Sustainable intensification of agriculture is one of the main strategies to provide global food security. However, its implementation raises enormous political, technological, and social challenges. ...Meeting these challenges will require, among other things, accurate information on the spatial and temporal patterns of agricultural land use and yield. Here, we investigate historical patterns of agricultural land use (1940–2012) and productivity (1990–2012) in Brazil using a new high‐resolution (approximately 1 km2) spatially explicit reconstruction. Although Brazilian agriculture has been historically known for its extensification over natural vegetation (Amazon and Cerrado), data from recent years indicate that extensification has slowed down and was replaced by a strong trend of intensification. Our results provide the first comprehensive historical overview of agricultural land use and productivity in Brazil, providing clear insights to guide future territorial planning, sustainable agriculture, policy, and decision‐making.
Summary
Trait‐based approaches are increasingly being used to test mechanisms underlying species assemblages and biotic interactions across a wide range of organisms including terrestrial arthropods ...and to investigate consequences for ecosystem processes. Such an approach relies on the standardized measurement of functional traits that can be applied across taxa and regions. Currently, however, unified methods of trait measurements are lacking for terrestrial arthropods and related macroinvertebrates (terrestrial invertebrates hereafter).
Here, we present a comprehensive review and detailed protocol for a set of 29 traits known to be sensitive to global stressors and to affect ecosystem processes and services. We give recommendations how to measure these traits under standardized conditions across various terrestrial invertebrate taxonomic groups.
We provide considerations and approaches that apply to almost all traits described, such as the selection of species and individuals needed for the measurements, the importance of intraspecific trait variability, how many populations or communities to sample and over which spatial scales.
The approaches outlined here provide a means to improve the reliability and predictive power of functional traits to explain community assembly, species diversity patterns and ecosystem processes and services within and across taxa and trophic levels, allowing comparison of studies and running meta‐analyses across regions and ecosystems.
This handbook is a crucial first step towards standardizing trait methodology across the most studied terrestrial invertebrate groups, and the protocols are aimed to balance general applicability and requirements for special cases or particular taxa. Therefore, we envision this handbook as a common platform to which researchers can further provide methodological input for additional special cases.
A lay summary is available for this article.
Lay Summary
The diagnosis of periodontal disease is commonly based on objective evaluations of the patient's medical/dental history as well as clinical and radiographic examinations. However, periodontal disease ...should also be evaluated subjectively through measures that quantify its impact on oral health‐related quality of life. The aim of this study was to evaluate the impact of periodontal disease on quality of life among adolescents, adults and older adults. A systematic search of the literature was performed for scientific articles published up to July 2015 using electronic databases and a manual search. Two independent reviewers performed the selection of the studies, extracted the data and assessed the methodological quality. Thirty‐four cross‐sectional studies involving any age group, except children, and the use of questionnaires for the assessment of the impact of periodontal disease on quality of life were included. Twenty‐five studies demonstrated that periodontal disease was associated with a negative impact on quality of life, with severe periodontitis exerting the most significant impact by compromising aspects related to function and esthetics. Unlike periodontitis, gingivitis was associated with pain as well as difficulties performing oral hygiene and wearing dentures. Gingivitis was also negatively correlated with comfort. The results indicate that periodontal disease may exert an impact on quality of life of individuals, with greater severity of the disease related to greater impact. Longitudinal studies with representative samples are needed to ensure validity of the findings.
A
bstract
Black holes in anti-de Sitter (AdS) backgrounds play a pivotal role in the gauge/gravity duality where they determine, among other things, the approach to equilibrium of the dual field ...theory. We undertake a detailed analysis of perturbed Kerr-AdS black holes in four- and five-dimensional spacetimes, including the computation of its quasinormal modes, hydrodynamic modes and superradiantly unstable modes. Our results shed light on the possibility of new black hole phases with a single Killing field, possible new holographic phenomena and phases in the presence of a rotating chemical potential, and close a crucial gap in our understanding of linearized perturbations of black holes in anti-de Sitter scenarios.
A
bstract
It has been argued that the strong cosmic censorship conjecture is violated by Reissner-Nordström-de Sitter black holes: for near-extremal black holes, generic scalar field perturbations ...arising from smooth initial data have finite energy at the Cauchy horizon even though they are not continuously differentiable there. In this paper, we consider the analogous problem for coupled gravitational and electromagnetic perturbations. We find that such perturbations exhibit a much worse violation of strong cosmic censorship: for a sufficiently large near-extremal black hole, perturbations arising from smooth initial data can be extended through the Cauchy horizon in an arbitrarily smooth way. This is in apparent contradiction with an old argument in favour of strong cosmic censorship. We resolve this contradiction by showing that this old argument is valid only for initial data that is not smooth. This is in agreement with the recent proposal that, to recover strong cosmic censorship, one must allow rough initial data.
A
bstract
The frequency spectra of the gravito-electromagnetic perturbations of the Kerr-Newman (KN) black hole with the slowest decay rate have been computed recently. It has been found that KN has ...two families — the photon sphere and the near-horizon families — of quasinormal modes (QNMs), which display the interesting phenomenon of eigenvalue repulsion. The perturbation equations, in spite of being a coupled system of two PDEs, are amenable to an analytic solution using the method of separation of variables in a near-horizon expansion around the extremal KN black hole. This leads to an analytical formula for the QNM frequencies that provides an excellent approximation to the numerical data near-extremality. In the present manuscript we provide an extended study of these properties that were not detailed in the original studies. This includes: 1) a full derivation of a gauge invariant system of two coupled PDEs that describes the perturbation equations
1
, 2) a derivation of the eikonal frequency approximation
2
,
3
and its comparison with the numerical QNM data, 3) a derivation of the near-horizon frequency approximation
3
and its comparison with the numerical QNMs, and 4) more details on the phenomenon of eigenvalue repulsion (also known as
level repulsion
,
avoided crossing
or
Wigner-Teller effect
) and a first principles understanding of it that was missing in the previous studies. Moreover, we provide the frequency spectra of other KN QNM families of interest to demonstrate that they are more damped than the ones we discuss in full detail.
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