Soil properties of bare patches in rangelands of South African's grasslands

A loss of grassy cover accompanied by the development of bare soil patches, are the most notable forms of rangeland degradation in grasslands of South Africa. Concerns are growing over the threat of loss of nutritious perennial grass species and the lack of regrowth of the bare patches. Grazing and different rangeland tenure systems -communal and freehold, which is equal to continuous and rotational grazing system - are considered to be of major importance for rangeland degradation. The continuous grazing system is seen to be more affected, but the development of bare patches is not restricted to communal land. We hypothesized that (1) soil properties of bare patches in South Africa´s grasslands are not different in different tenure systems, and (2) soil properties differ with size of bare patches, where big patches are more degraded. To test this, we sampled soils at communal and commercial land in the Thaba Nchu area of South Africa with the following design: we selected three farms per tenure system, 6 randomly chosen plots (100x100m) per farm, and within these plots we sampled 5 bare patches of different sizes (0-10 cm) per plot, where the soil sample (3 replicates) were taken out of the middle of the bare patch. Additionally, soils of adjacent grass were sampled. The results showed that in total, there were more bare patches in continuous grazing systems, evaluated by aerial pictures, but we couldn´t find any differences in bulk density and carbon stocks, between the tenure systems. Additionally, and surprisingly, we found no significant differences in soil organic carbon stocks between bare soil samples and grass samples. There was no clear relationship between bare patch size and nutrient contents. Other nutrients like phosphor were significantly enlarged at the bare patch compared to the grass samples. According to our results, we conclude, that the bare patches seem to develop in different pathways: i) along tracks of grazing animals, (ii) around termite hills, where the termite construction seems to be an initial starting point of bare patches and (iii) on staying and lying places of the grazing animals, which aslo explain the higher nutrient contents at the bare patches

Earth System Law

The existing body of international environmental law has been created in the context of a relatively stable and harmonious Holocene epoch. This assumed regulatory premise of Holocene stability and harmony has resulted in a collection of international environmental law norms that are unable to sufficiently address the governance challenges emanating from within the context of the Anthropocene’s complex, unstable, unpredictable, and intertwined earth system. Earth system law has recently been proposed as an alternative vision for international environmental law in the Anthropocene. Earth system law is intended to serve as an imaginative framework that can guide innovative questions regarding the difficulties posed to international environmental law in responding to the complex challenges of earth system governance, and as a roadmap for international environmental law to better address these challenges on an appropriate planetary level in the Anthropocene

Collectivity, Phase Transitions and Exceptional Points in Open Quantum Systems

Phase transitions in open quantum systems, which are associated with the formation of collective states of a large width and of trapped states with rather small widths, are related to exceptional points of the Hamiltonian. Exceptional points are the singularities of the spectrum and eigenfunctions, when they are considered as functions of a coupling parameter. In the present paper this parameter is the coupling strength to the continuum. It is shown that the positions of the exceptional points (their accumulation point in the thermodynamical limit) depend on the particular type and energy dependence of the coupling to the continuum in the same way as the transition point of the corresponding phase transition.Comment: 22 pages, 4 figure

[89Zr]Oxinate4 for long-term in vivo cell tracking by positron emission tomography

Purpose 111In (typically as [111In]oxinate3) is a gold standard radiolabel for cell tracking in humans by scintigraphy. A long half-life positron-emitting radiolabel to serve the same purpose using positron emission tomography (PET) has long been sought. We aimed to develop an 89Zr PET tracer for cell labelling and compare it with [111In]oxinate3 single photon emission computed tomography (SPECT). Methods [89Zr]Oxinate4 was synthesised and its uptake and efflux were measured in vitro in three cell lines and in human leukocytes. The in vivo biodistribution of eGFP-5T33 murine myeloma cells labelled using [89Zr]oxinate4 or [111In]oxinate3 was monitored for up to 14 days. 89Zr retention by living radiolabelled eGFP-positive cells in vivo was monitored by FACS sorting of liver, spleen and bone marrow cells followed by gamma counting. Results Zr labelling was effective in all cell types with yields comparable with 111In labelling. Retention of 89Zr in cells in vitro after 24 h was significantly better (range 71 to >90 %) than 111In (43–52 %). eGFP-5T33 cells in vivo showed the same early biodistribution whether labelled with 111In or 89Zr (initial pulmonary accumulation followed by migration to liver, spleen and bone marrow), but later translocation of radioactivity to kidneys was much greater for 111In. In liver, spleen and bone marrow at least 92 % of 89Zr remained associated with eGFP-positive cells after 7 days in vivo. Conclusion [89Zr]Oxinate4 offers a potential solution to the emerging need for a long half-life PET tracer for cell tracking in vivo and deserves further evaluation of its effects on survival and behaviour of different cell types

A critique of the Global Pact for the Environment: A stillborn initiative or the foundation for Lex Anthropocenae?

In May 2018 the process which may ultimately lead to the negotiation of a legally binding Global Pact for the Environment formally commenced under the auspices of the United Nations General Assembly. Expectations for the Pact are high, evidenced in particular by its multiple and overlapping objectives: to serve as a generic binding instrument of international environmental law (IEL) principles ; to integrate, consolidate, unify and ultimately entrench many of the fragmented principles of IEL; and to constitute the first global environmental human rights instrument. In the wake of the impending intergovernmental process, the paper offers a thorough critique of the draft Pact in its present iteration. We do so with the aim of evaluating the strengths and weaknesses of the present draft Pact by interrogating: a) its diplomatic and symbolic relevance and possible unique contribution at the policy level to global environmental law and governance; and b) its potential at the operational level of IEL and global environmental governance, focusing on the extent to which the draft Pact accommodates both existing and more recent rules and principles for environmental protection. As the Pact’s primary ambition is to become a universally binding global treaty, it would be churlish not to recognise its potential for innovation, as well as the considerable opportunity that the negotiation of the Pact will have to generate broad-sweeping and positive impacts. However, our central thesis is that only if the Global Pact were to incorporate ambitious normative provisions to strengthen those public and private global governance efforts that aim to halt the deterioration of Earth system integrity, as well as to maintain and improve integrity, will it be able to offer a firm foundation of the type of Anthropocene Law, termed here as the Lex Anthropocenae, required to confront head-on the deep socio-ecological crisis of the Anthropocene