Reality and causality in quantum gravity modified electrodynamics

We present a general description of the propagation properties of quantum gravity modified electrodynamics characterized by constitutive relations up to second order in the correction parameter. The effective description corresponds to an electrodynamics in a dispersive and absorptive non-local medium, where the Green functions and the refraction indices can be explicitly calculated. The reality of the electromagnetic field together with the requirement of causal propagation in a given referrence frame leads to restrictions in the form of such refraction indices. In particular, absorption must be present in all cases and, contrary to the usual assumption, it is the dominant aspect in those effective models which exhibit linear effects in the correction parameter not related to birefringence. In such a situation absorption is linear while propagation is quadratical in the correction parameter.Comment: 15 pages, LaTex, minor changes to clarify some points, version accepted for publicatio

Weakly Z symmetric manifolds

We introduce a new kind of Riemannian manifold that includes weakly-, pseudo- and pseudo projective- Ricci symmetric manifolds. The manifold is defined through a generalization of the so called Z tensor; it is named "weakly Z symmetric" and denoted by (WZS)_n. If the Z tensor is singular we give conditions for the existence of a proper concircular vector. For non singular Z tensor, we study the closedness property of the associated covectors and give sufficient conditions for the existence of a proper concircular vector in the conformally harmonic case, and the general form of the Ricci tensor. For conformally flat (WZS)_n manifolds, we derive the local form of the metric tensor.Comment: 13 page

A cross-country review of strategies of the German development cooperation to strengthen human resources

ABSTRACT: BACKGROUND: Recent years have seen growing awareness of the importance of human resources for health in health systems and with it an intensifying of the international and national policies in place to steer a response. This paper looks at how governments and donors in five countries - Cameroon, Indonesia, Malawi, Rwanda and Tanzania - have translated such policies into action. More detailed information with regard to initiatives of German development cooperation brings additional depth to the range and entry doors of human resources for health initiatives from the perspective of donor cooperation. METHODS: This qualitative study systematically presents different approaches and stages to human resources for health development in a cross-country comparison. An important reference to capture implementation at country level was grey literature such as policy documents and programme reports. In-depth interviews along a predefined grid with national and international stakeholders in the five countries provided information on issues related to human resources for health policy processes and implementation. RESULTS: All five countries have institutional entities in place and have drawn up national policies to address human resources for health. Only some of the countries have translated policies into strategies with defined targets and national programmes with budgets and operational plans. Traditional approaches of supporting training for individual health professionals continue to dominate. In some cases partners have played an advocacy and technical role to promote human resources for health development at the highest political levels, but usually they still focus on the provision of ad hoc training within their programmes, which may not be in line with national human resources for health development efforts or may even be counterproductive to them. Countries that face an emergency, such as Malawi, have intensified their efforts within a relatively short time and by using donor funding support also through new initiatives such as the Global Fund to Fight AIDS, Tuberculosis and Malaria. CONCLUSIONS: The country case studies illustrate the range of initiatives that have surged in recent years and some main trends in terms of donor initiatives. Though attention and priority attributed to human resources for health is increasing, there is still a focus on single initiatives and programmes. This can be explained in part by the complexity of the issue, and in part by its need to be addressed through a long-term approach including public sector and salary reforms that go beyond the health secto

DESIGN-DRIVEN INNOVATION: AVANT GARDE 50M SUPERYACHT UNDER 500GT

The reduced regulatory framework for superyachts under 500GT offers a significant opportunity for a greater percentage of interior volume to be assigned to guest activities, due to a reduction in both crew area requirements and fire insulation and the absence of certain requirements such as an emergency generator. There has been growth in the value of the superyacht charter market in recent years, with the 30m-50m segment representing 58% of the market in 2013. In 2012 33% of the World's superyachts were delivered to Europe with Loa averaging 42.5m. Therefore, there is market opportunity for a privately owned yacht built with consideration to generate the maximum possible income when chartered. Clients expect to have their emotional needs fulfilled to elicit feelings of luxury and pleasure. The design challenge here is to address the cultural specificities of luxury for a range of potential charter clients. Adaptability of space is critical to facilitate a range of user activities through optimising the reduced space is the sub 500GT segment. This paper presents a design proposal which engages in Design-Driven Innovation, resulting in an avant garde vessel, which effectively engages in a range of roles through the use of transformable interior space, which has a reconfigurable layout combined with a highly adaptable exterior space. This is in contrast to current designs, which tend to have a linear approach to the usability of a vessel through elements that can add valuable extra client space, such as platforms that unfurl. Due to the sub 500GT interior volume being stretched over 50 m, the resulting superstructure is sleek and well proportioned. The styling is fluid and biomimetic, resulting in an elegant dynamic form, which is in contrast to the more architectural forms of contemporary vessels. Due to the vast amounts of exterior space it is aimed at the high net worth owner who prefers to cruise the warmer climates such as the Mediterranean, resulting in a yacht more suited to outdoor leisure usage. The sundeck canopy is a biomimetic design feature, which is partly constructed from ETFE. This facilitates Passive Design implementation through the heating effect of air trapped in the leaf like structure, which promotes the stack effect air flow from the interior, reducing the HVAC load. The design proposal addresses the sustainable luxury agenda through the implementation of Passive Design, and the use of a transformable interior layout to achieve a high degree of space utilisation, thus providing a range of user activities emulating the experience of a larger vessel

DESIGN-DRIVEN INNOVATION: AVANT GARDE 50M SUPERYACHT UNDER 500GT

The reduced regulatory framework for superyachts under 500GT offers a significant opportunity for a greater percentage of interior volume to be assigned to guest activities, due to a reduction in both crew area requirements and fire insulation and the absence of certain requirements such as an emergency generator. There has been growth in the value of the superyacht charter market in recent years, with the 30m-50m segment representing 58% of the market in 2013. In 2012 33% of the World's superyachts were delivered to Europe with Loa averaging 42.5m. Therefore, there is market opportunity for a privately owned yacht built with consideration to generate the maximum possible income when chartered. Clients expect to have their emotional needs fulfilled to elicit feelings of luxury and pleasure. The design challenge here is to address the cultural specificities of luxury for a range of potential charter clients. Adaptability of space is critical to facilitate a range of user activities through optimising the reduced space is the sub 500GT segment. This paper presents a design proposal which engages in Design-Driven Innovation, resulting in an avant garde vessel, which effectively engages in a range of roles through the use of transformable interior space, which has a reconfigurable layout combined with a highly adaptable exterior space. This is in contrast to current designs, which tend to have a linear approach to the usability of a vessel through elements that can add valuable extra client space, such as platforms that unfurl. Due to the sub 500GT interior volume being stretched over 50 m, the resulting superstructure is sleek and well proportioned. The styling is fluid and biomimetic, resulting in an elegant dynamic form, which is in contrast to the more architectural forms of contemporary vessels. Due to the vast amounts of exterior space it is aimed at the high net worth owner who prefers to cruise the warmer climates such as the Mediterranean, resulting in a yacht more suited to outdoor leisure usage. The sundeck canopy is a biomimetic design feature, which is partly constructed from ETFE. This facilitates Passive Design implementation through the heating effect of air trapped in the leaf like structure, which promotes the stack effect air flow from the interior, reducing the HVAC load. The design proposal addresses the sustainable luxury agenda through the implementation of Passive Design, and the use of a transformable interior layout to achieve a high degree of space utilisation, thus providing a range of user activities emulating the experience of a larger vessel