Showing 1221 - 1230 of 2039 Items
Scattering equations and virtuous kinematic numerators and dual-trace functions
Date: 2014-01-01
Creator: Stephen G. Naculich
Access: Open access
- Inspired by recent developments on scattering equations, we present a constructive procedure for computing symmetric, amplitude-encoded, BCJ numerators for n-point gauge-theory amplitudes, thus satisfying the three virtues identified by Broedel and Carrasco. We also develop a constructive procedure for computing symmetric, amplitude-encoded dual-trace functions τ for n-point amplitudes. These can be used to obtain symmetric kinematic numerators that automatically satisfy color-kinematic duality. The S n symmetry of n-point gravity amplitudes formed from these symmetric dual-trace functions is completely manifest. Explicit expressions for four- and five-point amplitudes are presented. © 2014 The Author(s).
Statement by Denise Altvater on November 20, 2013
Date: 2013-11-20
Creator: Denise Altvater
Access: Open access
Statement by Margaret Semple collected by Rachel George on January 16, 2015
Date: 2015-01-16
Creator: Margaret Semple
Access: Open access
Statement by Michael Augustine collected by Rachel George on November 17, 2014
Date: 2014-11-17
Creator: Michael Augustine
Access: Open access
Large-scale chromosomal changes and associated fitness consequences in pathogenic fungi
Date: 2014-01-01
Creator: Anja Forche
Access: Open access
- Pathogenic fungi encounter many different host environments to which they must adapt rapidly to ensure growth and survival. They also must be able to cope with alterations in established niches during long-term persistence in the host. Many eukaryotic pathogens have evolved a highly plastic genome, and large-scale chromosomal changes including aneuploidy, and loss of heterozygosity (LOH) can arise under various in vitro and in vivo stresses. Both aneuploidy and LOH can arise quickly during a single cell cycle, and it is hypothesized that they provide a rapid, albeit imprecise, solution to adaptation to stress until better and more refined solutions can be acquired by the organism. While LOH, with the extreme case of haploidization in Candida albicans, can purge the genome from recessive lethal alleles and/or generate recombinant progeny with increased fitness, aneuploidy, in the absence or rarity of meiosis, can serve as a non-Mendelian mechanism for generating genomic variation. © Springer Science+Business Media 2014.
Glycans in pathogenic bacteria - potential for targeted covalent therapeutics and imaging agents
Date: 2014-04-08
Creator: Van N. Tra
Danielle H. Dube
Access: Open access
- A substantial obstacle to the existing treatment of bacterial diseases is the lack of specific probes that can be used to diagnose and treat pathogenic bacteria in a selective manner while leaving the microbiome largely intact. To tackle this problem, there is an urgent need to develop pathogen-specific therapeutics and diagnostics. Here, we describe recent evidence that indicates distinctive glycans found exclusively on pathogenic bacteria could form the basis of targeted therapeutic and diagnostic strategies. In particular, we highlight the use of metabolic oligosaccharide engineering to covalently deliver therapeutics and imaging agents to bacterial glycans. © 2014 The Partner Organisations.
islet reveals segmentation in the amphioxus hindbrain homolog
Date: 2000-04-01
Creator: William R. Jackman
James A. Langeland
Charles B. Kimmel
Access: Open access
- The vertebrate embryonic hindbrain is segmented into rhombomeres. Gene expression studies suggest that amphioxus, the closest invertebrate relative of vertebrates, has a hindbrain homolog. However, this region is not overtly segmented in amphioxus, raising the question of how hindbrain segmentation arose in chordate evolution. Vertebrate hindbrain segmentation includes the patterning of cranial motor neurons, which can be identified by their expression of the LIM-homeodomain transcription factor islet1. To learn if the amphioxus hindbrain homolog is cryptically segmented, we cloned an amphioxus gene closely related to islet1, which we named simply islet. We report that amphioxus islet expression includes a domain of segmentally arranged cells in the ventral hindbrain homolog. We hypothesize that these cells are developing motor neurons and reveal a form of hindbrain segmentation in amphioxus. Hence, vertebrate rhombomeres may derive from a cryptically segmented brain present in the amphioxus/vertebrate ancestor. Other islet expression domains provide evidence for amphioxus homologs of the pineal gland, adenohypophysis, and endocrine pancreas. Surprisingly, homologs of vertebrate islet1-expressing spinal motor neurons and Rohon-Beard sensory neurons appear to be absent. (C) 2000 Academic Press.
Invisible Women: Entrepreneurship, Innovation, and Family Firms in Nineteenth-Century France
Date: 2016-02-25
Creator: B. Zorina Khan
Access: Open access
- The French economy has been criticized for a lack of integration of women in business and for the prevalence of inefficient family firms. A sample drawn from patent and exhibition records is used to examine the role of women in enterprise and invention in France. Middle-class women were extensively engaged in entrepreneurship and innovation, and the empirical analysis indicates that their commercial efforts were significantly enhanced by association with family firms. Such formerly invisible achievements suggest a more productive role for family-based enterprises, as a means of incorporating relatively disadvantaged groups into the market economy as managers and entrepreneurs. This business model .... melds entrepreneurial passion with a long family tradition. - Wendel Company (1704-2014) 1
Oil Extraction and Benefit Sharing in an Illiberal Context: The Nenets and Komi-Izhemtsi Indigenous Peoples in the Russian Arctic
Date: 2018-05-04
Creator: Maria Tysiachniouk
Laura A. Henry
Machiel Lamers
Jan P.M. van Tatenhove
Access: Open access
- How can indigenous communities in illiberal regimes benefit from oil production? This paper compares the experience of two indigenous peoples in the Russian Arctic, the Nenets and the Komi-Izhemtsi, in their quest for environmental protection and the development of benefit-sharing arrangements with Lukoil, a Russian oil company. The Nenets people, recognized by the Russian state as indigenous, are marginalized political actors who identified a route to receiving compensation for loss of land and damage to the environment as well as economic benefits under the auspices of Russian law and Lukoil’s corporate policies. In contrast, the Komi-Izhemtsi, despite indigenous status in global institutions including the United Nations and the Arctic Council, are unrecognized as indigenous domestically and initially received no compensation. Their path to benefit sharing was more challenging as they partnered with local nongovernmental organizations and global environmentalists to pressure Lukoil to sign a benefit-sharing agreement. Ultimately, the comparison illustrates how transnational partnerships can empower indigenous people to gain benefits from natural resource exploitation even in illiberal political systems.
Oil and indigenous people in sub-Arctic Russia: Rethinking equity and governance in benefit sharing agreements
Date: 2018-03-01
Creator: Maria Tysiachniouk
Laura A. Henry
Machiel Lamers
Jan P.M. van Tatenhove
Access: Open access
- How can the interests of extractive industries and indigenous communities in the Arctic be balanced through benefit sharing policies? This paper analyses how the international oil consortia of Sakhalin Energy and Exxon Neftegaz Limited (ENL) on Sakhalin Island in Russia have introduced benefit sharing through tripartite partnerships. We demonstrate that the procedural and distributional equity of benefit sharing depend on corporate policies, global standards, pressure from international financial institutions, and local social movements connected in a governance generating network. Sakhalin Energy was profoundly influenced by international financial institutions’ global rules related to environmental and indigenous people's interests. The benefit sharing arrangement that evolved under these influences resulted in enhanced procedural equity for indigenous people, but has not prevented conflict with and within communities. In contrast, ENL was not significantly influenced by international financial institutions. Its more flexible and limited benefit sharing arrangement was shaped predominantly by global corporate policies, pressure from the regional government and the influence of Sakhalin Energy's model. The paper closes with policy recommendations on benefit sharing arrangements between extractive industries and indigenous communities across Arctic states that could be further developed by the Arctic Council Sustainable Development Working Group.