ant sub-castes and displayed higher capture efficiency. In contrast, males occupied a different trophic niche and showed reduced foraging effort and reduced prey capture and feeding efficiency compared with females and juveniles.Our data indicate that female-biased dimorphism in trophic morphology and body size correlate with sex-specific reproductive strategies. We propose that intersexual trophic niche partitioning is shaped primarily by fecundity selection in females, and results from sex-differences in the route to successful reproduction where females are

  9. Trophic Niche Differentiation in Rodents and Marsupials Revealed by Stable Isotopes.

    Directory of Open Access Journals (Sweden)

    Mauro Galetti

    Full Text Available Tropical rainforests support the greatest diversity of small mammals in the world, yet we have little understanding about the mechanisms that promote the coexistence of species. Diet partitioning can favor coexistence by lessening competition, and interspecific differences in body size and habitat use are usually proposed to be associated with trophic divergence. However, the use of classic dietary methods (e.g. stomach contents is challenging in small mammals, particularly in community-level studies, thus we used stable isotopes (δ13C and δ15N to infer about trophic niche. We investigated i how trophic niche is partitioned among rodent and marsupial species in three Atlantic forest sites and ii if interspecific body size and locomotor habit inequalities can constitute mechanisms underlying the isotopic niche partitioning. We found that rodents occupied a broad isotopic niche space with species distributed in different trophic levels and relying on diverse basal carbon sources (C3 and C4 plants. Surprisingly, on the other hand, marsupials showed a narrow isotopic niche, both in δ13C and δ15N dimensions, which is partially overlapped with rodents, contradicting their description as omnivores and generalists proposed classic dietary studies. Although body mass differences did not explained the divergence in isotopic values among species, groups of species with different locomotor habit presented clear differences in the position of the isotopic niche space, indicating that the use of different forest strata can favor trophic niche partitioning in small mammals communities. We suggest that anthropogenic impacts, such as habitat modification (logging, harvesting, can simplify the vertical structure of ecosystems and collapse the diversity of basal resources, which might affect negatively small mammals communities in Atlantic forests.

  10. Commodifying snow, taming the waters. Socio-ecological niche construction in an Alpine village.

    Science.gov (United States)

    Gross, Robert; Winiwarter, Verena

    White belts of snow clad mountains all over the world each winter. Even if there is no snow, the tourism industry is able to produce the white finery at the push of the button, thereby consuming large amounts of water. Studying Damüls, a well-known ski resort in Austria's westernmost province Vorarlberg, we can show that the development of a service sector within agro-pastoral landscapes was connected with novel water uses and massive interventions into Alpine landscapes. Human niche construction theory offers a unique avenue for studying the development of Alpine communities, but also highlights side effects accompanying the change from agrarian to tourism livelihoods. One aim of this paper is to broaden the scope of human niche construction theory. Inceptive, counteractive and relocational niche construction activities were coupled to the differentiation of actor groups. To incorporate social dynamics, indispensable for studies in environmental history, we propose the concept of socio-ecological niche construction. The paper investigates how villagers balanced resource limitations typical for an agrarian society with the differentiation of sub-niches, mediating selective forces on the population. When the valleys were industrialized, Damüls was almost given up as a permanent settlement. Then, tourists entered the stage, by and by turning the wheel of local development into a different direction. A tourism niche based on natural snow evolved from the 1930s onwards. While the socio-ecological niches of agriculture and tourism coexisted in the interwar years, this changed when ski lifts were built, embedded into a debt-based economy that made the tourism niche vulnerable to snow availability. Snow-dependency became a powerful selective force. It was mediated by the ski lift companies through a range of niche construction activities that turned water into an important resource of snowmaking systems.

  11. Improved Predictions of the Geographic Distribution of Invasive Plants Using Climatic Niche Models

    Science.gov (United States)

    Ramírez-Albores, Jorge E.; Bustamante, Ramiro O.

    2016-01-01

    Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of

  12. Tug of war in the haematopoietic stem cell niche: do myeloma plasma cells compete for the HSC niche?

    Science.gov (United States)

    Noll, J E; Williams, S A; Purton, L E; Zannettino, A C W

    2012-09-14

    In the adult mammal, normal haematopoiesis occurs predominantly in the bone marrow, where primitive haematopoietic stem cells (HSC) and their progeny reside in specialised microenvironments. The bone marrow microenvironment contains specific anatomical areas (termed niches) that are highly specialised for the development of certain blood cell types, for example HSCs. The HSC niche provides important cell-cell interactions and signalling molecules that regulate HSC self-renewal and differentiation processes. These same signals and interactions are also important in the progression of haematological malignancies, such as multiple myeloma (MM). This review provides an overview of the bone marrow microenvironment and its involvement in normal, physiological HSC maintenance and plasma cell growth throughout MM disease progression.

  13. Socializing with the neighbors: stem cells and their niche.

    Science.gov (United States)

    Fuchs, Elaine; Tumbar, Tudorita; Guasch, Geraldine

    2004-03-19

    The potential of stem cells in regenerative medicine relies upon removing them from their natural habitat, propagating them in culture, and placing them into a foreign tissue environment. To do so, it is essential to understand how stem cells interact with their microenvironment, the so-called stem cell niche, to establish and maintain their properties. In this review, we examine adult stem cell niches and their impact on stem cell biology.

  14. The influence of social niche on cultural niche construction: modelling changes in belief about marriage form in Taiwan

    Science.gov (United States)

    Lipatov, Mikhail; Brown, Melissa J.; Feldman, Marcus W.

    2011-01-01

    With introduction of social niche effects into a model of cultural change, the frequency of a practice cannot predict the frequency of its underlying belief. The combination of a general model with empirical data from a specific case illustrates the importance of collaboration between modellers and field researchers, and identifies the type of quantitative data necessary for analysing case studies. Demographic data from colonial-period household registers in Taiwan document a shift in marriage form within 40 years, from a mixture of uxorilocal marriages and virilocal marriages to the latter's dominance. Ethnographic data indicate marriage-related beliefs, costs, ethnic effects and colonial policies as well as the importance of horizontal cultural transmission. We present a formal model for the effects of moral beliefs about marriage and a population economic index on the decline of uxorilocal marriage. We integrate empirical marriage rates and an estimated economic index to produce five projections of the historical frequencies of one belief. These projections demonstrate how economic development may affect a cultural niche. They also indicate the need for future research on the relationship between wealth and cultural variability, the motivational force of cultural versus social factors, and the process of cultural niche construction. PMID:21320903

  15. Citizen-science, Geoethics and Human Niche

    Science.gov (United States)

    Bohle, Martin

    2017-04-01

    The anthropogenic biogeosphere or 'human niche' is the intersection of the biogeosphere and the sphere of human activities of social, economic, cultural and political nature. The application case for geoethics, namely "appropriate behaviours and practices, wherever human activities interact with the Earth system" [1], is about niche building. Geoethics is about the conduct of people and geoscientists, respectively their ordinary lifestyles and professional activities. Geoscience professionals notice the diverse economic, social and cultural living conditions of people, and the application cases of geosciences mirror the diversity of the global social sphere. Subsequently it is argued: A) when considering the ethical dimensions of global niche building then geosciences should feature 'citizen geoscience'; and B) when considering the functioning of a knowledge-based society under conditions of anthropogenic global change then 'citizen geoscience' facilitates applying that knowledge base. (A) Regarding 'niche building': The design of production systems and consumption patterns embeds geoscience know-how and relates it to the everyday life. Any citizen's activities purposefully interconnect to the biogeosphere for well-being, care-taking, and reproduction, although habitually without involving a geoscientist in professional capacity. In that implicit manner the everyday behaviours and practices of people influence Earth system dynamic. This renders their inherent geoscience know-how a public good as it makes their ignorance a public risk. A comfortable human niche for billions of people requires a global biogeosphere that is disrupted little by citizens' activities and exposes them to hazards that can be tamed. Quite the reverse, anthropogenic global change will disturb living conditions for many citizen. Much geoscience know-how will have to be deployed to tame disturbances in a socially sustainable manner. Sustainability in turn needs involvement of citizens in

  16. Pre-metastatic niches

    DEFF Research Database (Denmark)

    Peinado, Héctor; Zhang, Haiying; Matei, Irina R.

    2017-01-01

    It is well established that organs of future metastasis are not passive receivers of circulating tumour cells, but are instead selectively and actively modified by the primary tumour before metastatic spread has even occurred. Sowing the 'seeds' of metastasis requires the action of tumour......-secreted factors and tumour-shed extracellular vesicles that enable the 'soil' at distant metastatic sites to encourage the outgrowth of incoming cancer cells. In this Review, we summarize the main processes and new mechanisms involved in the formation of the pre-metastatic niche....

  17. The multi-niche crowding genetic algorithm: Analysis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Cedeno, Walter [Univ. of California, Davis, CA (United States)

    1995-09-01

    The ability of organisms to evolve and adapt to the environment has provided mother nature with a rich and diverse set of species. Only organisms well adapted to their environment can survive from one generation to the next, transferring on the traits, that made them successful, to their offspring. Competition for resources and the ever changing environment drives some species to extinction and at the same time others evolve to maintain the delicate balance in nature. In this disertation we present the multi-niche crowding genetic algorithm, a computational metaphor to the survival of species in ecological niches in the face of competition. The multi-niche crowding genetic algorithm maintains stable subpopulations of solutions in multiple niches in multimodal landscapes. The algorithm introduces the concept of crowding selection to promote mating among members with qirnilar traits while allowing many members of the population to participate in mating. The algorithm uses worst among most similar replacement policy to promote competition among members with similar traits while allowing competition among members of different niches as well. We present empirical and theoretical results for the success of the multiniche crowding genetic algorithm for multimodal function optimization. The properties of the algorithm using different parameters are examined. We test the performance of the algorithm on problems of DNA Mapping, Aquifer Management, and the File Design Problem. Applications that combine the use of heuristics and special operators to solve problems in the areas of combinatorial optimization, grouping, and multi-objective optimization. We conclude by presenting the advantages and disadvantages of the algorithm and describing avenues for future investigation to answer other questions raised by this study.

  18. Ambush marketing is dead ; long live ambush marketing – a re-definition and typology of an increasingly prevalent phenomenon

    OpenAIRE

    Chadwick, SM; Burton, N

    2017-01-01

    Ambush marketing is more than thirty years old, and its prevalence continues to grow. Recent cases indicate that brands perpetrating ambushes are becoming more creative, but the literature has failed to keep pace, offering scant analysis of the different forms that ambushing can take and the implications it can have, and little investigation or consideration from the ambusher’s perspective. This study proposes a new definition of ambushing and typology of the three types of ambush marketing s...

  19. Evolution of the Jatropha Biofuel Niche in Ghana

    DEFF Research Database (Denmark)

    Nygaard, Ivan; Bolwig, Simon

    spanning the period 1995–2004 and including detailed company case studies. Relating to the MLP framework the factors analysed influencing internal niche processes are alignment of expectations, network formation, and learning and knowledge sharing, while those relating to the GVC framework are value chain......, which contributed to the collapse of the jatropha sector in Ghana and thus to the failure to capitalise on the initially high expectations of biofuel production. We also found a low level of learning and knowledgesharing between jatropha niche actors in Ghana, which, alongside weak public R&D support...

  20. The Apple Phenomenon: the Impact of Modern Technologies on Subject

    OpenAIRE

    Kuldová, Michaela

    2013-01-01

    The Apple Phenomenon: the Impact of Modern Technologies on Subject Abstract The goal of the submitted thesis is the study of the company Apple Inc. in the context of how it is percieved by subjects. After a brief introduction of the company Apple Inc. we will focus on semiotic analysis of the brand Apple, its products and marketing strategies. The object of study will be also a present society, whose distinguishing feature is a consumption, and brand perception of a subject in connection with...

  1. AN ANALYSIS OF FUNDING DECISIONS FOR NICHE AGRICULTURAL PRODUCTS

    OpenAIRE

    HOWARD VAN AUKEN; SHAWN CARRAHER

    2012-01-01

    This paper examines the flow of funds from providers of capital to niche agricultural users of capital. Various programs through the US government, state/local economic development and private agencies work to improve the flow of capital to the niche agricultural sector. However, despite the expansion of programs aimed at providing financial resources to the agricultural sector, many sectors remain poorly served. Previous studies have suggested that agencies need to facilitate the flow of cap...

  2. SENSITIVITY OF THE INVESTOR'S TOWARDS STOCK MARKET INVESTMENT

    OpenAIRE

    M. Jaya

    2017-01-01

    Investment in stock market has become a common phenomenon for all the individuals. The growth of stock market contributes to national economic growth only when this growth translates into increased mobilization of resources, return from investment, and minimizing the risk attached to stock market investment. This survey has been conducted to find out the stock market investment pattern and risk diversification of retail equity investors. A well structured questionnaire which is pilot teste...

  3. Ontogenetic specialism in predators with multiple niche shifts prevents predator population recovery and establishment

    NARCIS (Netherlands)

    van Leeuwen, A.; Huss, M.; Gårdmark, A.; de Roos, A.M.

    2014-01-01

    The effects of ontogenetic niche shifts on community structure and dynamics are underexplored, despite the occurrence of such shifts in the majority of animal species. We studied the form of niche shifts in a predator that exhibits multiple ontogenetic niche shifts, and analyzed how this life

  4. Niche conservatism and phylogenetic clustering in a tribe of arid-adapted marsupial mice, the Sminthopsini.

    Science.gov (United States)

    García-Navas, Vicente; Westerman, Michael

    2018-05-28

    The progressive expansion of the Australian arid zone during the last 20 Ma appears to have spurred the diversification of several families of plants, vertebrates and invertebrates, yet such taxonomic groups appear to show limited niche radiation. Here, we test whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence in a tribe of marsupial mice (Sminthopsini; 23 taxa) that includes the most speciose genus of living dasyurids, the sminthopsins. To that end, we integrated phylogenetic data with ecological niche modelling, to enable us to reconstruct the evolution of climatic suitability within Sminthopsini. Niche overlap among species was low-moderate (but generally higher than expected given environmental background similarity), and the degree of phylogenetic clustering increased with aridity. Climatic niche reconstruction illustrates that there has been little apparent evolution of climatic tolerance within clades. Accordingly, climatic disparity tends to be accumulated among clades, suggesting considerable niche conservatism. Our results also indicate that evolution of climatic tolerances has been heterogeneous across different dimensions of climate (temperature vs. precipitation) and across phylogenetic clusters (Sminthopsis murina group vs. other groups). Although some results point to the existence of shifts in climatic niches during the speciation of sminthopsins, our study provides evidence for substantial phylogenetic niche conservatism in the group. We conclude that niche diversification had a low impact on the speciation of this tribe of small, but highly mobile marsupials. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  5. Environmental niche models for riverine desert fishes and their similarity according to phylogeny and functionality

    Science.gov (United States)

    Whitney, James E.; Whittier, Joanna B.; Paukert, Craig P.

    2017-01-01

    Environmental filtering and competitive exclusion are hypotheses frequently invoked in explaining species' environmental niches (i.e., geographic distributions). A key assumption in both hypotheses is that the functional niche (i.e., species traits) governs the environmental niche, but few studies have rigorously evaluated this assumption. Furthermore, phylogeny could be associated with these hypotheses if it is predictive of functional niche similarity via phylogenetic signal or convergent evolution, or of environmental niche similarity through phylogenetic attraction or repulsion. The objectives of this study were to investigate relationships between environmental niches, functional niches, and phylogenies of fishes of the Upper (UCRB) and Lower (LCRB) Colorado River Basins of southwestern North America. We predicted that functionally similar species would have similar environmental niches (i.e., environmental filtering) and that closely related species would be functionally similar (i.e., phylogenetic signal) and possess similar environmental niches (i.e., phylogenetic attraction). Environmental niches were quantified using environmental niche modeling, and functional similarity was determined using functional trait data. Nonnatives in the UCRB provided the only support for environmental filtering, which resulted from several warmwater nonnatives having dam number as a common predictor of their distributions, whereas several cool- and coldwater nonnatives shared mean annual air temperature as an important distributional predictor. Phylogenetic signal was supported for both natives and nonnatives in both basins. Lastly, phylogenetic attraction was only supported for native fishes in the LCRB and for nonnative fishes in the UCRB. Our results indicated that functional similarity was heavily influenced by evolutionary history, but that phylogenetic relationships and functional traits may not always predict the environmental distribution of species. However, the

  6. Comparison of Hematopoietic and Spermatogonial Stem Cell Niches from the Regenerative Medicine Aspect.

    Science.gov (United States)

    Köse, Sevil; Yersal, Nilgün; Önen, Selin; Korkusuz, Petek

    2018-06-08

    Recent advances require a dual evaluation of germ and somatic stem cell niches with a regenerative medicine perspective. For a better point of view of the niche concept, it is needed to compare the microenvironments of those niches in respect to several components. The cellular environment of spermatogonial stem cells' niche consists of Sertoli cells, Leydig cells, vascular endothelial cells, epididymal fat cells, peritubular myoid cells while hematopoietic stem cells have mesenchymal stem cells, osteoblasts, osteoclasts, megacaryocytes, macrophages, vascular endothelial cells, pericytes and adipocytes in their microenvironment. Not only those cells', but also the effect of the other factors such as hormones, growth factors, chemokines, cytokines, extracellular matrix components, biomechanical forces (like shear stress, tension or compression) and physical environmental elements such as temperature, oxygen level and pH will be clarified during the chapter. Because it is known that the microenvironment has an important role in the stem cell homeostasis and disease conditions, it is crucial to understand the details of the microenvironment and to be able to compare the niche concepts of the different types of stem cells from each other, for the regenerative interventions. Indeed, the purpose of this chapter is to point out the usage of niche engineering within the further studies in the regenerative medicine field. Decellularized, synthetic or non-synthetic scaffolds may help to mimic the stem cell niche. However, the shared or different characteristics of germ and somatic stem cell microenvironments are necessary to constitute a proper niche model. When considered from this aspect, it is possible to produce some strategies on the personalized medicine by using those artificial models of stem cell microenvironment.

  7. New Phenomenon of Commercial Corruption

    Directory of Open Access Journals (Sweden)

    Krzysztof Nowakowski

    2011-07-01

    Full Text Available This article is about increase corruption in private sector as commercial corruption. This establishes a wide understanding of that phenomenon in social science and law. Corruption and bribery are types of fraud and are linked with the private sector too. Although certain types of corruption will decline as the private sector grows and consolidates, other new types involving private sector firms may increase. The commercial corruption can be described as relation inside of an organization and as relation between firms. Corruption in private sector in Poland is connected with social distrust and specific organizational culture, too. Commercial corruption is a familiar feature of their societies and has been the focus of law enforcement and institutional reform. Many others problems do not change the fact that such corruption is a new important problem and causes lost of competitiveness and creates a substitute for fair market and competition in Polish economy and abroad.

  8. A Short Review on the Trend of Mobile Marketing Studies

    Directory of Open Access Journals (Sweden)

    Mohammad Ismail

    2011-07-01

    Full Text Available The purpose of this paper is to elucidate the major classification of the research in mobile marketing. It provides the trend and common approach in mobile marketing research. The paper aims to highlight the significant area in mobile marketing research and the needs for further understanding of the mobile marketing definition and its phenomenon. This paper has significant implications in terms of understanding the classification and the mobile marketing focusing area. This is a general review based on selected approximately forty-six journal publications which are published between year 2005 until 2010 from selected journals. Based on the selected reviewed literatures, the consumers’ adoption research only focuses on a few common areas. There is no agreement among the researchers on definition of mobile marketing and the conceptualization and phenomenon of mobile marketing remain unexplained. The value of this paper is that, it provides the fundamental guidelines for researchers on significant area to focus in the mobile marketing field and it also assists practitioners in identifying the research trend and major classifications which will assist them in designing the product and services to the right target market.

  9. The muscle stem cell niche : regulation of satellite cells during regeneration

    NARCIS (Netherlands)

    Boonen, K.J.M.; Post, M.J.

    2008-01-01

    Satellite cells are considered to be adult skeletal muscle stem cells. Their ability to regenerate large muscle defects is highly dependent on their specific niche. When these cells are cultured in vitro, the loss of this niche leads to a loss of proliferative capacity and defective regeneration

  10. ONLINE MARKETING. CHALLENGES AND OPORTUNITIES FOR THE MILITARY HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    Gheorghe MINCULETE

    2013-10-01

    Full Text Available The impact of the Internet on marketing is a radical phenomenon whose elements are diffi cult to quantify. The explosive dynamics of the phenomenon has determined unpredictable evolutions, shaking the very foundations of modern economics, and putting to the test modern managers’ ability, intelligence, and capacity to adapt. In this situation, online marketing is a challenge to organizations, taking into account the opportunities offered by the Internet at global level. In higher education, online marketing is a rapid way to form and develop the image of an institution regarding not only the implementation of strategies, policies, plans, and educational programs, but also the better use of products and services that accompany the offers according to the requests of beneficiaries or interested users. This article stresses the essential aspects of educational marketing whose requests become viable through e-marketing. To this end, we will approach the mechanism of online marketing, and further, we will concentrate on its applications for higher military education. In addition, we will approach eLearning as a modern electronic system to implement e-marketing objects.

  11. CROSS DRIFT ALCOVE/NICHE UTILITIES ANALYSIS

    International Nuclear Information System (INIS)

    S. Goodin

    1999-01-01

    The purpose of this analysis is to provide the design basis and general arrangement requirements of the non-potable water, waste water, compressed air and ventilation (post excavation) utilities required in support of the Cross Drift alcoves and niches

  12. Making Blood: The Haematopoietic Niche throughout Ontogeny

    Directory of Open Access Journals (Sweden)

    Mohammad A. Al-Drees

    2015-01-01

    Full Text Available Approximately one-quarter of all cells in the adult human body are blood cells. The haematopoietic system is therefore massive in scale and requires exquisite regulation to be maintained under homeostatic conditions. It must also be able to respond when needed, such as during infection or following blood loss, to produce more blood cells. Supporting cells serve to maintain haematopoietic stem and progenitor cells during homeostatic and pathological conditions. This coalition of supportive cell types, organised in specific tissues, is termed the haematopoietic niche. Haematopoietic stem and progenitor cells are generated in a number of distinct locations during mammalian embryogenesis. These stem and progenitor cells migrate to a variety of anatomical locations through the conceptus until finally homing to the bone marrow shortly before birth. Under stress, extramedullary haematopoiesis can take place in regions that are typically lacking in blood-producing activity. Our aim in this review is to examine blood production throughout the embryo and adult, under normal and pathological conditions, to identify commonalities and distinctions between each niche. A clearer understanding of the mechanism underlying each haematopoietic niche can be applied to improving ex vivo cultures of haematopoietic stem cells and potentially lead to new directions for transplantation medicine.

  13. Ecological Niche Modelling of Bank Voles in Western Europe

    Directory of Open Access Journals (Sweden)

    Sara Amirpour Haredasht

    2013-01-01

    Full Text Available The bank vole (Myodes glareolus is the natural host of Puumala virus (PUUV in vast areas of Europe. PUUV is one of the hantaviruses which are transmitted to humans by infected rodents. PUUV causes a general mild form of hemorrhagic fever with renal syndrome (HFRS called nephropathia epidemica (NE. Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover influences disease transmission by controlling both the spatial distribution of vectors or hosts, as well as by facilitating the human contact with them. In this study the use of ecological niche modelling (ENM for predicting the geographical distribution of bank vole population on the basis of spatial climate information is tested. The Genetic Algorithm for Rule-set Prediction (GARP is used to model the ecological niche of bank voles in Western Europe. The meteorological data, land cover types and geo-referenced points representing the locations of the bank voles (latitude/longitude in the study area are used as the primary model input value. The predictive accuracy of the bank vole ecologic niche model was significant (training accuracy of 86%. The output of the GARP models based on the 50% subsets of points used for testing the model showed an accuracy of 75%. Compared with random models, the probability of such high predictivity was low (χ2 tests, p < 10−6. As such, the GARP models were predictive and the used ecologic niche model indeed indicates the ecologic requirements of bank voles. This approach successfully identified the areas of infection risk across the study area. The result suggests that the niche modelling approach can be implemented in a next step towards the development of new tools for monitoring the bank vole’s population.

  14. Ecological niche modelling of bank voles in Western Europe.

    Science.gov (United States)

    Amirpour Haredasht, Sara; Barrios, Miguel; Farifteh, Jamshid; Maes, Piet; Clement, Jan; Verstraeten, Willem W; Tersago, Katrien; Van Ranst, Marc; Coppin, Pol; Berckmans, Daniel; Aerts, Jean-Marie

    2013-01-28

    The bank vole (Myodes glareolus) is the natural host of Puumala virus (PUUV) in vast areas of Europe. PUUV is one of the hantaviruses which are transmitted to humans by infected rodents. PUUV causes a general mild form of hemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica (NE). Vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. Land cover influences disease transmission by controlling both the spatial distribution of vectors or hosts, as well as by facilitating the human contact with them. In this study the use of ecological niche modelling (ENM) for predicting the geographical distribution of bank vole population on the basis of spatial climate information is tested. The Genetic Algorithm for Rule-set Prediction (GARP) is used to model the ecological niche of bank voles in Western Europe. The meteorological data, land cover types and geo-referenced points representing the locations of the bank voles (latitude/longitude) in the study area are used as the primary model input value. The predictive accuracy of the bank vole ecologic niche model was significant (training accuracy of 86%). The output of the GARP models based on the 50% subsets of points used for testing the model showed an accuracy of 75%. Compared with random models, the probability of such high predictivity was low (χ(2) tests, p < 10(-6)). As such, the GARP models were predictive and the used ecologic niche model indeed indicates the ecologic requirements of bank voles. This approach successfully identified the areas of infection risk across the study area. The result suggests that the niche modelling approach can be implemented in a next step towards the development of new tools for monitoring the bank vole's population.

  15. The impostor phenomenon

    DEFF Research Database (Denmark)

    Ringby, Betina; Østergaard, Gert Værge; Bønnelykke, Helle

    Persons suffering from the impostor phenomenon often fail to thrive and might be in danger of dropping out of studies. The impostor-phenomenon relates to people who are both skillful and capable, but sees themselves as frauds and as someone who is not worthy of good grades, appraisal for their work...

  16. Assessing the potential for establishment of western cherry fruit fly using ecological niche modeling.

    Science.gov (United States)

    Kumar, Sunil; Neven, Lisa G; Yee, Wee L

    2014-06-01

    Sweet cherries, Prunus avium (L.) L., grown in the western United States are exported to many countries around the world. Some of these countries have enforced strict quarantine rules and trade restrictions owing to concerns about the potential establishment and subsequent spread of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), a major quarantine pest of sweet cherry. We used 1) niche models (CLIMEX and MaxEnt) to map the climatic suitability, 2) North Carolina State University-Animal and Plant Health Inspection Service Plant Pest Forecasting System to examine chilling requirement, and 3) host distribution and availability to assess the potential for establishment of R. indifferens in areas of western North America where it currently does not exist and eight current or potential fresh sweet cherry markets: Colombia, India, Indonesia, Malaysia, Taiwan, Thailand, Venezuela, and Vietnam. Results from niche models conformed well to the current distribution of R. indifferens in western North America. MaxEnt and CLIMEX models had high performance and predicted climatic suitability in some of the countries (e.g., Andean range in Colombia and Venezuela, northern and northeastern India, central Taiwan, and parts of Vietnam). However, our results showed no potential for establishment of R. indifferens in Colombia, Indonesia, Malaysia, Taiwan, Thailand, Venezuela, and Vietnam when the optimal chilling requirement to break diapause (minimum temperature policy makers.

  17. Novel therapeutic strategies to target leukemic cells that hijack compartmentalized continuous hematopoietic stem cell niches.

    Science.gov (United States)

    Hira, Vashendriya V V; Van Noorden, Cornelis J F; Carraway, Hetty E; Maciejewski, Jaroslaw P; Molenaar, Remco J

    2017-08-01

    Acute myeloid leukemia and acute lymphoblastic leukemia cells hijack hematopoietic stem cell (HSC) niches in the bone marrow and become leukemic stem cells (LSCs) at the expense of normal HSCs. LSCs are quiescent and resistant to chemotherapy and can cause relapse of the disease. HSCs in niches are needed to generate blood cell precursors that are committed to unilineage differentiation and eventually production of mature blood cells, including red blood cells, megakaryocytes, myeloid cells and lymphocytes. Thus far, three types of HSC niches are recognized: endosteal, reticular and perivascular niches. However, we argue here that there is only one type of HSC niche, which consists of a periarteriolar compartment and a perisinusoidal compartment. In the periarteriolar compartment, hypoxia and low levels of reactive oxygen species preserve the HSC pool. In the perisinusoidal compartment, hypoxia in combination with higher levels of reactive oxygen species enables proliferation of progenitor cells and their mobilization into the circulation. Because HSC niches offer protection to LSCs against chemotherapy, we review novel therapeutic strategies to inhibit homing of LSCs in niches for the prevention of dedifferentiation of leukemic cells into LSCs and to stimulate migration of leukemic cells out of niches. These strategies enhance differentiation and proliferation and thus sensitize leukemic cells to chemotherapy. Finally, we list clinical trials of therapies that tackle LSCs in HSC niches to circumvent their protection against chemotherapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Economic and legal conceptual framework of viral marketing

    OpenAIRE

    Kostić Marija; Jovanović-Tončev Melita; Džamić Vladimir; Knežević Miroslav

    2015-01-01

    Electronic and online communications are modern, and perhaps the most common form of communication between individuals and legal entities, and thus have become one of the most used ways of market communication. Viral marketing is evolving into the dominant form of marketing and exchange of information for the purpose of advertising, promoting, or achieving other goals. In this paper we present and analyse the phenomenon of viral marketing-its purpose, effects, and power of influence, and disc...

  19. Pre-procambial cells are niches for pluripotent and totipotent stem-like cells for organogenesis and somatic embryogenesis in the peach palm: a histological study.

    Science.gov (United States)

    de Almeida, Marcilio; de Almeida, Cristina Vieira; Mendes Graner, Erika; Ebling Brondani, Gilvano; Fiori de Abreu-Tarazi, Monita

    2012-08-01

    The direct induction of adventitious buds and somatic embryos from explants is a morphogenetic process that is under the influence of exogenous plant growth regulators and its interactions with endogenous phytohormones. We performed an in vitro histological analysis in peach palm (Bactris gasipaes Kunth) shoot apexes and determined that the positioning of competent cells and their interaction with neighboring cells, under the influence of combinations of exogenously applied growth regulators (NAA/BAP and NAA/TDZ), allows the pre-procambial cells (PPCs) to act in different morphogenic pathways to establish niche competent cells. It is likely that there has been a habituation phenomenon during the regeneration and development of the microplants. This includes promoting the tillering of primary or secondary buds due to culturing in the absence of NAA/BAP or NAA/TDZ after a period in the presence of these growth regulators. Histological analyses determined that the adventitious roots were derived from the dedifferentiation of the parenchymal cells located in the basal region of the adventitious buds, with the establishment of rooting pole, due to an auxin gradient. Furthermore, histological and histochemical analyses allowed us to characterize how the PPCs provide niches for multipotent, pluripotent and totipotent stem-like cells for vascular differentiation, organogenesis and somatic embryogenesis in the peach palm. The histological and histochemical analyses also allowed us to detect the unicellular or multicellular origin of somatic embryogenesis. Therefore, our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. Our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to

  20. Drosophila Glypicans Regulate Follicle Stem Cell Maintenance and Niche Competition.

    Science.gov (United States)

    Su, Tsu-Yi; Nakato, Eriko; Choi, Pui Yee; Nakato, Hiroshi

    2018-04-09

    Adult stem cells reside in specialized microenvironments, called niches, which provide signals for stem cells to maintain their undifferentiated and self-renewing state. To maintain stem cell quality, several types of stem cells are known to be regularly replaced by progenitor cells through niche competition. However, the cellular and molecular bases for stem cell competition for niche occupancy are largely unknown. Here, we show that two Drosophila members of the glypican family of heparan sulfate proteoglycans (HSPGs), Dally and Dally-like (Dlp), differentially regulate follicle stem cell (FSC) maintenance and FSC competitiveness for niche occupancy. Lineage analyses of glypican mutant FSC clones showed that dally is essential for normal FSC maintenance. In contrast, dlp is a hyper-competitive mutation: dlp mutant FSC progenitors often eventually occupy the entire epithelial sheet. RNAi knockdown experiments showed that Dally and Dlp play both partially redundant and distinct roles in regulating Jak/Stat, Wg and Hh signaling in FSCs. The Drosophila FSC system offers a powerful genetic model to study the mechanisms by which HSPGs exert specific functions in stem cell replacement and competition. Copyright © 2018, Genetics.

  1. Environmental filtering drives the shape and breadth of the seed germination niche in coastal plant communities.

    Science.gov (United States)

    Fernández-Pascual, Eduardo; Pérez-Arcoiza, Adrián; Prieto, José Alberto; Díaz, Tomás E

    2017-05-01

    A phylogenetic comparative analysis of the seed germination niche was conducted in coastal plant communities of western Europe. Two hypotheses were tested, that (1) the germination niche shape (i.e. the preference for a set of germination cues as opposed to another) would differ between beaches and cliffs to prevent seedling emergence in the less favourable season (winter and summer, respectively); and (2) the germination niche breadth (i.e. the amplitude of germination cues) would be narrower in the seawards communities, where environmental filtering is stronger. Seeds of 30 specialist species of coastal plant communities were collected in natural populations of northern Spain. Their germination was measured in six laboratory treatments based on field temperatures. Germination niche shape was estimated as the best germination temperature. Germination niche breadth was calculated using Pielou's evenness index. Differences between plant communities in their germination niche shape and breadth were tested using phylogenetic generalized least squares regression (PGLS). Germination niche shape differed between communities, being warm-cued in beaches (best germination temperature = 20 °C) and cold-cued in cliffs (14 °C). Germination niche was narrowest in seawards beaches (Pielou's index = 0·89) and broadest in landwards beaches (0·99). Cliffs had an intermediate germination niche breadth (0·95). The relationship between niche and plant community had a positive phylogenetic signal for shape (Pagel's λ = 0·64) and a negative one for breadth (Pagel's λ = -1·71). Environmental filters shape the germination niche to prevent emergence in the season of highest threat for seedling establishment. The germination niche breadth is narrower in the communities with stronger environmental filters, but only in beaches. This study provides empirical support to a community-level generalization of the hypotheses about the environmental drivers of the germination

  2. Postglacial species displacement in Triturus newts deduced from asymmetrically introgressed mitochondrial DNA and ecological niche models

    Directory of Open Access Journals (Sweden)

    Wielstra Ben

    2012-08-01

    Full Text Available Abstract Background If the geographical displacement of one species by another is accompanied by hybridization, mitochondrial DNA can introgress asymmetrically, from the outcompeted species into the invading species, over a large area. We explore this phenomenon using the two parapatric crested newt species, Triturus macedonicus and T. karelinii, distributed on the Balkan Peninsula in south-eastern Europe, as a model. Results We first delimit a ca. 54,000 km2 area in which T. macedonicus contains T. karelinii mitochondrial DNA. This introgression zone bisects the range of T. karelinii, cutting off a T. karelinii enclave. The high similarity of introgressed mitochondrial DNA haplotypes with those found in T. karelinii suggests a recent transfer across the species boundary. We then use ecological niche modeling to explore habitat suitability of the location of the present day introgression zone under current, mid-Holocene and Last Glacial Maximum conditions. This area was inhospitable during the Last Glacial Maximum for both species, but would have been habitable at the mid-Holocene. Since the mid-Holocene, habitat suitability generally increased for T. macedonicus, whereas it decreased for T. karelinii. Conclusion The presence of a T. karelinii enclave suggests that T. karelinii was the first to colonize the area where the present day introgression zone is positioned after the Last Glacial Maximum. Subsequently, we propose T. karelinii was outcompeted by T. macedonicus, which captured T. karelinii mitochondrial DNA via introgressive hybridization in the process. Ecological niche modeling suggests that this replacement was likely facilitated by a shift in climate since the mid-Holocene. We suggest that the northwestern part of the current introgression zone was probably never inhabited by T. karelinii itself, and that T. karelinii mitochondrial DNA spread there through T. macedonicus exclusively. Considering the spatial distribution of the

  3. Examination of Market Segmentation among Medical Marijuana Dispensaries.

    Science.gov (United States)

    Cooke, Alexis; Freisthler, Bridget; Mulholland, Elycia

    2018-01-05

    As medical marijuana legislation becomes more common, concerns arise about the overconcentration of dispensaries, raising questions about the number of medicinal marijuana dispensaries (MMD) needed to serve medicinal users. This paper applies niche-marketing theory-which suggests dispensaries market to specific types of people-to examine if MMDs might be targeting recreational users. Observed differences between dispensary populations and between dispensary clients and local residents may indicate that dispensaries are drawing in patients based on factors other than medical need. Data were collected via exit surveys with patients at four dispensaries in Long Beach, CA. A total of 132 patients were surveyed regarding demographic data, purchase information, medical condition, and nearest cross street for their home address. Census tract information was collected for every dispensary. Chi-squared tests show significant associations between dispensary visited and race (χ 2 = 31.219, p market segmentation.

  4. Phenomenon detection device

    International Nuclear Information System (INIS)

    Suzuki, Yasuo.

    1994-01-01

    Detection signals for a specific phenomenon outputted from any of detectors are distributed by way of half mirrors and inputted to a logic discrimination circuit by way of a photoelectric convertor. The photoelectric convertor detects the quantity of light corresponding to the optical signals from more than two detectors which detected the phenomenon, and outputs detection signals to the logic discrimination circuit. If the phenomenon is detected, since both inputs turn ON in the logic discrimination circuit in accordance with the predetermined logical sum, the occurrence of a specific phenomenon is detected. Thus, an optical system substantially comprises half mirrors, reflection mirrors and photoelectric convertor in combination provides a logic circuit. Since the circuit which transmits signals of the detectors is constituted with an optical system using the half mirrors, the number of parts constituting the logic circuit can greatly be saved. In addition, since the optical system comprises mirrors or half mirrors which have been used so far, they can be used, once assembled, quasipermanently, and the reliability can be enhanced greatly. (N.H.)

  5. Evolution is a cooperative process: the biodiversity-related niches differentiation theory (BNDT) can explain why.

    Science.gov (United States)

    Gatti, Roberto Cazzolla

    2011-01-01

    A. McFayden and G.E. Hutchinson defined a niche as a multidimensional space or hypervolume within the environment that allows an individual or a species to survive, we consider niches as a fundamental ecological variable that regulate species' composition and relation in ecosystems. Successively the niche concept has been associated to the genetic term "phenotype" by MacArthurstressing the importance on what a species or a genome can show outside, either in the environmental functions or in body characteristics. Several indexes have been developed to evaluate the grade of overlapping and similarities of species' niches, even utilizing the theory of information. However, which are the factors that determine the number of species that can coexist in a determinate environment and why a generalist species do not compete until the exclusion of the remaining species to maximize its fitness, is still quite unknown. Moreover, there are few studies and theories that clearly explain why the number of niches is so variable through ecosystems and how can several species live in the same basal niche, intended in a comprehensive sense as the range of basic conditions (temperature, humidity, food-guild, etc.). Here I show that the number of niches in an ecosystem depends on the number of species present in a particular moment and that the species themselves allow the enhancement of niches in terms of space and number. I found that using a three-dimensional model as hypervolume and testing the theory on a Mediterranean, temperate and tropical forest ecosystem it is possible to demonstrate that each species plays a fundamental role in facilitating the colonization by other species by simply modifying the environment and exponentially increasing the available niches' space and number. I resumed these hypothesis, after some preliminary empiric tests, in the Biodiversity-related Niches Differentiation Theory (BNDT), stressing with these definition that the process of niches

  6. Differential cytokine contributions of perivascular haematopoietic stem cell niches.

    Science.gov (United States)

    Asada, Noboru; Kunisaki, Yuya; Pierce, Halley; Wang, Zichen; Fernandez, Nicolas F; Birbrair, Alexander; Ma'ayan, Avi; Frenette, Paul S

    2017-03-01

    Arterioles and sinusoids of the bone marrow (BM) are accompanied by stromal cells that express nerve/glial antigen 2 (NG2) and leptin receptor (LepR), and constitute specialized niches that regulate quiescence and proliferation of haematopoietic stem cells (HSCs). However, how niche cells differentially regulate HSC functions remains unknown. Here, we show that the effects of cytokines regulating HSC functions are dependent on the producing cell sources. Deletion of chemokine C-X-C motif ligand 12 (Cxcl12) or stem cell factor (Scf) from all perivascular cells marked by nestin-GFP dramatically depleted BM HSCs. Selective Cxcl12 deletion from arteriolar NG2 + cells, but not from sinusoidal LepR + cells, caused HSC reductions and altered HSC localization in BM. By contrast, deletion of Scf in LepR + cells, but not NG2 + cells, led to reductions in BM HSC numbers. These results uncover distinct contributions of cytokines derived from perivascular cells in separate vascular niches to HSC maintenance.

  7. Biogeochemical and Ecomorphological Niche Segregation of Mediterranean Woody Species along a Local Gradient

    OpenAIRE

    Enrique G. de la Riva; Enrique G. de la Riva; Teodoro Marañón; Cyrille Violle; Rafael Villar; Ignacio M. Pérez-Ramos

    2017-01-01

    According with niche theory the species are specialized in different ecological niches, being able to coexist as result of a differential use of resources. In this context, the biogeochemical niche hypothesis proposes that species have an optimal elemental composition which results from the link between the chemical and morphological traits for the optimum plant functioning. Thus, and attending to the limiting similarity concept, different elemental composition and plant structure among co-oc...

  8. Protection from UV light is an evolutionarily conserved feature of the haematopoietic niche

    Science.gov (United States)

    Kapp, Friedrich G.; Perlin, Julie R.; Hagedorn, Elliott J.; Gansner, John M.; Schwarz, Daniel E.; O'Connell, Lauren A.; Johnson, Nicholas; Amemiya, Chris; Fisher, David E.; Wolfle, Ute; Trompouki, Eirini; Niemeyer, Charlotte M.; Driever, Wolfgang; Zon, Leonard I.

    2018-01-01

    Haematopoietic stem and progenitor cells (HSPCs) require a specific microenvironment, the haematopoietic niche, which regulates HSPC behaviour. The location of this niche varies across species, but the evolutionary pressures that drive HSPCs to different microenvironments remain unknown. The niche is located in the bone marrow in adult mammals, whereas it is found in other locations in non-mammalian vertebrates, for example, in the kidney marrow in teleost fish. Here we show that a melanocyte umbrella above the kidney marrow protects HSPCs against ultraviolet light in zebrafish. Because mutants that lack melanocytes have normal steady-state haematopoiesis under standard laboratory conditions, we hypothesized that melanocytes above the stem cell niche protect HSPCs against ultraviolet-light-induced DNA damage. Indeed, after ultraviolet-light irradiation, unpigmented larvae show higher levels of DNA damage in HSPCs, as indicated by staining of cyclobutane pyrimidine dimers and have reduced numbers of HSPCs, as shown by cmyb (also known as myb) expression. The umbrella of melanocytes associated with the haematopoietic niche is highly evolutionarily conserved in aquatic animals, including the sea lamprey, a basal vertebrate. During the transition from an aquatic to a terrestrial environment, HSPCs relocated into the bone marrow, which is protected from ultraviolet light by the cortical bone around the marrow. Our studies reveal that melanocytes above the haematopoietic niche protect HSPCs from ultraviolet-light-induced DNA damage in aquatic vertebrates and suggest that during the transition to terrestrial life, ultraviolet light was an evolutionary pressure affecting the location of the haematopoietic niche.

  9. Evolutionary dynamics of ecological niche in three Rhinogobio fishes from the upper Yangtze River inferred from morphological traits

    Science.gov (United States)

    Wang, Meirong; Liu, Fei; Lin, Pengcheng; Yang, Shaorong; Liu, Huanzhang

    2015-01-01

    In the past decades, it has been debated whether ecological niche should be conserved among closely related species (phylogenetic niche conservatism, PNC) or largely divergent (traditional ecological niche theory and ecological speciation) and whether niche specialist and generalist might remain in equilibrium or niche generalist could not appear. In this study, we employed morphological traits to describe ecological niche and test whether different niche dimensions exhibit disparate evolutionary patterns. We conducted our analysis on three Rhinogobio fish species (R. typus,R. cylindricus, and R. ventralis) from the upper Yangtze River, China. Among the 32 measured morphological traits except body length, PCA extracted the first four principal components with their loading scores >1.000. To find the PNC among species, Mantel tests were conducted with the Euclidean distances calculated from the four principal components (representing different niche dimensions) against the pairwise distances calculated from mitochondrial cytochrome b sequence variations. The results showed that the second and the third niche dimension, both related to swimming ability and behavior, exhibited phylogenetic conservatism. Further comparison on niche breadth among these three species revealed that the fourth dimension of R. typus showed the greatest width, indicating that this dimension exhibited niche generalism. In conclusion, our results suggested that different niche dimensions could show different evolutionary dynamic patterns: they may exhibit PNC or not, and some dimensions may evolve generalism. PMID:25691981

  10. Helsinki market entry opportunity for a Vegan & Raw Danish restaurant chain 42˚RAW

    OpenAIRE

    Yablokova, Anna

    2015-01-01

    For those who follow and are interested in the vegan lifestyle, the scarce number of restaurants which offer suchlike products in Helsinki is evident. Comparing the local market with cities around the globe this impression can be proven with statistical data. Despite the world growing trend of healthy eating and living, Finland is still far behind even the neighbouring Nordic countries on the level of niche vegan industry. The purpose of this thesis was to research the Helsinki market and fin...

  11. Transition from non-renewable to renewable energy sources: fuel cells in Antarctica as an economically attractive niche

    International Nuclear Information System (INIS)

    Marschoff, C.M.

    1998-01-01

    There is a growing amount of evidence that indicates that fuel cells might be commercially attractive in several market niches in Latin America; however, political approval of demonstration projects has been elusive. In this paper, the results of an economic study carried out on the assumption of introducing an environmentally friendly fuel, such as methanol, for feeding fuel cell systems for electricity generation and heat production in the six bases that Argentina has in Antarctica are reported. It is seen that, in this particular case, there is a net cost benefit, even if the assets resulting from diminishing pollution in Antarctica are not taken into account. (Author)

  12. Notch signaling mediates the age-associated decrease in adhesion of germline stem cells to the niche.

    Directory of Open Access Journals (Sweden)

    Chen-Yuan Tseng

    2014-12-01

    Full Text Available Stem cells have an innate ability to occupy their stem cell niche, which in turn, is optimized to house stem cells. Organ aging is associated with reduced stem cell occupancy in the niche, but the mechanisms involved are poorly understood. Here, we report that Notch signaling is increased with age in Drosophila female germline stem cells (GSCs, and this results in their removal from the niche. Clonal analysis revealed that GSCs with low levels of Notch signaling exhibit increased adhesiveness to the niche, thereby out-competing their neighbors with higher levels of Notch; adhesiveness is altered through regulation of E-cadherin expression. Experimental enhancement of Notch signaling in GSCs hastens their age-dependent loss from the niche, and such loss is at least partially mediated by Sex lethal. However, disruption of Notch signaling in GSCs does not delay GSC loss during aging, and nor does it affect BMP signaling, which promotes self-renewal of GSCs. Finally, we show that in contrast to GSCs, Notch activation in the niche (which maintains niche integrity, and thus mediates GSC retention is reduced with age, indicating that Notch signaling regulates GSC niche occupancy both intrinsically and extrinsically. Our findings expose a novel role of Notch signaling in controlling GSC-niche adhesion in response to aging, and are also of relevance to metastatic cancer cells, in which Notch signaling suppresses cell adhesion.

  13. Individual diet variation in a marine fish assemblage: Optimal Foraging Theory, Niche Variation Hypothesis and functional identity

    Science.gov (United States)

    Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S.

    2017-02-01

    Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to

  14. Fuel cell added value for early market applications

    Science.gov (United States)

    Hardman, Scott; Chandan, Amrit; Steinberger-Wilckens, Robert

    2015-08-01

    Fuel Cells are often considered in the market place as just power providers. Whilst fuel cells do provide power, there are additional beneficial characteristics that should be highlighted to consumers. Due to the high price premiums associated with fuel cells, added value features need to be exploited in order to make them more appealing and increase unit sales and market penetration. This paper looks at the approach taken by two companies to sell high value fuel cells to niche markets. The first, SFC Energy, has a proven track record selling fuel cell power providers. The second, Bloom Energy, is making significant progress in the US by having sold its Energy Server to more than 40 corporations including Wal-Mart, Staples, Google, eBay and Apple. Further to these current markets, two prospective added value applications for fuel cells are discussed. These are fuel cells for aircraft APUs and fuel cells for fire prevention. These two existing markets and two future markets highlight that fuel cells are not just power providers. Rather, they can be used as solutions to many needs, thus being more cost effective by replacing a number of incumbent systems at the same time.

  15. Individual and species-specific traits explain niche size and functional role in spiders as generalist predators.

    Science.gov (United States)

    Sanders, Dirk; Vogel, Esther; Knop, Eva

    2015-01-01

    The function of a predator within a community is greatly based on its trophic niche, that is the number and the strength of feeding links. In generalist predators, which feed on a wide range of prey, the size and position of the trophic niche is likely determined by traits such as hunting mode, the stratum they occur in, their body size and age. We used stable isotope analyses ((13)C and (15)N) to measure the trophic niche size of nine spider species within a forest hedge community and tested for species traits and individual traits that influence stable isotope enrichment, niche size and resource use. The spiders Enoplognatha, Philodromus, Floronia, and Heliophanus had large isotopic niches, which correspond to a more generalistic feeding behaviour. In contrast, Araneus, Metellina and Agelena, as top predators in the system, had rather narrow niches. We found a negative correlation between trophic position and niche size. Differences in trophic position in spiders were explained by body size, hunting modes and stratum, while niche size was influenced by hunting mode. In Philodromus, the size of the trophic niche increased significantly with age. Fitting spiders to functional groups according to their mean body size, hunting mode and their habitat domain resulted in largely separated niches, which indicates that these traits are meaningful for separating functional entities in spiders. Functional groups based on habitat domain (stratum) caught the essential functional differences between the species with species higher up in the vegetation feeding on flying insects and herb and ground species also preying on forest floor decomposers. Interestingly, we found a gradient from large species using a higher habitat domain and having a smaller niche to smaller species foraging closer to the ground and having a larger niche. This shows that even within generalist predators, such as spiders, there is a gradient of specialism that can be predicted by functional traits.

  16. Convergent and divergent learning in photovoltaic pilot projects and subsequent niche development

    NARCIS (Netherlands)

    Mierlo, van B.

    2012-01-01

    A proposed strategy to facilitate the use and development of radical new sustainable technologies is the creation of niches. Learning in these niches and the social embedding of learning experiences can stimulate changes in existing sociotechnological regimes. Pilot projects in which new

  17. Niche construction through phenological plasticity: life history dynamics and ecological consequences.

    Science.gov (United States)

    Donohue, Kathleen

    2005-04-01

    The ability of an organism to alter the environment that it experiences has been termed 'niche construction'. Plants have several ways whereby they can determine the environment to which they are exposed at different life stages. This paper discusses three of these: plasticity in dispersal, flowering timing and germination timing. It reviews pathways through which niche construction alters evolutionary and ecological trajectories by altering the selective environment to which organisms are exposed, the phenotypic expression of plastic characters, and the expression of genetic variation. It provides examples whereby niche construction creates positive or negative feedbacks between phenotypes and environments, which in turn cause novel evolutionary constraints and novel life-history expression. Copyright New Phytologist (2005).

  18. FOREIGN FIGHTERS PHENOMENON IN THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    Florin-Alexandru LUCA

    2018-06-01

    Full Text Available Hybrid war is a reality; war does not depend only on conventional means, but includes communication and propaganda strategies whose role is increasingly important. In the last few years, terrorist cells have spent and keep spending many energies in a global propaganda business. This activity is a fundamental aspect of the conflict. This promotion campaign serves several purposes: legitimating its authority, recruiting militants and motivating sympathizers, and intimidating and conditioning those whose cells they consider enemies. What draws our attention is the sophisticated level of professionalism they demonstrate in managing propaganda and terror. This paper seeks to provide a broader view of the European Foreign Fighters (FF phenomenon by analyzing this target group from a marketing point of view in order to lay the foundations for a strategy to counteract them.

  19. Internal Markets for Innovation

    DEFF Research Database (Denmark)

    Wolfram, Pierre; Brem, Alexander

    2014-01-01

    of R&D to affiliated companies in the same business group. The challenges are analysed for affiliates in order to engage themselves in group-internal markets, for instance to avoid bottlenecks in the product development or to improve their technological knowledge. To research this phenomenon, a case...... study is accomplished by investigating a Multinational company whose affiliates are self-reliant and horizontally diversified. Mixed methods are applied by having structured depth interviews with the responsible R&D managers as well as by sending a survey out to associated project managers. The study...... indicates that the organizational complexity, infrastructures within the business group and the impact of external market structures play an essential role for the usage and effectiveness of group-internal markets. Hence, the insights offer valuable clues why internal markets have advantages...

  20. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Directory of Open Access Journals (Sweden)

    Cécile eCoste

    2015-06-01

    Full Text Available Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL12-abundant reticular (CAR cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs, which have been recently identified as neural crest-derived cells (NCSCs. Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-to-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

  1. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Science.gov (United States)

    Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

    2015-01-01

    Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

  2. Ecological niche dimensionality and the evolutionary diversification of stick insects.

    Directory of Open Access Journals (Sweden)

    Patrik Nosil

    Full Text Available The degree of phenotypic divergence and reproductive isolation between taxon pairs can vary quantitatively, and often increases as evolutionary divergence proceeds through various stages, from polymorphism to population differentiation, ecotype and race formation, speciation, and post-speciational divergence. Although divergent natural selection promotes divergence, it does not always result in strong differentiation. For example, divergent selection can fail to complete speciation, and distinct species pairs sometimes collapse ('speciation in reverse'. Widely-discussed explanations for this variability concern genetic architecture, and the geographic arrangement of populations. A less-explored possibility is that the degree of phenotypic and reproductive divergence between taxon pairs is positively related to the number of ecological niche dimensions (i.e., traits subject to divergent selection. Some data supporting this idea stem from laboratory experimental evolution studies using Drosophila, but tests from nature are lacking. Here we report results from manipulative field experiments in natural populations of herbivorous Timema stick insects that are consistent with this 'niche dimensionality' hypothesis. In such insects, divergent selection between host plants might occur for cryptic colouration (camouflage to evade visual predation, physiology (to detoxify plant chemicals, or both of these niche dimensions. We show that divergent selection on the single niche dimension of cryptic colouration can result in ecotype formation and intermediate levels of phenotypic and reproductive divergence between populations feeding on different hosts. However, greater divergence between a species pair involved divergent selection on both niche dimensions. Although further replication of the trends reported here is required, the results suggest that dimensionality of selection may complement genetic and geographic explanations for the degree of

  3. Megakaryocytes promote murine osteoblastic HSC niche expansion and stem cell engraftment after radioablative conditioning.

    Science.gov (United States)

    Olson, Timothy S; Caselli, Anna; Otsuru, Satoru; Hofmann, Ted J; Williams, Richard; Paolucci, Paolo; Dominici, Massimo; Horwitz, Edwin M

    2013-06-27

    Successful hematopoietic stem cell (HSC) transplantation requires donor HSC engraftment within specialized bone marrow microenvironments known as HSC niches. We have previously reported a profound remodeling of the endosteal osteoblastic HSC niche after total body irradiation (TBI), defined as relocalization of surviving megakaryocytes to the niche site and marked expansion of endosteal osteoblasts. We now demonstrate that host megakaryocytes function critically in expansion of the endosteal niche after preparative radioablation and in the engraftment of donor HSC. We show that TBI-induced migration of megakaryocytes to the endosteal niche depends on thrombopoietin signaling through the c-MPL receptor on megakaryocytes, as well as CD41 integrin-mediated adhesion. Moreover, niche osteoblast proliferation post-TBI required megakaryocyte-secreted platelet-derived growth factor-BB. Furthermore, blockade of c-MPL-dependent megakaryocyte migration and function after TBI resulted in a significant decrease in donor HSC engraftment in primary and competitive secondary transplantation assays. Finally, we administered thrombopoietin to mice beginning 5 days before marrow radioablation and ending 24 hours before transplant to enhance megakaryocyte function post-TBI, and found that this strategy significantly enhanced donor HSC engraftment, providing a rationale for improving hematopoietic recovery and perhaps overall outcome after clinical HSC transplantation.

  4. Ecological divergence and conservatism: spatiotemporal patterns of niche evolution in a genus of livebearing fishes (Poeciliidae: Xiphophorus).

    Science.gov (United States)

    Culumber, Zachary W; Tobler, Michael

    2016-02-19

    Ecological factors often have a strong impact on spatiotemporal patterns of biodiversity. The integration of spatial ecology and phylogenetics allows for rigorous tests of whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence. We address this question in a genus of livebearing fishes for which the role of sexual selection in speciation has long been studied, but in which the potential role of ecological divergence during speciation has not been tested. By combining reconstruction of ancestral climate tolerances and disparity indices, we show that the earliest evolutionary split in Xiphophorus was associated with significant divergence for temperature variables. Niche evolution and present day niches were most closely associated with each species' geographic distribution relative to a biogeographic barrier, the Trans-Mexican Volcanic Belt. Tests for similarity of the environmental backgrounds of closely related species suggested that the relative importance of niche conservatism and divergence during speciation varied among the primary clades of Xiphophorus. Closely related species in the two swordtail clades exhibited higher levels of niche overlap than expected given environmental background similarity indicative of niche conservatism. In contrast, almost all species of platyfish had significantly divergent niches compared to environmental backgrounds, which is indicative of niche divergence. The results suggest that the relative importance of niche conservatism and divergence differed among the clades of Xiphophorus and that traits associated with niche evolution may be more evolutionarily labile in the platyfishes. Our results ultimately suggest that the taxonomic scale of tests for conservatism and divergence could greatly influence inferences of their relative importance in the speciation process.

  5. Intestinal Stem Cell Niche: The Extracellular Matrix and Cellular Components

    Directory of Open Access Journals (Sweden)

    Laween Meran

    2017-01-01

    Full Text Available The intestinal epithelium comprises a monolayer of polarised columnar cells organised along the crypt-villus axis. Intestinal stem cells reside at the base of crypts and are constantly nourished by their surrounding niche for maintenance, self-renewal, and differentiation. The cellular microenvironment including the adjacent Paneth cells, stromal cells, smooth muscle cells, and neural cells as well as the extracellular matrix together constitute the intestinal stem cell niche. A dynamic regulatory network exists among the epithelium, stromal cells, and the matrix via complex signal transduction to maintain tissue homeostasis. Dysregulation of these biological or mechanical signals could potentially lead to intestinal injury and disease. In this review, we discuss the role of different intestinal stem cell niche components and dissect the interaction between dynamic matrix factors and regulatory signalling during intestinal stem cell homeostasis.

  6. Development and aging of a brain neural stem cell niche.

    Science.gov (United States)

    Conover, Joanne C; Todd, Krysti L

    2017-08-01

    In the anterior forebrain, along the lateral wall of the lateral ventricles, a neurogenic stem cell niche is found in a region referred to as the ventricular-subventricular zone (V-SVZ). In rodents, robust V-SVZ neurogenesis provides new neurons to the olfactory bulb throughout adulthood; however, with increasing age stem cell numbers are reduced and neurogenic capacity is significantly diminished, but new olfactory bulb neurons continue to be produced even in old age. Humans, in contrast, show little to no new neurogenesis after two years of age and whether V-SVZ neural stem cells persist in the adult human brain remains unclear. Here, we review functional and organizational differences in the V-SVZ stem cell niche of mice and humans, and examine how aging affects the V-SVZ niche and its associated functions. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Niche differentiation and expansion of plant species are associated with mycorrhizal symbiosis

    NARCIS (Netherlands)

    Gerz, Maret; Guillermo Bueno, C.; Ozinga, Wim A.; Zobel, Martin; Moora, Mari

    2018-01-01

    Mycorrhizal symbiosis is a widespread association between plant roots and mycorrhizal fungi, which is thought to contribute to plant niche differentiation and expansion. However, this has so far not been explicitly tested. To address the effect of mycorrhizal symbiosis on plants’ realized niches, we

  8. Disjunct populations of European vascular plant species keep the same climatic niches

    DEFF Research Database (Denmark)

    Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild

    2015-01-01

    separated for thousands of years. Location: European Alps and Fennoscandia. Methods: Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly......Aim: Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been...... to be largely valid for arctic-alpine plants....

  9. Doctoral education in a successful ecological niche

    DEFF Research Database (Denmark)

    Christensen, Mette Krogh; Lund, Ole

    2014-01-01

    Scholarly communities are dependent on and often measured by their ability to attract and develop doctoral students. Recent literature suggests that most scholarly communities entail ecological niches in which the doctoral students learn the codes and practices of research. In this article, we...... successful doctoral education because it: 1) fleshes out the professional attitude that is necessary for becoming a successful researcher in the department, 2) shapes and adapts the doctoral students’ desires to grasp and identify with the department’s practices, and 3) provides the doctoral students...... explore the microclimate in an ecological niche of doctoral education. Based on a theoretical definition of microclimate as the emotional atmosphere that ties group members together and affects their actions, we conducted a case study that aimed to describe the key features of the microclimate...

  10. A Short Review on the Trend of Mobile Marketing Studies

    OpenAIRE

    Mohammad Ismail; Razli Che Razak

    2011-01-01

    The purpose of this paper is to elucidate the major classification of the research in mobile marketing. It provides the trend and common approach in mobile marketing research. The paper aims to highlight the significant area in mobile marketing research and the needs for further understanding of the mobile marketing definition and its phenomenon. This paper has significant implications in terms of understanding the classification and the mobile marketing focusing area. This is a general revie...

  11. Growth prospects for the Brazilian reinsurance market

    Directory of Open Access Journals (Sweden)

    Carlos Honorato Teixeira

    2011-07-01

    Full Text Available In 2008, resolution 168 of the National Council of Private Insurance (CNSP allowed international reinsurers to request authorization to operate in Brazil from the Superintendence of Private Insurance (SUSEP. This led to changes in the insurance and reinsurance markets. There is a lack of in-depth studies to evaluate the growth of the reinsurance market since its effective opening, taking into account macroeconomic factors and market reserve. This study aims to evaluate the size of the reinsurance market by examining: the main sectors of business that yield reinsurance, market concentration, share of GDP, and expectations for future growth. The main objective of this paper is to provide companies in the reinsurance segment with assistance in identifying the potential market, understanding its complexity: their main competitors, and possible operational niches. In addition, it provides new and existing reinsurers with an overview of difficulties in the market and the strategic positioning that the company must adopt in order to act more effectively within the industry. To achieve these goals, it analyzes the reinsurance market in detail, proposes methods or steps to take to define strategic positioning in the market, and offers a graphic "Performance vs. Importance Matrix." There is potential demand available to the insurance market which remains unmet. Despite the initial difficulties for companies operating in the sector, the market has demonstrated its potential for continued growth since its effective opening, which will ultimately attract reinsurers, making the market highly competitive.Key words: Reinsurance. Insurance. Growth Perspective.

  12. The meanings of discounts in contemporary art markets: the case of India

    NARCIS (Netherlands)

    Komarova, N.

    2015-01-01

    Although discounts in art markets are commonplace, the phenomenon remains largely unresearched. This paper looks at how art market actors understand the functions of discounts, focusing on ‘suppliers’ of the market and drawing on qualitative interviews with artists and art dealers from New Delhi and

  13. Stem Cell Spheroids and Ex Vivo Niche Modeling: Rationalization and Scaling-Up.

    Science.gov (United States)

    Chimenti, Isotta; Massai, Diana; Morbiducci, Umberto; Beltrami, Antonio Paolo; Pesce, Maurizio; Messina, Elisa

    2017-04-01

    Improved protocols/devices for in vitro culture of 3D cell spheroids may provide essential cues for proper growth and differentiation of stem/progenitor cells (S/PCs) in their niche, allowing preservation of specific features, such as multi-lineage potential and paracrine activity. Several platforms have been employed to replicate these conditions and to generate S/PC spheroids for therapeutic applications. However, they incompletely reproduce the niche environment, with partial loss of its highly regulated network, with additional hurdles in the field of cardiac biology, due to debated resident S/PCs therapeutic potential and clinical translation. In this contribution, the essential niche conditions (metabolic, geometric, mechanical) that allow S/PCs maintenance/commitment will be discussed. In particular, we will focus on both existing bioreactor-based platforms for the culture of S/PC as spheroids, and on possible criteria for the scaling-up of niche-like spheroids, which could be envisaged as promising tools for personalized cardiac regenerative medicine, as well as for high-throughput drug screening.

  14. The thermal niche of Neotropical nectar-feeding bats: Its evolution and application to predict responses to global warming.

    Science.gov (United States)

    Ortega-García, Stephanie; Guevara, Lázaro; Arroyo-Cabrales, Joaquín; Lindig-Cisneros, Roberto; Martínez-Meyer, Enrique; Vega, Ernesto; Schondube, Jorge E

    2017-09-01

    The thermal niche of a species is one of the main determinants of its ecology and biogeography. In this study, we determined the thermal niche of 23 species of Neotropical nectar-feeding bats of the subfamily Glossophaginae (Chiroptera, Phyllostomidae). We calculated their thermal niches using temperature data obtained from collection records, by generating a distribution curve of the maximum and minimum temperatures per locality, and using the inflection points of the temperature distributions to estimate the species optimal (STZ) and suboptimal (SRZ) zones of the thermal niche. Additionally, by mapping the values of the STZ and SRZ on a phylogeny of the group, we generated a hypothesis of the evolution of the thermal niches of this clade of nectar-feeding bats. Finally, we used the characteristics of their thermal niches to predict the responses of these organisms to climate change. We found a large variation in the width and limits of the thermal niches of nectar-feeding bats. Additionally, while the upper limits of the thermal niches varied little among species, their lower limits differ wildly. The ancestral reconstruction of the thermal niche indicated that this group of Neotropical bats evolved under cooler temperatures. The two clades inside the Glossophaginae differ in the evolution of their thermal niches, with most members of the clade Choeronycterines evolving "colder" thermal niches, while the majority of the species in the clade Glossophagines evolving "warmer" thermal niches. By comparing thermal niches with climate change models, we found that all species could be affected by an increase of 1°C in temperature at the end of this century. This suggests that even nocturnal species could suffer important physiological costs from global warming. Our study highlights the value of scientific collections to obtain ecologically significant physiological data for a large number of species.

  15. Niche Extracellular Matrix Components and Their Influence on HSC.

    Science.gov (United States)

    Domingues, Mélanie J; Cao, Huimin; Heazlewood, Shen Y; Cao, Benjamin; Nilsson, Susan K

    2017-08-01

    Maintenance of hematopoietic stem cells (HSC) takes place in a highly specialized microenvironment within the bone marrow. Technological improvements, especially in the field of in vivo imaging, have helped unravel the complexity of the niche microenvironment and have completely changed the classical concept from what was previously believed to be a static supportive platform, to a dynamic microenvironment tightly regulating HSC homeostasis through the complex interplay between diverse cell types, secreted factors, extracellular matrix molecules, and the expression of different transmembrane receptors. To add to the complexity, non-protein based metabolites have also been recognized as a component of the bone marrow niche. The objective of this review is to discuss the current understanding on how the different extracellular matrix components of the niche regulate HSC fate, both during embryonic development and in adulthood. Special attention will be provided to the description of non-protein metabolites, such as lipids and metal ions, which contribute to the regulation of HSC behavior. J. Cell. Biochem. 118: 1984-1993, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  16. Mechanistic species distribution modeling reveals a niche shift during invasion.

    Science.gov (United States)

    Chapman, Daniel S; Scalone, Romain; Štefanić, Edita; Bullock, James M

    2017-06-01

    Niche shifts of nonnative plants can occur when they colonize novel climatic conditions. However, the mechanistic basis for niche shifts during invasion is poorly understood and has rarely been captured within species distribution models. We quantified the consequence of between-population variation in phenology for invasion of common ragweed (Ambrosia artemisiifolia L.) across Europe. Ragweed is of serious concern because of its harmful effects as a crop weed and because of its impact on public health as a major aeroallergen. We developed a forward mechanistic species distribution model based on responses of ragweed development rates to temperature and photoperiod. The model was parameterized and validated from the literature and by reanalyzing data from a reciprocal common garden experiment in which native and invasive populations were grown within and beyond the current invaded range. It could therefore accommodate between-population variation in the physiological requirements for flowering, and predict the potentially invaded ranges of individual populations. Northern-origin populations that were established outside the generally accepted climate envelope of the species had lower thermal requirements for bud development, suggesting local adaptation of phenology had occurred during the invasion. The model predicts that this will extend the potentially invaded range northward and increase the average suitability across Europe by 90% in the current climate and 20% in the future climate. Therefore, trait variation observed at the population scale can trigger a climatic niche shift at the biogeographic scale. For ragweed, earlier flowering phenology in established northern populations could allow the species to spread beyond its current invasive range, substantially increasing its risk to agriculture and public health. Mechanistic species distribution models offer the possibility to represent niche shifts by varying the traits and niche responses of individual

  17. [Niche and interspecific association of the dominant fish in the south coastal waters of Wenzhou, China].

    Science.gov (United States)

    Dong, Jing Rui; Shui, Bo Nian; Hu, Cheng Ye; Shui, Yu Yue; DU, Xiao; Tian, Kuo

    2017-05-18

    The studies about the niche and interspecific association in China were mainly focused on the plants, birds and marine animals, and seldom on fish. Based on the fishery resources survey in spring (May) and autumn (September) in 2015, the associations among major fish species in south coastal waters of Wenzhou were investigated. The methods including niche breadth, niche overlap, variance ratio (VR), Χ 2 -test, association coefficient (AC), percentage of co-occurrence (PC) and point correlation coefficients (Ф) were used. The results showed that 47 fish species were identified, including 9 orders, 27 families and 41 genera. Four species were dominant species and 9 were important species, which together accounted for 17%. The niche breadth cluster analysis demonstrated two clearly identifiable ecological niches. The first one referred to wide niche that included Harpodon nehereus, Collichthys lucidus, Engraulis japonicas, Pampus echinogaster, Argyrosomus argentatus, Polynemus sextarius, Decapterus maruadsi and Trichiurus haumela, and the second one was narrow niche that included Muraenesox cinereus, Amblychaeturichthys hexanema, Cunoglossus robustus, Pseudosciaena polyactis and Ilisha elongate. The niche overlap value of the main fish was 0-0.90, indicating that there was difference in the resource utilization among the species. The ecological niche widths of C. robustus and M. cinereus were narrow, and the overlap values were high. This indicated that there was competition between these two species. The VR analysis revealed significant positive correlation among the main fish species. In view of the advantages of Ф value, which could reduce the impact of the analysis results of Χ 2 -test, AC and PC to the interspecific association, the Ф value method was selected in this study, and the association of 63 couples were positive. Both the interspecific association and ecological niche had different degrees of correlation with the stability of community structure

  18. Divergence is not enough: the use of ecological niche models for the validation of taxon boundaries.

    Science.gov (United States)

    Dagnino, D; Minuto, L; Casazza, G

    2017-11-01

    Delimiting taxon boundaries is crucial for any evolutionary research and conservation regulation. In order to avoid mistaken description of species, the approach of integrative taxonomy recommends considering multidisciplinary lines of evidence, including ecology. Unfortunately, ecological data are often difficult to quantify objectively. Here we test and discuss the potential use of ecological niche models for validating taxon boundaries, using three pairs of closely related plant taxa endemic to the south-western Alps as a case study. We also discuss the application of ecological niche models for species delimitation and the implementation of different approaches. Niche overlap, niche equivalency and niche similarity were assessed both in multidimensional environmental space and in geographic space to look for differences in the niche of three pairs of closely related plant taxa. We detected a high degree of niche differentiation between taxa although this result seems not due to differences in habitat selection. The different statistical tests gave contrasting outcomes between environmental and geographic spaces. According to our results, niche divergence does not seem to support taxon boundaries at species level, but may have had important consequences for local adaptation and in generating phenotypic diversity at intraspecific level. Environmental space analysis should be preferred to geographic space as it provides more clear results. Even if the different analyses widely disagree in their conclusions about taxon boundaries, our study suggests that ecological niche models may help taxonomists to reach a decision. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. A hybrid niched-island genetic algorithm applied to a nuclear core optimization problem

    International Nuclear Information System (INIS)

    Pereira, Claudio M.N.A.

    2005-01-01

    Diversity maintenance is a key-feature in most genetic-based optimization processes. The quest for such characteristic, has been motivating improvements in the original genetic algorithm (GA). The use of multiple populations (called islands) has demonstrating to increase diversity, delaying the genetic drift. Island Genetic Algorithms (IGA) lead to better results, however, the drift is only delayed, but not avoided. An important advantage of this approach is the simplicity and efficiency for parallel processing. Diversity can also be improved by the use of niching techniques. Niched Genetic Algorithms (NGA) are able to avoid the genetic drift, by containing evolution in niches of a single-population GA, however computational cost is increased. In this work it is investigated the use of a hybrid Niched-Island Genetic Algorithm (NIGA) in a nuclear core optimization problem found in literature. Computational experiments demonstrate that it is possible to take advantage of both, performance enhancement due to the parallelism and drift avoidance due to the use of niches. Comparative results shown that the proposed NIGA demonstrated to be more efficient and robust than an IGA and a NGA for solving the proposed optimization problem. (author)

  20. Single-cell analyses identify bioengineered niches for enhanced maintenance of hematopoietic stem cells.

    Science.gov (United States)

    Roch, Aline; Giger, Sonja; Girotra, Mukul; Campos, Vasco; Vannini, Nicola; Naveiras, Olaia; Gobaa, Samy; Lutolf, Matthias P

    2017-08-09

    The in vitro expansion of long-term hematopoietic stem cells (HSCs) remains a substantial challenge, largely because of our limited understanding of the mechanisms that control HSC fate choices. Using single-cell multigene expression analysis and time-lapse microscopy, here we define gene expression signatures and cell cycle hallmarks of murine HSCs and the earliest multipotent progenitors (MPPs), and analyze systematically single HSC fate choices in culture. Our analysis revealed twelve differentially expressed genes marking the quiescent HSC state, including four genes encoding cell-cell interaction signals in the niche. Under basal culture conditions, most HSCs rapidly commit to become early MPPs. In contrast, when we present ligands of the identified niche components such as JamC or Esam within artificial niches, HSC cycling is reduced and long-term multipotency in vivo is maintained. Our approach to bioengineer artificial niches should be useful in other stem cell systems.Haematopoietic stem cell (HSC) self-renewal is not sufficiently understood to recapitulate in vitro. Here, the authors generate gene signature and cell cycle hallmarks of single murine HSCs, and use identified endothelial receptors Esam and JamC as substrates to enhance HSC growth in engineered niches.

  1. Urban niche dynamics of Kaifeng city%开封市的城市生态位变化分析

    Institute of Scientific and Technical Information of China (English)

    丁圣彦; 李志恒

    2007-01-01

    Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study concerningdifferent functional modules of Kaifeng city urban ecosystem. Niche theory and techniques were used to analyze the changes of these functional modules in the period 1994-2003. The results showed that, in the period 1994-2003: (1) Niche value of the atmospheric environment and urban virescence modules increased, while niche value of the water environment and sound environment modules decreased; (2) niche value of the tertiary industry module increased, niche value of the secondary industry module decreased, while niche value of the primary industry module showed little change; and (3) niche value of the infrastructure, resource distribution, and production & social security modules increased, while niche value of the population module decreased. This study may contribute to macroscopic planning of urban functional modules,economic development, and environmental protection.

  2. LES AMIS D'ESCOFFIER AND THE POST-DEPRESSION LABOR MARKET FOR CHEFS DE CUISINE IN AMERICA

    Directory of Open Access Journals (Sweden)

    Martin T. Ollif

    2001-01-01

    Full Text Available This essay uses a cultural studies approach to analyze the effort of the gourmet society Les Amis d'Escoffier to re-create the niche market for chefs’ services in the waning years of the Great Depression. It examines the depressed labor market for chefs after 1912 as well as aspects of the chefs’ culture that informed the unusual rules and rituals Les Amis used to educate wealthy men in gourmandaise. It concludes that, regardless of how successful the society was in its original goal, culture as well as functional response shaped the chefs’ remedy to their labor market problems.

  3. Bridging the Service Divide: Dual Labor Niches and Embedded Opportunities in Restaurant Work

    Directory of Open Access Journals (Sweden)

    Eli R. Wilson

    2018-01-01

    Full Text Available Restaurants and other interactive service workplaces in the United States serve as labor niches for two very different kinds of workers doing different tasks. Immigrant Latinos primarily work “back-of-the-house” jobs doing manual tasks, while class-privileged whites work “front-of-the-house” jobs performing customer-facing tasks. How do these social and structural cleavages between dual labor niches affect the workplace dynamic? Drawing on ethnographic research in upscale Los Angeles restaurants, I describe the closed boundaries between these distinct labor niches and the valuable bridging between them performed by certain workers who are able to ease social tensions and buffer the service labor process. I discuss the implications of these findings for the study of contemporary immigrant labor niches and the nature of the opportunities within them and between them.

  4. Ecological allometries and niche use dynamics across Komodo dragon ontogeny

    Science.gov (United States)

    Purwandana, Deni; Ariefiandy, Achmad; Imansyah, M. Jeri; Seno, Aganto; Ciofi, Claudio; Letnic, Mike; Jessop, Tim S.

    2016-04-01

    Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined how body size variation in Komodo dragons ( Varanus komodoensis) influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subsequent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ˜20 kg body mass before decreasing daily movement suggesting reduced foraging effort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon's transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by exploiting prey across multiple trophic levels.

  5. Identification of hepatic niche harboring human acute lymphoblastic leukemic cells via the SDF-1/CXCR4 axis.

    Directory of Open Access Journals (Sweden)

    Itaru Kato

    Full Text Available In acute lymphoblastic leukemia (ALL patients, the bone marrow niche is widely known to be an important element of treatment response and relapse. Furthermore, a characteristic liver pathology observed in ALL patients implies that the hepatic microenvironment provides an extramedullary niche for leukemic cells. However, it remains unclear whether the liver actually provides a specific niche. The mechanism underlying this pathology is also poorly understood. Here, to answer these questions, we reconstituted the histopathology of leukemic liver by using patients-derived primary ALL cells into NOD/SCID/Yc (null mice. The liver pathology in this model was similar to that observed in the patients. By using this model, we clearly demonstrated that bile duct epithelial cells form a hepatic niche that supports infiltration and proliferation of ALL cells in the liver. Furthermore, we showed that functions of the niche are maintained by the SDF-1/CXCR4 axis, proposing a novel therapeutic approach targeting the extramedullary niche by inhibition of the SDF-1/CXCR4 axis. In conclusion, we demonstrated that the liver dissemination of leukemia is not due to nonselective infiltration, but rather systematic invasion and proliferation of leukemic cells in hepatic niche. Although the contribution of SDF-1/CXCR4 axis is reported in some cancer cells or leukemic niches such as bone marrow, we demonstrated that this axis works even in the extramedullary niche of leukemic cells. Our findings form the basis for therapeutic approaches that target the extramedullary niche by inhibiting the SDF-1/CXCR4 axis.

  6. Secreted protein Del-1 regulates myelopoiesis in the hematopoietic stem cell niche.

    Science.gov (United States)

    Mitroulis, Ioannis; Chen, Lan-Sun; Singh, Rashim Pal; Kourtzelis, Ioannis; Economopoulou, Matina; Kajikawa, Tetsuhiro; Troullinaki, Maria; Ziogas, Athanasios; Ruppova, Klara; Hosur, Kavita; Maekawa, Tomoki; Wang, Baomei; Subramanian, Pallavi; Tonn, Torsten; Verginis, Panayotis; von Bonin, Malte; Wobus, Manja; Bornhäuser, Martin; Grinenko, Tatyana; Di Scala, Marianna; Hidalgo, Andres; Wielockx, Ben; Hajishengallis, George; Chavakis, Triantafyllos

    2017-10-02

    Hematopoietic stem cells (HSCs) remain mostly quiescent under steady-state conditions but switch to a proliferative state following hematopoietic stress, e.g., bone marrow (BM) injury, transplantation, or systemic infection and inflammation. The homeostatic balance between quiescence, self-renewal, and differentiation of HSCs is strongly dependent on their interactions with cells that constitute a specialized microanatomical environment in the BM known as the HSC niche. Here, we identified the secreted extracellular matrix protein Del-1 as a component and regulator of the HSC niche. Specifically, we found that Del-1 was expressed by several cellular components of the HSC niche, including arteriolar endothelial cells, CXCL12-abundant reticular (CAR) cells, and cells of the osteoblastic lineage. Del-1 promoted critical functions of the HSC niche, as it regulated long-term HSC (LT-HSC) proliferation and differentiation toward the myeloid lineage. Del-1 deficiency in mice resulted in reduced LT-HSC proliferation and infringed preferentially upon myelopoiesis under both steady-state and stressful conditions, such as hematopoietic cell transplantation and G-CSF- or inflammation-induced stress myelopoiesis. Del-1-induced HSC proliferation and myeloid lineage commitment were mediated by β3 integrin on hematopoietic progenitors. This hitherto unknown Del-1 function in the HSC niche represents a juxtacrine homeostatic adaptation of the hematopoietic system in stress myelopoiesis.

  7. Niche conservatism and dispersal limitation cause large-scale phylogenetic structure in the New World palm flora

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Svenning, J.-C.; Baker, William J.

    similarity decays after speciation depends on the rates of niche evolution and dispersal. If dispersal is slow compared to the tempo of lineage diversification, distributions change little during clade diversification. Phylogenetic niche conservatism precludes distributional shifts in environmental space......, and to the degree that distributions are limited by the niche, also in geographic space. Using phylogenetic turnover methods, we simultaneously analysed the distributions of all New World palms (n=547) and inferred to which degree phylogenetic niche conservatism and dispersal limitation, respectively, caused...

  8. Current and future niche of North and Central American sand flies (Diptera: psychodidae in climate change scenarios.

    Directory of Open Access Journals (Sweden)

    David Moo-Llanes

    Full Text Available Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i potential change in niche breadth, ii direction and magnitude of niche centroid shifts, iii shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3, for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%, while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases.

  9. Current and Future Niche of North and Central American Sand Flies (Diptera: Psychodidae) in Climate Change Scenarios

    Science.gov (United States)

    Moo-Llanes, David; Ibarra-Cerdeña, Carlos N.; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; González, Camila; Ramsey, Janine M.

    2013-01-01

    Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i) potential change in niche breadth, ii) direction and magnitude of niche centroid shifts, iii) shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3), for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%), while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases. PMID:24069478

  10. Strategic niche management and sustainable innovation journeys : theory, findings, research agenda, and policy

    NARCIS (Netherlands)

    Schot, J.W.; Geels, F.W.

    2008-01-01

    This article discusses empirical findings and conceptual elaborations of the last 10 years in strategic niche management research (SNM). The SNM approach suggests that sustainable innovation journeys can be facilitated by creating technological niches, i.e. protected spaces that allow the

  11. Customer social network affects marketing strategy: A simulation analysis based on competitive diffusion model

    Science.gov (United States)

    Hou, Rui; Wu, Jiawen; Du, Helen S.

    2017-03-01

    To explain the competition phenomenon and results between QQ and MSN (China) in the Chinese instant messaging software market, this paper developed a new population competition model based on customer social network. The simulation results show that the firm whose product with greater network externality effect will gain more market share than its rival when the same marketing strategy is used. The firm with the advantage of time, derived from the initial scale effect will become more competitive than its rival when facing a group of common penguin customers within a social network, verifying the winner-take-all phenomenon in this case.

  12. Intersexual Trophic Niche Partitioning in an Ant-Eating spider (Araneae: Zodariidae)

    DEFF Research Database (Denmark)

    Pekár, Stanislav; Martisová, Martina; Bilde, T.

    2011-01-01

    lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants...... that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning. Methodology/Principal Findings Comparative analysis of trophic morphology (the chelicerae) and body size of males, females and juveniles...... demonstrated highly female biased SSD (Sexual Size Dimorphism) in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size...

  13. Interfacial phenomenon theory

    International Nuclear Information System (INIS)

    Kim, Jong Deuk

    2000-02-01

    This book is composed of 8 chapters. It tells what interfacial phenomenon is by showing interfacial energy, characteristic of interface and system of interface from chapter 1. It also introduces interfacial energy and structure theory, molecular structure and orientation theory, and interfacial electricity phenomenon theory in the following 3 chapters. It still goes on by introducing super molecule cluster, disequilibrium dispersion, and surface and film through 3 chapters. And the last chapter is about colloid and application of interface.

  14. On the Differential Market Reaction to Dividend Announcement: Evidence from an Emerging Equity Market

    Directory of Open Access Journals (Sweden)

    Muntazir Hussain

    2013-09-01

    Full Text Available The corporate finance literature for market reaction to dividend announcements reports mixed results: some of studies support a positive response of markets as a result of dividend announcement whereas some report negative. This study is an attempt to investigate the heterogeneous market reaction to dividend announcement for 73 firms listed in the Karachi Stock Exchange. We investigated this phenomenon with a novel methodology using both the event study and multivariate regression for the possible effects of firm-specific factors associated with dividend announcements. We report that the market reaction is one-sided as the majority of companies in the sample are with positive CAR for the given period. We cannot ignore the importance of firm-specific factors that have an effect on the dividends but we conclude that the majority of companies in the sample period portray a positive CAR and the market reaction is positive.

  15. Recommendations to increase customer conversion rates through website optimization and online marketing Case company: RCS Training Center

    OpenAIRE

    Bogdanova, Daria

    2016-01-01

    The goal of this thesis is to establish effective online marketing strategy for a small B2C wellness studio. The commissioning company RCS Training Center wishes to attract more customers through their website and social media sites, such as Facebook and Instagram. This objective is justified by the popularity of the wellness and fitness niche online, which creates big market potential in the homeland and internationally. However, popularity also means high competition. A lack of experience i...

  16. Macrophages Contribute to the Spermatogonial Niche in the Adult Testis

    Directory of Open Access Journals (Sweden)

    Tony DeFalco

    2015-08-01

    Full Text Available The testis produces sperm throughout the male reproductive lifespan by balancing self-renewal and differentiation of spermatogonial stem cells (SSCs. Part of the SSC niche is thought to lie outside the seminiferous tubules of the testis; however, specific interstitial components of the niche that regulate spermatogonial divisions and differentiation remain undefined. We identified distinct populations of testicular macrophages, one of which lies on the surface of seminiferous tubules, in close apposition to areas of tubules enriched for undifferentiated spermatogonia. These macrophages express spermatogonial proliferation- and differentiation-inducing factors, such as colony-stimulating factor 1 (CSF1 and enzymes involved in retinoic acid (RA biosynthesis. We show that transient depletion of macrophages leads to a disruption in spermatogonial differentiation. These findings reveal an unexpected role for macrophages in the spermatogonial niche in the testis and raise the possibility that macrophages play previously unappreciated roles in stem/progenitor cell regulation in other tissues.

  17. The extraocular muscle stem cell niche is resistant to ageing and disease

    Directory of Open Access Journals (Sweden)

    Luigi eFormicola

    2014-12-01

    Full Text Available Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs include a fibroadipogenic progenitor population (FAPs that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy, the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs.

  18. The Benefit of Targeting Trending Niche Marketing Segments and Re-positioning of a Company : Choosing the winning marketing strategies for Reebok

    OpenAIRE

    Erus, Oscar

    2016-01-01

    This thesis will discuss different phases of Reebok’s development and study the underlying causes. The thesis will seek to understand which factors of strategic marketing made the company a market leader in the late 1980s and which factors caused the company to be unsuccessful in keeping the position. The company got lost in the process and failed to bounce back even though Reebok had the knowhow and financial capability to take seri-ous actions. This seemed to eventually lead to a bankrupt u...

  19. Niche versus neutrality: a dynamical analysis

    Science.gov (United States)

    Michael Kalyuzhny; Efrat Seri; Rachel Chocron; Curtis H. Flather; Ronen Kadmon; Nadav M. Shnerb

    2014-01-01

    Understanding the forces shaping ecological communities is of crucial importance for basic science and conservation. After 50 years in which ecological theory has focused on either stable communities driven by niche-based forces or nonstable “neutral” communities driven by demographic stochasticity, contemporary theories suggest that ecological communities are driven...

  20. Meat export competitiveness of European Union countries on global markets

    Directory of Open Access Journals (Sweden)

    Štefan Bojnec

    2014-10-01

    Full Text Available The purpose of this research is to provide insight into the export competitiveness of meat products of the European Union (EU-27 member states on global markets. The revealed comparative advantage index is used to analyze the levels, compositions, and evolutions in patterns of development in the export competitiveness of meat products and their levels of stability at the product level. Except for some niche meat products, a larger number of the EU-27 member states have experienced comparative disadvantages on global markets over the analysed years of 2000 to 2011. The revealed comparative advantages on the global markets are the most robust for Ireland, Spain, the Netherlands, France, Belgium, Denmark, Poland, Cyprus and Hungary. The revealed comparative advantage indices and their survival rates differ across the meat product groups. The heterogeneity in export competitiveness of the EU-27 member states suggests the importance of the differentiation of meat products in competitive export specialization on global markets.

  1. The niche construction of cultural complexity: interactions between innovations, population size and the environment.

    Science.gov (United States)

    Fogarty, Laurel; Creanza, Nicole

    2017-12-05

    Niche construction is a process through which organisms alter their environments and, in doing so, influence or change the selective pressures to which they are subject. 'Cultural niche construction' refers specifically to the effect of cultural traits on the selective environments of other biological or cultural traits and may be especially important in human evolution. In addition, the relationship between population size and cultural accumulation has been the subject of extensive debate, in part because anthropological studies have demonstrated a significant association between population size and toolkit complexity in only a subset of studied cultures. Here, we review the role of cultural innovation in constructing human evolutionary niches and introduce a new model to describe the accumulation of human cultural traits that incorporates the effects of cultural niche construction. We consider the results of this model in light of available data on human toolkit sizes across populations to help elucidate the important differences between food-gathering societies and food-producing societies, in which niche construction may be a more potent force. These results support the idea that a population's relationship with its environment, represented here by cultural niche construction, should be considered alongside population size in studies of cultural complexity.This article is part of the themed issue 'Process and pattern in innovations from cells to societies'. © 2017 The Author(s).

  2. Niche construction and the evolution of leadership

    NARCIS (Netherlands)

    Spisak, B.R.; O'Brien, M.; Nicholson, N.; van Vugt, M.

    2015-01-01

    We use the concept of niche construction - the process whereby individuals, through their activities, interactions, and choices, modify their own and each other's environments - as an example of how biological evolution and cultural evolution interacted to form an integrative foundation of modern

  3. Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.

    Directory of Open Access Journals (Sweden)

    William B Monahan

    Full Text Available The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus. Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004 further shows that: (i existing fundamental and occupied niche centroids did not undergo directional change, (ii interannual changes in the two niche centroids were correlated, (iii temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced

  4. Niche divergence builds the case for ecological speciation in skinks of the Plestiodon skiltonianus species complex

    Science.gov (United States)

    Wogan, Guinevere O.U.; Richmond, Jonathan Q.

    2015-01-01

    Adaptation to different thermal environments has the potential to cause evolutionary changes that are sufficient to drive ecological speciation. Here, we examine whether climate-based niche divergence in lizards of the Plestiodon skiltonianus species complex is consistent with the outcomes of such a process. Previous work on this group shows that a mechanical sexual barrier has evolved between species that differ mainly in body size and that the barrier may be a by-product of selection for increased body size in lineages that have invaded xeric environments; however, baseline information on niche divergence among members of the group is lacking. We quantified the climatic niche using mechanistic physiological and correlative niche models and then estimated niche differences among species using ordination techniques and tests of niche overlap and equivalency. Our results show that the thermal niches of size-divergent, reproductively isolated morphospecies are significantly differentiated and that precipitation may have been as important as temperature in causing increased shifts in body size in xeric habitats. While these findings alone do not demonstrate thermal adaptation or identify the cause of speciation, their integration with earlier genetic and behavioral studies provides a useful test of phenotype–environment associations that further support the case for ecological speciation in these lizards.

  5. Gamification as a strategy of internal marketing

    Directory of Open Access Journals (Sweden)

    José Luis Ruizalba Robledo

    2013-12-01

    Full Text Available Purpose: Theoretical analysis of the phenomenon of gamification and its possible application as a tool for internal marketing, in order to increase job satisfaction and commitment through engagement.Design/methodology/approach: Firstly, review of the literature on gamification and its background within game social reality. Secondly, presentation of several business cases where gamification has been applied.Findings: Focusing the subject of gamification within the field of internal marketing. In addition, a theoretical model of gamification as a tool to improve some consequences on employees’ behavior, such as job satisfaction and commitment through engagement, is proposed,. Various specific hypotheses for future research are proposed based on this model..Practical implications: Because of the situation of research on internal marketing and gamification, practical implications cannot be deduced in the short term, although they may arise as long as there is empirical evidence of its usefulness.Social implications: Currently there is no empirical evidence to infer social implications.Originality/value: Gamification is a very recent phenomenon that has been scarcely studied.

  6. The determining trends of the retail payment market

    OpenAIRE

    BERGQVIST, CHRISTIAN; PETTERSSON, ERIK

    2016-01-01

    The retail payment market can be seen as a high velocity market, where the rate of change is high. The future for the retail payment market is uncertain to a large extent. A relatively new phenomenon is the entrance of third party payment providers (hereafter; TPP) who are utilizing the incumbent banks account infrastructure in order access information or initiate payments. A legislation named PSD2 will increase the TPP’s possibilities to utilize the bank’s infrastructure. This makes it possi...

  7. Business, market and intellectual property analysis of polymer solar cells

    DEFF Research Database (Denmark)

    Damgaard Nielsen, Torben; Cruickshank, C.; Foged, S.

    2010-01-01

    and manufacturing cost leaves little room for competition on the thin film photovoltaic market. However, polymer solar cells do enable the competitive manufacture of low cost niche products and is viewed as financially viable in its currently available form in a large volume approximation. Finally, it is found......The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent...... and intellectual property situation is also given and a patent map of polymer solar cells is drawn in a European context. It is found that the business potential of polymer solar cells is large when taking the projections for future performance into account while the currently available performance...

  8. Developing Customer Trust in E-Commerce Using Inbound Marketing Strategies

    Directory of Open Access Journals (Sweden)

    Adrian MICU

    2017-06-01

    Full Text Available Developing a new argument that digital content is a factor for inbound marketing campaigns is redundant, considering there are numerous papers in the relevant literature. The aim of this paper is to use FsQCA to demonstrate the direct implications of quality content as a trust factor on the acquisition of search engine traffic. Concluding on strategies to build customer confidence in e-commerce, based on educative and representative content on a particular niche. In this research, we've analyzed 18 causal conditions collected from different online references to reach the outcome. These findings can help marketing managers to develop strategies to attract a relevant audience for e-commerce websites.

  9. Retro Design and Nostalgic Marketing: Influence of nostalgic trend in consumer behavior

    Directory of Open Access Journals (Sweden)

    Alline Sardinha Cordeiro Morais

    2016-04-01

    Full Text Available The presence of elements that refer to nostalgia in many sectors of contemporary society has been studied by researchers from various areas. In marketing, nostalgia is perceived as a market trend that attracts consumers through their past emotions. This article aims to analyze the factors that drive the retro phenomenon, given the evolution of consumption, the current values that govern the relationship between brands and consumers through an exploratory research, also seeking to understand this phenomenon, determining concepts in relation to retro culture and its peculiarities.

  10. Ecological allometries and niche use dynamics across Komodo dragon ontogeny.

    Science.gov (United States)

    Purwandana, Deni; Ariefiandy, Achmad; Imansyah, M Jeri; Seno, Aganto; Ciofi, Claudio; Letnic, Mike; Jessop, Tim S

    2016-04-01

    Ontogenetic allometries in ecological habits and niche use are key responses by which individuals maximize lifetime fitness. Moreover, such allometries have significant implications for how individuals influence population and community dynamics. Here, we examined how body size variation in Komodo dragons (Varanus komodoensis) influenced ecological allometries in their: (1) prey size preference, (2) daily movement rates, (3) home range area, and (4) subsequent niche use across ontogeny. With increased body mass, Komodo dragons increased prey size with a dramatic switch from small (≤10 kg) to large prey (≥50 kg) in lizards heavier than 20 kg. Rates of foraging movement were described by a non-linear concave down response with lizard increasing hourly movement rates up until ∼20 kg body mass before decreasing daily movement suggesting reduced foraging effort in larger lizards. In contrast, home range area exhibited a sigmoid response with increased body mass. Intrapopulation ecological niche use and overlap were also strongly structured by body size. Thus, ontogenetic allometries suggest Komodo dragon's transition from a highly active foraging mode exploiting small prey through to a less active sit and wait feeding strategy focused on killing large ungulates. Further, our results suggest that as body size increases across ontogeny, the Komodo dragon exhibited marked ontogenetic niche shifts that enabled it to function as an entire vertebrate predator guild by exploiting prey across multiple trophic levels.

  11. Mesenchymal stem cells in human placental chorionic villi reside in a vascular Niche

    NARCIS (Netherlands)

    Castrechini, N. M.; Murthi, P.; Gude, N. M.; Erwich, J. J. H. M.; Gronthos, S.; Zannettino, A.; Brennecke, S. R.; Kalionis, B.; Brennecke, S.P.

    The chorionic villi of human term placentae are a rich source of mesenchymal stem cells (PMSCs) The stem cell "niche" within the chorionic villi regulates how PMSCs participate in placental tissue generation, maintenance and repair, but the anatomic location of the niche has not been defined A

  12. The Effect of Marketing Strategies Construct on Firm Performance: Results from Pilot Survey

    Directory of Open Access Journals (Sweden)

    Fazal Akbar

    2017-04-01

    Full Text Available The difficulties that face small and medium organization in any field are severe nowadays. The importance of SMEs is vital. Different researchers have proposed different success factors for small and medium organization, like finance, skilled workforce, technology, innovation and most importantly marketing. Marketing is the spine of any organization, through marketing firms bring innovation, awareness of competitors, awareness of products, building relation with customers. A good marketing strategy increases the sale of product for sure. The small and medium organization face difficulties in doing marketing, because of limited finance, limited or unskilled staff, unawareness of marketing strategies, no or less use of media. This paper presents the pilot survey result for the study of effect of marketing strategies construct (entrepreneurial, guerrilla, relationship, ambush, viral and niche marketing, on firm performance. Descriptive statistics, normality, reliability and preliminary factor analysis (EFA test were run, all the data were presented in tables below. The result shows that all the questionnaire were normally distributed, and the outcomes are all normal.

  13. When does it pay to invest in a patch? The evolution of intentional niche construction.

    Science.gov (United States)

    Mohlenhoff, Kathryn A; Codding, Brian F

    2017-09-01

    Humans modify their environments in ways that significantly transform the earth's ecosystems. Recent research suggests that such niche-constructing behaviors are not passive human responses to environmental variation, but instead should be seen as active and intentional management of the environment. Although such research is useful in highlighting the interactive dynamics between humans and their natural world, the niche-construction framework, as currently applied, fails to explain why people would decide to modify their environments in the first place. To help resolve this problem, we use a model of technological intensification to analyze the cost-benefit trade-offs associated with niche construction as a form of patch investment. We use this model to assess the costs and benefits of three paradigmatic cases of intentional niche construction in Western North America: the application of fire in acorn groves, the manufacture of fishing weirs, and the adoption of maize agriculture. Intensification models predict that investing in patch modification (niche construction) only provides a net benefit when the amount of resources needed crosses a critical threshold that makes the initial investment worthwhile. From this, it follows that low-cost investments, such as burning in oak groves, should be quite common, while more costly investments, such as maize agriculture, should be less common and depend on the alternatives available in the local environment. We examine how patterns of mobility, risk management, territoriality, and private property also co-evolve with the costs and benefits of niche construction. This approach illustrates that explaining niche-constructing behavior requires understanding the economic trade-offs involved in patch investment. Integrating concepts from niche construction and technological intensification models within a behavioral ecological framework provides insights into the coevolution and active feedback between adaptive behaviors and

  14. β3-Adrenergic Regulation of EPC Features Through Manipulation of the Bone Marrow MSC Niche.

    Science.gov (United States)

    Vafaei, Rana; Nassiri, Seyed Mahdi; Siavashi, Vahid

    2017-12-01

    Mesenchymal stem cells (MSCs) reside in a specific niche in the bone marrow, however, biological features of this niche are still not fully understood. Given the interactions of MSCs with endothelial cells in different tissues, bone marrow MSC niche may influence the biological features of endothelial progenitor cells (EPCs). To understand the role of the sympathetic nervous system in regulation of the MSC niche, we examined whether the manipulation of the MSC niche via β3-adrenergic signals will affect EPC features. A selective β3 agonist (BRL37344) or a β3 antagonist (SR59230A) was administered in mice for 2 weeks to determine the potential effects of these regimens on the population of CD133 + stem cells in the bone marrow. Then, bone marrow-derived MSCs and EPCs were harvested and expanded from the mice to examine the effect of changes in the MSC niche on EPC features. Improved MSC colony forming potency with increased bone marrow stromal cell-derived factor 1 (SDF-1) (also known as C-X-C motif chemokine 12 [CXCL12]) expression was shown as a result of intensification of the bone marrow adrenergic signals through BRL37344 injection. On the other hand, the blockage of these signals limited the expression level of SDF-1 and resulted in bone marrow enrichment of CD133 + cells. Manipulation of the MSC niche and decreased SDF-1 expression via SR59230A injection also prompted EPCs to form more colonies with augmented proliferation and differentiation capacity. Overall, our results indicate that the β3-adrenergic signals regulate the MSC niche, thereby resulting in modulation of EPC biological features. J. Cell. Biochem. 118: 4753-4761, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  15. A Stromal Cell Niche for Human and Mouse Type 3 Innate Lymphoid Cells.

    Science.gov (United States)

    Hoorweg, Kerim; Narang, Priyanka; Li, Zhi; Thuery, Anne; Papazian, Natalie; Withers, David R; Coles, Mark C; Cupedo, Tom

    2015-11-01

    Adaptive immunity critically depends on the functional compartmentalization of secondary lymphoid organs. Mesenchymal stromal cells create and maintain specialized niches that support survival, activation, and expansion of T and B cells, and integrated analysis of lymphocytes and their niche has been instrumental in understanding adaptive immunity. Lymphoid organs are also home to type 3 innate lymphoid cells (ILC3), innate effector cells essential for barrier immunity. However, a specialized stromal niche for ILC3 has not been identified. A novel lineage-tracing approach now identifies a subset of murine fetal lymphoid tissue organizer cells that gives rise exclusively to adult marginal reticular cells. Moreover, both cell types are conserved from mice to humans and colocalize with ILC3 in secondary lymphoid tissues throughout life. In sum, we provide evidence that fetal stromal organizers give rise to adult marginal reticular cells and form a dedicated stromal niche for innate ILC3 in adaptive lymphoid organs. Copyright © 2015 by The American Association of Immunologists, Inc.

  16. Evolution of niche preference in Sphagnum peat mosses.

    Science.gov (United States)

    Johnson, Matthew G; Granath, Gustaf; Tahvanainen, Teemu; Pouliot, Remy; Stenøien, Hans K; Rochefort, Line; Rydin, Håkan; Shaw, A Jonathan

    2015-01-01

    Peat mosses (Sphagnum) are ecosystem engineers-species in boreal peatlands simultaneously create and inhabit narrow habitat preferences along two microhabitat gradients: an ionic gradient and a hydrological hummock-hollow gradient. In this article, we demonstrate the connections between microhabitat preference and phylogeny in Sphagnum. Using a dataset of 39 species of Sphagnum, with an 18-locus DNA alignment and an ecological dataset encompassing three large published studies, we tested for phylogenetic signal and within-genus changes in evolutionary rate of eight niche descriptors and two multivariate niche gradients. We find little to no evidence for phylogenetic signal in most component descriptors of the ionic gradient, but interspecific variation along the hummock-hollow gradient shows considerable phylogenetic signal. We find support for a change in the rate of niche evolution within the genus-the hummock-forming subgenus Acutifolia has evolved along the multivariate hummock-hollow gradient faster than the hollow-inhabiting subgenus Cuspidata. Because peat mosses themselves create some of the ecological gradients constituting their own habitats, the classic microtopography of Sphagnum-dominated peatlands is maintained by evolutionary constraints and the biological properties of related Sphagnum species. The patterns of phylogenetic signal observed here will instruct future study on the role of functional traits in peatland growth and reconstruction. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  17. System architecture and market aspects of an European Land Mobile Satellite System via EMS

    Science.gov (United States)

    Ananasso, F.; Mistretta, I.

    1992-03-01

    The paper describes an implementation scenario of a Land Mobile Satellite System via the EMS (European Mobile System) payload embarked on Italsat F-2. Some emphasis is given on market issues aiming at singling out business niches of Land Mobile Satellite Services (LMSS) in Europe. Other crucial issues exist such as: the alternate/competitive systems, the problems of interworking with other existing and/or planned systems, the definition of network architecture that better fits the user requirements, the marketing strategy and, last but not least, the financial evaluation of the project. The paper, on the basis of a study performed by Telespazio on behalf of ESA, discusses some of these issues with emphasis on competitive market aspects.

  18. INDUSTRIAL DESIGN ELEMENTS IN MARKETING

    Directory of Open Access Journals (Sweden)

    TOCARIU Liliana

    2015-06-01

    Full Text Available Industrial design represents an important 20th century phenomenon, which contributed to the spectacular development of human society. There are a lot of domains in which the insertion of the industrial design methods and theories is extremely necessary, becoming common practice. Marketing uses industrial design elements in order to draw up advertisements for products, to develop logos or packaging with all its attached factors, to organise promotional sales with the view of penetrating a certain market or of appealing to a large number of consumers.

  19. Experience in open markets

    International Nuclear Information System (INIS)

    Bachman, G.; Way, R.; O'Donnell, J.

    1997-01-01

    The topic of discussion in this session was experience in open markets. The session was led by Guido Bachman, President of the Independent Power Producers' Society of Alberta (IPPSA), assisted by panel members Richard Way, Director of Energy Risk Management at TransAlta, John O'Donnell, Professor of Finance at Michigan State University, and Kelly Lail, Manager of Power Acquisition at B.C. Hydro. Way spoke of the experiences with market restructuring in Alberta, describing the consultative and legislative process which determined the structure of the Alberta Power Pool (APP). The Pool began operations in January 1996. Currently there are 33 participants from generators, to distributors and marketers. Supply and demand are managed by APP by setting an hourly price based on offers and bids. Both generators and distributors get the hourly pool price, so the input price and export price of the pool are the same, however, generators and distributors are free to enter into 'contract for difference' agreements. O'Donnell discussed the status of competition in Michigan. He stressed the importance of Ontario to the Michigan market, echoing the conviction of U.S. regulators that a freer economy works better. Kelly Lail spoke of the unbundling of B.C. Hydro into several generating, transmission and distribution companies in preparation for moving from exclusive service to exclusive wholesale competition. He predicted that the fierce competition will lead to a an industry shakeout, leaving only one big (B.C. Hydro) and a few niche players

  20. Meat export competitiveness of European Union countries on global markets

    OpenAIRE

    Štefan Bojnec; Imre Fertő

    2014-01-01

    The purpose of this research is to provide insight into the export competitiveness of meat products of the European Union (EU-27) member states on global markets. The revealed comparative advantage index is used to analyze the levels, compositions, and evolutions in patterns of development in the export competitiveness of meat products and their levels of stability at the product level. Except for some niche meat products, a larger number of the EU-27 member states have experienced comparativ...

  1. Landscape heterogeneity drives intra-population niche variation and reproduction in an arctic top predator.

    Science.gov (United States)

    L'hérault, Vincent; Franke, Alastair; Lecomte, Nicolas; Alogut, Adam; Bêty, Joël

    2013-09-01

    While intra-population variability in resource use is ubiquitous, little is known of how this measure of niche diversity varies in space and its role in population dynamics. Here we examined how heterogeneous breeding environments can structure intra-population niche variation in both resource use and reproductive output. We investigated intra-population niche variation in the Arctic tundra ecosystem, studying peregrine falcon (Falco peregrinus tundrius, White) breeding within a terrestrial-marine gradient near Rankin Inlet, Nunavut, Canada. Using stable isotope analysis, we found that intra-population niches varied at the individual level; we examined within-nest and among-nest variation, though only the latter varied along the terrestrial-marine gradient (i.e., increased among-nest variability among birds nesting within the marine environment, indicating higher degree of specialization). Terrestrial prey species (small herbivores and insectivores) were consumed by virtually all falcons. Falcons nesting within the marine environment made use of marine prey (sea birds), but depended heavily on terrestrial prey (up to 90% of the diet). Using 28-years of peregrine falcon nesting data, we found a positive relationship between the proportion of terrestrial habitat surrounding nest sites and annual nestling production, but no relationship with the likelihood of successfully rearing at least one nestling reaching 25 days old. Annually, successful inland breeders raised 0.47 more young on average compared to offshore breeders, which yields potential fitness consequences for this long-living species. The analyses of niche and reproductive success suggest a potential breeding cost for accessing distant terrestrial prey, perhaps due to additional traveling costs, for those individuals with marine nest site locations. Our study indicates how landscape heterogeneity can generate proximate (niche variation) and ultimate (reproduction) consequences on a population of generalist

  2. Development of biomass power plant technologies in Malaysia: niche development and the formation of innovative capabilities

    DEFF Research Database (Denmark)

    Hansen, Ulrich Elmer

    The objective of this thesis is to contribute to advance further the emerging research agenda on the transfer and diffusion of low-carbon technologies in developing countries by adopting a study of the development of biomass power plant technologies in Malaysia. The main research question addresses...... successive periods of fieldwork in Malaysia. The thesis conceptualises the diffusion of biomass technologies in Malaysia as a niche development process and finds that the development of a palm oil biomass waste-to-energy niche in Malaysia has only made limited progress despite a period of twenty years...... of niche formation. The thesis identifies the reluctance to implement an efficient energy policy as the main limiting factor for niche development in this case. Although a number of donor programs have advocated the introduction of a stronger enabling framework for niche development, they have generally...

  3. Untangling the relationships among regional occupancy, species traits, and niche characteristics in stream invertebrates

    Science.gov (United States)

    Heino, Jani; Grönroos, Mira

    2014-01-01

    The regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small-grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position (NP), but it showed a weaker relationship with niche breadth (NB). Abundance was at best weakly related to these explanatory niche-based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites. PMID:24963387

  4. The hidden Niemann-Pick type C patient: clinical niches for a rare inherited metabolic disease.

    Science.gov (United States)

    Hendriksz, Christian J; Anheim, Mathieu; Bauer, Peter; Bonnot, Olivier; Chakrapani, Anupam; Corvol, Jean-Christophe; de Koning, Tom J; Degtyareva, Anna; Dionisi-Vici, Carlo; Doss, Sarah; Duning, Thomas; Giunti, Paola; Iodice, Rosa; Johnston, Tracy; Kelly, Dierdre; Klünemann, Hans-Hermann; Lorenzl, Stefan; Padovani, Alessandro; Pocovi, Miguel; Synofzik, Matthis; Terblanche, Alta; Then Bergh, Florian; Topçu, Meral; Tranchant, Christine; Walterfang, Mark; Velten, Christian; Kolb, Stefan A

    2017-05-01

    Niemann-Pick disease type C (NP-C) is a rare, inherited neurodegenerative disease of impaired intracellular lipid trafficking. Clinical symptoms are highly heterogeneous, including neurological, visceral, or psychiatric manifestations. The incidence of NP-C is under-estimated due to under-recognition or misdiagnosis across a wide range of medical fields. New screening and diagnostic methods provide an opportunity to improve detection of unrecognized cases in clinical sub-populations associated with a higher risk of NP-C. Patients in these at-risk groups ("clinical niches") have symptoms that are potentially related to NP-C, but go unrecognized due to other, more prevalent clinical features, and lack of awareness regarding underlying metabolic causes. Twelve potential clinical niches identified by clinical experts were evaluated based on a comprehensive, non-systematic review of literature published to date. Relevant publications were identified by targeted literature searches of EMBASE and PubMed using key search terms specific to each niche. Articles published in English or other European languages up to 2016 were included. Several niches were found to be relevant based on available data: movement disorders (early-onset ataxia and dystonia), organic psychosis, early-onset cholestasis/(hepato)splenomegaly, cases with relevant antenatal findings or fetal abnormalities, and patients affected by family history, consanguinity, and endogamy. Potentially relevant niches requiring further supportive data included: early-onset cognitive decline, frontotemporal dementia, parkinsonism, and chronic inflammatory CNS disease. There was relatively weak evidence to suggest amyotrophic lateral sclerosis or progressive supranuclear gaze palsy as potential niches. Several clinical niches have been identified that harbor patients at increased risk of NP-C.

  5. Tax Evasion Causes and Prevenience or Rebutment Way of Tax Dodger Phenomenon

    Directory of Open Access Journals (Sweden)

    Corina Nichitcin

    2010-12-01

    Full Text Available Tax evasion phenomenon, having negative impact on many levels, must be constantly pursued in order to minimize tax circumvention and control section in the issue of tax fraud. From international theory and experience it is known that normal functioning of market economy is conditioned by promotion of certain efficient policies and adequate legislation implementation. So, as Republic of Moldova is no exception among countries where tax evasion is, the study of this subject is up-to-date and it is required for presenting these problems at national and international levels.

  6. HOOLIGANISM – CONTEMPORARY SOCIAL PHENOMENON

    Directory of Open Access Journals (Sweden)

    MARIA LULESCU

    2012-05-01

    Full Text Available The proposed scientific theme is going to approach and study the hooliganism phenomenon as a contemporary social matter, in terms of conceptual and etiological. The present work has four main purposes: (1- that of explaining the meaning of hooliganism social phenomenon; (2- that of discovering the origins of hooliganism; (3- that of knowing which are the causes that encourages the occurence of the hooliganism; (4- that of knowing how to control and minimize this phenomenon.

  7. Introducing MERGANSER: A Flexible Framework for Ecological Niche Modeling

    Science.gov (United States)

    Klawonn, M.; Dow, E. M.

    2015-12-01

    Ecological Niche Modeling (ENM) is a collection of techniques to find a "fundamental niche", the range of environmental conditions suitable for a species' survival in the absence of inter-species interactions, given a set of environmental parameters. Traditional approaches to ENM face a number of obstacles including limited data accessibility, data management problems, computational costs, interface usability, and model validation. The MERGANSER system, which stands for Modeling Ecological Residency Given A Normalized Set of Environmental Records, addresses these issues through powerful data persistence and flexible data access, coupled with a clear presentation of results and fine-tuned control over model parameters. MERGANSER leverages data measuring 72 weather related phenomena, land cover, soil type, population, species occurrence, general species information, and elevation, totaling over 1.5 TB of data. To the best of the authors' knowledge, MERGANSER uses higher-resolution spatial data sets than previously published models. Since MERGANSER stores data in an instance of Apache SOLR, layers generated in support of niche models are accessible to users via simplified Apache Lucene queries. This is made even simpler via an HTTP front end that generates Lucene queries automatically. Specifically, a user need only enter the name of a place and a species to run a model. Using this approach to synthesizing model layers, the MERGANSER system has successfully reproduced previously published niche model results with a simplified user experience. Input layers for the model are generated dynamically using OpenStreetMap and SOLR's spatial search functionality. Models are then run using either user-specified or automatically determined parameters after normalizing them into a common grid. Finally, results are visualized in the web interface, which allows for quick validation. Model results and all surrounding metadata are also accessible to the user for further study.

  8. The nutritional nexus: linking niche, habitat variability and prey composition in a generalist marine predator.

    Science.gov (United States)

    Machovsky-Capuska, Gabriel E; Miller, Mark G R; Silva, Fabiola R O; Amiot, Christophe; Stockin, Karen A; Senior, Alistair M; Schuckard, Rob; Melville, David; Raubenheimer, David

    2018-06-05

    1.Our understanding of the niche concept will remain limited while the quantity and range of different food types eaten remains a dominant proxy for niche breadth, as this does not account for the broad ecological context that governs diet. Linking nutrition, physiology and behaviour are critical to predict the extent to which a species adjusts its nutritional niche breadth at the levels of prey ("prey composition niche", defined as the range of prey compositions eaten), and diet ("realized nutritional niche" is the range of diets composed through feeding on the prey). 2.Here we studied adult-chick rearing Australasian gannets (Morus serrator) to propose an integrative approach using sea surface temperature anomalies (SSTa), geographic location and bathymetry over different years, to explore their relationship with the nutritional composition of prey and diets (i.e., prey composition and nutritional niche breadth), habitat use and foraging behavior. 3.We found that gannets feed on prey that varied widely in their nutritional composition (have a broad prey composition niche), and composed diets from these prey that likewise varied in composition (have a broad realized nutritional niche), suggesting generalism at two levels of macronutrient selection. 4.Across seasons, we established "nutritional landscapes" (hereafter nutriscapes), linking the nutritional content of prey (wet mass protein to-lipid ratio -P:L-) to the most likely geographic area of capture and bathymetry. Nutriscapes varied in their P:L from 6.06 to 15.28, over time, space and bathymetry (0 to 150 m). 5.During warm water events (strong positive SSTa), gannets expanded their foraging habitat, increased their foraging trip duration and consumed prey and diets with low macronutrient content (wet mass proportions of P and L). They were also constrained to the smallest prey composition and realized nutritional niche breadths. 6.Our findings are consistent with previous suggestions that dietary generalism

  9. A practical guideline for examining a uterine niche using ultrasonography in non-pregnant women: a modified Delphi method amongst European experts.

    Science.gov (United States)

    Jordans, I P M; de Leeuw, R; Stegwee, S I; Amso, N N; Barri-Soldevila, P N; van den Bosch, T; Bourne, T; Brolmann, H A M; Donnez, O; Dueholm, M; Hehenkamp, W J K; Jastrow, N; Jurkovic, D; Mashiach, R; Naji, O; Streuli, I; Timmerman, D; Vd Voet, L F; Huirne, J A F

    2018-03-14

    To generate a uniform, internationally recognized guideline for detailed uterine niche evaluation by ultrasonography in non-pregnant women using a modified Delphi method amongst international experts. Fifteen international gynecological experts were recruited by their membership of the European niche taskforce group. All experts were physicians with extensive experience in niche evaluation in clinical practice and/or authors of niche studies. Relevant items for niche measurement were determined based on the results of a literature search and recommendations of a focus group. Two online questionnaires were sent to the expert panel and one group meeting was organized. Consensus was predefined as a consensus rate of at least 70%. In total 15 experts participated in this study. Consensus was reached for a total of 42 items on niche evaluation, including definitions, relevance, method of measurement and tips for visualization of the niche. All experts agreed on the proposed guideline for niche evaluation in non-pregnant women as presented in this paper. Consensus between niche experts was achieved on all items regarding ultrasonographic niche measurement. This article is protected by copyright. All rights reserved.

  10. Co-niche construction between hosts and symbionts

    Indian Academy of Sciences (India)

    Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche space of organisms. Symbionts can act together with their hosts to co-construct host organs, within which symbionts are housed. Once established within hosts, symbionts can also influence various aspects of host ...

  11. Tracking niche variation over millennial timescales in sympatric killer whale lineages.

    Science.gov (United States)

    Foote, Andrew D; Newton, Jason; Ávila-Arcos, María C; Kampmann, Marie-Louise; Samaniego, Jose A; Post, Klaas; Rosing-Asvid, Aqqalu; Sinding, Mikkel-Holger S; Gilbert, M Thomas P

    2013-10-07

    Niche variation owing to individual differences in ecology has been hypothesized to be an early stage of sympatric speciation. Yet to date, no study has tracked niche width over more than a few generations. In this study, we show the presence of isotopic niche variation over millennial timescales and investigate the evolutionary outcomes. Isotopic ratios were measured from tissue samples of sympatric killer whale Orcinus orca lineages from the North Sea, spanning over 10 000 years. Isotopic ratios spanned a range similar to the difference in isotopic values of two known prey items, herring Clupea harengus and harbour seal Phoca vitulina. Two proxies of the stage of speciation, lineage sorting of mitogenomes and genotypic clustering, were both weak to intermediate indicating that speciation has made little progress. Thus, our study confirms that even with the necessary ecological conditions, i.e. among-individual variation in ecology, it is difficult for sympatric speciation to progress in the face of gene flow. In contrast to some theoretical models, our empirical results suggest that sympatric speciation driven by among-individual differences in ecological niche is a slow process and may not reach completion. We argue that sympatric speciation is constrained in this system owing to the plastic nature of the behavioural traits under selection when hunting either mammals or fish.

  12. Supply chain and marketing of sea grapes, Caulerpa racemosa (Forsskål) J. Agardh (Chlorophyta: Caulerpaceae) in Fiji, Samoa and Tonga.

    Science.gov (United States)

    Morris, C; Bala, S; South, G R; Lako, J; Lober, M; Simos, T

    2014-01-01

    This report describes for the first time the supply chain of Caulerpa racemosa in three Pacific Island countries. The harvesting and marketing of C. racemosa are important subsistence activities for villagers in Fiji and Samoa, less so in Tonga. At least 150 harvesters are involved in Fiji, some 100 in Samoa and only a handful in Tonga. The annual combined crop is of some 123 t valued at around US$266,492. In Fiji, it is projected that supply does not meet local demand and there is a potential export market that is currently operating at a pilot project level. In Samoa, the supply is considered adequate for the current market. In Tonga, harvesting is carried out by a few families and supplies a niche market in that country. The possibilities of field cultivation of Caulerpa have been explored but, at present, with only limited success in Samoa. The supply chain is simple in all three countries, and only in Fiji are middlemen involved in the distribution process. The limitations for marketing include the fact that only a few sites supply most of the crop in all the three countries, that all sites need to be conserved through sustainable harvesting methods, the short shelf life of the crop and a lack of information on the carrying capacity of harvest sites. Caulerpa remains a crop that fulfils a niche market but has the potential to be scaled up for additional livelihood development in the future.

  13. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems

    Science.gov (United States)

    Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar

    2016-10-01

    Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.

  14. Niche as a determinant of word fate in online groups.

    Directory of Open Access Journals (Sweden)

    Eduardo G Altmann

    2011-05-01

    Full Text Available Patterns of word use both reflect and influence a myriad of human activities and interactions. Like other entities that are reproduced and evolve, words rise or decline depending upon a complex interplay between their intrinsic properties and the environments in which they function. Using Internet discussion communities as model systems, we define the concept of a word niche as the relationship between the word and the characteristic features of the environments in which it is used. We develop a method to quantify two important aspects of the size of the word niche: the range of individuals using the word and the range of topics it is used to discuss. Controlling for word frequency, we show that these aspects of the word niche are strong determinants of changes in word frequency. Previous studies have already indicated that word frequency itself is a correlate of word success at historical time scales. Our analysis of changes in word frequencies over time reveals that the relative sizes of word niches are far more important than word frequencies in the dynamics of the entire vocabulary at shorter time scales, as the language adapts to new concepts and social groupings. We also distinguish endogenous versus exogenous factors as additional contributors to the fates of words, and demonstrate the force of this distinction in the rise of novel words. Our results indicate that short-term nonstationarity in word statistics is strongly driven by individual proclivities, including inclinations to provide novel information and to project a distinctive social identity.

  15. Bifurcation into functional niches in adaptation.

    Science.gov (United States)

    White, Justin S; Adami, Christoph

    2004-01-01

    One of the central questions in evolutionary biology concerns the dynamics of adaptation and diversification. This issue can be addressed experimentally if replicate populations adapting to identical environments can be investigated in detail. We have studied 501 such replicas using digital organisms adapting to at least two fundamentally different functional niches (survival strategies) present in the same environment: one in which fast replication is the way to live, and another where exploitation of the environment's complexity leads to complex organisms with longer life spans and smaller replication rates. While these two modes of survival are closely analogous to those expected to emerge in so-called r and K selection scenarios respectively, the bifurcation of evolutionary histories according to these functional niches occurs in identical environments, under identical selective pressures. We find that the branching occurs early, and leads to drastic phenotypic differences (in fitness, sequence length, and gestation time) that are permanent and irreversible. This study confirms an earlier experimental effort using microorganisms, in that diversification can be understood at least in part in terms of bifurcations on saddle points leading to peak shifts, as in the picture drawn by Sewall Wright.

  16. Pulling the Trigger or Not: Factors Affecting Behavior of Initiating a Position in Derivatives Markets

    NARCIS (Netherlands)

    Pennings, J.M.E.

    2002-01-01

    The behavior of managers in initiating a derivatives market position brings to the surface an interesting phenomenon: sometimes managers initiate a position in derivatives markets (i.e., futures and options markets) and sometimes they do not, even though the price volatility of the underlying asset

  17. The Impact of Viral Marketing Through Social Media on BCD's Consumer Brand Knowledge

    OpenAIRE

    Kusumadjaja, Levina

    2014-01-01

    Due to the continous increase in viral marketing's popularity phenomenon that causes viral marketing to later become a strategic requirement for marketers worldwide, a necessity to assess the effectiveness of viral marketing in achieveing its objectives in leveraging brand and products has emerged. This research was accomplished to study the impact of viral marketing through social media on consumer brand knowledge of a franchised Taiwanese bubble tea company, BCD. The company utilizes viral...

  18. The human socio-cognitive niche and its evolutionary origins

    Science.gov (United States)

    Whiten, Andrew; Erdal, David

    2012-01-01

    Hominin evolution took a remarkable pathway, as the foraging strategy extended to large mammalian prey already hunted by a guild of specialist carnivores. How was this possible for a moderately sized ape lacking the formidable anatomical adaptations of these competing ‘professional hunters’? The long-standing answer that this was achieved through the elaboration of a new ‘cognitive niche’ reliant on intelligence and technology is compelling, yet insufficient. Here we present evidence from a diversity of sources supporting the hypothesis that a fuller answer lies in the evolution of a new socio-cognitive niche, the principal components of which include forms of cooperation, egalitarianism, mindreading (also known as ‘theory of mind’), language and cultural transmission, that go far beyond the most comparable phenomena in other primates. This cognitive and behavioural complex allows a human hunter–gatherer band to function as a unique and highly competitive predatory organism. Each of these core components of the socio-cognitive niche is distinctive to humans, but primate research has increasingly identified related capacities that permit inferences about significant ancestral cognitive foundations to the five pillars of the human social cognitive niche listed earlier. The principal focus of the present study was to review and integrate this range of recent comparative discoveries. PMID:22734055

  19. The inverse niche model for food webs with parasites

    Science.gov (United States)

    Warren, Christopher P.; Pascual, Mercedes; Lafferty, Kevin D.; Kuris, Armand M.

    2010-01-01

    Although parasites represent an important component of ecosystems, few field and theoretical studies have addressed the structure of parasites in food webs. We evaluate the structure of parasitic links in an extensive salt marsh food web, with a new model distinguishing parasitic links from non-parasitic links among free-living species. The proposed model is an extension of the niche model for food web structure, motivated by the potential role of size (and related metabolic rates) in structuring food webs. The proposed extension captures several properties observed in the data, including patterns of clustering and nestedness, better than does a random model. By relaxing specific assumptions, we demonstrate that two essential elements of the proposed model are the similarity of a parasite's hosts and the increasing degree of parasite specialization, along a one-dimensional niche axis. Thus, inverting one of the basic rules of the original model, the one determining consumers' generality appears critical. Our results support the role of size as one of the organizing principles underlying niche space and food web topology. They also strengthen the evidence for the non-random structure of parasitic links in food webs and open the door to addressing questions concerning the consequences and origins of this structure.

  20. Wnt ligand presentation and reception: from the stem cell niche to tissue engineering.

    Science.gov (United States)

    Mills, Kate M; Szczerkowski, James L A; Habib, Shukry J

    2017-08-01

    Stem cells reside in niches where spatially restricted signals maintain a delicate balance between stem cell self-renewal and differentiation. Wnt family proteins are particularly suited for this role as they are modified by lipids, which constrain and spatially regulate their signalling range. In recent years, Wnt/β-catenin signalling has been shown to be essential for the self-renewal of a variety of mammalian stem cells. In this review, we discuss Wnt-responsive stem cells in their niche, and mechanisms by which Wnt ligands are presented to responsive cells. We also highlight recent progress in molecular visualization that has allowed for the monitoring of Wnt signalling within the stem cell compartment and new approaches to recapitulate this niche signalling in vitro Indeed, new technologies that present Wnt in a localized manner and mimic the three-dimensional microenvironment of stem cells will advance our understanding of Wnt signalling in the stem cell niche. These advances will expand current horizons to exploit Wnt ligands in the rapidly evolving fields of tissue engineering and regenerative medicine. © 2017 The Authors.

  1. Climatic niche evolution is faster in sympatric than allopatric lineages of the butterfly genus Pyrgus.

    Science.gov (United States)

    Pitteloud, Camille; Arrigo, Nils; Suchan, Tomasz; Mastretta-Yanes, Alicia; Vila, Roger; Dincă, Vlad; Hernández-Roldán, Juan; Brockmann, Ernst; Chittaro, Yannick; Kleckova, Irena; Fumagalli, Luca; Buerki, Sven; Pellissier, Loïc; Alvarez, Nadir

    2017-04-12

    Understanding how speciation relates to ecological divergence has long fascinated biologists. It is assumed that ecological divergence is essential to sympatric speciation, as a mechanism to avoid competition and eventually lead to reproductive isolation, while divergence in allopatry is not necessarily associated with niche differentiation. The impact of the spatial context of divergence on the evolutionary rates of abiotic dimensions of the ecological niche has rarely been explored for an entire clade. Here, we compare the magnitude of climatic niche shifts between sympatric versus allopatric divergence of lineages in butterflies. By combining next-generation sequencing, parametric biogeography and ecological niche analyses applied to a genus-wide phylogeny of Palaearctic Pyrgus butterflies, we compare evolutionary rates along eight climatic dimensions across sister lineages that diverged in large-scale sympatry versus allopatry. In order to examine the possible effects of the spatial scale at which sympatry is defined, we considered three sets of biogeographic assignments, ranging from narrow to broad definition. Our findings suggest higher rates of niche evolution along all climatic dimensions for sister lineages that diverge in sympatry, when using a narrow delineation of biogeographic areas. This result contrasts with significantly lower rates of climatic niche evolution found in cases of allopatric speciation, despite the biogeographic regions defined here being characterized by significantly different climates. Higher rates in allopatry are retrieved when biogeographic areas are too widely defined-in such a case allopatric events may be recorded as sympatric. Our results reveal the macro-evolutionary significance of abiotic niche differentiation involved in speciation processes within biogeographic regions, and illustrate the importance of the spatial scale chosen to define areas when applying parametric biogeographic analyses. © 2017 The Author(s).

  2. Adopting Strategic Niche Management to Evaluate EV Demonstration Projects in China

    Directory of Open Access Journals (Sweden)

    Yixi Xue

    2016-02-01

    Full Text Available Electric Vehicles (EVs are considered to be a potential viable technology to address the persistent unsustainable problems in transport sector. In this paper, we focus on analyzing the transition processes of EVs in China because the sustainability of developing countries is essential for the worldwide sustainability. The two-round demonstration programs of EVs in China were analyzed by adopting the strategic niche management (SNM approach so as to find out what niche protection has been provided and which obstacles hamper the further development of EVs. The results show that the financial subsidy is the most important protective measure. However, the diffusion results of EVs in different pilot cities are greatly different. The main reason lies in the uneven geographical landscape. In addition, some obstacles were exposed during the niche internal processes including low quality of expectations and poor alignment within the network. Based on the analysis results, we develop a list of suggestions that are important to consider when developing EVs.

  3. The analysis of marketing concept implementation in domestic enterprises

    Directory of Open Access Journals (Sweden)

    Đorđević Dejan

    2016-01-01

    Full Text Available Global markets and modern business conditions require from enterprises to change their business philosophy and ways of behaviour in their business practice. Nowadays, in IT society, knowledge has become the basic resource. Marketing enables knowledge management by making possibilities for increasing knowledge productivity of other business functions in enterprises. Relationship marketing signifies a considerable advance in marketing approach, going from thinking exclusively about competition and conflict categories towards the categories of collaboration and interdependence. Domestic enterprises are facing problems with achieving competitive abilities on global markets and one of significant causes of this phenomenon is inappropriate implementation of marketing concept and modern methods and techniques of marketing management. This paper presents current global trends in theory and practice of marketing and marketing management along with critical analysis and recommendations for improving marketing practice in domestic enterprises.

  4. Guilt decreasing marketing communication: an unexplored appeal

    OpenAIRE

    B. BUSACCA; SOSCIA I; PITRELLI E

    2007-01-01

    The phenomenon of guilt is relevant to a variety of consumption situations and practitioners around the world have continued to use it as a communication appeal. Marketing literature demonstrated that guilt as a distinct emotion can be aroused by advertising. Nevertheless, the capacity of advertising to decrease guilt was neglected by marketing scholars and the aim of this research is to assess the role of the guilt decreasing appeal in reducing anticipated guilt. Findings demonstrate the eff...

  5. Role of the Stem Cell Niche in Hormone-induced Tumorigenesis in Fetal Mouse Mammary Epithelium

    National Research Council Canada - National Science Library

    Chepko, Gloria; Hilakivi-Clarke, Leena

    2006-01-01

    Develop an immunohistochemical method for identifying stem cells and stem cell niches, and to use this to determine if in utero estrogenic overstimulation causes changes in the number of stem cells or their niches...

  6. Developing Customer Trust in E-Commerce Using Inbound Marketing Strategies

    OpenAIRE

    Adrian MICU; Marius GERU; Angela-Eliza MICU

    2017-01-01

    Developing a new argument that digital content is a factor for inbound marketing campaigns is redundant, considering there are numerous papers in the relevant literature. The aim of this paper is to use FsQCA to demonstrate the direct implications of quality content as a trust factor on the acquisition of search engine traffic. Concluding on strategies to build customer confidence in e-commerce, based on educative and representative content on a particular niche. In this research, we've analy...

  7. Phylogeny and niche conservatism in North and Central American triatomine bugs (Hemiptera: Reduviidae: Triatominae), vectors of Chagas' disease.

    Science.gov (United States)

    Ibarra-Cerdeña, Carlos N; Zaldívar-Riverón, Alejandro; Peterson, A Townsend; Sánchez-Cordero, Víctor; Ramsey, Janine M

    2014-10-01

    The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios.

  8. Methods for Estimation of Market Power in Electric Power Industry

    Science.gov (United States)

    Turcik, M.; Oleinikova, I.; Junghans, G.; Kolcun, M.

    2012-01-01

    The article is related to a topical issue of the newly-arisen market power phenomenon in the electric power industry. The authors point out to the importance of effective instruments and methods for credible estimation of the market power on liberalized electricity market as well as the forms and consequences of market power abuse. The fundamental principles and methods of the market power estimation are given along with the most common relevant indicators. Furthermore, in the work a proposal for determination of the relevant market place taking into account the specific features of power system and a theoretical example of estimating the residual supply index (RSI) in the electricity market are given.

  9. Volatility in financial markets: The impact of the global financial crisis

    OpenAIRE

    Valls Ruiz, Natàlia

    2014-01-01

    This dissertation focuses on volatility in financial markets, with a special concern for: (i) volatility transmission between different financial markets and asset categories and, (ii) the effect of macroeconomic announcements on the returns, volatility and correlation of stock markets. These issues are analysed taking into account the phenomenon of asymmetric volatility and incorporating the period of financial turmoil caused by the Global Financial Crisis. The study focuses the attention on...

  10. Regulatory Competition in Global Financial Markets

    DEFF Research Database (Denmark)

    Ringe, Georg

    2016-01-01

    Regulatory arbitrage in financial markets refers to a number of strategies that market participants use to avoid the reach of regulation, in particular by virtue of moving trading abroad or relocating activities or operations of financial institutions to other jurisdictions. Where this happens...... institutions' excessive risk-taking. If such risk-taking would be judged by market discipline instead of posing a risk to global financial stability, the main downside of regulatory competition could be restrained. Within the boundaries of such a system, competition could then operate and contribute...... their standards solely to attract business and thereby impose externalities on the worldwide financial market by undermining financial stability as a global public good. Policymakers worldwide are experimenting with remedies to respond to the phenomenon. I introduce the importance of an effective special...

  11. Ecology: a niche for cyanobacteria containing chlorophyll d

    DEFF Research Database (Denmark)

    Kühl, Michael; Chen, Min; Ralph, Peter J

    2005-01-01

    we demonstrate photosynthetic activity in Acaryochloris-like phototrophs that live underneath minute coral-reef invertebrates (didemnid ascidians) in a shaded niche enriched in near-infrared light. This discovery clarifies how these cyanobacteria are able to thrive as free-living organisms...

  12. Average niche breadths of species in lake macrophyte communities respond to ecological gradients variably in four regions on two continents.

    Science.gov (United States)

    Alahuhta, Janne; Virtala, Antti; Hjort, Jan; Ecke, Frauke; Johnson, Lucinda B; Sass, Laura; Heino, Jani

    2017-05-01

    Different species' niche breadths in relation to ecological gradients are infrequently examined within the same study and, moreover, species niche breadths have rarely been averaged to account for variation in entire ecological communities. We investigated how average environmental niche breadths (climate, water quality and climate-water quality niches) in aquatic macrophyte communities are related to ecological gradients (latitude, longitude, altitude, species richness and lake area) among four distinct regions (Finland, Sweden and US states of Minnesota and Wisconsin) on two continents. We found that correlations between the three different measures of average niche breadths and ecological gradients varied considerably among the study regions, with average climate and average water quality niche breadth models often showing opposite trends. However, consistent patterns were also found, such as widening of average climate niche breadths and narrowing of average water quality niche breadths of aquatic macrophytes along increasing latitudinal and altitudinal gradients. This result suggests that macrophyte species are generalists in relation to temperature variations at higher latitudes and altitudes, whereas species in southern, lowland lakes are more specialised. In contrast, aquatic macrophytes growing in more southern nutrient-rich lakes were generalists in relation to water quality, while specialist species are adapted to low-productivity conditions and are found in highland lakes. Our results emphasise that species niche breadths should not be studied using only coarse-scale data of species distributions and corresponding environmental conditions, but that investigations on different kinds of niche breadths (e.g., climate vs. local niches) also require finer resolution data at broad spatial extents.

  13. Foxl1-Expressing Mesenchymal Cells Constitute the Intestinal Stem Cell NicheSummary

    Directory of Open Access Journals (Sweden)

    Reina Aoki

    2016-03-01

    Full Text Available Background & Aims: Intestinal epithelial stem cells that express leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5 and/or B cell specific Moloney murine leukemia virus integration site 1 (Bmi1 continuously replicate and generate differentiated cells throughout life. Previously, Paneth cells were suggested to constitute an epithelium-intrinsic niche that regulates the behavior of these stem cells. However, ablating Paneth cells has no effect on the maintenance of functional stem cells. Here, we show definitively that a small subset of mesenchymal subepithelial cells expressing the winged-helix transcription factor forkhead box l1 (Foxl1 are a critical component of the intestinal stem cell niche. Methods: We genetically ablated Foxl1+ mesenchymal cells in adult mice using 2 separate models by expressing either the human or simian diphtheria toxin receptor under Foxl1 promoter control. Conclusions: Killing Foxl1+ cells by diphtheria toxin administration led to an abrupt cessation of proliferation of both epithelial stem- and transit-amplifying progenitor cell populations that was associated with a loss of active Wnt signaling to the intestinal epithelium. Therefore, Foxl1-expressing mesenchymal cells constitute the fundamental niche for intestinal stem cells. Keywords: Intestinal Stem Cell Niche, Wnt, Mesenchyme

  14. Affordances and Landscapes: Overcoming the Nature-Culture Dichotomy through Niche Construction Theory.

    Science.gov (United States)

    Heras-Escribano, Manuel; De Pinedo-García, Manuel

    2017-01-01

    In this paper we reject the nature-culture dichotomy by means of the idea of affordance or possibility for action, which has important implications for landscape theory. Our hypothesis is that, just as the idea of affordance can serve to overcome the subjective-objective dichotomy, the ideas of landscape and ecological niche, properly defined, would allow us to also transcend the nature-culture dichotomy. First, we introduce an overview of landscape theory, emphasizing processual landscape theory as the most suitable approach for satisfying both cultural and naturalist approaches. After that, we introduce the idea of affordance and we analyze a tension between sociocultural and transcultural affordances (affordances that depend on cultural conventions and affordances that depend on lawful information and bodily aspects of agents). This tension has various implications for landscape theory and ecological niches. Our proposal is that sociocultural and transcultural aspects of affordances could be systematically accommodated if we apply niche construction theory (the theory that explains the process by which organisms modify their selective environments) as a methodological framework for explaining the emergence of ecological niches. This approach will lead us to an integrative account of landscapes as the products of the interaction between human and environmental elements, making it a clear example of a concept that transcends the nature-culture dichotomy.

  15. Cellular players of hematopoietic stem cell mobilization in the bone marrow niche.

    Science.gov (United States)

    Tay, Joshua; Levesque, Jean-Pierre; Winkler, Ingrid G

    2017-02-01

    Hematopoietic stem cells (HSC) reside in perivascular regions of the bone marrow (BM) embedded within a complex regulatory unit called the niche. Cellular components of HSC niches include vascular endothelial cells, mesenchymal stromal progenitor cells and a variety of mature hematopoietic cells such as macrophages, neutrophils, and megakaryocytes-further regulated by sympathetic nerves and complement components as described in this review. Three decades ago the discovery that cytokines induce a large number of HSC to mobilize from the BM into the blood where they are easily harvested, revolutionised the field of HSC transplantation-curative for immune-deficiencies and some malignancies. However, despite now routine use of granulocyte-colony stimulating factor (G-CSF) to mobilise HSC for transplant, only in last 15 years has research on the mechanisms behind why and how HSC can be induced to move into the blood began. These studies have revealed the complexity of the niche that retains HSC in the BM. This review describes how BM niches and HSC themselves change during administration of G-CSF-or in the recovery phase of chemotherapy-to facilitate movement of HSC into the blood, and research now leading to development of novel therapeutics to further boost HSC mobilization and transplant success.

  16. Assessing the Plurality of Actors and Policy Interactions: Agent-Based Modelling of Renewable Energy Market Integration

    Directory of Open Access Journals (Sweden)

    Marc Deissenroth

    2017-01-01

    Full Text Available The ongoing deployment of renewable energy sources (RES calls for an enhanced integration of RES into energy markets, accompanied by a new set of regulations. In Germany, for instance, the feed-in tariff legislation for renewables has been successively replaced by first optional and then obligatory marketing of RES on competitive wholesale markets. This paper introduces an agent-based model that allows studying the impact of changing energy policy instruments on the economic performance of RES operators and marketers. The model structure, its components, and linkages are presented in detail; an additional case study demonstrates the capability of our sociotechnical model. We find that changes in the political framework cannot be mapped directly to RES operators as behaviour of intermediary market actors has to be considered as well. Characteristics and strategies of intermediaries are thus an important factor for successful RES marketing and further deployment. It is shown that the model is able to assess the emergence and stability of market niches.

  17. Prediction of the niche effect for single flat panels with or without attached sound absorbing materials.

    Science.gov (United States)

    Sgard, Franck; Atalla, Noureddine; Nélisse, Hugues

    2015-01-01

    The sound transmission loss (STL) of a test sample measured in sound transmission facilities is affected by the opening in which it is located. This is called the niche effect. This paper uses a modal approach to study the STL of a rectangular plate with or without an attached porous material located inside a box-shaped niche. The porous material is modeled as a limp equivalent fluid. The proposed model is validated by comparison with finite element/boundary element computations. Using a condensation of the pressure fields in the niche, the niche effect is interpreted in terms of a modification of the modal blocked pressure fields acting on the panel induced by the front cavity and by a modification of the radiation efficiency of the panel modes due to the presence of the back cavity. The modal approach is then used to investigate the impact of (1) the presence of a porous material attached to the panel on the niche effect and (2) the niche effect on the assessment of the porous material insertion loss. A simplified model for the porous material based on a transfer matrix approach is also proposed to predict the STL of the system and its validity is discussed.

  18. Estrategias de comunicación y marketing urbano

    Directory of Open Access Journals (Sweden)

    Georges Benko

    2000-12-01

    Full Text Available El marketing territorial es un fenómeno antiguo, pero después de los años 80 experimenta una intensificación. La rivalidad y la competencia se hacen patentes entre las ciudades y las regiones. La renovación de las estrategias de comunicación y de los fundamentos económicos y sociales: la mun- dialización y la extensión de la competencia; la puesta en valor de lo local; la evolución rápida de las herramientas de comunicación y finalmente la evolución misma del marketing. Este artículo analiza este nuevo campo de estudio que está ligado a la representación de los espacios y a sus propios métodos.Territorial marketing is an ancient phenomenon, but since the 1980’s, it has intensified. Rivalry and competition between cities and regions are clearly put at the fore. This renewal of communication strategies has economic and social foundations: globalization and widening of competition; the local as a social and economic phenomenon; the fast evolution of communication; and, finally, the evolution of marketing itself. This article analyses this new field of study, linked to the representation of space, and its methods

  19. Multifaceted Roles of Connexin 43 in Stem Cell Niches.

    Science.gov (United States)

    Genet, Nafiisha; Bhatt, Neha; Bourdieu, Antonin; Hirschi, Karen K

    2018-01-01

    Considerable progress has been made in the field of stem cell research; nonetheless, the use of stem cells for regenerative medicine therapies, for either endogenous tissue repair or cellular grafts post injury, remains a challenge. To better understand how to maintain stem cell potential in vivo and promote differentiation ex vivo, it is fundamentally important to elucidate the interactions between stem cells and their surrounding partners within their distinct niches. Among the vast array of proteins depicted as mediators for cell-to-cell interactions, connexin-comprised gap junctions play pivotal roles in the regulation of stem cell fate both in vivo and in vitro. This review summarizes and illustrates the current knowledge regarding the multifaceted roles of Cx43, specifically, in various stem cell niches.

  20. Marketing Cameroon as a Cultural Tourism Destination to Finnish Tourists

    OpenAIRE

    Akuri, Lucien; Landa Celestin, Ndingi

    2013-01-01

    Cultural tourism is already a global phenomenon and has been increasingly promoted in the forms such as heritage, arts, creative, rural and urban cultural tourism, amongst others, and their sub-sections. The marketing of these cultural tourism forms and their attractions by various tourism destinations to target markets is still complex and thus, a major challenge. The study investigates the ways in which Cameroon with very rich and diverse cultural products and attractions can be markete...

  1. The impact of failure: unsuccessful bacterial invasions steer the soil microbial community away from the invader's niche.

    Science.gov (United States)

    Mallon, C A; Le Roux, X; van Doorn, G S; Dini-Andreote, F; Poly, F; Salles, J F

    2018-03-01

    Although many environments like soils are constantly subjected to invasion by alien microbes, invaders usually fail to succeed, succumbing to the robust diversity often found in nature. So far, only successful invasions have been explored, and it remains unknown to what extent an unsuccessful invasion can impact resident communities. Here we hypothesized that unsuccessful invasions can cause impacts to soil functioning by decreasing the diversity and niche breadth of resident bacterial communities, which could cause shifts to community composition and niche structure-an effect that is likely exacerbated when diversity is compromised. To examine this question, diversity gradients of soil microbial communities were subjected to invasion by the frequent, yet oft-unsuccessful soil invader, Escherichia coli, and evaluated for changes to diversity, bacterial community composition, niche breadth, and niche structure. Contrary to expectations, diversity and niche breadth increased across treatments upon invasion. Community composition and niche structure were also altered, with shifts of niche structure revealing an escape by the resident community away from the invader's resources. Importantly, the extent of the escape varied in response to the community's diversity, where less diverse communities experienced larger shifts. Thus, although transient and unsuccessful, the invader competed for resources with resident species and caused tangible impacts that modified both the diversity and functioning of resident communities, which can likely generate a legacy effect that influences future invasion attempts.

  2. Relationship Marketing - Best Practice in the Banking Sector

    Directory of Open Access Journals (Sweden)

    Cătălina Chirica

    2013-02-01

    Full Text Available This paper aims to highlight best practice in relationship marketing because of adjusted companies’ strategies in a turbulent, unstable, and dynamic economic environment. By best practice, we understand specific marketing tools and strategies built upon real needs and heterogeneous consumer preferences, addressed directly in a relevant way, aiming at clients’ long-term retention. We should also take into consideration the highly competitive market, with rapid changes in purchase and consumption behavior, while the ever-increasing degree of technology changes fundamentally not only the speed, but also the information content. Since past years we can talk about consumer behavior analysis based on multiple criteria, including the emotional or moral components, consumers’ expectations, and life style, as understanding such variables is the main pillar of relationship marketing. The main objectives rely upon building long-term relations, client retention, and loyalty. As part of marketing efforts, the communication component has an increasingly important role, approaching niches with tailored messages, inviting clients to open dialogue. Economic changes, extensive use of technology, migration towards online and optimization of communication channels opened the doors for digital era, when relationship marketing and client relationship management (CRM represent not a merely working premise, but an essential ground. Best practice in relationship marketing proves that this cannot be applied in any way and at any time, as this paper highlights the main components of building and implementing such a system.

  3. Economically sustainable: market synergies in hydrogen systems

    International Nuclear Information System (INIS)

    Hart, D.

    2000-01-01

    As interest in the use of hydrogen as an energy carrier grows, it is important to understand the advantages and disadvantages of a market-based approach to its introduction. While there will always be niche markets in which it makes sense to employ what is currently a comparatively expensive form of energy storage and delivery, this will not enable the sort of large-scale penetration that will allow for economies of mass-manufacture to bring the cost of hydrogen down. In addition, energy markets are becoming increasingly liberalised, and because of this it is important to understand the sort of market pressures that are arising where none have existed before. These pressures may actually lead to opportunities for hydrogen in energy storage and for use in power generation and transport fuel modes, and allow market penetration to occur more rapidly than might be the case in a centralised energy structure. In the liberalised energy market within the UK, for example, there are two areas of potentially major growth in hydrogen production and consumption: energy storage for renewable generators; and backup systems at weak electricity grid links. The first of these is due, in part, to potential changes in regulation governing the way that electricity is sold into the market, while the second is dependent more on an increasingly congested electricity grid and the high costs of building supplementary infrastructure. In both cases there is potential for the early use of hydrogen energy systems in an economically competitive environment. (author)

  4. Contemporary marketing trends: from one-to-one marketing and the service-dominant logic to M2M communications and netnography

    Directory of Open Access Journals (Sweden)

    Daj, A.

    2012-01-01

    Full Text Available In recent years, a strong and unexpected growth in take-up and use of digital devices and applications - phenomenon known under the term “Web 2.0” - enabled wide-ranging interaction and collaboration between consumers. Thus, users actually become participants (co-creators not end-users that are strengthened through the network (as a collective resource. The newly acquired knowledge has led to a profound change in the way marketing professionals conceive marketing, as a whole, and the marketing mix, in particular. Therefore, the new mindset of contemporary marketers emphasizes the importance of co-generating value by involving customers in the design and improvement process of goods and rendered services.

  5. Ontogenetic niche shifts in three Vaccinium species on a sub-alpine mountain side

    DEFF Research Database (Denmark)

    Auffret, Alistair G.; Meineri, Eric; Bruun, Hans Henrik

    2010-01-01

    Background: Climate warming in arctic and alpine regions is expected to result in the altitudinal migration of plant species, but current predictions neglect differences between species' regeneration niche and established niche. Aims: To examine potential recruitment of Vaccinium myrtillus, V. ul...

  6. Observed fitness may affect niche overlap in competing species via selective social information use.

    Science.gov (United States)

    Loukola, Olli J; Seppänen, Janne-Tuomas; Krams, Indrikis; Torvinen, Satu S; Forsman, Jukka T

    2013-10-01

    Social information transmission is important because it enables horizontal spread of behaviors, not only between conspecifics but also between individuals of different species. Because interspecific social information use is expected to take place among species with similar resource needs, it may have major consequences for the emergence of local adaptations, resource sharing, and community organization. Social information use is expected to be selective, but the conditions promoting it in an interspecific context are not well known. Here, we experimentally test whether pied flycatchers (Ficedula hypoleuca) use the clutch size of great tits (Parus major) in determining the quality of the observed individual and use it as a basis of decision making. We show that pied flycatchers copied or rejected a novel nest site feature preference of great tits experimentally manipulated to exhibit high or low fitness (clutch size), respectively. Our results demonstrate that the social transmission of behaviors across species can be highly selective in response to observed fitness, plausibly making the phenomenon adaptive. In contrast with the current theory of species coexistence, overlap between realized niches of species could dynamically increase or decrease depending on the observed success of surrounding individuals.

  7. UNTANGLING THE FUNGAL NICHE: A TRAIT-BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Thomas W Crowther

    2014-10-01

    Full Text Available Fungi are prominent components of most terrestrial ecosystems, both in terms of biomass and ecosystem functioning, but the hyper-diverse nature of most communities has obscured the search for unifying principles governing community organization. In particular, unlike plants and animals, observational studies provide little evidence for the existence of niche processes in structuring fungal communities at broad spatial scales. This limits our capacity to predict how communities, and their functioning, vary across landscapes. We outline how a shift in focus, from taxonomy towards functional traits, might prove to be valuable in the search for general patterns in fungal ecology. We build on theoretical advances in plant and animal ecology to provide an empirical framework for a trait-based approach in fungal community ecology. Drawing upon specific characteristics of the fungal system, we highlight the significance of drought stress and combat in structuring free-living fungal communities. We propose a conceptual model to formalize how trade-offs between stress-tolerance and combative dominance are likely to organize communities across environmental gradients. Given that the survival of a fungus in a given environment is contingent on its ability to tolerate antagonistic competitors, measuring variation in combat trait expression along environmental gradients provides a means of elucidating realized, from fundamental niche spaces. We conclude that, using a trait-based understanding of how niche processes structure fungal communities across time and space, we can ultimately link communities with ecosystem functioning. Our trait-based framework highlights fundamental uncertainties that require testing in the fungal system, given their potential to uncover general mechanisms in fungal ecology.

  8. Foraging niche segregation in Malaysian babblers (Family: Timaliidae.

    Directory of Open Access Journals (Sweden)

    Mohammad Saiful Mansor

    Full Text Available Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i how these babblers forage in the wild and use vegetation to obtain food, and ii how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause' law of competitive exclusion, which states two species occupying the same niche will not stably coexist.

  9. Foraging niche segregation in Malaysian babblers (Family: Timaliidae).

    Science.gov (United States)

    Mansor, Mohammad Saiful; Ramli, Rosli

    2017-01-01

    Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum) in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i) how these babblers forage in the wild and use vegetation to obtain food, and ii) how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause' law of competitive exclusion, which states two species occupying the same niche will not stably coexist.

  10. Spermatogonial stem cell markers and niche in equids.

    Directory of Open Access Journals (Sweden)

    Guilherme M J Costa

    Full Text Available Spermatogonial stem cells (SSCs are the foundation of spermatogenesis and are located in a highly dynamic microenvironment called "niche" that influences all aspects of stem cell function, including homing, self-renewal and differentiation. Several studies have recently identified specific proteins that regulate the fate of SSCs. These studies also aimed at identifying surface markers that would facilitate the isolation of these cells in different vertebrate species. The present study is the first to investigate SSC physiology and niche in stallions and to offer a comparative evaluation of undifferentiated type A spermatogonia (Aund markers (GFRA1, PLZF and CSF1R in three different domestic equid species (stallions, donkeys, and mules. Aund were first characterized according to their morphology and expression of the GFRA1 receptor. Our findings strongly suggest that in stallions these cells were preferentially located in the areas facing the interstitium, particularly those nearby blood vessels. This distribution is similar to what has been observed in other vertebrate species. In addition, all three Aund markers were expressed in the equid species evaluated in this study. These markers have been well characterized in other mammalian species, which suggests that the molecular mechanisms that maintain the niche and Aund/SSCs physiology are conserved among mammals. We hope that our findings will help future studies needing isolation and cryopreservation of equids SSCs. In addition, our data will be very useful for studies that aim at preserving the germplasm of valuable animals, and involve germ cell transplantation or xenografts of equids testis fragments/germ cells suspensions.

  11. Foraging niche segregation in Malaysian babblers (Family: Timaliidae)

    Science.gov (United States)

    Mansor, Mohammad Saiful; Ramli, Rosli

    2017-01-01

    Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum) in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i) how these babblers forage in the wild and use vegetation to obtain food, and ii) how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause’ law of competitive exclusion, which states two species occupying the same niche will not stably coexist. PMID:28253284

  12. DYNAMICS OF THE ROMANIAN ILLEGAL DRUG MARKETS

    Directory of Open Access Journals (Sweden)

    Irina Caunic

    2011-06-01

    Full Text Available Globalization has led to an increase in commercial activities running on the illegal markets, its dynamics being largely determined by the balance between profitability and the major risks involved. Revenuesare significant, one example being those obtained from drug industry. In recent years, illicit drug trafficking has seen in Romania an unprecedented escalation, as a result of market liberalization and the movement of per sons and because of the extending the phenomenon both among producers and consumers. This article examines the size of the Romanian illegal drug markets, the countries of origin and drugtransit routes, as well as the profits made by the drug trafficking networks.

  13. Micro-Level Adaptation, Macro-Level Selection, and the Dynamics of Market Partitioning.

    Science.gov (United States)

    García-Díaz, César; van Witteloostuijn, Arjen; Péli, Gábor

    2015-01-01

    This paper provides a micro-foundation for dual market structure formation through partitioning processes in marketplaces by developing a computational model of interacting economic agents. We propose an agent-based modeling approach, where firms are adaptive and profit-seeking agents entering into and exiting from the market according to their (lack of) profitability. Our firms are characterized by large and small sunk costs, respectively. They locate their offerings along a unimodal demand distribution over a one-dimensional product variety, with the distribution peak constituting the center and the tails standing for the peripheries. We found that large firms may first advance toward the most abundant demand spot, the market center, and release peripheral positions as predicted by extant dual market explanations. However, we also observed that large firms may then move back toward the market fringes to reduce competitive niche overlap in the center, triggering nonlinear resource occupation behavior. Novel results indicate that resource release dynamics depend on firm-level adaptive capabilities, and that a minimum scale of production for low sunk cost firms is key to the formation of the dual structure.

  14. Division within the North American boreal forest: Ecological niche divergence between the Bicknell's Thrush (Catharus bicknelli) and Gray-cheeked Thrush (C. minimus).

    Science.gov (United States)

    FitzGerald, Alyssa M

    2017-07-01

    Sister species that diverged in allopatry in similar environments are expected to exhibit niche conservatism. Using ecological niche modeling and a multivariate analysis of climate and habitat data, I test the hypothesis that the Bicknell's Thrush ( Catharus bicknelli ) and Gray-cheeked Thrush ( C. mimimus ), sister species that breed in the North American boreal forest, show niche conservatism. Three tree species that are important components of breeding territories of both thrush species were combined with climatic variables to create niche models consisting of abiotic and biotic components. Abiotic-only, abiotic+biotic, and biotic-only models were evaluated using the area under the curve (AUC) criterion. Abiotic+biotic models had higher AUC scores and did not over-project thrush distributions compared to abiotic-only or biotic-only models. From the abiotic+biotic models, I tested for niche conservatism or divergence by accounting for the differences in the availability of niche components by calculating (1) niche overlap from ecological niche models and (2) mean niche differences of environmental values at occurrence points. Niche background similarity tests revealed significant niche divergence in 10 of 12 comparisons, and multivariate tests revealed niche divergence along 2 of 3 niche axes. The Bicknell's Thrush breeds in warmer and wetter regions with a high abundance of balsam fir ( Abies balsamea ), whereas Gray-cheeked Thrush often co-occurs with black spruce ( Picea mariana ). Niche divergence, rather than conservatism, was the predominant pattern for these species, suggesting that ecological divergence has played a role in the speciation of the Bicknell's Thrush and Gray-cheeked Thrush. Furthermore, because niche models were improved by the incorporation of biotic variables, this study validates the inclusion of relevant biotic factors in ecological niche modeling to increase model accuracy.

  15. Uncovering a Cover: Marketing Swedish Crime Fiction in a Transnational Context

    OpenAIRE

    Nilsson, Louise

    2016-01-01

    During the twenty-first century, Swedish crime fiction became an international phenomenon and turned into a million-dollar industry. Besides being translated all over the world, the crime novels are converted into movies and TV series in Sweden, while remakes of these films are produced abroad. This success story is closely interwoven with the international book market and publishing houses’ marketing strategies. This article investigates how domestic literature is marketed in a globalized bo...

  16. CARDS MARKET – A RESISTANT MARKET TO CRISIS

    Directory of Open Access Journals (Sweden)

    Tudose Geanina - Gabriela

    2012-07-01

    Full Text Available At the same time with the development of market and consumer behavior of Romanians, the growth rate of cards market accelerated. Of course, infrastructure and acceptance network were very important, they are the factors that allowed the widespread use of cards. Currently, any natural person or legal entity is engaged in commercial relationships involving financial transactions, the electronic payments having an important role, representing virtually future transactions, both nationally and across borders. The financial institutions have made a more rapid segmentation of the portfolio of cards and began to focus increasingly on services and benefits situated behind the payment instruments. Meanwhile, cardholders were becoming more educated and sophisticated, knowing what to ask of cards. More, many financial institutions have adapted so that network to accept chip cards. On the Romanian market, the chip cards will increase which are much more effective in terms of security transactions, as well as for co-branded cards, that offers the possibility of the loyalty of the customers. They will try to get as many benefits from different types of cards, but at the same time, they will focus on niche products, business cards, cards for shopping or for payment of public services. The scientific paper aims to capture aspects that emphasize the fact that the permanent market monitoring and the continuous adaptation of it will become necessary for the next period. The current client is more demanding, more educated and less tolerant in the relation to the suppliers of any kind and especially with those of financial services. The tendency to use co-branded cards for everyday payments will increase as merchants and issuing banks will attach more and more benefits on these cards, which will ultimately increase trading volumes on the card to merchants. The bank clients benefited of the cutting - edge technologies, of dual cards functionality - debit and credit.

  17. The Guaranty Trust Bank of Nigeria: From niche positioning to mass-market branding

    OpenAIRE

    Maklan, Stan; Knox, Simon; Michel, Stefan

    2009-01-01

    This case describes a strategic marketing dilemma facing Tayo Aderinokun, the cofounder and managing director (CEO) of the highly successful Guaranty Trust Bank (GTBank) of Nigeria. In its initial 15 years, GTBank has grown dramatically to become the most respected corporate bank in Nigeria, renowned for both its professionalism and high ethical standards. However, the environment is changing dramatically, and the bank needs to grow quickly in order to survive: perhaps doubl...

  18. ECRB ALCOVE AND NICHE GROUND SUPPORT ANALYSIS

    International Nuclear Information System (INIS)

    J.W. Keifer

    1999-01-01

    The purpose of the analysis is to provide design bases for Enhanced Characterization of the Repository Block (ECRB) alcove and niche ground support drawings. The objective is to evaluate the ESF Alcove Ground Support Analysis (Ref 5.1) to determine if the calculations technically bound the ECRB alcoves and to address specific differences in the conditions and constraints

  19. Isotopic niche partitioning between two apex predators over time.

    Science.gov (United States)

    Drago, Massimiliano; Cardona, Luis; Franco-Trecu, Valentina; Crespo, Enrique A; Vales, Damián G; Borella, Florencia; Zenteno, Lisette; Gonzáles, Enrique M; Inchausti, Pablo

    2017-07-01

    Stable isotope analyses have become an important tool in reconstructing diets, analysing resource use patterns, elucidating trophic relations among predators and understanding the structure of food webs. Here, we use stable carbon and nitrogen isotope ratios in bone collagen to reconstruct and compare the isotopic niches of adult South American fur seals (Arctocephalus australis; n = 86) and sea lions (Otaria flavescens; n = 49) - two otariid species with marked morphological differences - in the Río de la Plata estuary (Argentina - Uruguay) and the adjacent Atlantic Ocean during the second half of the 20th century and the beginning of the 21st century. Samples from the middle Holocene (n = 7 fur seals and n = 5 sea lions) are also included in order to provide a reference point for characterizing resource partitioning before major anthropogenic modifications of the environment. We found that the South American fur seals and South American sea lions had distinct isotopic niches during the middle Holocene. Isotopic niche segregation was similar at the beginning of the second half of the 20th century, but has diminished over time. The progressive convergence of the isotopic niches of these two otariids during the second half of the 20th century and the beginning of the 21st century is most likely due to the increased reliance of South American fur seals on demersal prey. This recent dietary change in South American fur seals can be explained by at least two non-mutually exclusive mechanisms: (i) the decrease in the abundance of sympatric South American sea lions as a consequence of small colony size and high pup mortality resulting from commercial sealing; and (ii) the decrease in the average size of demersal fishes due to intense fishing of the larger class sizes, which may have increased their accessibility to those eared seals with a smaller mouth gape, that is, South American fur seals of both sexes and female South American sea lions. © 2017 The Authors

  20. Combgap Promotes Ovarian Niche Development and Chromatin Association of EcR-Binding Regions in BR-C.

    Science.gov (United States)

    Hitrik, Anna; Popliker, Malka; Gancz, Dana; Mukamel, Zohar; Lifshitz, Aviezer; Schwartzman, Omer; Tanay, Amos; Gilboa, Lilach

    2016-11-01

    The development of niches for tissue-specific stem cells is an important aspect of stem cell biology. Determination of niche size and niche numbers during organogenesis involves precise control of gene expression. How this is achieved in the context of a complex chromatin landscape is largely unknown. Here we show that the nuclear protein Combgap (Cg) supports correct ovarian niche formation in Drosophila by controlling ecdysone-Receptor (EcR)- mediated transcription and long-range chromatin contacts in the broad locus (BR-C). Both cg and BR-C promote ovarian growth and the development of niches for germ line stem cells. BR-C levels were lower when Combgap was either reduced or over-expressed, indicating an intricate regulation of the BR-C locus by Combgap. Polytene chromosome stains showed that Cg co-localizes with EcR, the major regulator of BR-C, at the BR-C locus and that EcR binding to chromatin was sensitive to changes in Cg levels. Proximity ligation assay indicated that the two proteins could reside in the same complex. Finally, chromatin conformation analysis revealed that EcR-bound regions within BR-C, which span ~30 KBs, contacted each other. Significantly, these contacts were stabilized in an ecdysone- and Combgap-dependent manner. Together, these results highlight Combgap as a novel regulator of chromatin structure that promotes transcription of ecdysone target genes and ovarian niche formation.

  1. Replacement of harmful animal use in life science education: the approach and activities of InterNICHE.

    Science.gov (United States)

    Jukes, Nick

    2004-06-01

    Harmful animal use in undergraduate education is increasingly being replaced by alternatives, such as computer software, manikins and simulators, ethically sourced animal cadavers, apprentice work with animal patients, and student self-experimentation. Combinations of such alternatives can better meet teaching objectives, reduce costs and avoid the negative pedagogical and social impact of animal experimentation. Since 1988, the International Network for Humane Education (InterNICHE, formerly EuroNICHE) has been working with teachers to replace harmful animal use and has been supporting students' right to conscientious objection. This paper presents the approach, history and current activities of InterNICHE. With a vision of 100% replacement, the network aims for empowerment by networking information and providing support. It works with the belief that most teachers want investment in the best quality and most humane education possible. The forthcoming second edition of the InterNICHE book, from Guinea Pig to Computer Mouse,1 includes practical details of progressive teaching aids and approaches, as well as case studies from teachers who employ such alternatives. In 1999, InterNICHE produced the film Alternatives in Education, now available in 20 languages. Such resources are complemented by outreach trips and conferences and an Alternatives Loan System, which offers products for familiarisation and assessment. The InterNICHE website (www.interniche.org) was launched in 2001.

  2. DLC as a Marketing Tool in the Video Game Industry

    OpenAIRE

    Brádlerová, Andrea

    2017-01-01

    This thesis deals with the phenomenon of DLC in the context of marketing communication. DLC or downloadable content expanding the basic game, is a relatively new concept in the video game industry and its role is increasingly important in marketing communication in video games. The main focus of this thesis is to map DLC and analyze its importance in marketing communication and public relations of video game titles of various genres. Theoretical part of the thesis is focused on explaining the...

  3. Climatic niche conservatism and biogeographical non-equilibrium in Eschscholzia californica (Papaveraceae), an invasive plant in the Chilean Mediterranean region.

    Science.gov (United States)

    Peña-Gómez, Francisco T; Guerrero, Pablo C; Bizama, Gustavo; Duarte, Milén; Bustamante, Ramiro O

    2014-01-01

    Species climate requirements are useful for predicting their geographic distribution. It is often assumed that the niche requirements for invasive plants are conserved during invasion, especially when the invaded regions share similar climate conditions. California and central Chile have a remarkable degree of convergence in their vegetation structure, and a similar Mediterranean climate. Such similarities make these geographic areas an interesting natural experiment for testing climatic niche dynamics and the equilibrium of invasive species in a new environment. We tested to see if the climatic niche of Eschscholzia californica is conserved in the invaded range (central Chile), and we assessed whether the invasion process has reached a biogeographical equilibrium, i.e., occupy all the suitable geographic locations that have suitable conditions under native niche requirements. We compared the climatic niche in the native and invaded ranges as well as the projected potential geographic distribution in the invaded range. In order to compare climatic niches, we conducted a Principal Component Analysis (PCA) and Species Distribution Models (SDMs), to estimate E. californica's potential geographic distribution. We also used SDMs to predict altitudinal distribution limits in central Chile. Our results indicated that the climatic niche occupied by E. californica in the invaded range is firmly conserved, occupying a subset of the native climatic niche but leaving a substantial fraction of it unfilled. Comparisons of projected SDMs for central Chile indicate a similarity, yet the projection from native range predicted a larger geographic distribution in central Chile compared to the prediction of the model constructed for central Chile. The projected niche occupancy profile from California predicted a higher mean elevation than that projected from central Chile. We concluded that the invasion process of E. californica in central Chile is consistent with climatic niche

  4. Affordances and Landscapes: Overcoming the Nature–Culture Dichotomy through Niche Construction Theory

    Science.gov (United States)

    Heras-Escribano, Manuel; De Pinedo-García, Manuel

    2018-01-01

    In this paper we reject the nature–culture dichotomy by means of the idea of affordance or possibility for action, which has important implications for landscape theory. Our hypothesis is that, just as the idea of affordance can serve to overcome the subjective–objective dichotomy, the ideas of landscape and ecological niche, properly defined, would allow us to also transcend the nature–culture dichotomy. First, we introduce an overview of landscape theory, emphasizing processual landscape theory as the most suitable approach for satisfying both cultural and naturalist approaches. After that, we introduce the idea of affordance and we analyze a tension between sociocultural and transcultural affordances (affordances that depend on cultural conventions and affordances that depend on lawful information and bodily aspects of agents). This tension has various implications for landscape theory and ecological niches. Our proposal is that sociocultural and transcultural aspects of affordances could be systematically accommodated if we apply niche construction theory (the theory that explains the process by which organisms modify their selective environments) as a methodological framework for explaining the emergence of ecological niches. This approach will lead us to an integrative account of landscapes as the products of the interaction between human and environmental elements, making it a clear example of a concept that transcends the nature–culture dichotomy. PMID:29375426

  5. Weak Evidence of Regeneration Habitat but Strong Evidence of Regeneration Niche for a Leguminous Shrub

    Science.gov (United States)

    Delerue, Florian; Gonzalez, Maya; Michalet, Richard; Pellerin, Sylvain; Augusto, Laurent

    2015-01-01

    The identification of an ecological niche specific to the regeneration phase has mobilised significant attention. However, the importance of the regeneration niche concept remains unclear. Our main objective was to study the existence of such a regeneration niche for a leguminous shrub, Ulex europaeus. This study was carried out in southwest France in the context of water and nutrient stresses (mainly phosphorus limitation) due to the presence of nutrient-poor sandy soils. We analysed the regeneration of the species from the germination of seeds and emergence of new seedlings until the seedlings reached young shrub size. Our design included a P fertilisation treatment. We also investigated microsite characteristics (micro-topography and vegetation development) as they can interact with meteorological conditions and determine water availability for seeds and seedlings. We found that P availability controlled seedling growth and the time necessary to reach young shrub size. Water availability appeared to impact the species germination and seedlings survival. We also found that P and water availability depended on the interactions between microsite characteristics and climatic variations. Finally we found evidence that P and water availability are important ecological factors shaping the regeneration niche of the species, but we found weak evidence that any microsite would be appropriate for the regeneration of the species in the long term. Future studies regarding regeneration niches need to distinguish more clearly the ecological factors important for regeneration (the regeneration niche per se) and the physical world where the seedlings appear and develop (the regeneration habitat). PMID:26098877

  6. Weak Evidence of Regeneration Habitat but Strong Evidence of Regeneration Niche for a Leguminous Shrub.

    Directory of Open Access Journals (Sweden)

    Florian Delerue

    Full Text Available The identification of an ecological niche specific to the regeneration phase has mobilised significant attention. However, the importance of the regeneration niche concept remains unclear. Our main objective was to study the existence of such a regeneration niche for a leguminous shrub, Ulex europaeus. This study was carried out in southwest France in the context of water and nutrient stresses (mainly phosphorus limitation due to the presence of nutrient-poor sandy soils. We analysed the regeneration of the species from the germination of seeds and emergence of new seedlings until the seedlings reached young shrub size. Our design included a P fertilisation treatment. We also investigated microsite characteristics (micro-topography and vegetation development as they can interact with meteorological conditions and determine water availability for seeds and seedlings. We found that P availability controlled seedling growth and the time necessary to reach young shrub size. Water availability appeared to impact the species germination and seedlings survival. We also found that P and water availability depended on the interactions between microsite characteristics and climatic variations. Finally we found evidence that P and water availability are important ecological factors shaping the regeneration niche of the species, but we found weak evidence that any microsite would be appropriate for the regeneration of the species in the long term. Future studies regarding regeneration niches need to distinguish more clearly the ecological factors important for regeneration (the regeneration niche per se and the physical world where the seedlings appear and develop (the regeneration habitat.

  7. Pleiotrophin Regulates the Retention and Self-Renewal of Hematopoietic Stem Cells in the Bone Marrow Vascular Niche

    Directory of Open Access Journals (Sweden)

    Heather A. Himburg

    2012-10-01

    Full Text Available The mechanisms through which the bone marrow (BM microenvironment regulates hematopoietic stem cell (HSC fate remain incompletely understood. We examined the role of the heparin-binding growth factor pleiotrophin (PTN in regulating HSC function in the niche. PTN−/− mice displayed significantly decreased BM HSC content and impaired hematopoietic regeneration following myelosuppression. Conversely, mice lacking protein tyrosine phosphatase receptor zeta, which is inactivated by PTN, displayed significantly increased BM HSC content. Transplant studies revealed that PTN action was not HSC autonomous, but rather was mediated by the BM microenvironment. Interestingly, PTN was differentially expressed and secreted by BM sinusoidal endothelial cells within the vascular niche. Furthermore, systemic administration of anti-PTN antibody in mice substantially impaired both the homing of hematopoietic progenitor cells to the niche and the retention of BM HSCs in the niche. PTN is a secreted component of the BM vascular niche that regulates HSC self-renewal and retention in vivo.

  8. DRIVING SUSTAINABLE INNOVATION IN CONSTRUCTION COMPANIES

    DEFF Research Database (Denmark)

    Thuesen, Christian Langhoff; Koch, Christian

    2011-01-01

    By adopting a theoretical framework from strategic niche management research (SNM) this paper presents an analysis of the innovation system of the Danish Construction industry. Theories within SNM look upon innovation in a sector as a socio-technical phenomenon and identify three levels of socio...... for innovation in the construction industry. By bridging SNM with business development activities through an adapted version of Ansoffs growth matrix, companies continuously and consciously can develop a competitive advantage by targeting new and existing markets with new or existing competencies...

  9. A study on certain determinants of export performance in a particular market

    OpenAIRE

    2015-01-01

    D.Com. (Economics) Chapter 1 defines the investigated problem and presents the methodology of the study. The phenomenon studied (the dependent variable) is the export performance (as defined in the study) of country A's products in country B's market. The independent variables are the following characteristics : Capital intensity, unskilled labour intensity, skilled labour intensity, use of local raw materials, marketing mix variables, total marketing efforts, size of production & marketin...

  10. Multi-user cognitive radio network resource allocation based on the adaptive niche immune genetic algorithm

    International Nuclear Information System (INIS)

    Zu Yun-Xiao; Zhou Jie

    2012-01-01

    Multi-user cognitive radio network resource allocation based on the adaptive niche immune genetic algorithm is proposed, and a fitness function is provided. Simulations are conducted using the adaptive niche immune genetic algorithm, the simulated annealing algorithm, the quantum genetic algorithm and the simple genetic algorithm, respectively. The results show that the adaptive niche immune genetic algorithm performs better than the other three algorithms in terms of the multi-user cognitive radio network resource allocation, and has quick convergence speed and strong global searching capability, which effectively reduces the system power consumption and bit error rate. (geophysics, astronomy, and astrophysics)

  11. Climatic niche conservatism and ecological opportunity in the explosive radiation of arvicoline rodents (Arvicolinae, Cricetidae).

    Science.gov (United States)

    Lv, Xue; Xia, Lin; Ge, Deyan; Wu, Yongjie; Yang, Qisen

    2016-05-01

    Climatic niche conservatism shapes patterns of diversity in many taxonomic groups, while ecological opportunity (EO) can trigger rapid speciation that is less constrained by the amount of time a lineage has occupied a given habitat. These two processes are well studied, but limited research has considered their joint and relative roles in shaping diversity patterns. We characterized climatic and biogeographic variables for 102 species of arvicoline rodents (Arvicolinae, Cricetidae), testing the effects of climatic niche conservatism and EO on arvicoline diversification as lineages transitioned between biogeographic regions. We found that the amount of time a lineage has occupied a precipitation niche is positively correlated with diversity along a precipitation gradient, suggesting climatic niche conservatism. In contrast, shift in diversification rate explained diversity patterns along a temperature gradient. Our results suggest that an indirect relationship exists between temperature and diversification that is associated with EO as arvicoline rodents colonized warm Palearctic environments. Climatic niche conservatism alone did not fully explain diversity patterns under density-dependence, highlighting the additional importance of EO-related processes in promoting the explosive radiation in arvicoline rodents and shaping diversity pattern among biogeographic regions and along climatic gradients. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  12. The Management of Unsold Food in Outdoor Market Areas: Food Operators’ Behaviour and Attitudes

    Directory of Open Access Journals (Sweden)

    Giovanni Peira

    2018-04-01

    Full Text Available Food wastage has been widely discussed and investigated from different perspectives in literature. The EU-28 produces about 88 million tonnes of food wastage every year, making the awareness of this phenomenon a vital matter. This paper focuses on the outdoor-market operators’ perception and behaviour towards the food waste phenomenon in a particular phase of the agro-food supply chain. It assesses the different approaches used to manage unsold produce and its destination. A sample of 214 market retailers in the Greater Torino market areas of Italy were identified, to whom a questionnaire was administered by interview to analyze the main actors involved in the food-wastage process and profile them according to their perception, behaviour, and attitude. The results show that there are three distinct kinds of market operators, i.e., farmers, peddlers, and hybrids. Their attitudes and behaviour towards unsold food differ, as does their inclination towards a sustainable approach, which depends on their personal experience and role in the supply chain. Moreover, the results provide some relevant elements that may contribute to improving the management of the food-waste phenomenon. Moreover, they bring some useful evidence to light that could lay the basis of more effective tools to be put at the disposal of various institutions.

  13. The vasculature as a neural stem cell niche.

    Science.gov (United States)

    Otsuki, Leo; Brand, Andrea H

    2017-11-01

    Neural stem cells (NSCs) are multipotent, self-renewing progenitors that generate progeny that differentiate into neurons and glia. NSCs in the adult mammalian brain are generally quiescent. Environmental stimuli such as learning or exercise can activate quiescent NSCs, inducing them to proliferate and produce new neurons and glia. How are these behaviours coordinated? The neurovasculature, the circulatory system of the brain, is a key component of the NSC microenvironment, or 'niche'. Instructive signals from the neurovasculature direct NSC quiescence, proliferation, self-renewal and differentiation. During ageing, a breakdown in the niche accompanies NSC dysfunction and cognitive decline. There is much interest in reversing these changes and enhancing NSC activity by targeting the neurovasculature therapeutically. Here we discuss principles of neurovasculature-NSC crosstalk, and the implications for the design of NSC-based therapies. We also consider the emerging contributions to this field of the model organism Drosophila melanogaster. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Competitive Patterns in the Danish Organic Industry & its Usefulness in Predicting Development in other EU Markets

    DEFF Research Database (Denmark)

    Vestergaard, Jens; Linneberg, Mai Skjøtt

    2003-01-01

    The organic market in Denmark is not a niche market any longer as it was in the late 1980s. The development has followed the typical pattern for diffusion of innovations and by 2002 the market supply seemed to have surpassed the equilibrium supply by around 30% and a potential adjustment is ahead...... the industry. In general, Denmark can be regarded as a frontrunner in organic development. Therefore, important clues concerning the development in other EU countries can be found, and the following points are analysed to evaluate if similar developments can be expected. Can the Danish diffusion path...... for organic development be expected in other countries? Will the supply in other EU markets also surpass market equilibrium? Are the Danish experiences with respect to policy choices and power-play of dominant players in processing and distribution industry of general relevance? Are the maturity gains...

  15. Economic and legal conceptual framework of viral marketing

    Directory of Open Access Journals (Sweden)

    Kostić Marija

    2015-01-01

    Full Text Available Electronic and online communications are modern, and perhaps the most common form of communication between individuals and legal entities, and thus have become one of the most used ways of market communication. Viral marketing is evolving into the dominant form of marketing and exchange of information for the purpose of advertising, promoting, or achieving other goals. In this paper we present and analyse the phenomenon of viral marketing-its purpose, effects, and power of influence, and discuss it in terms of ethical and legal standards. Special emphasis is placed on the right to privacy and personal data protection, harassment, acting in good faith and in accordance with good business practices, the presentation of false or fraudulent information. The advantages and disadvantages of this type of marketing activity have been observed.

  16. Prospects for Jatropha biofuels in Tanzania: An analysis with Strategic Niche Management

    International Nuclear Information System (INIS)

    Eijck, Janske van; Romijn, Henny

    2008-01-01

    The paper reports on research in Tanzania about the scope for developing biofuels from an oil-seed bearing plant called Jatropha curcas Linnaeus. The plant is widely seen to have potential to help combat the greenhouse effect, help to stop local soil erosion, create additional income for the rural poor, and provide a major source of energy both locally and internationally. The principal analytic tool is Strategic Niche Management (SNM), an approach rooted in evolutionary innovation theory. We analyse how the scope for an energy transition is influenced by factors at three societal levels: the overarching 'landscape'; the sectoral setting or 'regime'; and the 'niche' level where the innovation develops and diffuses. Valuable niche processes were found in a few areas, especially in cultivation, but we conclude that there are still many obstacles in Tanzania's prevailing energy regime. The development of Jatropha biofuels is still in an early phase. We list policy recommendations and discuss some methodological issues arising from the use of SNM

  17. Proximity-based differential single cell analysis of the niche to identify stem/progenitor cell regulators

    Science.gov (United States)

    Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Celso, Cristina Lo; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-fu; Scadden, David T

    2016-01-01

    SUMMARY Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on differential single-cell gene expression analysis of mesenchymal osteolineage cells close to and further removed from hematopoietic stem/progenitor cells to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. Amongst the genes which were preferentially expressed in proximal cells, we functionally examined three secreted or cell surface molecules not previously connected to HSPC biology: the secreted RNase Angiogenin, the cytokine IL18 and the adhesion molecule Embigin and discovered that all of these factors are HSPC quiescence regulators. Our proximity-based differential single cell approach therefore reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance understanding of microenvironmental regulation of stem cell function. PMID:27524439

  18. Key-Phenomenon and Religious Meaning

    Directory of Open Access Journals (Sweden)

    Lomuscio Vincenzo

    2017-09-01

    Full Text Available In this paper I develop a phenomenology of religious experience through the notion of keyphenomenon. My analysis moves from a general phenomenology of situation, in which we have to relate different phenomena according to a sense. What does “according to a sense” mean? My suggestion is that we should look for a relationship among these data when we find a key-phenomenon (among a series of phenomena that would enlighten all the others. This key-phenomenon would show a non-phenomenal meaning which would make all the others understandable. Each other datum, therefore, becomes the witness of invisible meaning through a key-witness. The key-phenomenon we choose determines the role (i.e., the truth of each datum within its situation. This phenomenological relationship belongs to both the sense of day-life situations, and that one of possible religious situations. If the religious interpretation of a situation depends on our choice of key-phenomenon, or key-witness, we have to define what kind of keyphenomenon constitutes a religious intuition.

  19. INSTITUTIONAL ENVIRONMENT OF THE AGRICULTURAL MARKET FORMATION PROCESS

    Directory of Open Access Journals (Sweden)

    S. Revenko

    2013-11-01

    Full Text Available This article considers institutional aspects of the organized agricultural market formation process. Theoretical base to distinguish institute and institutes is given. In order to find out main influential institutes of the “organization” phenomenon author analyses Ukrainian institutional environment that is under construction process. Author considers main processes which are running during the organized market formation. Author researches theoretical approaches to the institutional staff. In order to structure the most common approaches and theoretical knowledge of this problem author proposes few schemes. Author’s points of view for many questions of the organized market formation process are proposed. Researcher analyzes effectiveness of the institutes and governmental regulation of the agricultural market. Readers can find strategically new approach to the agricultural market formation policy from the governmental point of view. Essence of the socioeconomic formation of agricultural market is considered. Main factors of agriculture market formation are outlined. Agricultural market structural parts consideration systematic approach is proposed. Ineffectiveness of the agriculture market relations without regulation process is proved. The most unfavorable reasons of the agricultural market formation are determined.

  20. Segmentation and Time-of-Day Patterns in Foreign Exchange Markets

    OpenAIRE

    Angelo Ranaldo

    2007-01-01

    This paper sheds light on a puzzling pattern in foreign exchange markets: Domestic currencies appreciate (depreciate) systematically during foreign (domestic) working hours. These time-of-day patterns are statistically and economically highly significant. They pervasively persist across many years, even after accounting for calendar effects. This phenomenon is difficult to reconcile with the random walk and market efficiency hypothesis. Microstructural and behavioural explanations suggest tha...

  1. Keeping stem cells under control: new insights into the mechanisms that limit niche-stem cell signaling within the reproductive system

    OpenAIRE

    Inaba, Mayu; Yamashita, Yukiko M.; Buszczak, Michael

    2016-01-01

    Adult stem cells reside in specialized microenvironments called niches that maintain stem cells in an undifferentiated and self-renewing state. Despite extensive studies on the signaling pathways that operate within stem cells and their niches, the mechanisms that restrict niche signal exclusively to stem cells remained elusive: such a mechanism is crucially important to ensure that stem cells undergo self-renewal while their progeny, often located just one cell diameter away from the niche, ...

  2. Technology Entrepreneurship in Emerging Markets: An Exploration of Entrepreneurial Models Prevalent in India

    Directory of Open Access Journals (Sweden)

    Shiv S Tripathi

    2018-01-01

    Full Text Available Are the features and processes of entrepreneurship – such as wealth creation, risk taking, vision, identification of a niche market, launching new products, and so on – common across the world? Many would assume they would be. However, firms that are entrepreneurial in nature and belong to emerging markets may or may not follow the established models of developed economies. In this study, we sought to explore various types of entrepreneurial models that are prevalent in an emerging market. For this purpose, we collected primary and secondary data to identify characteristics of technology-based entrepreneurial firms in India. Based on the two dimensions of degree of demand/supply and expected loss/risk, we identify four models of entrepreneurship – incremental, proactive, radical, and reactive – and illustrate each model with examples from Indian companies.

  3. Rainwater Harvesting and Social Networks: Visualising Interactions for Niche Governance, Resilience and Sustainability

    Directory of Open Access Journals (Sweden)

    Sarah Ward

    2016-11-01

    Full Text Available Visualising interactions across urban water systems to explore transition and change processes requires the development of methods and models at different scales. This paper contributes a model representing the network interactions of rainwater harvesting (RWH infrastructure innovators and other organisations in the UK RWH niche to identify how resilience and sustainability feature within niche governance in practice. The RWH network interaction model was constructed using a modified participatory social network analysis (SNA. The SNA was further analysed through the application of a two-part analytical framework based on niche management and the safe, resilient and sustainable (‘Safe and SuRe’ framework. Weak interactions between some RWH infrastructure innovators and other organisations highlighted reliance on a limited number of persuaders to influence the regime and landscape, which were underrepresented. Features from niche creation and management were exhibited by the RWH network interaction model, though some observed characteristics were not represented. Additional Safe and SuRe features were identified covering diverse innovation, responsivity, no protection, unconverged expectations, primary influencers, polycentric or adaptive governance and multiple learning-types. These features enable RWH infrastructure innovators and other organisations to reflect on improving resilience and sustainability, though further research in other sectors would be useful to verify and validate observation of the seven features.

  4. LNG links remote supplies and markets

    International Nuclear Information System (INIS)

    Avidan, A.A.; Gardner, R.E.; Nelson, D.; Borrelli, E.N.; Rethore, T.J.

    1997-01-01

    Liquefied natural gas (LNG) has established a niche for itself by matching remote gas supplies to markets that both lacked indigenous gas reserves and felt threatened in the aftermath of the energy crises of the 1970s and 1980s. It has provided a cost-effective energy source for these markets, while also offering an environmentally friendly fuel long before that was fashionable. The introduction of natural-gas use via LNG in the early years (mostly into France and Japan) has also allowed LNG to play a major role in developing gas infrastructure. Today, natural gas, often supplied as LNG, is particularly well-suited for use in the combined cycle technology used in independent power generation projects (IPPs). Today, LNG players cannot simply focus on monetizing gas resources. Instead, they must adapt their projects to meet the needs of changing markets. The impact of these changes on the LNG industry has been felt throughout the value chain from finding and producing gas, gas treatment, liquefaction, transport as a liquid, receiving terminals and regasification, and finally, to consumption by power producers, industrial users, and households. These factors have influenced the evolution of the LNG industry and have implications for the future of LNG, particularly in the context of worldwide natural gas

  5. Adaptation and niche construction in human prehistory: a case study from the southern Scandinavian Late Glacial.

    Science.gov (United States)

    Riede, Felix

    2011-03-27

    The niche construction model postulates that human bio-social evolution is composed of three inheritance domains, genetic, cultural and ecological, linked by feedback selection. This paper argues that many kinds of archaeological data can serve as proxies for human niche construction processes, and presents a method for investigating specific niche construction hypotheses. To illustrate this method, the repeated emergence of specialized reindeer (Rangifer tarandus) hunting/herding economies during the Late Palaeolithic (ca 14.7-11.5 kyr BP) in southern Scandinavia is analysed from a niche construction/triple-inheritance perspective. This economic relationship resulted in the eventual domestication of Rangifer. The hypothesis of whether domestication was achieved as early as the Late Palaeolithic, and whether this required the use of domesticated dogs (Canis familiaris) as hunting, herding or transport aids, is tested via a comparative analysis using material culture-based phylogenies and ecological datasets in relation to demographic/genetic proxies. Only weak evidence for sustained niche construction behaviours by prehistoric hunter-gatherer in southern Scandinavia is found, but this study nonetheless provides interesting insights into the likely processes of dog and reindeer domestication, and into processes of adaptation in Late Glacial foragers.

  6. Novel therapeutic strategies to target leukemic cells that hijack compartmentalized continuous hematopoietic stem cell niches

    NARCIS (Netherlands)

    Hira, Vashendriya V. V.; van Noorden, Cornelis J. F.; Carraway, Hetty E.; Maciejewski, Jaroslaw P.; Molenaar, Remco J.

    2017-01-01

    Acute myeloid leukemia and acute lymphoblastic leukemia cells hijack hematopoietic stem cell (HSC) niches in the bone marrow and become leukemic stem cells (LSCs) at the expense of normal HSCs. LSCs are quiescent and resistant to chemotherapy and can cause relapse of the disease. HSCs in niches are

  7. ASPECTS REGARDING THE USE OF SOCIAL MEDIA IN QUALITATIVE MARKETING RESEARCH

    Directory of Open Access Journals (Sweden)

    Mirela Cristina VOICU

    2015-07-01

    Full Text Available In order to carry out an efficient marketing activity, it is well known that entrepreneurs have to find out, first of all, where and how consumers spend their time, what are the communication channels and forms they prefer and then try to interact with the customers on their territory and on their own terms. The forms of communication that are gaining momentum currently, are taking place online, especially in the social media. A growing number of consumers have become open towards and familiar with social media, sharing their opinions daily through these means. Since the emergence of the social media phenomenon, its use has grown and has become widespread in a short period of time. In response to this phenomenon, social media marketing has developed at a similar pace and in a similar direction, and this is also reflected in the existing opportunities for using social media in qualitative marketing research.

  8. Ovarian Stem Cell Niche and Follicular Renewal in Mammals

    Czech Academy of Sciences Publication Activity Database

    Bukovský, Antonín

    2011-01-01

    Roč. 294, č. 8 (2011), s. 1284-1306 ISSN 1932-8486 Institutional research plan: CEZ:AV0Z50520701 Keywords : ovary * stem cell niche * neo-oogenesis Subject RIV: EA - Cell Biology Impact factor: 1.473, year: 2011

  9. MARKETING PROGRAMS FOR GREEN PRODUCTS IN ACHIEVING ECOLOGICAL SUSTAINABILITY

    OpenAIRE

    Gabriela CĂPĂȚÎNĂ; Roxana-Denisa STOENESCU

    2015-01-01

    This article explores one dimension of green marketing programs: their potential application as a solution in achieving and maintaining the ecological sustainability on global market. We examine the necessity to develop and launch green products which can respond to environment degradation as a treatment against this phenomenon. This paper is structured in three sections: the first section is related to a clear delimitation and a better understanding of terms; the second one is an overvi...

  10. Branding Prince Edward County as a Gastronomic Niche Tourism Destination: A Case Study

    OpenAIRE

    Geneviève Brisson; Rocci Luppicini

    2015-01-01

    Increasingly, gastronomy is playing a role in people's motivation for travel, and destinations are making food and beverages their main attraction. This study explored the growing field of gastronomic tourism, a type of niche tourism, through the theoretical framework of destination branding theory. Using a qualitative case study research design, this research examined the branding of the emergent region of Prince Edward County, Ontario, Canada as a gastronomic niche tourism destination from ...

  11. Optimal tax progressivity in imperfect labour markets

    DEFF Research Database (Denmark)

    Sørensen, Peter Birch

    1999-01-01

    that there may be an optimal degree of tax progressivity where the marginal welfare gain from reduced involuntary unemployment is just offset by the marginal welfare loss from lower productivity. This paper sets up four different models of an imperfect labour market in order to identify the degree of tax......All modern labour market theories capable of explaining involuntary unemployment as an equilibrium phenomenon imply that increased income tax progressivity reduces unemployment, but they also imply that higher progressivity tends to reduce work effort and labour productivity. This suggests...

  12. Electronic market places in the energy

    International Nuclear Information System (INIS)

    Mons, L.

    2001-12-01

    Electronic market places in the energy domain occurred at the end of the 90's in the US and have started to develop in Europe in the year 2000. About 60 platforms are registered today and this development can be explained by the advantages raised by such an infrastructure: simplification of purchase procedures, reduction of delays in the purchase decision, reduction of administrative costs etc.. However, today none of these electronic market places is profitable and several have closed down. On the other hand, this tool will certainly become necessary in the future and all energy actors are developing projects in this way. This study analyzes the electronic market places phenomenon in the energy domain using 10 market places examples with their key-factors of success. It draws out a complete status of the initiatives developed today and presents some scenarios of evolution. (J.S.)

  13. The neural crest is a source of mesenchymal stem cells with specialized hematopoietic stem cell niche function.

    Science.gov (United States)

    Isern, Joan; García-García, Andrés; Martín, Ana M; Arranz, Lorena; Martín-Pérez, Daniel; Torroja, Carlos; Sánchez-Cabo, Fátima; Méndez-Ferrer, Simón

    2014-09-25

    Mesenchymal stem cells (MSCs) and osteolineage cells contribute to the hematopoietic stem cell (HSC) niche in the bone marrow of long bones. However, their developmental relationships remain unclear. In this study, we demonstrate that different MSC populations in the developing marrow of long bones have distinct functions. Proliferative mesoderm-derived nestin(-) MSCs participate in fetal skeletogenesis and lose MSC activity soon after birth. In contrast, quiescent neural crest-derived nestin(+) cells preserve MSC activity, but do not generate fetal chondrocytes. Instead, they differentiate into HSC niche-forming MSCs, helping to establish the HSC niche by secreting Cxcl12. Perineural migration of these cells to the bone marrow requires the ErbB3 receptor. The neonatal Nestin-GFP(+) Pdgfrα(-) cell population also contains Schwann cell precursors, but does not comprise mature Schwann cells. Thus, in the developing bone marrow HSC niche-forming MSCs share a common origin with sympathetic peripheral neurons and glial cells, and ontogenically distinct MSCs have non-overlapping functions in endochondrogenesis and HSC niche formation.

  14. Plant diversification promotes biocontrol services in peach orchards by shaping the ecological niches of insect herbivores and their natural enemies

    DEFF Research Database (Denmark)

    Wan, Nian Feng; Ji, Xiang Yun; Deng, Jian Yu

    2018-01-01

    Ecological niche indicators have been scarcely adopted to assess the biological control of insect herbivores by their natural enemies. We hypothesize that plant diversification promotes the biocontrol services by narrowing the niches of herbivores and broadening the niches of natural enemies....... Our study reveals that plant diversification promotes the biocontrol services by shaping the niche of herbivores and natural enemies, and provides a new assessment method to understand the biodiversity-niche-ecosystem management interactions........ In a large-scale experiment, we found that the abundance of natural enemies was increased by 38.1%, and the abundance of insect herbivores was decreased by 16.9% in peach orchards with plant diversification (treatment) compared to ones with monoculture (control). Stratified sampling indicated...

  15. PTEN Signaling in the Postnatal Perivascular Progenitor Niche Drives Medulloblastoma Formation.

    Science.gov (United States)

    Zhu, Guo; Rankin, Sherri L; Larson, Jon D; Zhu, Xiaoyan; Chow, Lionel M L; Qu, Chunxu; Zhang, Jinghui; Ellison, David W; Baker, Suzanne J

    2017-01-01

    Loss of the tumor suppressor gene PTEN exerts diverse outcomes on cancer in different developmental contexts. To gain insight into the effect of its loss on outcomes in the brain, we conditionally inactivated the murine Pten gene in neonatal neural stem/progenitor cells. Pten inactivation created an abnormal perivascular proliferative niche in the cerebellum that persisted in adult animals but did not progress to malignancy. Proliferating cells showed undifferentiated morphology and expressed the progenitor marker Nestin but not Math1, a marker of committed granule neuron progenitors. Codeletion of Pten and Trp53 resulted in fully penetrant medulloblastoma originating from the perivascular niche, which exhibited abnormal blood vessel networks and advanced neuronal differentiation of tumor cells. EdU pulse-chase experiments demonstrated a perivascular cancer stem cell population in Pten/Trp53 double mutant medulloblastomas. Genetic analyses revealed recurrent somatic inactivations of the tumor suppressor gene Ptch1 and a recapitulation of the sonic hedgehog subgroup of human medulloblastomas. Overall, our results showed that PTEN acts to prevent the proliferation of a progenitor niche in postnatal cerebellum predisposed to oncogenic induction of medulloblastoma. Cancer Res; 77(1); 123-33. ©2016 AACR. ©2016 American Association for Cancer Research.

  16. Bone marrow macrophages maintain hematopoietic stem cell (HSC) niches and their depletion mobilizes HSCs.

    Science.gov (United States)

    Winkler, Ingrid G; Sims, Natalie A; Pettit, Allison R; Barbier, Valérie; Nowlan, Bianca; Helwani, Falak; Poulton, Ingrid J; van Rooijen, Nico; Alexander, Kylie A; Raggatt, Liza J; Lévesque, Jean-Pierre

    2010-12-02

    In the bone marrow, hematopoietic stem cells (HSCs) reside in specific niches near osteoblast-lineage cells at the endosteum. To investigate the regulation of these endosteal niches, we studied the mobilization of HSCs into the bloodstream in response to granulocyte colony-stimulating factor (G-CSF). We report that G-CSF mobilization rapidly depletes endosteal osteoblasts, leading to suppressed endosteal bone formation and decreased expression of factors required for HSC retention and self-renewal. Importantly, G-CSF administration also depleted a population of trophic endosteal macrophages (osteomacs) that support osteoblast function. Osteomac loss, osteoblast suppression, and HSC mobilization occurred concomitantly, suggesting that osteomac loss could disrupt endosteal niches. Indeed, in vivo depletion of macrophages, in either macrophage Fas-induced apoptosis (Mafia) transgenic mice or by administration of clodronate-loaded liposomes to wild-type mice, recapitulated the: (1) loss of endosteal osteoblasts and (2) marked reduction of HSC-trophic cytokines at the endosteum, with (3) HSC mobilization into the blood, as observed during G-CSF administration. Together, these results establish that bone marrow macrophages are pivotal to maintain the endosteal HSC niche and that the loss of such macrophages leads to the egress of HSCs into the blood.

  17. Manipulation of signaling thresholds in "engineered stem cell niches" identifies design criteria for pluripotent stem cell screens.

    Directory of Open Access Journals (Sweden)

    Raheem Peerani

    Full Text Available In vivo, stem cell fate is regulated by local microenvironmental parameters. Governing parameters in this stem cell niche include soluble factors, extra-cellular matrix, and cell-cell interactions. The complexity of this in vivo niche limits analyses into how individual niche parameters regulate stem cell fate. Herein we use mouse embryonic stem cells (mESC and micro-contact printing (microCP to investigate how niche size controls endogenous signaling thresholds. microCP is used to restrict colony diameter, separation, and degree of clustering. We show, for the first time, spatial control over the activation of the Janus kinase/signal transducer and activator of transcription pathway (Jak-Stat. The functional consequences of this niche-size-dependent signaling control are confirmed by demonstrating that direct and indirect transcriptional targets of Stat3, including members of the Jak-Stat pathway and pluripotency-associated genes, are regulated by colony size. Modeling results and empirical observations demonstrate that colonies less than 100 microm in diameter are too small to maximize endogenous Stat3 activation and that colonies separated by more than 400 microm can be considered independent from each other. These results define parameter boundaries for the use of ESCs in screening studies, demonstrate the importance of context in stem cell responsiveness to exogenous cues, and suggest that niche size is an important parameter in stem cell fate control.

  18. Ecological Niche Modeling of Risk Factors for H7N9 Human Infection in China

    Directory of Open Access Journals (Sweden)

    Min Xu

    2016-06-01

    Full Text Available China was attacked by a serious influenza A (H7N9 virus in 2013. The first human infection case was confirmed in Shanghai City and soon spread across most of eastern China. Using the methods of Geographic Information Systems (GIS and ecological niche modeling (ENM, this research quantitatively analyzed the relationships between the H7N9 occurrence and the main environmental factors, including meteorological variables, human population density, bird migratory routes, wetland distribution, and live poultry farms, markets, and processing factories. Based on these relationships the probability of the presence of H7N9 was predicted. Results indicated that the distribution of live poultry processing factories, farms, and human population density were the top three most important determinants of the H7N9 human infection. The relative contributions to the model of live poultry processing factories, farms and human population density were 39.9%, 17.7% and 17.7%, respectively, while the maximum temperature of the warmest month and mean relative humidity had nearly no contribution to the model. The paper has developed an ecological niche model (ENM that predicts the spatial distribution of H7N9 cases in China using environmental variables. The area under the curve (AUC values of the model were greater than 0.9 (0.992 for the training samples and 0.961 for the test data. The findings indicated that most of the high risk areas were distributed in the Yangtze River Delta. These findings have important significance for the Chinese government to enhance the environmental surveillance at multiple human poultry interfaces in the high risk area.

  19. Feeding niches of four large herbivores in the Hluhluwe Game ...

    African Journals Online (AJOL)

    Feeding niches of four large herbivores in the Hluhluwe Game Reserve, Natal. ... equus burchelli burchelli; feeding; grass; grasses; habitat; herbivores; hluhluwe game reserve; kwazulu-natal; large herbivores; ... AJOL African Journals Online.

  20. Supply Chain Development: Insights from Strategic Niche Management

    Science.gov (United States)

    Caniels, Marjolein C. J.; Romijn, Henny A.

    2008-01-01

    Purpose: The purpose of this paper is to contribute to the study of supply chain design from the perspective of complex dynamic systems. Unlike extant studies that use formal simulation modelling and associated methodologies rooted in the physical sciences, it adopts a framework rooted in the social sciences, strategic niche management, which…

  1. Niches for the Long-Term Maintenance of Tissue-Resident Memory T Cells

    Science.gov (United States)

    Takamura, Shiki

    2018-01-01

    Tissue-resident memory T cells (TRM cells) are a population of immune cells that reside in the lymphoid and non-lymphoid organs without recirculation through the blood. These important cells occupy and utilize unique anatomical and physiological niches that are distinct from those for other memory T cell populations, such as central memory T cells in the secondary lymphoid organs and effector memory T cells that circulate through the tissues. CD8+ TRM cells typically localize in the epithelial layers of barrier tissues where they are optimally positioned to act as sentinels to trigger antigen-specific protection against reinfection. CD4+ TRM cells typically localize below the epithelial layers, such as below the basement membrane, and cluster in lymphoid structures designed to optimize interactions with antigen-presenting cells upon reinfection. A key feature of TRM populations is their ability to be maintained in barrier tissues for prolonged periods of time. For example, skin CD8+ TRM cells displace epidermal niches originally occupied by γδ T cells, thereby enabling their stable persistence for years. It is also clear that the long-term maintenance of TRM cells in different microenvironments is dependent on multiple tissue-specific survival cues, although the specific details are poorly understood. However, not all TRM persist over the long term. Recently, we identified a new spatial niche for the maintenance of CD8+ TRM cells in the lung, which is created at the site of tissue regeneration after injury [termed repair-associated memory depots (RAMD)]. The short-lived nature of RAMD potentially explains the short lifespans of CD8+ TRM cells in this particular tissue. Clearly, a better understanding of the niche-dependent maintenance of TRM cells will be important for the development of vaccines designed to promote barrier immunity. In this review, we discuss recent advances in our understanding of the properties and nature of tissue-specific niches that

  2. Environmental niche divergence among three dune shrub sister species with parapatric distributions.

    Science.gov (United States)

    Chozas, Sergio; Chefaoui, Rosa M; Correia, Otília; Bonal, Raúl; Hortal, Joaquín

    2017-05-01

    The geographical distributions of species are constrained by their ecological requirements. The aim of this work was to analyse the effects of environmental conditions, historical events and biogeographical constraints on the diversification of the three species of the western Mediterranean shrub genus Stauracanthus , which have a parapatric distribution in the Iberian Peninsula. Ecological niche factor analysis and generalized linear models were used to measure the response of all Stauracanthus species to the environmental gradients and map their potential distributions in the Iberian Peninsula. The bioclimatic niche overlap between the three species was determined by using Schoener's index. The genetic differentiation of the Iberian and northern African populations of Stauracanthus species was characterized with GenalEx. The effects on genetic distances of the most important environmental drivers were assessed through Mantel tests and non-metric multidimensional scaling. The three Stauracanthus species show remarkably similar responses to climatic conditions. This supports the idea that all members of this recently diversified clade retain common adaptations to climate and consequently high levels of climatic niche overlap. This contrasts with the diverse edaphic requirements of Stauracanthus species. The populations of the S. genistoides-spectabilis clade grow on Miocene and Pliocene fine-textured sedimentary soils, whereas S. boivinii , the more genetically distant species, occurs on older and more coarse-textured sedimentary substrates. These patterns of diversification are largely consistent with a stochastic process of geographical range expansion and fragmentation coupled with niche evolution in the context of spatially complex environmental fluctuations. : The combined analysis of the distribution, realized environmental niche and phylogeographical relationships of parapatric species proposed in this work allows integration of the biogeographical

  3. IMPLEMENTATION OF MARKETING IN RURAL TOURISM AS A PRAGMATIC DEVELOPMENT AGENDA

    Directory of Open Access Journals (Sweden)

    Chumachenko Yuliia

    2018-03-01

    Full Text Available Introduction. In the context of integration processes and the transition to a market economy, innovative forms of management and the search for alternative or related activities for gaining competitive advantages and obtaining additional profit become more and more important. This tendency takes place not only in specific business units, but also in industries and business complexes in general. Therefore, these available resources and opportunities, new forms and activities within the business segment and market niche should to be introduced. Purpose. The purpose of the article is to highlight the essence of rural tourism, study its types and forms, as well as substantiate the need for the development of this service for the development of rural areas. The main task is to demonstrate the role and necessity of using the marketing system for the effective development of rural tourism, indicating its advantages and peculiarities of practical implementation. Results. As a result of the study, the general characteristics of rural tourism, its types and place in the general structure of agrarian-industrial complex are determined. The difference between the definitions of «rural tourism», «agro tourism» and «green tourism», which is often identified, however, has distinctive features and features. The existing definition of the definition of «rural tourism» is investigated and the author’s own definition is formed. The weight of green tourism in the socio-economic development of the village and region as a whole is proved. The level of application of marketing in the development of this direction and its main problems are determined. Examples of marketing tools that are successfully applied in the world are presented and recommended to be used for the development of green tourism in Ukraine. Conclusions. Rural tourism is a new direction of development, which is a symbiosis of the tourist and recreational sphere and agro-industrial complex, in

  4. Rates of change in climatic niches in plant and animal populations are much slower than projected climate change

    Science.gov (United States)

    Jezkova, Tereza

    2016-01-01

    Climate change may soon threaten much of global biodiversity. A critical question is: can species undergo niche shifts of sufficient speed and magnitude to persist within their current geographic ranges? Here, we analyse niche shifts among populations within 56 plant and animal species using time-calibrated trees from phylogeographic studies. Across 266 phylogeographic groups analysed, rates of niche change were much slower than rates of projected climate change (mean difference > 200 000-fold for temperature variables). Furthermore, the absolute niche divergence among populations was typically lower than the magnitude of projected climate change over the next approximately 55 years for relevant variables, suggesting the amount of change needed to persist may often be too great, even if these niche shifts were instantaneous. Rates were broadly similar between plants and animals, but especially rapid in some arthropods, birds and mammals. Rates for temperature variables were lower at lower latitudes, further suggesting that tropical species may be especially vulnerable to climate change. PMID:27881748

  5. Shifts in the ecological niche of Lutzomyia peruensis under climate change scenarios in Peru.

    Science.gov (United States)

    Moo-Llanes, D A; Arque-Chunga, W; Carmona-Castro, O; Yañez-Arenas, C; Yañez-Trujillano, H H; Cheverría-Pacheco, L; Baak-Baak, C M; Cáceres, A G

    2017-06-01

    The Peruvian Andes presents a climate suitable for many species of sandfly that are known vectors of leishmaniasis or bartonellosis, including Lutzomyia peruensis (Diptera: Psychodidae), among others. In the present study, occurrences data for Lu. peruensis were compiled from several items in the scientific literature from Peru published between 1927 and 2015. Based on these data, ecological niche models were constructed to predict spatial distributions using three algorithms [Support vector machine (SVM), the Genetic Algorithm for Rule-set Prediction (GARP) and Maximum Entropy (MaxEnt)]. In addition, the environmental requirements of Lu. peruensis and three niche characteristics were modelled in the context of future climate change scenarios: (a) potential changes in niche breadth; (b) shifts in the direction and magnitude of niche centroids, and (c) shifts in elevation range. The model identified areas that included environments suitable for Lu. peruensis in most regions of Peru (45.77%) and an average altitude of 3289 m a.s.l. Under climate change scenarios, a decrease in the distribution areas of Lu. peruensis was observed for all representative concentration pathways. However, the centroid of the species' ecological niche showed a northwest direction in all climate change scenarios. The information generated in this study may help health authorities responsible for the supervision of strategies to control leishmaniasis to coordinate, plan and implement appropriate strategies for each area of risk, taking into account the geographic distribution and potential dispersal of Lu. peruensis. © 2017 The Royal Entomological Society.

  6. Validation of the Impostor Phenomenon among Managers.

    Science.gov (United States)

    Rohrmann, Sonja; Bechtoldt, Myriam N; Leonhardt, Mona

    2016-01-01

    Following up on earlier investigations, the present research aims at validating the construct impostor phenomenon by taking other personality correlates into account and to examine whether the impostor phenomenon is a construct in its own right. In addition, gender effects as well as associations with dispositional working styles and strain are examined. In an online study we surveyed a sample of N = 242 individuals occupying leadership positions in different sectors. Confirmatory factor analyses provide empirical evidence for the discriminant validity of the impostor phenomenon. In accord with earlier studies we show that the impostor phenomenon is accompanied by higher levels of anxiety, dysphoric moods, emotional instability, a generally negative self-evaluation, and perfectionism. The study does not reveal any gender differences concerning the impostor phenomenon. With respect to working styles, persons with an impostor self-concept tend to show perfectionist as well as procrastinating behaviors. Moreover, they report being more stressed and strained by their work. In sum, the findings show that the impostor phenomenon constitutes a dysfunctional personality style. Practical implications are discussed.

  7. Reproductive niche conservatism in the isolated New Zealand flora over 23 million years.

    Science.gov (United States)

    Conran, John G; Lee, William G; Lee, Daphne E; Bannister, Jennifer M; Kaulfuss, Uwe

    2014-10-01

    The temporal stability of plant reproductive features on islands has rarely been tested. Using flowers, fruits/cones and seeds from a well-dated (23 Ma) Miocene Lagerstätte in New Zealand, we show that across 23 families and 30 genera of forest angiosperms and conifers, reproductive features have remained constant for more than 20 Myr. Insect-, wind- and bird-pollinated flowers and wind- and bird-dispersed diaspores all indicate remarkable reproductive niche conservatism, despite widespread environmental and biotic change. In the past 10 Myr, declining temperatures and the absence of low-latitude refugia caused regional extinction of thermophiles, while orogenic processes steepened temperature, precipitation and nutrient gradients, limiting forest niches. Despite these changes, the palaeontological record provides empirical support for evidence from phylogeographical studies of strong niche conservatism within lineages and biomes. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  8. Umbilical cord mesenchyme stem cell local intramuscular injection for treatment of uterine niche

    Science.gov (United States)

    Fan, Dazhi; Wu, Shuzhen; Ye, Shaoxin; Wang, Wen; Guo, Xiaoling; Liu, Zhengping

    2017-01-01

    Abstract Background: Uterine niche is defined as a triangular anechoic structure at the site of the scar or a gap in the myometrium at the site of a previous caesarean section. The main clinical manifestations are postmenstrual spotting and intrauterine infection, which may seriously affect the daily life of nonpregnant women. Trials have shown an excellent safety and efficacy for the potential of mesenchymal stem cells (MSCs) as a therapeutic option for scar reconstruction. Therefore, this study is designed to investigate the safety and efficacy of using MSCs in the treatment for the uterine niche. Methods/design: This phase II clinical trial is a single-center, prospective, randomized, double-blind, placebo-controlled with 2 arms. One hundred twenty primiparous participants will be randomly (1:1 ratio) assigned to receive direct intramuscular injection of MSCs (a dose of 1∗107 cells in 1 mL of 0.9% saline) (MSCs group) or an identical-appearing 1 mL of 0.9% saline (placebo-controlled group) near the uterine incision. The primary outcome of this trial is to evaluate the proportion of participants at 6 months who is found uterine niche in the uterus by transvaginal utrasonography. Adverse events will be documented in a case report form. The study will be conducted at the Department of Obstetric of Southern Medical University Affiliated Maternal & Child Health Hospital of Foshan. Discussion: This trial is the first investigation of the potential for therapeutic use of MSCs for the management of uterine niche after cesarean delivery. Conclusion: This protocol will help to determine the efficacy and safety of MSCs treatment in uterine niche and bridge the gap with regards to the current preclinical and clinical evidence. Trial registration number: NCT02968459 (Clinical Trials.gov: http://clinicaltrials.gov/). PMID:29095305

  9. Integrating life stages into ecological niche models: a case study on tiger beetles.

    Science.gov (United States)

    Taboada, Angela; von Wehrden, Henrik; Assmann, Thorsten

    2013-01-01

    Detailed understanding of a species' natural history and environmental needs across spatial scales is a primary requisite for effective conservation planning, particularly for species with complex life cycles in which different life stages occupy different niches and respond to the environment at different scales. However, niche models applied to conservation often neglect early life stages and are mostly performed at broad spatial scales. Using the endangered heath tiger beetle (Cicindela sylvatica) as a model species, we relate presence/absence and abundance data of locally dispersing adults and sedentary larvae to abiotic and biotic variables measured in a multiscale approach within the geographic extent relevant to active conservation management. At the scale of hundreds of meters, fine-grained abiotic conditions (i.e., vegetation structure) are fundamental determinants of the occurrence of both life stages, whereas the effect of biotic factors is mostly contained in the abiotic signature. The combination of dense heath vegetation and bare ground areas is thus the first requirement for the species' preservation, provided that accessibility to the suitable habitat is ensured. At a smaller scale (centimetres), the influence of abiotic factors on larval occurrence becomes negligible, suggesting the existence of important additional variables acting within larval proximity. Sustained significant correlations between neighbouring larvae in the models provide an indication of the potential impact of neighbourhood crowding on the larval niche within a few centimetres. Since the species spends the majority of its life cycle in the larval stage, it is essential to consider the hierarchical abiotic and biotic processes affecting the larvae when designing practical conservation guidelines for the species. This underlines the necessity for a more critical evaluation of the consequences of disregarding niche variation between life stages when estimating niches and

  10. [Allelopathic effects of Artemisia sacrorum population in typical steppe based on niche theory].

    Science.gov (United States)

    Wang, Hui; Xie, Yong-Sheng; Cheng, Ji-Min; She, Xiao-Yan

    2012-03-01

    By using modified Levins niche width index and Pianka niche overlap index, this paper analyzed the ecological competition between constructive and dominant species in a typical steppe. The stem- and leaf extracts from the constructive species (Artemisia sacrorum) were utilized to study their allelopathic potential on the seed germination and plant growth of the dominant species (Stipa bungeana, Thymus mongolicus, S. grandis, and Leymus secalinus), and the ecological position of A. sacrorum in the steppe succession. In the steppe, S. bungeana had the widest niche width (0.99), followed by T. mongolicus (0.94), A. sacrorum (0.82), S. grandis (0.76), and L. secalinus (0.73). The niche overlap value between A. sacrorum and S. bungeana, S. bungeana and T. mongolicus, T. mongolicus and S. grandis, and A. sacrorum and T. mongolicus was 0.90, 0.95, 0.94, and 0.86, respectively. The allelopathic effects of A. sacrorum extracts varied with their concentration. For the seed germination, root growth, and shoot growth of the dominant species, A. sacrorum extracts showed a trend of promoting at low concentrations and inhibiting at high concentrations. The extracts of A. sacrorum had a stronger promotion effect on the root growth of S. bungeana than on that of T. mongolicus, but a stronger inhibition effect on the shoot growth of T. mongolicus than on that of S. bungeana. Methanol extracts had stronger allelopathic effects than aqueous extracts. The high niche overlap between A. sacrorum and S. bungeana, and T. mongolicus and S. grandis indicated that the steppe community would continue succession to S. bungeana, while A. sacrorum population was only an important transitional stage during the succession. The allelopathic effect of A. sacrorum played a driving role in the succession process.

  11. Within-population isotopic niche variability in savanna mammals: disparity between carnivores and herbivores

    Directory of Open Access Journals (Sweden)

    Daryl eCodron

    2016-02-01

    Full Text Available Large mammal ecosystems have relatively simple food webs, usually comprising three – and sometimes only two – trophic links. Since many syntopic species from the same trophic level therefore share resources, dietary niche partitioning features prominently within these systems. In African and other subtropical savannas, stable carbon isotopes readily distinguish between herbivore species for which foliage and other parts of dicot plants (13C-depleted C3 vegetation are the primary resource (browsers and those for which grasses (13C-enriched C4 vegetation are staples (grazers. Similarly, carbon isotopes distinguish between carnivore diets that may be richer in either browser, grazer, or intermediate-feeding prey. Here, we investigate levels of carbon and nitrogen isotopic niche variation and niche partitioning within populations (or species of carnivores and herbivores from South African savannas. We emphasize predictable differences in within-population trends across trophic levels: we expect that herbivore populations, which require more foraging effort due to higher intake requirements, are far less likely to display within-population resource partitioning than carnivore populations. Our results reveal generally narrower isotopic niche breadths in herbivore than carnivore populations, but more importantly we find lower levels of isotopic differentiation across individuals within herbivore species. While these results offer some support for our general hypothesis, the current paucity of isotopic data for African carnivores limits our ability to test the complete set of predictions arising from our hypothesis. Nevertheless, given the different ecological and ecophysiological constraints to foraging behaviour within each trophic level, comparisons across carnivores and herbivores, which are possible within such simplified foodwebs, make these systems ideal for developing a process-based understanding of conditions underlying the evolution of

  12. Twitter and society

    CERN Document Server

    Weller, Katrin; Burgess, Jean; Mahrt, Merja

    2013-01-01

    Since its launch in 2006, Twitter has evolved from a niche service to a mass phenomenon; it has become instrumental for everyday communication as well as for political debates, crisis communication, marketing, and cultural participation. But the basic idea behind it has stayed the same: users may post short messages (tweets) of up to 140 characters and follow the updates posted by other users. Drawing on the experience of leading international Twitter researchers from a variety of disciplines and contexts, this is the first book to document the various notions and concepts of Twitter communica

  13. The big data phenomenon: The business and public impact

    Directory of Open Access Journals (Sweden)

    Chroneos-Krasavac Biljana

    2016-01-01

    Full Text Available The subject of the research in this paper is the emergence of big data phenomenon and application of big data technologies for business' needs with the specific emphasis on marketing and trade. The purpose of the research is to make a comprehensive overview of different discussions about the characteristics, application possibilities, achievements, constraints and the future of big data development. Based on the relevant literature, the concept of big data is presented and the potential of large impact of big data on business activities is discussed. One of the key findings indicates that the most prominent change that big data brings to the business arena is the appearance of new business models, as well as revisions of the existing ones. Substantial part of the paper is devoted to the marketing and marketing research which are under the strong impact of big data. The most exciting outcomes of the research in this domain concerns the new abilities in profiling the customers. In addition to the vast amount of structured data which are used in marketing for a long period, big data initiatives suggest the inclusion of semi-structured and unstructured data, opening up the room for substantial improvements in customer profile analysis. Considering the usage of information communication technologies (ICT as a prerequisite for big data project success, the concept of Networked Readiness Index (NRI is presented and the position of Serbia and regional countries in NRI framework is analyzed. The main outcome of the analysis points out that Serbia, with its NRI score took the lowest position in the region, excluding Albania. Also, Serbia is lagging behind the appropriate EU mean values regarding all observed composite indicators - pillars. Further on, this analysis reveals the domains of ICT usage in Serbia, which could be focused for an improvement and where incentives can be made. These domains are: political and regulatory environment, business and

  14. Hematopoietic stem and progenitor cells regulate the regeneration of their niche by secreting Angiopoietin-1

    Science.gov (United States)

    Zhou, Bo O; Ding, Lei; Morrison, Sean J

    2015-01-01

    Hematopoietic stem cells (HSCs) are maintained by a perivascular niche in bone marrow but it is unclear whether the niche is reciprocally regulated by HSCs. Here, we systematically assessed the expression and function of Angiopoietin-1 (Angpt1) in bone marrow. Angpt1 was not expressed by osteoblasts. Angpt1 was most highly expressed by HSCs, and at lower levels by c-kit+ hematopoietic progenitors, megakaryocytes, and Leptin Receptor+ (LepR+) stromal cells. Global conditional deletion of Angpt1, or deletion from osteoblasts, LepR+ cells, Nes-cre-expressing cells, megakaryocytes, endothelial cells or hematopoietic cells in normal mice did not affect hematopoiesis, HSC maintenance, or HSC quiescence. Deletion of Angpt1 from hematopoietic cells and LepR+ cells had little effect on vasculature or HSC frequency under steady-state conditions but accelerated vascular and hematopoietic recovery after irradiation while increasing vascular leakiness. Hematopoietic stem/progenitor cells and LepR+ stromal cells regulate niche regeneration by secreting Angpt1, reducing vascular leakiness but slowing niche recovery. DOI: http://dx.doi.org/10.7554/eLife.05521.001 PMID:25821987

  15. Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators.

    Science.gov (United States)

    Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel A; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Lo Celso, Cristina; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-Fu; Scadden, David T

    2016-10-06

    Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on the differential single-cell gene expression analysis of mesenchymal osteolineage cells close to, and further removed from, hematopoietic stem/progenitor cells (HSPCs) to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. We functionally examined, among the genes that were preferentially expressed in proximal cells, three secreted or cell-surface molecules not previously connected to HSPC biology-the secreted RNase angiogenin, the cytokine IL18, and the adhesion molecule Embigin-and discovered that all of these factors are HSPC quiescence regulators. Therefore, our proximity-based differential single-cell approach reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance the understanding of microenvironmental regulation of stem cell function. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Predicting fundamental and realized distributions based on thermal niche: A case study of a freshwater turtle

    Science.gov (United States)

    Rodrigues, João Fabrício Mota; Coelho, Marco Túlio Pacheco; Ribeiro, Bruno R.

    2018-04-01

    Species distribution models (SDM) have been broadly used in ecology to address theoretical and practical problems. Currently, there are two main approaches to generate SDMs: (i) correlative, which is based on species occurrences and environmental predictor layers and (ii) process-based models, which are constructed based on species' functional traits and physiological tolerances. The distributions estimated by each approach are based on different components of species niche. Predictions of correlative models approach species realized niches, while predictions of process-based are more akin to species fundamental niche. Here, we integrated the predictions of fundamental and realized distributions of the freshwater turtle Trachemys dorbigni. Fundamental distribution was estimated using data of T. dorbigni's egg incubation temperature, and realized distribution was estimated using species occurrence records. Both types of distributions were estimated using the same regression approaches (logistic regression and support vector machines), both considering macroclimatic and microclimatic temperatures. The realized distribution of T. dorbigni was generally nested in its fundamental distribution reinforcing theoretical assumptions that the species' realized niche is a subset of its fundamental niche. Both modelling algorithms produced similar results but microtemperature generated better results than macrotemperature for the incubation model. Finally, our results reinforce the conclusion that species realized distributions are constrained by other factors other than just thermal tolerances.

  17. Labor Market Efficiency as One of the Pillars of the Global Competitiveness of an Economy - Conclusions for the Labor Market Regimes of the EU Countries

    Directory of Open Access Journals (Sweden)

    Izabela Ostoj

    2015-04-01

    Full Text Available Labor market activity may have an effect on global economy competitiveness. This issue has been described as "labor market efficiency" (LME, which is a constituent of The Global Competitiveness Index published by The World Economic Forum (WEF. The article's purpose is to clarify the phenomenon of LME and explain the mechanisms which help the constituents affect economy competitiveness. The structure of LME points at the meaning of labor market regime, especially after considering the fact that European Union countries operate within various models of regime. The analysis of the LME diversity may help determine what type of labor market regimes are most efficient in enhancing economy competitiveness

  18. IPO Pricing with Bookbuilding and a When-Issued Market

    OpenAIRE

    Stomper, Alex; Aussenegg, Wolfgang; Pichler, Pegaret

    2004-01-01

    This paper examines the German IPO pricing process which combines bookbuilding with a liquid pre-IPO when-issued market. We find no partial adjustment phenomenon, as has been documented for U.S. IPOs. We thus find no evidence that bookbuilding provides information for IPO pricing, beyond the information that is required to set preliminary price ranges. Once price ranges are set, when-issued trading commences and indicates how IPOs should be priced in the primary market. However, the evidence ...

  19. When do plant radiations influence community assembly? The importance of historical contingency in the race for niche space.

    Science.gov (United States)

    Tanentzap, Andrew J; Brandt, Angela J; Smissen, Rob D; Heenan, Peter B; Fukami, Tadashi; Lee, William G

    2015-07-01

    Plant radiations are widespread but their influence on community assembly has rarely been investigated. Theory and some evidence suggest that radiations can allow lineages to monopolize niche space when founding species arrive early into new bioclimatic regions and exploit ecological opportunities. These early radiations may subsequently reduce niche availability and dampen diversification of later arrivals. We tested this hypothesis of time-dependent lineage diversification and community dominance using the alpine flora of New Zealand. We estimated ages of 16 genera from published phylogenies and determined their relative occurrence across climatic and physical gradients in the alpine zone. We used these data to reconstruct occupancy of environmental space through time, integrating palaeoclimatic and palaeogeological changes. Our analysis suggested that earlier-colonizing lineages encountered a greater availability of environmental space, which promoted greater species diversity and occupancy of niche space. Genera that occupied broader niches were subsequently more dominant in local communities. An earlier time of arrival also contributed to greater diversity independently of its influence in accessing niche space. We suggest that plant radiations influence community assembly when they arise early in the occupancy of environmental space, allowing them to exclude later-arriving colonists from ecological communities by niche preemption. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. To predict the niche, model colonization and extinction

    Science.gov (United States)

    Charles B. Yackulic; James D. Nichols; Janice Reid; Ricky Der

    2015-01-01

    Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the species’ niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both...

  1. MOBBING PHENOMENON - FACTORS OF DISCRIMINATION AND STRESS

    Directory of Open Access Journals (Sweden)

    ROMANESCU MARCEL LAURENTIU

    2017-02-01

    Full Text Available This article focuses on exemplifying the features of discrimination phenomenon in the workplace, a phenomenon that has appeared in the Romanian social studies only in the last 4 years. Mobbing phenomenon has been analyzed by several countries in Europe such as England, France, Germany; after these analyzes it has been found that this phenomenon refers only to actions of intense psychological pressure. Actions are geared to a single employee, in order to cause it to leave its job. Without these measures, dismissal of the employee would lead to numerous legal problems on the employer. In conclusion, employee who is the subject of mobbing phenomenon must endure a long period of time a series of injustices focused on himself, but also extremely high humiliation, which determines him to mentally give up and take the decision to resign.

  2. Placing Brazil's heavy acid oils on international markets

    International Nuclear Information System (INIS)

    Szklo, Alexandre Salem; Machado, Giovani; Schaeffer, Roberto; Felipe Simoes, Andre; Barboza Mariano, Jacqueline

    2006-01-01

    This paper identifies the international market niches of Brazil's heavy acid oils. It analyzes the perspectives for making wider use of heavy acid oils, assessing their importance for certain oil-producing regions such as Brazil, Venezuela, West Africa, the North Sea and China. Within this context, the oil produced in the Marlim Field offshore Brazil is of specific interest, spurred by the development of its commercial brand name for placement on international markets and backed by ample production volumes. This analysis indicates keener international competition among acid oils produced in Brazil, the North Sea and the West Coast of Africa, through to 2010. However, over the long term, refinery conversion capacity is the key factor for channeling larger volumes of heavy acid oils to the international market. In this case, the future of acid oil producers will depend on investments in refineries close to oil product consumption centers. For Brazil, this means investments in modifying its refineries and setting up partnerships in the downstream segment for consumer centers absorbing all products of high added value, such as the USA and even Southeast Asia and Western Europe

  3. Stem Cell Niches in Glioblastoma: A Neuropathological View

    Directory of Open Access Journals (Sweden)

    Davide Schiffer

    2014-01-01

    Full Text Available Glioblastoma (GBM stem cells (GSCs, responsible for tumor growth, recurrence, and resistance to therapies, are considered the real therapeutic target, if they had no molecular mechanisms of resistance, in comparison with the mass of more differentiated cells which are insensitive to therapies just because of being differentiated and nonproliferating. GSCs occur in tumor niches where both stemness status and angiogenesis are conditioned by the microenvironment. In both perivascular and perinecrotic niches, hypoxia plays a fundamental role. Fifteen glioblastomas have been studied by immunohistochemistry and immunofluorescence for stemness and differentiation antigens. It has been found that circumscribed necroses develop inside hyperproliferating areas that are characterized by high expression of stemness antigens. Necrosis developed inside them because of the imbalance between the proliferation of tumor cells and endothelial cells; it reduces the number of GSCs to a thin ring around the former hyperproliferating area. The perinecrotic GSCs are nothing else that the survivors remnants of those populating hyperproliferating areas. In the tumor, GSCs coincide with malignant areas so that the need to detect where they are located is not so urgent.

  4. Satellite Cells and the Muscle Stem Cell Niche

    Science.gov (United States)

    Yin, Hang; Price, Feodor

    2013-01-01

    Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration. PMID:23303905

  5. The Analysis of Research on Internet Marketing

    Directory of Open Access Journals (Sweden)

    Vida Davidavičienė

    2014-09-01

    Full Text Available The targeted development of internet marketing faces the dynamic environment and its alterations that occur both – in business terms and conditions and in the use of e­tools and applicable concepts. The growing importance of internet marketing is indicated by a growth in e­markets, an increasing number of new generation consumers, investments of organizations in e­based decisions, a strong interest of scientists representing different fields as well as by widening the base of knowledge related to the above introduced phenomenon. Despite a continuously increasing amount of scientific literature on Internet marketing, this area of research is still at the initial stage. The article is aimed at analysing the fields of ongoing researches into Internet marketing and at identifying the areas required for deeper examination. The article has applied for the methods such as a comparative analysis and summary of scientific literature, information comparison and techniques for grouping and the graphical visualization of information.

  6. Time- and depth-wise trophic niche shifts in Antarctic benthos.

    Science.gov (United States)

    Calizza, Edoardo; Careddu, Giulio; Sporta Caputi, Simona; Rossi, Loreto; Costantini, Maria Letizia

    2018-01-01

    Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes

  7. Niche partitioning of feeding microhabitats produces a unique function for herbivorous rabbitfishes (Perciformes, Siganidae) on coral reefs

    Science.gov (United States)

    Fox, R. J.; Bellwood, D. R.

    2013-03-01

    Niche theory predicts that coexisting species minimise competition by evolving morphological or behavioural specialisations that allow them to spread out along resource axes such as space, diet and temporal activity. These specialisations define how a species interacts with its environment and, by extension, determine its functional role. Here, we examine the feeding niche of three species of coral reef-dwelling rabbitfishes (Siganidae, Siganus). By comparing aspects of their feeding behaviour (bite location, bite rate, foraging distance) with that of representative species from two other abundant herbivorous fish families, the parrotfishes (Labridae, Scarus) and surgeonfishes (Acanthuridae, Acanthurus), we examine whether rabbitfishes have a feeding niche distinct from other members of the herbivore guild. Measurements of the penetration of the fishes' snouts and bodies into reef concavities when feeding revealed that rabbitfish fed to a greater degree from reef crevices and interstices than other herbivores. There was just a 40 % overlap in the penetration-depth niche between rabbitfish and surgeonfish and a 45 % overlap between rabbitfish and parrotfish, compared with the almost complete niche overlap (95 %) recorded for parrotfish and surgeonfish along this spatial niche axis. Aspects of the morphology of rabbitfish which may contribute to this niche segregation include a comparatively longer, narrower snout and narrower head. Our results suggest that sympatric coexistence of rabbitfish and other reef herbivores is facilitated by segregation along a spatial (and potentially dietary) axis. This segregation results in a unique functional role for rabbitfishes among roving herbivores that of "crevice-browser": a group that specifically feeds on crevice-dwelling algal or benthic organisms. This functional trait may have implications for reef ecosystem processes in terms of controlling the successional development of crevice-based algal communities, reducing their

  8. Sport Management and Marketing: Overview and Recommendation for Future Research. [Gestión y marketing deportivo: Revisión y recomendación para investigaciones futuras].

    Directory of Open Access Journals (Sweden)

    Yong Jae Ko

    2013-07-01

    Full Text Available The sport industry is a large and fast growing industry. The U.S. market only counted for as much as $400-435 billion in 2012 (Plunkett’s Sport Industry Almanac. The conventional definition of the industry includes “the products offered to its buyers are sport, fitness, recreation, or leisure-related and may be activities, goods, services, people, places, or ideas” (Pitts & Stotlar, 1996, p.3. However, today’s sport market is extending its border by engulfing the entertainment industry and becoming a global cultural phenomenon (Gillentine, 2012.Reflecting the industry’s growth, the academic field of sport management is now in strong demand to educate professionals in the sport industry. Specifically, the special task force of the U.S. National Association for Sport and Physical Education (NASPE and North American Society for Sport Management (NASSM defined sport management as “the field of study offering the specialization training and education necessary for individuals seeking careers in any of the many segments of the industry.” Since the Journal of Sport Management was first published in 1987, 15 scholarly journals emerged to accommodate the demand for effective communication specifically targeted toward sport management and marketing. At the same time, the growing market size of the sport industry as a cultural phenomenon received scholarly attention from other disciplines such as management, marketing and economics (Gillentine, 2012.

  9. Malaria in Africa: vector species' niche models and relative risk maps.

    Directory of Open Access Journals (Sweden)

    Alexander Moffett

    2007-09-01

    Full Text Available A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km. Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes. For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The "additive" model assumes no interaction; the "minimax" model assumes maximum relative risk due to any vector in a cell; and the "competitive exclusion" model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease.

  10. [Rhytidectomy and Raynaud's phenomenon: about two cases].

    Science.gov (United States)

    Nicolas, J; Labbé, D

    2004-12-01

    Raynaud's phenomenon is a currently vascular syndrome (8 to 10% of women and 3 to 5% of men). It was defined as episodic ischaemia of the fingers, toes, nose, ears and nipples, which presents clinically as pallor, cyanosis, and often rubor of the skins, in response to cold, emotional stimuli and vasoconstriction agents. The phenomenon is caused by a vasoconstriction of arterials skin. In severe forms of the phenomenon, we can see ulcerations and necrosis. We report here two cases of rhytidectomy flap necrosis in Raynaud's Phenomenon. After review of literature, we explain the elements of physiopathology whose can explain these complications and we try to establish recommendations to these complications.

  11. Inter-specific and seasonal comparison of the niches occupied by small cetaceans off north-west Iberia

    DEFF Research Database (Denmark)

    Fernandez Garcia, Rut; MacLeod, C. D.; Pierce, G. J.

    2013-01-01

    Knowledge of species' ecological niches can be used to assess ecological interactions between different taxa. Sixteen species of cetaceans have been recorded in Galician waters and niche partitioning is expected to occur among these species in order to allow them to co-exist. In this study, the n...

  12. An analysis of markets for small-scale, advanced coal-combustion technology in Spain, Italy, and Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Placet, M.; Gerry, P.A.; Kenski, D.M.; Kern, D.M.; Nehring, J.L.; Szpunar, C.B.

    1989-09-01

    This report discusses the examination of potential overseas markets for using small-scale, US-developed, advanced coal-combustion technologies (ACTs). In previous work, member countries of the Organization for Economic Cooperation and Development (OECD) were rated on their potential for using ACTs through a comprehensive screening methodology. The three most promising OECD markets were found to be Spain, Italy, and Turkey. This report provides in-depth analyses of these three selected countries. First, it addresses changes in the European Community with particular reference to the 1992 restructuring and its potential effect on the energy situation in Europe, specifically in the three subject countries. It presents individual country studies that examine demographics, economics, building infrastructures, and energy-related factors. Potential niches for ACTs are explored for each country through regional analyses. Marketing channels, strategies, and the trading environments in each country are also discussed. The information gathered indicates that Turkey is a most promising market, Spain is a fairly promising market, and Italy appears to be a somewhat limited market for US ACTs. 76 refs., 16 figs., 14 tabs.

  13. Different Motile Behaviors of Human Hematopoietic Stem versus Progenitor Cells at the Osteoblastic Niche

    Directory of Open Access Journals (Sweden)

    Katie Foster

    2015-11-01

    Full Text Available Despite advances in our understanding of interactions between mouse hematopoietic stem cells (HSCs and their niche, little is known about communication between human HSCs and the microenvironment. Using a xenotransplantation model and intravital imaging, we demonstrate that human HSCs display distinct motile behaviors to their hematopoietic progenitor cell (HPC counterparts, and the same pattern can be found between mouse HSCs and HPCs. HSCs become significantly less motile after transplantation, while progenitor cells remain motile. We show that human HSCs take longer to find their niche than previously expected and suggest that the niche be defined as the position where HSCs stop moving. Intravital imaging is the only technique to determine where in the bone marrow stem cells stop moving, and future analyses should focus on the environment surrounding the HSC at this point.

  14. Co-niche construction between hosts and symbionts: ideas and ...

    Indian Academy of Sciences (India)

    RENEE M. BORGES

    2017-07-05

    Jul 5, 2017 ... Centre for Ecological Sciences, Indian Institute of Science, Bengaluru 560 012, India ... Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche ..... order to facilitate interactions with ants, plants provide ... of mutualistic pollinators develops within the pollinated ...

  15. Are Financial Markets an Aspect of Quantum World?

    Directory of Open Access Journals (Sweden)

    O. Racorean

    2015-01-01

    Full Text Available Writing the article “Time independent pricing of options in range bound markets” [1], the question in the title came naturally to my mind. It is stated, in the above article, that in certain market conditions the stock price is subjected to an equation that exactly matches a time independent Schrodinger equation. The time independent equation for options valuation is used further to explain a stock market phenomenon that resembles an α particle decay tunneling effect. The transmission coefficient for the stock price tunneling effect it is also deduced. Although, it may not have important impact in quantum physics, the philosophical aspects residing in the use of quantum mechanics for stock market specific are very important.

  16. A suspicious reason for Raynaud's phenomenon: Intrauterine device.

    Science.gov (United States)

    Diken, Adem I; Yalçınkaya, Adnan; Aksoy, Eray; Yılmaz, Seyhan; Çağlı, Kerim

    2015-06-01

    Primary Raynaud's phenomenon may be insistent in patients under medical therapy, and intrauterine devices may be an unnoticed reason in these patients. Fluctuations in female sex hormone status were reported to be associated with the emergence of primary Raynaud's phenomenon symptoms. The use of intrauterine devices was not reported to be associated with Raynaud's phenomenon previously. Intrauterine device may stimulate vascular hyperactivity regarding hormonal or unknown mechanisms that result in Raynaud's phenomenon. We present a postmenopausal patient who complained of primary Raynaud's phenomenon symptoms and had recovery after the removal of her copper intrauterine device. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Unveiling current Guanaco distribution in chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests.

    Science.gov (United States)

    González, Benito A; Samaniego, Horacio; Marín, Juan Carlos; Estades, Cristián F

    2013-01-01

    Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distribution of the recently resolved phylogeography of guanaco (Lama guanicoe) lineages on the western slope of the southern Andes. Using a maximum entropy framework, field data, and information on climate, topography, human density, and vegetation cover, we identify differences between the two subspecies (L.g.cacsilensis, L.g.guanicoe) and their intermediate-hybrid lineage, that most likely determine the distribution of this species. While aridity seems to be a major factor influencing the distribution at the species-level (annual precipitation ecological and/or evolutionary processes are shaping the niche of guanacos in Chile, producing discrepancies when comparing range distribution at the species-level (81,756 km(2)) with lineages-level (65,321 km(2)). The subspecies-specific description of niche structure is provided here based upon detailed spatial distribution of the lineages of guanacos in Chile. Such description provides a scientific tool to further develop large scale plans for habitat conservation and preservation of intraspecific genetic variability for this far ranging South American camelid, which inhabits a diversity of ecoregion types from Andean puna to subpolar forests.

  18. Phylogenetic climatic niche conservatism and evolution of climatic suitability in Neotropical Angraecinae (Vandeae, Orchidaceae) and their closest African relatives.

    Science.gov (United States)

    Kolanowska, Marta; Grochocka, Elżbieta; Konowalik, Kamil

    2017-01-01

    In the present study we investigate the concept of phylogenetic niche conservatism (PNC) within the American species of angraecoid orchids ( Campylocentrum and Dendrophylax ) and their closest relatives in the Old World ( Angraecum ) using ecological niche modelling (ENM). The predicted niche occupancy profiles were matched with the outcomes of previous phylogenetic studies to reconstruct the evolution of climatic suitability within the orchid group studied and evaluate the role of niche differentiation in the speciation of Angraecinae. No correlation between preferred niches and taxonomic relationships within the orchid group studied was revealed. The climatic suitability of the majority of the species overlapped each other, either fully or partially. This pattern is also present in the species of other orchid genera. Our research confirms a significant level of PNC in Orchidaceae, even within taxa exhibiting a transatlantic disjunction. The analysis of the evolution of climatic suitability indicated that the adaptation to various climatic conditions is not a factor that has driven speciation within orchids studied.

  19. Phylogenetic climatic niche conservatism and evolution of climatic suitability in Neotropical Angraecinae (Vandeae, Orchidaceae) and their closest African relatives

    Czech Academy of Sciences Publication Activity Database

    Kolanowska, Marta; Grochocka, E.; Konowalik, K.

    2017-01-01

    Roč. 5, may (2017), č. článku e3328. ISSN 2167-8359 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:86652079 Keywords : campylocentrum orchidaceae * molecular phylogenetics * environmental niches * costa-rica * diversity * models * speciation * ecology * pollination * divergence * Angraecinae * Ecological niche modeling * Orchidaceae * Phylogenetic niche conservatism * Angraecum * Campylocentrum * Dendrophylax Subject RIV: EH - Ecology, Behaviour OBOR OECD: Biodiversity conservation Impact factor: 2.177, year: 2016

  20. Unveiling current Guanaco distribution in chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests.

    Directory of Open Access Journals (Sweden)

    Benito A González

    Full Text Available Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distribution of the recently resolved phylogeography of guanaco (Lama guanicoe lineages on the western slope of the southern Andes. Using a maximum entropy framework, field data, and information on climate, topography, human density, and vegetation cover, we identify differences between the two subspecies (L.g.cacsilensis, L.g.guanicoe and their intermediate-hybrid lineage, that most likely determine the distribution of this species. While aridity seems to be a major factor influencing the distribution at the species-level (annual precipitation <900 mm, we also document important differences in niche specificity for each subspecies, where distribution of Northern lineage is explained mainly by elevation (mean = 3,413 m and precipitation seasonality (mean = 161 mm, hybrid lineage by annual precipitation (mean = 139 mm, and Southern subspecies by annual precipitation (mean = 553 mm, precipitation seasonality (mean = 21 mm and grass cover (mean = 8.2%. Among lineages, we detected low levels of niche overlap: I (Similarity Index = 0.06 and D (Schoener's Similarity Index = 0.01; and higher levels when comparing Northern and Southern subspecies with hybrids lineage ( I = 0.32-0.10 and D = 0.12-0.03, respectively. This suggests that important ecological and/or evolutionary processes are shaping the niche of guanacos in Chile, producing discrepancies when comparing range distribution at the species-level (81,756 km(2 with lineages-level (65,321 km(2. The subspecies-specific description of niche structure is provided here based upon detailed spatial distribution of the lineages of guanacos in Chile. Such description

  1. PP composites with Hybrid Nanofillers: NTC phenomenon

    International Nuclear Information System (INIS)

    Sarlin, Juha; Immonen, Kirsi

    2010-01-01

    Electric conductive plastic composites have a wide potential for commercial applications, some examples are EMI shielding housings and components in automotive industry and in consumer electronics, equipments in health care sector and fuel cell components. A phenomenon in conductive composites, especially in composites with carbon based fillers, is change of thermal induced change in conductivity as a result of morphological transitions. Usually the observed changes are practically irreversible. The phenomenon may cause increasing resistivity, usually called as 'positive temperature coefficient' (PTC) or decreasing resistivity, called 'negative temperature coefficient' (NTC), where the new morphology created by heat treatment is more favorable for electric conductivity compared to the original state. The existence of NTC is a sing of the lost potential in material design and processing. Therefore detailed information about the phenomenon gives us tools to develop high performance conductive materials. It this paper we discuss about NTC phenomenon observed in PP composites with CNT or in-situ synthesized CNT-PANi hybrid nanofiller with an amphiphilic dispersing agent. The goal of the paper is not to present a comprehensive model of this phenomenon; we present some experimental results which may be related to polymer-filler interactions. These details are a part of this complicated phenomenon.

  2. Discovery of fungus-mite mutualism in a unique niche

    NARCIS (Netherlands)

    Roets, F; Wingfield, M J; Crous, P W; Dreyer, L L

    2007-01-01

    The floral heads (infructescences) of South African Protea L. represent a most unusual niche for fungi of the economically important genus Ophiostoma Syd. and P. Syd. emend. Z.W. de Beer et al. Current consensus holds that most members of Ophiostoma are vectored by tree-infesting bark beetles.

  3. Human cultures as niche constructions within the solar system

    NARCIS (Netherlands)

    Van de Vliert, Evert

    This commentary seeks to refine Kashima’s (2016) timely and topical but too-general call for embedding culture within the planetary ecosystem. My starting point is that cultures are to an underestimated extent ongoing niche constructions within the merry-go-round of the Sun’s radiation, the Earth’s

  4. S100 chemokines mediate bookmarking of premetastatic niches

    Science.gov (United States)

    Rafii, Shahin; Lyden, David

    2010-01-01

    Primary tumours release soluble factors, including VEGF-A, TGFβ and TNFα, which induce expression of the chemokines S100A8 and S100A9 in the myeloid and endothelial cells within the lung before tumour metastasis. These chemokine-activated premetastatic niches support adhesion and invasion of disseminating malignant cells, thereby establishing a fertile habitat for metastatic tumours. PMID:17139281

  5. Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids.

    Science.gov (United States)

    Karunarathne, Piyal; Schedler, Mara; Martínez, Eric J; Honfi, Ana I; Novichkova, Anastasiia; Hojsgaard, Diego

    2018-05-11

    Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids

  6. Niche separation in flycatcher-like species in the lowland rainforests of Malaysia.

    Science.gov (United States)

    Mansor, Mohammad Saiful; Ramli, Rosli

    2017-07-01

    Niche theory suggests that sympatric species reduce interspecific competition through segregation of shared resources by adopting different attack manoeuvres. However, the fact that flycatcher-like bird species exclusively use the sally manoeuvre may thus challenge this view. We studied the foraging ecology of three flycatcher-like species (i.e. Paradise-flycatcher Terpsiphone sp., Black-naped Monarch Hypothymis azurea, and Rufous-winged Philentoma Philentoma pyrhoptera) in the Krau Wildlife Reserve in central Peninsular Malaysia. We investigated foraging preferences of each bird species and the potential niche partitioning via spatial or behavioural segregation. Foraging substrate was important parameter that effectively divided paradise-flycatcher from Black-naped Monarch and Rufous-winged Philentoma, where monarch and philentoma foraged mainly on live green leaves, while paradise-flycatcher foraged on the air. They also exhibited different foraging height preferences. Paradise-flycatcher, for instance, preferred the highest studied strata, while Black-naped Monarch foraged mostly in lower strata, and Rufous-winged Philentoma made use of the lowest strata. This study indicates that niche segregation occurs among sympatric species through foraging substrate and attack manoeuvres selection. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Immigration and the Housing Market: The Case of Castel Volturno, in Campania Region, Italy

    Directory of Open Access Journals (Sweden)

    Fabiana Forte

    2018-01-01

    Full Text Available According to Eurostat, Italy is the fifth country of the European Union per immigrant population. The complexity of the phenomenon, as it has evolved in recent years, leads to analyzing it from a specific point of view, that of the real estate market. The article represents the early stage of research on the housing condition of the immigrant population in the Southern Italy and its effect on the housing market. First, we describe the spatial segregation phenomenon affecting the immigrant population in Campania Region; then we analyze data of the municipality of Castel Volturno, which has one of the greater migratory pressure throughout the whole region. We provide statistical regressions correlating housing prices and socio-economic features from 2006 to 2016. The results confirm the findings of the current literature on the subject: there is a specific phenomenon associated with the presence of an immigrant population residing in conjunction with a reduction of housing prices.

  8. Competition policies on the electricity markets

    International Nuclear Information System (INIS)

    Dubois, U.

    2008-01-01

    This article puts forward a critical analysis of European competition instruments and practices in terms of market power on the electricity wholesale markets. Due to the speck nature of electrical activities, competition policies come up against difficulties of market power identification at first, since there is no model for detecting perfectly the potential or real exertion of market power in this sector. What is more, since competition authorities rely on specific intervention methods, their ability to limit the exertion of market power is relatively low. For a large number of their interventions involves controlling concentrations. In the light of this double phenomenon, this article discusses some recent developments of European competition policies on the electricity wholesale markets. The sector inquiry of 2007 seems to mark the start of a new competition policy practice in the electricity sector. The initiative and decision-making power now seem to be nesting mainly at a European level where action is not only to be found in terms of controlling mergers and acquisitions, but also stretches to involve an in-depth evaluation of the way the different markets work. This action is manifested in decisions to investigate some companies as well as legislative proposals in the framework of the third package. Thus we are moving towards a greater monitoring of electricity markets using more formal supervision instruments and on a more continuous basis. (author)

  9. Wnt6 maintains anterior escort cells as an integral component of the germline stem cell niche.

    Science.gov (United States)

    Wang, Xiaoxi; Page-McCaw, Andrea

    2018-02-07

    Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. In Drosophila ovaries, germline stem cells depend on cap cells for self-renewing signals and physical attachment. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are absolutely required for germline stem cell maintenance. When escort cells die from impaired Wnt signaling or hid expression, the loss of anterior escort cells causes loss of germline stem cells. Anterior escort cells function as an integral niche component by promoting DE-cadherin anchorage and by transiently expressing the Dpp ligand to promote full-strength BMP signaling in germline stem cells. Anterior escort cells are maintained by Wnt6 ligands produced by cap cells; without Wnt6 signaling, anterior escort cells die leaving vacancies in the niche, leading to loss of germline stem cells. Our data identify anterior escort cells as constituents of the germline stem cell niche, maintained by a cap cell-produced Wnt6 survival signal. © 2018. Published by The Company of Biologists Ltd.

  10. The Satellite Cell Niche Regulates the Balance between Myoblast Differentiation and Self-Renewal via p53.

    Science.gov (United States)

    Flamini, Valentina; Ghadiali, Rachel S; Antczak, Philipp; Rothwell, Amy; Turnbull, Jeremy E; Pisconti, Addolorata

    2018-03-13

    Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Mouse Incisor Stem Cell Niche and Myb Transcription Factors

    Czech Academy of Sciences Publication Activity Database

    Švandová, Eva; Veselá, Barbora; Šmarda, J.; Hampl, A.; Radlanski, R.J.; Matalová, Eva

    2015-01-01

    Roč. 44, č. 5 (2015), s. 338-344 ISSN 0340-2096 R&D Projects: GA ČR GAP304/11/1418; GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : c-Myb * stem cell niches Subject RIV: EA - Cell Biology Impact factor: 0.615, year: 2015

  12. Plug-In Hybrid Electric Vehicle Market Introduction Study: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sikes, Karen [Sentech, Inc.; Gross, Thomas [Sentech, Inc.; Lin, Zhenhong [ORNL; Sullivan, John [University of Michigan Transportation Research Institute; Cleary, Timothy [Sentech, Inc.; Ward, Jake [U.S. Department of Energy

    2010-02-01

    Oak Ridge National Laboratory (ORNL), Sentech, Inc., Pacific Northwest National Laboratory (PNNL)/University of Michigan Transportation Research Institute (UMTRI), and the U.S. Department of Energy (DOE) have conducted a Plug-in Hybrid Electric Vehicle (PHEV) Market Introduction Study to identify and assess the effect of potential policies, regulations, and temporary incentives as key enablers for a successful market debut. The timeframe over which market-stimulating incentives would be implemented - and the timeframe over which they would be phased out - are suggested. Possible sources of revenue to help fund these mechanisms are also presented. In addition, pinch points likely to emerge during market growth are identified and proposed solutions presented. Finally, modeling results from ORNL's Market Acceptance of Advanced Automotive Technologies (MA3T) Model and UMTRI's Virtual AutoMotive MarketPlace (VAMMP) Model were used to quantify the expected effectiveness of the proposed policies and to recommend a consensus strategy aimed at transitioning what begins as a niche industry into a thriving and sustainable market by 2030. The primary objective of the PHEV Market Introduction Study is to identify the most effective means for accelerating the commercialization of PHEVs in order to support national energy and economic goals. Ideally, these mechanisms would maximize PHEV sales while minimizing federal expenditures. To develop a robust market acceleration program, incentives and policies must be examined in light of: (1) clarity and transparency of the market signals they send to the consumer; (2) expenditures and resources needed to support them; (3) expected impacts on the market for PHEVs; (4) incentives that are compatible and/or supportive of each other; (5) complexity of institutional and regulatory coordination needed; and (6) sources of funding.

  13. Koebner Phenomenon and Mycosis Fungoides

    Directory of Open Access Journals (Sweden)

    Eve Lebas

    2015-10-01

    Full Text Available Mycosis fungoides (MF is the most frequent type of primary cutaneous T-cell/NK-cell lymphoma. The Koebner phenomenon is defined as the appearance of cutaneous lesions on previously noninvolved skin following trauma and is observed in a series of cutaneous diseases including psoriasis, lichen planus, viral warts, molluscum contagiosum, etc. In this case report, 3 patients with longstanding MF are presented, the 1st with the appearance of a circumscribed early-stage type MF lesion rapidly following a surgical excision of an infundibular cyst, the 2nd with the appearance of a unique unilateral palmar tumoral MF lesion at the pressure site of a crutch, and the 3rd presented localized MF early stage lesions at the friction site of a belt. This report suggests that some MF patients may experience Koebner phenomenon-induced MF lesions and that MF should be added to the long list of skin diseases potentially exhibiting the Koebner phenomenon.

  14. Osteoblastic and Vascular Endothelial Niches, Their Control on Normal Hematopoietic Stem Cells, and Their Consequences on the Development of Leukemia

    Directory of Open Access Journals (Sweden)

    Bella S. Guerrouahen

    2011-01-01

    Full Text Available Stem cell self-renewal is regulated by intrinsic mechanisms and extrinsic signals mediated via specialized microenvironments called “niches.” The best-characterized stem cell is the hematopoietic stem cell (HSC. Self-renewal and differentiation ability of HSC are regulated by two major elements: endosteal and vascular regulatory elements. The osteoblastic niche localized at the inner surface of the bone cavity might serve as a reservoir for long-term HSC storage in a quiescent state. Whereas the vascular niche, which consists of sinusoidal endothelial cell lining blood vessel, provides an environment for short-term HSC proliferation and differentiation. Both niches act together to maintain hematopoietic homeostasis. In this paper, we provide some principles applying to the hematopoietic niches, which will be useful in the study and understanding of other stem cell niches. We will discuss altered microenvironment signaling leading to myeloid lineage disease. And finally, we will review some data on the development of acute myeloid leukemia from a subpopulation called leukemia-initiating cells (LIC, and we will discuss on the emerging evidences supporting the influence of the microenvironment on chemotherapy resistance.

  15. Phylogenetic constraints in key functional traits behind species' climate niches

    DEFF Research Database (Denmark)

    Kellermann, Vanessa; Loeschcke, Volker; Hoffmann, Ary A

    2012-01-01

    Species distributions are often constrained by climatic tolerances that are ultimately determined by evolutionary history and/or adaptive capacity, but these factors have rarely been partitioned. Here, we experimentally determined two key climatic niche traits (desiccation and cold resistance) fo...

  16. Hysteresis phenomenon in nuclear reactor dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Pirayesh, Behnam; Pazirandeh, Ali [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Nuclear Engineering, Science and Research Branch; Akbari, Monireh [Shahid Rajaee Teacher Training Univ., Tehran (Iran, Islamic Republic of). Dept. of Mathematics

    2017-05-15

    This paper applies a nonlinear analysis method to show that hysteresis phenomenon, due to the Saddle-node bifurcation, may occur in the nuclear reactor. This phenomenon may have significant effects on nuclear reactor dynamics and can even be the beginning of a nuclear reactor accident. A system of four dimensional nonlinear ordinary differential equations was considered to study the hysteresis phenomenon in a typical nuclear reactor. It should be noted that the reactivity was considered as a nonlinear function of state variables. The condition for emerging hysteresis was investigated using Routh-Hurwitz criterion and Sotomayor's theorem for saddle node bifurcation. A numerical analysis is also provided to illustrate the analytical results.

  17. Sustainable energy transitions in emerging economies: The formation of a palm oil biomass waste-to-energy niche in Malaysia 1990–2011

    International Nuclear Information System (INIS)

    Hansen, Ulrich Elmer; Nygaard, Ivan

    2014-01-01

    The economic development in emerging economies in Southeast Asia has significantly increased the use of fossil fuel based energy. This has severe implications for global climate change, and against this background, scholars within the sustainable transition tradition have taken an interest in addressing how transitions towards more sustainable development pathways in this region may be achieved. This paper contributes to the abovementioned literature by examining the conducive and limiting factors for development and proliferation of a palm oil biomass waste-to-energy niche in Malaysia during the period 1990–2011. Rising oil prices, strong pressure on the palm oil industry from environmental groups, and a persisting palm oil biomass waste disposal problem in Malaysia appear to have been conducive to niche proliferation, and on top of this national renewable energy policies and large-scale donor programmes have specifically supported the utilisation of palm oil biomass waste for energy. However, in spite of this, the niche development process has only made slow progress. The paper identifies reluctant implementation of energy policy, rise in biomass resource prices, limited network formation and negative results at the niche level, as the main factors hindering niche development. - Highlights: • We examine crucial factors for developing a biomass-to-energy niche in Malaysia. • In spite of interventions for policy support the niche has only made slow progress. • Oil prices, NGO pressure, waste problems and policy support were the enabling factors. • First, reluctant implementation of energy policy was hindering niche development. • Later, low performance level of implemented plants was hindering niche development

  18. Asymmetric conditional volatility in international stock markets

    Science.gov (United States)

    Ferreira, Nuno B.; Menezes, Rui; Mendes, Diana A.

    2007-08-01

    Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the SP 500, FTSE 100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of changes in macroeconomic variables, we find no significant evidence of asymmetric behaviour of the stock market returns. There are some signs that the Portuguese Stock Market tends to show somewhat less market efficiency than other markets since the effect of the shocks appear to take a longer time to dissipate.

  19. Informal Marketing: A Commercialization Model Guided by Brazilian Jeitinho, Informality and Entrepreneurship

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Silva de Souza

    2014-08-01

    Full Text Available In Brazil, street vendors and hawkers, currently recognized as micro-entrepreneurs, commonly are developing unconventional marketing strategies in informal markets, that is, with characteristics of intuition, improvisation and lawlessness. Remarkably, these marketing strategies have shown good sales results, highlighting the following question: What kind of marketing is that which is not in the handbooks of marketing and is overlooked by leading authors in the field? Considering this problem, this study aims to propose an explanatory model for this “marketing” phenomenon, theoretically grounded and within empirical basis, in the light of theories that address the psychological makeup of the Brazilian Jeitinho, the culture of informality and Entrepreneurship. Thus, we propose a concept that fills a gap over the traditional marketing theories existing. 

  20. Imaging-Based Screen Identifies Laminin 411 as a Physiologically Relevant Niche Factor with Importance for i-Hep Applications

    Directory of Open Access Journals (Sweden)

    John Ong

    2018-03-01

    Full Text Available Summary: Use of hepatocytes derived from induced pluripotent stem cells (i-Heps is limited by their functional differences in comparison with primary cells. Extracellular niche factors likely play a critical role in bridging this gap. Using image-based characterization (high content analysis; HCA of freshly isolated hepatocytes from 17 human donors, we devised and validated an algorithm (Hepatocyte Likeness Index; HLI for comparing the hepatic properties of cells against a physiological gold standard. The HLI was then applied in a targeted screen of extracellular niche factors to identify substrates driving i-Heps closer to the standard. Laminin 411, the top hit, was validated in two additional induced pluripotent stem cell (iPSC lines, primary tissue, and an in vitro model of α1-antitrypsin deficiency. Cumulatively, these data provide a reference method to control and screen for i-Hep differentiation, identify Laminin 411 as a key niche protein, and underscore the importance of combining substrates, soluble factors, and HCA when developing iPSC applications. : Rashid and colleagues demonstrate the utility of a high-throughput imaging platform for identification of physiologically relevant extracellular niche factors to advance i-Heps closer to their primary tissue counterparts. The extracellular matrix (ECM protein screen identified Laminin 411 as an important niche factor facilitating i-Hep-based disease modeling in vitro. Keywords: iPS hepatocytes, extracellular niche, image-based screening, disease modeling, laminin