Seeing is believing: A rapid diagnostic platform for pathogen detection based on the acetylcholinesterase‐catalyzed hydrolysis reaction has been developed. Owing to signal amplification strategies, ...the sensitivity of this assay is comparable to that of PCR. In addition, the readout of the assay is based on solution color change, which can be easily observed by the naked eye alone.
Ultrasensitive and quantitative detection of cancer biomarkers is an unmet challenge because of their ultralow concentrations in clinical samples. Although gold nanoparticle (AuNP)-based immunoassays ...offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges. This article describes a quantitative colorimetric immunoassay based on glucose oxidase (GOx)-catalyzed growth of 5 nm AuNPs that can detect cancer biomarkers from attomolar to picomolar levels. In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude. The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.
Astronomical wide-field imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new ...wide-field interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependences of casa's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarization correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2–12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that combining w-stacking with the w-snapshot algorithm does not significantly improve computing requirements over pure w-stacking. The source code of our new imager is publicly released.
Grapevine salt tolerance Zhou‐Tsang, A.; Wu, Y.; Henderson, S.W. ...
Australian journal of grape and wine research,
April 2021, 2021-04-00, 20210401, Letnik:
27, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Salinity, which is predominantly an issue for agricultural systems in arid and semi‐arid regions, has the potential to impair grape production and wine quality, and its impact on the grape and wine ...industries is predicted to increase with climate change. Research on the physiological and molecular changes that occur in salt‐affected vines has unveiled complex osmotic and ionic responses that include oxidative stress, water loss, photoinhibition, growth inhibition and necrosis. Proposed salt tolerance mechanisms include elevated antioxidant production, hydric regulation and salt exclusion from shoots and berries. These later of these mechanisms is found in certain Vitis genotypes that, when grafted as rootstocks, can protect fruit‐bearing scions from accumulating significant amounts of saline ions from soils, most notably through the presence of specific transport proteins that are involved in regulating the transfer of ions from root to shoot via the xylem. Significant gaps in knowledge remain, however, regarding salt tolerance mechanisms for Vitis species, with many mechanisms inferred from other species or documented only at the level of gene expression. A better understanding of the mechanisms that confer salt tolerance in Vitis species is needed to improve the production of new germplasm that is locally adapted and better suited to the challenges of a changing climate. Hence, this review covers the current knowledge on the characteristics that are associated with salt damage and tolerance in grapevine cultivars and rootstocks and highlights possible future avenues that will enable development of new options for the industry to combat salinity.
The carbon balance of tropical ecosystems remains uncertain, with top-down atmospheric studies suggesting an overall sink and bottom-up ecological approaches indicating a modest net source. Here we ...use 12 years (2003 to 2014) of MODIS pantropical satellite data to quantify net annual changes in the aboveground carbon density of tropical woody live vegetation, providing direct, measurement-based evidence that the world’s tropical forests are a net carbon source of 425.2 ± 92.0 teragrams of carbon per year (Tg C year−1). This net release of carbon consists of losses of 861.7 ± 80.2 Tg C year−1 and gains of 436.5 ± 31.0 Tg C year−1. Gains result from forest growth; losses result from deforestation and from reductions in carbon density within standing forests (degradation or disturbance), with the latter accounting for 68.9% of overall losses.
An increasing number of genetic variants have been implicated in autism spectrum disorders (ASDs), and the functional study of such variants will be critical for the elucidation of autism ...pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, induced pluripotent stem cell (iPSC)-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with insulin-like growth factor-1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway may benefit from these drugs. We also demonstrate that methyl CpG binding protein-2 (MeCP2) levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.
ABSTRACT We report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644−5953 (Pictor II or Pic ...II) is a low surface brightness ( within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of . The physical size ( ) and low luminosity ( ) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644−5953 (Pic II) is located from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644−5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.
Immunohistochemistry is no longer a technique used only for research but is employed increasingly for diagnosis and for the assessment of therapeutic biomarkers. The latter, in particular, often ...require a semiquantitative evaluation of the extent of their presence. There are many factors that can affect this that relate to the method: fixation of tissue, duration and type of antigen retrieval, antibody specificity, antibody dilution and detection systems. Other complexities relate to assessment. Different scoring systems are used for either the same or different antigens. Cut‐off levels for assessing whether a tissue is ‘positive’ or ‘negative’ can vary for the same antigen. Whilst there are quality assurance schemes for the methodology that have improved standards of staining, there are no similar schemes that relate to interpretation, although errors here can create as many problems. There have been improvements in automated analysis but availability is limited and it is still predominantly a research tool. In order for quantification of immunohistochemistry to be a reliable and reputable tool, there must be easy to use, reproducible, standardized protocols for assessment which are international. Improvements in automated analysis with wider applicability could lead to standardization.
We present the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we ...determined the abundances of nine stars in Car II, including the first abundances of an RR Lyrae star in an ultra-faint dwarf galaxy (UFD), and two stars in Car III. The chemical abundances demonstrate that both systems are clearly galaxies and not globular clusters. The stars in these galaxies mostly display abundance trends matching those of other similarly faint dwarf galaxies: enhanced but declining /Fe ratios, iron-peak elements matching the stellar halo, and unusually low neutron-capture element abundances. One star displays a low outlying Sc/Fe = −1.0. We detect a large Ba scatter in Car II, likely due to inhomogeneous enrichment by low-mass asymptotic giant branch star winds. The most striking abundance trend is for Mg/Ca in Car II, which decreases from +0.4 to −0.4 and indicates clear variation in the initial progenitor masses of enriching core-collapse supernovae. So far, the only UFDs displaying a similar Mg/Ca trend are likely satellites of the Large Magellanic Cloud. We find two stars with Fe/H ≤ −3.5 whose abundances likely trace the first generation of metal-free Population III stars and are well fit by Population III core-collapse supernova yields. An appendix describes our new abundance uncertainty analysis that propagates line-by-line stellar parameter uncertainties.
We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM ...survey is the widest fractional bandwidth all-sky survey to date, ideal for identifying peaked-spectrum sources at low radio frequencies. Our peaked-spectrum sources are the low-frequency analogs of gigahertz-peaked spectrum (GPS) and compact-steep spectrum (CSS) sources, which have been hypothesized to be the precursors to massive radio galaxies. Our sample more than doubles the number of known peaked-spectrum candidates, and 95% of our sample have a newly characterized spectral peak. We highlight that some GPS sources peaking above 5 GHz have had multiple epochs of nuclear activity, and we demonstrate the possibility of identifying high-redshift (z > 2) galaxies via steep optically thin spectral indices and low observed peak frequencies. The distribution of the optically thick spectral indices of our sample is consistent with past GPS/CSS samples but with a large dispersion, suggesting that the spectral peak is a product of an inhomogeneous environment that is individualistic. We find no dependence of observed peak frequency with redshift, consistent with the peaked-spectrum sample comprising both local CSS sources and high-redshift GPS sources. The 5 GHz luminosity distribution lacks the brightest GPS and CSS sources of previous samples, implying that a convolution of source evolution and redshift influences the type of peaked-spectrum sources identified below 1 GHz. Finally, we discuss sources with optically thick spectral indices that exceed the synchrotron self-absorption limit.
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