129 research outputs found
Delivering improved nutrient stewardship in China: the knowledge, attitudes and practices of farmers and advisers
There is a need to assess and re-orient agricultural knowledge and innovation systems (AKIS) in China, aiming to rebalance the importance of productivity alongside the stewardship of farm inputs, natural resources and broader protection of the environment; a new ethos is needed. Analysis and recommendations for this are provided
Neuronal autophagy and neurodegenerative diseases
Autophagy is a dynamic cellular pathway involved in the turnover of proteins, protein complexes, and organelles through lysosomal degradation. The integrity of postmitotic neurons is heavily dependent on high basal autophagy compared to non-neuronal cells as misfolded proteins and damaged organelles cannot be diluted through cell division. Moreover, neurons contain the specialized structures for intercellular communication, such as axons, dendrites and synapses, which require the reciprocal transport of proteins, organelles and autophagosomes over significant distances from the soma. Defects in autophagy affect the intercellular communication and subsequently, contributing to neurodegeneration. The presence of abnormal autophagic activity is frequently observed in selective neuronal populations afflicted in common neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. These observations have provoked controversy regarding whether the increase in autophagosomes observed in the degenerating neurons play a protective role or instead contribute to pathogenic neuronal cell death. It is still unknown what factors may determine whether active autophagy is beneficial or pathogenic during neurodegeneration. In this review, we consider both the normal and pathophysiological roles of neuronal autophagy and its potential therapeutic implications for common neurodegenerative diseases
Talampanel reduces the level of motoneuronal calcium in transgenic mutant SOD1 mice only if applied presymptomatically
We tested the efficacy of treatment with talampanel in a mutant SOD1 mouse model of ALS by measuring intracellular calcium levels and loss of spinal motor neurons. We intended to mimic the clinical study; hence, treatment was started when the clinical symptoms were already present. The data were compared with the results of similar treatment started at a presymptomatic stage. Transgenic and wild-type mice were treated either with talampanel or with vehicle, starting in pre-symptomatic or symptomatic stages. The density of motor neurons was determined by the physical disector, and their intracellular calcium level was assayed electron microscopically. Results showed that motor neurons in the SOD1 mice exhibited an elevated calcium level, which could be reduced, but not restored, with talampanel only when the treatment was started presymptomatically. Treatment in either presymptomatic or symptomatic stages failed to rescue the motor neurons. We conclude that talampanel reduces motoneuronal calcium in a mouse model of ALS, but its efficacy declines as the disease progresses, suggesting that medication initiation in the earlier stages of the disease might be more effective
Microbial diversity and biogeography in Arctic soils
Microorganisms dominate terrestrial environments in the polar regions and Arctic soils are known to harbour significant microbial diversity, far more diverse and numerous in the region than was once thought. Furthermore, the geographic distribution and structure of Arctic microbial communities remains elusive, despite their important roles in both biogeochemical cycling and in the generation and decomposition of climate active gases. Critically, Arctic soils are estimated to store over 1500 Pg of carbon and thus, have the potential to generate positive feedback within the climate system. As the Arctic region is currently undergoing rapid change, the likelihood of faster release of greenhouse gases such as CO2 , CH4 and N2 O is increasing. Understanding the microbial communities in the region, in terms of their diversity, abundance and functional activity, is key to producing accurate models of greenhouse gas release. This review brings together existing data to determine what we know about microbial diversity and biogeography in Arctic soils
Understanding Plant-Microbe Interactions for Phytoremediation of Petroleum-Polluted Soil
Plant-microbe interactions are considered to be important processes determining
the efficiency of phytoremediation of petroleum pollution, however relatively
little is known about how these interactions are influenced by petroleum
pollution. In this experimental study using a microcosm approach, we examined
how plant ecophysiological traits, soil nutrients and microbial activities were
influenced by petroleum pollution in Phragmites australis, a
phytoremediating species. Generally, petroleum pollution reduced plant
performance, especially at early stages of plant growth. Petroleum had negative
effects on the net accumulation of inorganic nitrogen from its organic forms
(net nitrogen mineralization (NNM)) most likely by decreasing the inorganic
nitrogen available to the plants in petroleum-polluted soils. However, abundant
dissolved organic nitrogen (DON) was found in petroleum-polluted soil. In order
to overcome initial deficiency of inorganic nitrogen, plants by dint of high
colonization of arbuscular mycorrhizal fungi might absorb some DON for their
growth in petroleum-polluted soils. In addition, through using a real-time
polymerase chain reaction method, we quantified hydrocarbon-degrading bacterial
traits based on their catabolic genes (i.e. alkB (alkane
monooxygenase), nah (naphthalene dioxygenase) and
tol (xylene monooxygenase) genes). This enumeration of
target genes suggests that different hydrocarbon-degrading bacteria experienced
different dynamic changes during phytoremediation and a greater abundance of
alkB was detected during vegetative growth stages. Because
phytoremediation of different components of petroleum is performed by different
hydrocarbon-degrading bacteria, plants’ ability of phytoremediating
different components might therefore vary during the plant life cycle.
Phytoremediation might be most effective during the vegetative growth stages as
greater abundances of hydrocarbon-degrading bacteria containing
alkB and tol genes were observed at these
stages. The information provided by this study enhances our understanding of the
effects of petroleum pollution on plant-microbe interactions and the roles of
these interactions in the phytoremediation of petroleum-polluted soil
Effects of aerobic training on exercise-related oxidative stress in mitochondrial myopathies
A New Positioning Method Based on Multiple Ultrasonic Sensors for Autonomous Mobile Robot
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