988 research outputs found
Arbuscular mycorrhizal community composition associated with two plant species in a grassland ecosystem
Arbuscular mycorrhizal (AM) fungi are biotrophic symbionts colonizing about two-thirds of land plant species and found in all ecosystems. They are of major importance in plant nutrient supply and their diversity is suggested to be an important determinant of plant community composition. The diversity of the AM fungal community composition in the roots of two plant species (Agrostis capillaris and Trifolium repens) that co-occurred in the same grassland ecosystem was characterized using molecular techniques. We analysed the small subunit (SSU) ribosomal RNA gene amplified from a total root DNA extract using AM fungal-specific primers. A total of 2001 cloned fragments from 47 root samples obtained on four dates were analysed by restriction fragment length polymorphism, and 121 of them were sequenced. The diversity found was high: a total of 24 different phylotypes (groups of phylogenetically related sequences) colonized the roots of the two host species. Phylogenetic analyses demonstrate that 19 of these phylotypes belonged to the Glomaceae, three to the Acaulosporaceae and two to the Gigasporaceae. Our study reveals clearly that the AM fungal community colonizing T. repens differed from that colonizing A. capillaris, providing evidence for AM fungal host preference. In addition, our results reveal dynamic changes in the AM fungal community through time
Designing participation processes for water management and beyond
This article addresses the question of how to design participation processes in water management and other fields. Despite a lot of work on participation, and especially its evaluation, this question has received little attention in the research literature. However, it is important, because previous research has made it clear that participation may yield important benefits for humans and the environment but that these benefits do not occur automatically. One precondition is sound design. The design of participation processes has been addressed in detail in the so-called "craft" literature but more rarely in the scientific literature. This article helps close this gap by systematically analyzing and comparing five design guides to determine whether it is possible to combine them into a more robust guide. The article confirms that possibility and presents a preliminary outline for such a guide. Principles for participatory process orientation are presented, as well as numerous partially iterative steps. The adaptive process is laid out in a way intended to help designers determine the objectives of the participation process and the initial design context, and make preplanning choices that eventually lead to the selection of suitable participation mechanisms. There are also design tools that facilitate this work. We discuss how our findings are largely compatible with previous research on participation, notably the work on criteria for "good" or "effective" participation processes. We also argue that our article advances research on an important remaining question in the scientific literature on participation: What process should be chosen in which context
Aiding multi-level decision-making processes for climate change mitigation and adaptation
Progress towards climate change aware regional sustainable development is affected by actions at multiple spatial scales and governance levels and equally impacts actions at these scales. Many authors and policy practitioners consider therefore that decisions over policy, mitigation strategies and capacity for adaptation to climate change require construction and coordination over multiple levels of governance to arrive at acceptable local, regional and global management strategies. However, how such processes of coordination and decision-aiding can occur and be maintained and improved over time is a major challenge in need of investigation. We take on this challenge by proposing research-supported methods of aiding multi-level decision-making processes in this context. Four example regionally focussed multi-level case studies from diverse socio-political contexts are outlined-estuarine management in Australia's Lower Hawkesbury, flood and drought management in Bulgaria's Upper Iskar Basin, climate policy integration in Spain's Comunidad Valenciana and food security in Bangladesh's Faridpur District-from which insights are drawn. Our discussion focuses on exploring these insights including: (1) the possible advantages of informal research-supported processes and specifically those that provide individual arenas of participation for different levels of stakeholders; (2) the complexity of organisation processes required for aiding multi-level decision-making processes; and (3) to what extent progress towards integrated regional policies for climate change aware sustainable development can be achieved through research-supported processes. We finish with a speculative section that provides ideas and directions for future research
Expression of Cholera Toxin BâProinsulin Fusion Protein in Lettuce and Tobacco Chloroplasts â Oral Administration Protects Against Development of Insulitis in Non-Obese Diabetic Mice
Lettuce and tobacco chloroplast transgenic lines expressing the cholera toxin B subunitâhuman proinsulin (CTB-Pins) fusion protein were generated. CTB-Pins accumulated up to ~16% of total soluble protein (TSP) in tobacco and up to ~2.5% of TSP in lettuce. Eight milligrams of powdered tobacco leaf material expressing CTB-Pins or, as negative controls, CTBâgreen fluorescent protein (CTB-GFP) or interferonâGFP (IFN-GFP), or untransformed leaf, were administered orally, each week for 7 weeks, to 5-week-old female non-obese diabetic (NOD) mice. The pancreas of CTB-Pins-treated mice showed decreased infiltration of cells characteristic of lymphocytes (insulitis); insulin-producing ÎČ-cells in the pancreatic islets of CTB-Pins-treated mice were significantly preserved, with lower blood or urine glucose levels, by contrast with the few ÎČ-cells remaining in the pancreatic islets of the negative controls. Increased expression of immunosuppressive cytokines, such as interleukin-4 and interleukin-10 (IL-4 and IL-10), was observed in the pancreas of CTB-Pins-treated NOD mice. Serum levels of immunoglobulin G1 (IgG1), but not IgG2a, were elevated in CTB-Pins-treated mice. Taken together, T-helper 2 (Th2) lymphocyte-mediated oral tolerance is a likely mechanism for the prevention of pancreatic insulitis and the preservation of insulin-producing ÎČ-cells. This is the first report of expression of a therapeutic protein in transgenic chloroplasts of an edible crop. Transplastomic lettuce plants expressing CTB-Pins grew normally and transgenes were maternally inherited in T1 progeny. This opens up the possibility for the low-cost production and delivery of human therapeutic proteins, and a strategy for the treatment of various other autoimmune diseases
Pioneer 10 Doppler data analysis: disentangling periodic and secular anomalies
This paper reports the results of an analysis of the Doppler tracking data of
Pioneer probes which did show an anomalous behaviour. A software has been
developed for the sake of performing a data analysis as independent as possible
from that of J. Anderson et al. \citep{anderson}, using the same data set. A
first output of this new analysis is a confirmation of the existence of a
secular anomaly with an amplitude about 0.8 nms compatible with that
reported by Anderson et al. A second output is the study of periodic variations
of the anomaly, which we characterize as functions of the azimuthal angle
defined by the directions Sun-Earth Antenna and Sun-Pioneer. An
improved fit is obtained with periodic variations written as the sum of a
secular acceleration and two sinusoids of the angles and .
The tests which have been performed for assessing the robustness of these
results are presented.Comment: 13 pages, 6 figures, minor amendment
Spectral Analysis of Guanine and Cytosine Fluctuations of Mouse Genomic DNA
We study global fluctuations of the guanine and cytosine base content (GC%)
in mouse genomic DNA using spectral analyses. Power spectra S(f) of GC%
fluctuations in all nineteen autosomal and two sex chromosomes are observed to
have the universal functional form S(f) \sim 1/f^alpha (alpha \approx 1) over
several orders of magnitude in the frequency range 10^-7< f < 10^-5 cycle/base,
corresponding to long-ranging GC% correlations at distances between 100 kb and
10 Mb. S(f) for higher frequencies (f > 10^-5 cycle/base) shows a flattened
power-law function with alpha < 1 across all twenty-one chromosomes. The
substitution of about 38% interspersed repeats does not affect the functional
form of S(f), indicating that these are not predominantly responsible for the
long-ranged multi-scale GC% fluctuations in mammalian genomes. Several
biological implications of the large-scale GC% fluctuation are discussed,
including neutral evolutionary history by DNA duplication, chromosomal bands,
spatial distribution of transcription units (genes), replication timing, and
recombination hot spots.Comment: 15 pages (figures included), 2 figure
Recognition of reptile predator scent is innate in an endangered lizard species
Chemical cues can alert prey to the presence of predators before the predator is within visual proximity. Recognition of a predatorâs scent is therefore an important component of predator awareness. We presented predator and control scents to wild, wild-born captive, and predator-naive captive-born pygmy bluetongue lizards to determine (1) whether lizards respond to reptile chemical cues differently from controls, (2) whether captive lizards respond more strongly to a known predator than to other predatory reptiles, (3) whether captive-born lizards recognise predators innately, whether captive-born lizards have reduced predator recognition compared with wild lizards and whether time spent in captivity reduces responses to predators, and (4) whether the avoidance response to predator detection differs between naive and experienced lizards. There was no significant difference in the number of tongue flicks to predator scent among wild, wild-born and captive-born lizards, suggesting that predator detection is innate in the pygmy bluetongue lizard and time in captivity did not reduce predator recognition. The number of tongue flicks directed towards brown snake scent was significantly higher than that to the novel and water controls for all lizard origins. Lizards of all origins continued to bask in the presence of predator scents, suggesting that chemical cues alone may be insufficient to instigate an avoidance response and other cues may be required.Tara L. Daniell, Mark N. Hutchinson, Phil Ainsley and Michael G. Gardne
Why We Can No Longer Ignore Consecutive Disasters
In recent decades, a striking number of countries have suffered from consecutive disasters: events whose impacts overlap both spatially and temporally, while recovery is still under way. The risk of consecutive disasters will increase due to growing exposure, the interconnectedness of human society, and the increased frequency and intensity of nontectonic hazard. This paper provides an overview of the different types of consecutive disasters, their causes, and impacts. The impacts can be distinctly different from disasters occurring in isolation (both spatially and temporally) from other disasters, noting that full isolation never occurs. We use existing empirical disaster databases to show the global probabilistic occurrence for selected hazard types. Current stateâofâthe art risk assessment models and their outputs do not allow for a thorough representation and analysis of consecutive disasters. This is mainly due to the many challenges that are introduced by addressing and combining hazards of different nature, and accounting for their interactions and dynamics. Disaster risk management needs to be more holistic and codesigned between researchers, policy makers, first responders, and companies
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