3,091 research outputs found
Principal 2-bundles and their gauge 2-groups
In this paper we introduce principal 2-bundles and show how they are
classified by non-abelian Cech cohomology. Moreover, we show that their gauge
2-groups can be described by 2-group-valued functors, much like in classical
bundle theory. Using this, we show that, under some mild requirements, these
gauge 2-groups possess a natural smooth structure. In the last section we
provide some explicit examples.Comment: 40 pages; v3: completely revised and extended, classification
corrected, name changed, to appear in Forum Mat
Big Data in Maritime Archaeology: Challenges and Prospects from the Middle East and North Africa
The Middle East and North Africa have witnessed a surfeit of geospatial data collection projects, resulting in big databases with powerful deductive capacities. Despite the valuable insights and expansive evidentiary record offered by those databases, emphasis on anthropogenic threats to cultural heritage, combined with a limited integration of local perspectives, have raised important questions on the ethical and epistemological dimensions of big data. This paper contextualizes maritime cultural heritage (MCH) in those debates through the lens of the Maritime Endangered Archaeology in the Middle East and North Africa project (MarEA). MarEA is developing a unique for the region database for MCH designed to amalgamate a baseline record emphasizing spatial location, state of preservation, and vulnerability. This record will form a stepping stone toward finer-grained research on MCH and its interdisciplinary intersections. It is also developed as an information resource to facilitate local collaborators in prioritizing site monitoring and developing documentation, management, and mitigation strategies
The amyloidogenic potential and behavioral correlates of stress
Observations of elevated basal cortisol levels in Alzheimer's disease (AD) patients prompted the hypothesis that stress and glucocorticoids (GC) may contribute to the development and/or maintenance of AD. Consistent with that hypothesis, we show that stress and GC provoke misprocessing of amyloid precursor peptide in the rat hippocampus and prefrontal cortex, resulting in increased levels of the peptide C-terminal fragment 99 (C99), whose further proteolytic cleavage results in the generation of amyloid-beta (Abeta). We also show that exogenous Abeta can reproduce the effects of stress and GC on C99 production and that a history of stress strikingly potentiates the C99-inducing effects of Abeta and GC. Previous work has indicated a role for Abeta in disruption of synaptic function and cognitive behaviors, and AD patients reportedly show signs of heightened anxiety. Here, behavioral analysis revealed that like stress and GC, Abeta administration causes spatial memory deficits that are exacerbated by stress and GC; additionally, Abeta, stress and GC induced a state of hyperanxiety. Given that the intrinsic properties of C99 and Abeta include neuroendangerment and behavioral impairment, our findings suggest a causal role for stress and GC in the etiopathogenesis of AD, and demonstrate that stressful life events and GC therapy can have a cumulative impact on the course of AD development and progression.CC and IS were supported by
stipends from the Max Planck Society and EU Marie
Curie Training Fellowships (at University College
London, UK). The collaboration between the German
and Portuguese laboratories was supported through
the German–Portuguese Luso-Alemas Program
(DAAD/GRICES). This study was conducted within
the framework of the EU-supported integrated project
‘CRESCENDO’ (Contract FP6-018652)
Survey sequencing and radiation hybrid mapping to construct comparative maps.
In MURPHY WJ (ed.) Phylogenomics, Humana Press. (Methods in Molecular Biology, 422)International audienceRadiation hybrid (RH) mapping has become one of the most well-established techniques for economically and efficiently navigating genomes of interest. The success of the technique relies on random chromosome breakage of a target genome, which is then captured by recipient cells missing a preselected marker. Selection for hybrid cells that have DNA fragments bearing the marker of choice, plus a random set of DNA fragments from the initial irradiation, generates a set of cell lines that recapitulates the genome of the target organism several-fold. Markers or genes of interest are analyzed by PCR using DNA isolated from each cell line. Statistical tools are applied to determine both the linear order of markers on each chromosome, and the confidence of each placement. The resolution of the resulting map relies on many factors, most notably the degree of breakage from the initial radiation as well as the number of hybrid clones and mean retention value.A high-resolution RH map of a genome derived from low pass or survey sequencing (coverage from 1 to 2 times) can provide essentially the same comparative data on gene order that is derived from high-coverage (greater than x7) genome sequencing. When combined with fluorescence in situ hybridization, RH maps are complete and ordered blueprints for each chromosome. They give information about the relative order and spacing of genes and markers, and allow investigators to move between target and reference genomes, such as those of mouse or human, with ease although the approach is not limited to mammal genomes
Big Data in Maritime Archaeology: Challenges and Prospects from the Middle East and North Africa
The Middle East and North Africa have witnessed a surfeit of geospatial data collection projects, resulting in big databases with powerful deductive capacities. Despite the valuable insights and expansive evidentiary record offered by those databases, emphasis on anthropogenic threats to cultural heritage, combined with a limited integration of local perspectives, have raised important questions on the ethical and epistemological dimensions of big data. This paper contextualizes maritime cultural heritage (MCH) in those debates through the lens of the Maritime Endangered Archaeology in the Middle East and North Africa project (MarEA). MarEA is developing a unique for the region database for MCH designed to amalgamate a baseline record emphasizing spatial location, state of preservation, and vulnerability. This record will form a stepping stone toward finer-grained research on MCH and its interdisciplinary intersections. It is also developed as an information resource to facilitate local collaborators in prioritizing site monitoring and developing documentation, management, and mitigation strategies.</p
-Algebras, the BV Formalism, and Classical Fields
We summarise some of our recent works on -algebras and quasi-groups
with regard to higher principal bundles and their applications in twistor
theory and gauge theory. In particular, after a lightning review of
-algebras, we discuss their Maurer-Cartan theory and explain that any
classical field theory admitting an action can be reformulated in this context
with the help of the Batalin-Vilkovisky formalism. As examples, we explore
higher Chern-Simons theory and Yang-Mills theory. We also explain how these
ideas can be combined with those of twistor theory to formulate maximally
superconformal gauge theories in four and six dimensions by means of
-quasi-isomorphisms, and we propose a twistor space action.Comment: 19 pages, Contribution to Proceedings of LMS/EPSRC Durham Symposium
Higher Structures in M-Theory, August 201
Maritime Cultural Heritage and Urbanisation in the Middle East and North Africa
Urbanisation, comprising development, land reclamation and
population growth along coastal margins, continues to place significant pressure on the maritime cultural heritage (MCH), particularly in the Middle East and North Africa (MENA) region. Thus, there
is a growing need for ascertaining the extent of the affected MCH
resource and its condition. One such assessment is being undertaken by the Maritime Endangered Archaeology (MarEA) project,
which is generating a unique informed database of the maritime
resource in the MENA region. Through a regional overview combined with focused assessment on two case studies – Marsa Matruh
(Egypt) and Bahrain – this paper demonstrates the threat urbanisation poses and the damage it has inflicted on MCH. The analyses
and documentation that MarEA produces via remote sensing, deskbased and field-based assessments, constitutes a valuable resource
that, at the very least, exists in digital perpetuity. It establishes
a record that can be drawn upon to formulate targeted strategies
and initiatives inclusive of the maritime cultural heritage resource
Invitation to grief in the family context
Grief is a family affair, yet it is commonly viewed as an individual phenomenon. As an international, interdisciplinary team, we explore grief within a family context across theoretical, research, practice, and educational domains. Families are complex and working with this complexity is challenging but necessary for a holistic view of grief. We therefore encourage an increased focus on theorizing, researching, practicing, and educating using innovative approaches to address the complexities of grief within the context of families. Learnings from within each domain will affirm and enhance the development of family-level thinking and approaches
Road safety management capacity review
Introduction
Study Context
Following on from the government’s manifesto to an annual reduction in road deaths and injuries, the
British Road Safety Statement 2015 (BRSS) set out the government’s commitment to invest further in
continuing road safety activity, and to conduct a Road Safety Management Capacity Review (RSMCR).
A RSMCR is a strategic assessment, benchmarking and capacity building tool, originally developed by
the World Bank's Global Road Safety Facility, to guide investments and assist countries in
strengthening road safety management. It is recommended for use by the OECD/International
Transport Forum and the World Road Association as a first step in further developing and extending
effective Safe System investment strategies, plans and projects in all countries and contexts.
In May 2017, the DfT commissioned a RSMCR to benchmark and understand the current status of
institutional delivery of road safety in Britain, and to identify practical and actionable opportunities for
strengthening joint working, local innovation, and efficiency on a national and local basis.
Safe System
The overarching theme of the BRSS is the government’s adoption of the recommended Safe System
approach to preventing death and serious injuries in road collisions. Its application is cited as a key
national priority in the UK. While building on current practice, some re-alignment in national road
safety focus and activity will be necessary over time. Safe System implementation towards zero deaths
and serious injuries is a long-term project and is in different stages of development in different
countries and jurisdictions.
Safe System comprises both an explicit goal and strategy. The long-term Safe System goal is for the
ultimate prevention of deaths and serious injuries, through incremental targeted improvements within
a specified safety performance framework. The Safe System strategy aims for a more forgiving road
system that takes human fallibility and vulnerability into account. The road traffic system is planned,
designed, operated and used such that people are protected from death and serious injury in road
collisions.
Aims and Objectives of the Review
The overarching aim of the RSMCR is to identify practical and actionable opportunities for
strengthening joint working, local innovation, and efficiency on a national and local basis. In particular
the RSMCR seeks to understand the current status of institutional delivery of road safety in Britain by:
Examining national, regional and local structures, responsibilities, accountabilities, relationships
and coordination;
Examining whether management effort and resources at all levels are being targeted effectively
at designing, and enabling or delivering evidence-based interventions and initiatives that can
have the greatest impact in preventing and reducing the number of road users killed and
seriously injured;
Assessing the current road safety delivery landscape against the Safe System road safety
management assessment framework and determining whether there is an imbalance in
resource effort for each element and at each level (national, regional and local);
Investigating how institutional capacity can be cost-effectively strengthened, within the context
of the BRSS, to deliver a Safe System approach to road safety; and
Identifying areas and means for improved joint working, local innovation and efficiency
Maritime endangered archaeology of the Middle East and North Africa: the MarEA project
The ‘Maritime Endangered Archaeology’ (MarEA) project is conducting remote, large-scale identification and assessment of vulnerable maritime heritage to assist in its management in the face of challenges such as climate change and rapid urbanisation
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