646 research outputs found
The effect of forage management on carbon storage in pastureland and rotation
Non-Peer ReviewedDegraded land with less than 1.5% organic carbon (class 4 and 5 land) in the Parkland of Western
Canada has significant potential, from 5 to 15 Mg C ha-1 depending on management, for carbon storage
with forages in the Parkland. The potential ranges from 5 to 15 Mg C ha-1, over a period from 15 to 20
years, depending on fertility management of forages in pasture and initial levels of soil organic carbon.
Nitrogen fertilizer increased organic carbon stored in reseeded pastures at Pathlow and Brandon relative
to paddocks without fertilizer. Over a period of 12 years (1978-1989) in the Pathlow study, 21.9 Mg C ha-
1 (0-15 cm) was stored when N fertilizer was applied at an annual rate of 45 kg ha-1 compared to the
control treatment, which was attributed to accumulation of plant debris and roots at the surface. Increases
in organic carbon did not persist 10 years after N fertilizer was discontinued at the study at Pathlow,
Saskatchewan. At Brandon, Manitoba, fertilized grass pasture stored 16.2 Mg C ha-1 (0-50 cm) compared
to unfertilized bromegrass from 1994 to 1999. Long-term forage rotations at Melfort showed no
significant difference in the wheat phase of a F-W-W-H-H-W rotation due to nitrogen fertilizer (147.3 Mg
C ha-1 150.7 Mg C ha-1) over a period from 1957 to 1994. This was attributed to the high levels of soil
carbon in soils at Melfort. Forages in rotation had no significant effect on organic carbon in a study at
Glenlea MB conducted from 1992 to 1999, though a range from 110.8 to 145.7 Mg C ha-1 was observed.
Significant differences may occur in the long term as organic carbon accumulates in the treatments at
Glenlea
Abdominal functional electrical stimulation to improve respiratory function after spinal cord injury: a systematic review and meta-analysis
Objectives: Abdominal functional electrical stimulation (abdominal FES) is the application of a train of electrical pulses to the abdominal muscles, causing them to contract. Abdominal FES has been used as a neuroprosthesis to acutely augment respiratory function and as a rehabilitation tool to achieve a chronic increase in respiratory function after abdominal FES training, primarily focusing on patients with spinal cord injury (SCI). This study aimed to review the evidence surrounding the use of abdominal FES to improve respiratory function in both an acute and chronic manner after SCI.
Settings: A systematic search was performed on PubMed, with studies included if they applied abdominal FES to improve respiratory function in patients with SCI.
Methods: Fourteen studies met the inclusion criteria (10 acute and 4 chronic). Low participant numbers and heterogeneity across studies reduced the power of the meta-analysis. Despite this, abdominal FES was found to cause a significant acute improvement in cough peak flow, whereas forced exhaled volume in 1âs approached significance. A significant chronic increase in unassisted vital capacity, forced vital capacity and peak expiratory flow was found after abdominal FES training compared with baseline.
Conclusions: This systematic review suggests that abdominal FES is an effective technique for improving respiratory function in both an acute and chronic manner after SCI. However, further randomised controlled trials, with larger participant numbers and standardised protocols, are needed to fully establish the clinical efficacy of this technique
P2X7 Receptor Primes IL-1ÎČ and the NLRP3 Inflammasome in Astrocytes Subjected to Mechanical Strain
Inflammatory responses play a key role in many neural pathologies, with localized signaling from non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. Stimulation of the NLRP3 inflammasome is a two-stage process. The priming stage involves upregulation of the biosynthesis of the structural components while activation results in their assembly into the actual inflammasome complex and subsequent activation. The priming step can be rate limiting and can connect insult to chronic inflammation but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammatory conditions is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure (IOP) increased mRNA for inflammasome components IL-1ÎČ, NLRP3, ASC, CASP1 and IL-6 in rat and mouse retinas. The P2X7 receptor was implicated in the in vivo mechanosensitive priming of IL-1ÎČ and IL-6 transcription and translation. In vitro experiments with optic nerve head astrocytes demonstrated enhanced expression of the IL-1ÎČ and IL-6 genes following stretching or swelling. The increase in IL-1ÎČ expression was inhibited by degradation of extracellular ATP with apyrase, blocking pannexin hemichannels with carbenoxolone, probenecid or 10Panx1 peptide, P2X7 receptor antagonists (BBG, A839977 or A740003) as well inhibition of the NFÎșB transcription factor with Bay 11-7082. The swelling-dependent fall in expression of the NFÎșB inhibitor IÎșB-α was reduced by treatment of cells with A839977 and in P2X7 knockout mice. In summary, our data suggest that mechanical trauma to the retina results in priming of the NLRP3 inflammasome components and upregulated IL-6 expression and release. This was dependent upon ATP release through pannexin hemichannels and autostimulation of the P2X7 receptor. Since the P2X7 receptor can also trigger inflammasome activation it appears to have a central role in linking mechanical strain to neuroinflammation
A general role for TANGO1, encoded by MIA3, in secretory pathway organization and function
Complex machinery is required to drive secretory cargo export from the endoplasmic reticulum (ER), which is an essential process in eukaryotic cells. In vertebrates, the MIA3 gene encodes two major forms of transport and Golgi organization protein 1 (TANGO1S and TANGO1L), which have previously been implicated in selective trafficking of procollagen. Using genome engineering of human cells, light microscopy, secretion assays, genomics and proteomics, we show that disruption of the longer form, TANGO1L, results in relatively minor defects in secretory pathway organization and function, including having limited impacts on procollagen secretion. In contrast, loss of both long and short forms results in major defects in cell organization and secretion. These include a failure to maintain the localization of ERGIC53 (also known as LMAN1) and SURF4 to the ERâGolgi intermediate compartment and dramatic changes to the ultrastructure of the ERâGolgi interface. Disruption of TANGO1 causes significant changes in early secretory pathway gene and protein expression, and impairs secretion not only of large proteins, but of all types of secretory cargo, including small soluble proteins. Our data support a general role for MIA3/TANGO1 in maintaining secretory pathway structure and function in vertebrate cells
Developing pathways to clarify pathogenicity of unclassified variants in osteogenesis imperfecta genetic analysis
Background
With increased access to genetic testing, variants of uncertain significance (VUS) where pathogenicity is uncertain are being increasingly identified. More than 85% Osteogenesis Imperfecta (OI) patients have pathogenic variants in COL1A1/A2. However, when a VUS is identified, there are no pathways in place for determining significance.
Objective
Define a diagnostic pathway to confirm pathogenicity, providing patients with definitive genetic diagnosis, accurate recurrence risks, and prenatal testing options.
Methods
Functional studies on collagen secretion from cultured patient fibroblasts combined with detailed phenotyping and segregation family studies.
Results
We demonstrate data from a family with a VUS identified in type I collagen.
Familyâ1
Sixâyearâold boy with failureâtoâgain weight, talipes, fractures, on and off treatment with Pamidronate as diagnosis of OI uncertain. Transiliac bone biopsy at 2 years of age demonstrated active new bone formation within periosteum; bone cortices were normal thickness but increased porosity. Trabecular bone showed features of advanced osteoporosis. Genetic testing identified a de novo COL1A1 c.206_208delTGT, p.Leu69del variant. Sibling with similar phenotype but no fractures as yet, tested positive for variant raising concerns regarding her diagnosis, and management.
Results from three independent experiments (cell immunofluorescence, collagen secretion assay by Western Blot, and unbiased proteomics) from cultured patient fibroblasts demonstrate COL1A1 c.206_208delTGT, p.Leu69del variant causing a substantial defect to collagen extracellular matrix assembly confirming variant pathogenicity.
Conclusion
Access to genetic testing in OI is increasing as advances in genetic technologies decreases cost; a clinical diagnostic pathway needs to be implemented for managing variants identified by such testing
Knowing your place and commanding space:de/constructions of gendered embodiment in mixed-sex karate
Feminists have long acknowledged that gendered divisions in access to spaces of leisure, and how women and men physically take up that space, reproduces gender inequality. This article will explore how karate practitioners participate in the space of mixed-sex karate practice and how such uses of space de/construct gendered embodiments and a gender hierarchy. Data presented is drawn from nine months of ethnographic emersion within three karate clubs and fifteen photo-elicitation interviews with karate participants from the three clubs. The findings of this paper suggest that whilst women often occupied spaces of expertise within the karate hall, gendered distinctions in uses of space emerged in the more subtle ways in which women and men used their voice, responded to the tacit and smelt dilemmas of sweat, and moved their bodies across physical space. This research highlights both the potential of physical leisure practice to âundoâ conventional gendered embodiments that particularly restrict womenâs intentionality in the world (Young, 1980), and the power of spatially-attuned research to illuminate the minute ways in which unequal gender relations are naturalised, legitimised and done
T1R3: A human calcium taste receptor
Many animals can detect the taste of calcium but it is unclear how or whether humans have this ability. We show here that calcium activates hTAS1R3-transfected HEK293 cells and that this response is attenuated by lactisole, an inhibitor of hT1R3. Moreover, trained volunteers report that lactisole reduces the calcium intensity of calcium lactate. Thus, humans can detect calcium by taste, T1R3 is a receptor responsible for this, and lactisole can reduce the taste perception of calcium by acting on T1R3
Recommended from our members
Modeling Analysis of Primary Controls on Net Ecosystem Productivity of Seven Boreal and Temperate Coniferous Forests Across a Continental Transect
Process-based models are effective tools to synthesize and/or extrapolate measured carbon (C) exchanges from individual sites to large scales. In this study, we used a C- and nitrogen (N)-cycle coupled ecosystem model named CN-CLASS (Carbon Nitrogen-Canadian Land Surface Scheme) to study the role of primary climatic controls and site-specific C stocks on the net ecosystem productivity (NEP) of seven intermediate-aged to mature coniferous forest sites across an eastâwest continental transect in Canada. The model was parameterized using a common set of parameters, except for two used in empirical canopy conductanceâassimilation, and leaf areaâsapwood relationships, and then validated using observed eddy covariance flux data. Leaf Rubisco-N dynamics that are associated with soilâplant N cycling, and depend on canopy temperature, enabled the model to simulate site-specific gross ecosystem productivity (GEP) reasonably well for all seven sites. Overall GEP simulations had relatively smaller differences compared with observations vs. ecosystem respiration (RE), which was the sum of many plant and soil components with larger variability and/or uncertainty associated with them. Both observed and simulated data showed that, on an annual basis, boreal forest sites were either carbon-neutral or a weak C sink, ranging from 30 to 180 g C mâ2 yrâ1; while temperate forests were either a medium or strong C sink, ranging from 150 to 500 g C mâ2 yrâ1, depending on forest age and climatic regime. Model sensitivity tests illustrated that air temperature, among climate variables, and aboveground biomass, among major C stocks, were dominant factors impacting annual NEP. Vegetation biomass effects on annual GEP, RE and NEP showed similar patterns of variability at four boreal and three temperate forests. Air temperature showed different impacts on GEP and RE, and the response varied considerably from site to site. Higher solar radiation enhanced GEP, while precipitation differences had a minor effect. Magnitude of forest litter content and soil organic matter (SOM) affected RE. SOM also affected GEP, but only at low levels of SOM, because of low N mineralization that limited soil nutrient (N) availability. The results of this study will help to evaluate the impact of future climatic changes and/or forest C stock variations on C uptake and loss in forest ecosystems growing in diverse environments.Earth and Planetary Science
Puumala hantavirus Infection in Humans and in the Reservoir Host, Ardennes Region, France
We compared the occurrence of nephropathia epidemica cases, over a multi-annual population cycle, in northeastern France with the hantavirus serology for bank voles captured in the same area. We discuss hypotheses to explain the pattern of infection in both humans and rodents and their synchrony
The P2Y12 Receptor Antagonist Ticagrelor Reduces Lysosomal pH and Autofluorescence in Retinal Pigmented Epithelial Cells From the ABCA4-/- Mouse Model of Retinal Degeneration
The accumulation of partially degraded lipid waste in lysosomal-related organelles may contribute to pathology in many aging diseases. The presence of these lipofuscin granules is particularly evident in the autofluorescent lysosome-associated organelles of the retinal pigmented epithelial (RPE) cells, and may be related to early stages of age-related macular degeneration. While lysosomal enzymes degrade material optimally at acidic pH levels, lysosomal pH is elevated in RPE cells from the ABCA4-/- mouse model of Stargardt\u27s disease, an early onset retinal degeneration. Lowering lysosomal pH through cAMP-dependent pathways decreases accumulation of autofluorescent material in RPE cells in vitro, but identification of an appropriate receptor is crucial for manipulating this pathway in vivo. As the P2Y12 receptor for ADP is coupled to the inhibitory Gi protein, we asked whether blocking the P2Y12 receptor with ticagrelor could restore lysosomal acidity and reduce autofluorescence in compromised RPE cells from ABCA4-/- mice. Oral delivery of ticagrelor giving rise to clinically relevant exposure lowered lysosomal pH in these RPE cells. Ticagrelor also partially reduced autofluorescence in the RPE cells of ABCA4-/- mice. In vitro studies in ARPE-19 cells using more specific antagonists AR-C69931 and AR-C66096 confirmed the importance of the P2Y12 receptor for lowering lysosomal pH and reducing autofluorescence. These observations identify P2Y12 receptor blockade as a potential target to lower lysosomal pH and clear lysosomal waste in RPE cells. © 2018 Lu, Gómez, Lim, Guha, O\u27Brien-Jenkins, Coffey, Campagno, McCaughey, Laties, Carlsson and Mitchell
- âŠ