808 research outputs found
Training programs in remote sensing for professionals, students and the general public
What remote sensing is, how and why it is used, and why more people should be trained in the field is discussed. Suggestions are offered concerning differences in teaching technicians, the general public, and children in schools
Unraveling genetic variation among white spruce families generated through different breeding strategies: Heritability, growth, physiology, hormones and gene expression
Tree improvement programs select genotypes for faster growth, at both early and late stages, to increase yields over unimproved material, and the improvement is frequently attributed to genetic control in growth parameters among genotypes. Underutilized genetic variability among genotypes also has the potential to ensure future gains are possible. However, the genetic variation in growth, physiology and hormone control among genotypes generated from different breeding strategies has not been well characterized in conifers. We assessed growth, biomass, gas exchange, gene expression and hormone levels in white spruce seedlings obtained from three different breeding strategies (controlled crosses, polymix pollination, open pollination) using parents grafted into a clonal seed orchard in Alberta, Canada. A pedigree-based best linear unbiased prediction (ABLUP) mixed model was implemented to quantify variability and narrow-sense heritability for target traits. The levels of several hormones and expression of gibberellin-related genes in apical internodes were also determined. Over the first two years of development, the estimated heritabilities for height, volume, total dry biomass, above ground dry biomass, root:shoot ratio and root length, varied between 0.10 and 0.21, with height having the highest value. The ABLUP values showed large genetic variability in growth and physiology traits both between families from different breeding strategies, and within families. The principal component analysis showed that developmental and hormonal traits explained 44.2% and 29.4% of the total phenotypic variation between the three different breeding strategies and two growth groups. In general, controlled crosses from the fast growth group showed the best apical growth, with more accumulation of indole-3-acetic acid, abscisic acid, phaseic acid, and a 4-fold greater gene expression of PgGA3ox1 in genotypes from controlled crosses versus those from open pollination. However, in some cases, open pollination from the fast and slow growth groups showed the best root development, higher water use efficiency (iWUE and δ13C) and more accumulation of zeatin and isopentenyladenosine. In conclusion, tree domestication can lead to trade-offs between growth, carbon allocation, photosynthesis, hormone levels and gene expression, and we encourage the use of this phenotypic variation identified in improved and unimproved trees to advance white spruce tree improvement programs
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Monitoring and modeling of household air quality related to use of different Cookfuels in Paraguay.
In Paraguay, 49% of the population depends on biomass (wood and charcoal) for cooking. Residential biomass burning is a major source of fine particulate matter (PM2.5 ) and carbon monoxide (CO) in and around the household environment. In July 2016, cross-sectional household air pollution sampling was conducted in 80 households in rural Paraguay. Time-integrated samples (24 hours) of PM2.5 and continuous CO concentrations were measured in kitchens that used wood, charcoal, liquefied petroleum gas (LPG), or electricity to cook. Qualitative and quantitative household-level variables were captured using questionnaires. The average PM2.5 concentration (μg/m3 ) was higher in kitchens that burned wood (741.7 ± 546.4) and charcoal (107.0 ± 68.6) than in kitchens where LPG (52.3 ± 18.9) or electricity (52.0 ± 14.8) was used. Likewise, the average CO concentration (ppm) was higher in kitchens that used wood (19.4 ± 12.6) and charcoal (7.6 ± 6.5) than in those that used LPG (0.5 ± 0.6) or electricity (0.4 ± 0.6). Multivariable linear regression was conducted to generate predictive models for indoor PM2.5 and CO concentrations (predicted R2 = 0.837 and 0.822, respectively). This study provides baseline indoor air quality data for Paraguay and presents a multivariate statistical approach that could be used in future research and intervention programs
Servicio de información de mercados de productos agropecuarios: experiencia y requerimientos para su implantación en Colombia.
Flight Readiness of Mochii S: Portable Spectroscopic Scanning Electron Microscope Facility on the International Space Station (ISS)
The ISS (International Space Station) currently lacks the capability to image and chemically analyze nano-to-micron scale particles from numerous engineering systems. To identify these particles, we must wait for a re-entry vehicle to return them from low earth orbit for ground-based SEM (Scanning Electron Microscope) / EDS (Energy Dispersive X-Ray Spectroscopy) analysis. This may take months, potentially delaying the affected system. Having an EDS-equipped SEM (Mochii S) aboard the ISS will accelerate response time thereby enhancing crew and vehicle safety by rapid and accurate identification of microscopic threats, especially in time-critical situations.The Mochii S payload will be stationed in the Japanese Experiment Module (JEM) powered by 120 VAC (Volts Alternating Current) inverter and connected to station Ethernet and WiFi (Fig. 1). To date the Mochii S payload has undergone testing for command and data handling, power quality, flight vibration, and radiation testing at Johnson Space Center (JSC). Mochii's high-RPM (Revolutions Per Minute) rotating vacuum pumps and high voltage systems have been reviewed to meet safety standards by JSC (Johnson Space Center) Engineering. Topology of the system in the JEM module has been baselined by ISS Safety and JAXA (Japan Space Exploration Agency). Digital controls to and from ISS over Joint Station LAN (Local Area Network) uplink have been simulated and the latencies and data rates have been found to be sufficient for successful operation of the payload from ground.Transporting sensitive electron optical instruments aboard a rocket that sustains 7G acceleration for 8 minutes and then operating it the unique microgravity (micro-g) environment is no trivial matter. To meet strict safety requirements and increase robustness for mission success, over 500 unique verifications must be completed before the payload is certified for spaceflight. Two of which will be discussed in detail are: vibroacoustic testing and magnetic susceptibility shielding and validation
Sistema de valoración del control postural de bajo costo
El control postural es la capacidad de mantenerse estable y mantener una alineación correcta del cuerpo, coordinando las articulaciones y músculos para evitar la caÃda en condiciones tanto estáticas como dinámicas.CONACYT – Consejo Nacional de Ciencia y TecnologÃaPROCIENCI
N-enhancement in GN-z11: First evidence for supermassive stars nucleosynthesis in proto-globular clusters-like conditions at high redshift ?
Unusually high N/O abundances were recently reported for a very compact,
intensively star-forming object GN-z11 at z=10.6 from JWST/NIRSpec
observations. We present an empirical comparison with the C, N, and O abundance
ratios in Galactic globular clusters (GCs) over a large metallicity range. We
show that hot hydrogen-burning nucleosynthesis within supermassive stars (SMS)
formed through runaway collisions can consistently explain the observed
abundances ratio in GN-z11 and in GCs. This suggests that a proto-globular
cluster hosting a SMS could be at the origin of the strong N-enrichment in
GN-z11. Our model predicts the behavior of N/O, C/O, and Ne/O ratios as a
function of metallicity, which can be tested if high-z objects similar to
GN-z11 are detected with JWST in the future. Further studies and statistics
will help differentiate the proto-GC scenario from the Wolf-Rayet scenario that
we quantify with a population synthesis model, and shed more light on this
peculiar object.Comment: Submitted to A&A Letter
Global Solution to the Relativistic Enskog Equation With Near-Vacuum Data
We give two hypotheses of the relativistic collision kernal and show the
existence and uniqueness of the global mild solution to the relativistic Enskog
equation with the initial data near the vacuum for a hard sphere gas.Comment: 6 page
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Methylation panel is a diagnostic biomarker for Barrett’s oesophagus in endoscopic biopsies and non-endoscopic cytology specimens
Objective Barrett’s Oesophagus is a premalignant condition that occurs in the context of gastro-oesophageal reflux. However, most Barrett’s cases are undiagnosed because of reliance on endoscopy. We have developed a non-endoscopic tool; the Cytosponge™ which when combined with TFF3 immunohistochemistry can diagnose Barrett’s. We investigated whether a quantitative methylation test that is not reliant on histopathological analysis could be used to diagnose Barrett’s oesophagus.
Design Differentially methylated genes between Barrett’s and normal squamous oesophageal biopsies were identified from whole methylome data and confirmed using MethyLight PCR in biopsy samples of squamous oesophagus, gastric cardia and Barrett’s oesophagus. Selected genes were then tested on Cytosponge™ BEST2 trial samples comprising a pilot cohort (n=20 cases, n=10 controls) and a validation cohort (n=149 cases, n=129 controls).
Results Eighteen genes were differentially methylated in patients with Barrett’s compared to squamous controls. Hypermethylation of TFPI2, TWIST1, ZNF345 and ZNF569 was confirmed in Barrett’s biopsies compared with biopsies from squamous oesophagus and gastric cardia (p<0.05). When tested in Cytosponge™ samples these four genes were hypermethylated in patients with Barrett’s oesophagus compared to patients with reflux symptoms (p<0.001). The optimum biomarker to diagnose Barrett’s was TFPI2 with a sensitivity and specificity of 82.2% and 95.7 % respectively.
Conclusion TFPI2, ZNF345 and ZNF569 CpG methylation has promise as a diagnostic biomarker panel for Barrett’s when used in combination with a simple and cost effective non-endoscopic cell collection device.The BEST2 study was funded by Cancer Research UK (C14478/ A12088). RCF receives core funding from the Medical Research Council. The study received infrastructure support from the Cambridge Human Research Tissue Bank, which is supported by the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre and the Experimental Cancer Medicine Centre
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