ORCID Profile
0000-0002-8941-6031
Current Organisations
IT University of Copenhagen
,
ETH Zurich
,
Tianjin University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Springer Science and Business Media LLC
Date: 25-07-2012
DOI: 10.1038/NATURE11318
Abstract: The rapid disruption of tropical forests probably imperils global bio ersity more than any other contemporary phenomenon. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses. As pressures mount, it is vital to know whether existing reserves can sustain their bio ersity. A critical constraint in addressing this question has been that data describing a broad array of bio ersity groups have been unavailable for a sufficiently large and representative s le of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions. Our analysis reveals great variation in reserve ‘health’: about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of bio ersity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious bio ersity declines.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-06-2020
Abstract: Hunters exhibit high skill across the life span, in iduals vary substantially in skill, and age-related peaks vary across sites.
Publisher: Cold Spring Harbor Laboratory
Date: 30-06-2023
DOI: 10.1101/2023.06.29.547023
Abstract: Xanthomonas translucens pv. graminis ( Xtg ) is a major bacterial pathogen of economically important forage grasses, causing severe yield losses. So far, genomic resources for this pathovar consisted mostly of draft genome sequences, and only one complete genome sequence was available, preventing comprehensive comparative genomic analyses. Such comparative analyses are essential in understanding the mechanisms involved in the virulence of pathogens and to identify virulence factors involved in pathogenicity. In this study, we produced high-quality, complete genome sequences of four strains of Xtg , complementing the recently obtained complete genome sequence of the Xtg pathotype strain. These genomic resources allowed for a comprehensive comparative analysis, which revealed a high genomic plasticity with many chromosomal rearrangements, although the strains were highly related, with 99.9 to 100% average nucleotide identity. A high number of transposases were exclusively found in Xtg and corresponded to 413 to 457 insertion/excision transposable elements per strain. These mobile genetic elements are likely to be involved in the observed genomic plasticity and may play an important role in the adaptation of Xtg . The pathovar was found to lack a type IV secretion system, and it possessed the smallest set of type III effectors in the species. However, three XopE and XopX family effectors were found, while in the other pathovars of the species two or less were present. Additional genes that were specific to the pathovar were identified, including a unique set of minor pilins of the type IV pilus, 17 TonB-dependent receptors (TBDRs), and 11 degradative enzymes. These results suggest a high adaptability of Xtg , conferred by the abundance of mobile genetic elements, which may have led to the loss of many features. Conserved features that were specific to Xtg were identified, and further investigation will help to determine genes that are essential to pathogenicity and host adaptation of Xtg .
Publisher: Cambridge University Press (CUP)
Date: 24-07-2023
DOI: 10.1017/JFM.2023.475
Abstract: Short-wave group forcing is a major driving mechanism of infragravity waves. The subharmonic response to wave group forcing approaches resonance in shallow water where the group velocity is equal to the shallow-water wave-propagating speed. Currently, there is a lack of understanding of the connection between the free and bound components of group-induced infragravity waves and the consistency among existing solutions for off- and near-resonance conditions in intermediate and shallow water. Here, a unified solution of group-induced subharmonics is derived based on Green's function for the first time. The new solution is valid for any resonance intensity and is able to describe group-induced subharmonic behaviour at all water depths consistently from a new angle. The proposed solution reduces to existing solutions for intermediate depth (Longuet-Higgins & Stewart, J. Fluid Mech. , vol. 13, 1962, pp. 481–504 Zou, Phys. Oceanogr. , vol. 41, 2011, pp. 1842–1859), shallow water and/or over a plane sloping beach (Van Leeuwen, PhD thesis, TU Delft, 1992 Schäffer, J. Fluid Mech. , vol. 247, 1993, pp. 551–588 Janssen et al. , J. Geophys. Res. , vol. 108, 2003, p. 3252 Contardo et al. , J. Phys. Oceanogr. , vol. 51, 2021, pp. 1465–1487 Liao et al. , J. Phys. Oceanogr. , vol. 51, 2021, pp. 2749–2765). Unlike previous solutions, the Green's function-based solution describes all subharmonics as free subharmonics continuously radiated away from each point source in the group-induced forcing field determined by wave radiation stress gradients. The superposition of all these free subharmonics yields so-called bound subharmonics by previous studies due to group-modulated emission of each free subharmonic through the source field bound to the wave group. Therefore, this solution provides theoretical evidence that the group-induced subharmonic at any observation point is dependent on the surrounding radiation stress field and topography. Under full-resonance conditions in shallow water, downwave-propagating subharmonics excited at all source locations interfere with each other constructively therefore, their superposed litude is proportional to the travel distance of wave groups. Combined with the conventional moving-breakpoint forcing model, the predicted litude of the subharmonic in the surf zone by the present solution is in good agreement with laboratory observations.
Location: China
No related grants have been discovered for Martin Reinhardt Nielsen.