171 research outputs found
Progress and prospects of glucosinolate pathogen resistance in some brassica plants
Plants are constantly defending themselves against an array of assaults by pathogenic organisms. This has led to the evolution of precise and elaborate chemical defense systems involving glucosinolates (GSLs) in cruciferous plants. These GSLs and their hydrolysis products are biologically active and are implicated as enabling formidable plant defense processes in certain economically important members of Brassicaceae like broccoli, cabbage and mustard seed. This review provides a comprehensive report of how indole and aliphatic GSLs mitigate incidents of plant pathogenesis. By evaluating the roles of GSLs in plant-pathogen interaction of some brassica plants, this review highlights the associated mechanism that culminates in disease suppression. Moreover, seven economically important brassica pathogens were reviewed in terms of their ability to disrupt proper plant functioning as well as the mechanisms by which GSLs and their hydrolysis products in Brassica lower the susceptibility to them. Future perspectives of the application of GSLs in plant pathogen resistance using advanced molecular techniques are also discussed
Trait positions for elevated invasiveness in adaptive ecological networks
Our ability to predict the outcome of invasion declines rapidly as non-native species progress through intertwined ecological barriers to establish and spread in recipient ecosystems. This is largely due to the lack of systemic knowledge on key processes at play as species establish self-sustaining populations within the invaded range. To address this knowledge gap, we present a mathematical model that captures the eco-evolutionary dynamics of native and non-native species interacting within an ecological network. The model is derived from continuous-trait evolutionary game theory (i.e., Adaptive Dynamics) and its associated concept of invasion fitness which depicts dynamic demographic performance that is both trait mediated and density dependent. Our approach allows us to explore how multiple resident and non-native species coevolve to reshape invasion performance, or more precisely invasiveness, over trait space. The model clarifies the role of specific traits in enabling non-native species to occupy realised opportunistic niches. It also elucidates the direction and speed of both ecological and evolutionary dynamics of residing species (natives or non-natives) in the recipient network under different levels of propagule pressure. The versatility of the model is demonstrated using four examples that correspond to the invasion of (i) a horizontal competitive community; (ii) a bipartite mutualistic network; (iii) a bipartite antagonistic network; and (iv) a multi-trophic food web. We identified a cohesive trait strategy that enables the success and establishment of non-native species to possess high invasiveness. Specifically, we find that a non-native species can achieve high levels of invasiveness by possessing traits that overlap with those of its facilitators (and mutualists), which enhances the benefits accrued from positive interactions, and by possessing traits outside the range of those of antagonists, which mitigates the costs accrued from negative interactions. This ‘central-to-reap, edge-to-elude’ trait strategy therefore describes the strategic trait positions of non-native species to invade an ecological network. This model provides a theoretical platform for exploring invasion strategies in complex adaptive ecological networks
Improved value and carbon footprint by complete utilization of corncob lignocellulose
Lignocellulose, as the most abundant type of inedible biomass, is considered as a promising renewable feedstock for making fuels, chemicals, and materials. However, its complex structure makes most of current biorefinery processes suffer from low resource utilization rates, high energy consumption or ill-defined market orientation of the obtained products. Here, we propose and evaluate the EXA (Ethanol, Xylose, Adhesive) biorefinery strategy based on current xylose industry. This process integrates four conversion and separation stages to consecutively produce ethanol, xylose, and adhesive with total carbon utilization of 79.6%. The key innovation is the establishment of an easy-to-operate process for direct production of high-quality adhesive from a lignin-rich liquid fraction that makes the overall process significantly more sustainable. Techno-economic analysis (TEA) shows that the revenue of proposed EXA process increases more than 110 times compares with the current process and life cycle assessment (LCA) demonstrates a much lower CO2 footprint from an environmental burden per unit of revenue perspective
Return of 4U~1730--22 after 49 years silence: the peculiar burst properties of the 2021/2022 outbursts observed by Insight-HXMT
After in quiescence for 49 years, 4U~1730--22 became active and had two
outbursts in 2021 \& 2022; ten thermonuclear X-ray bursts were detected with
Insight-HXMT. Among them, the faintest burst showed a double-peaked profile,
placing the source as the 5th accreting neutron star (NS) exhibiting
double/triple-peaked type-I X-ray bursts; the other bursts showed photospheric
radius expansion (PRE). The properties of double-peaked non-PRE burst indicate
that it could be related to a stalled burning front. For the five bright PRE
bursts, apart from the emission from the neutron star (NS) surface, we find the
residuals both in the soft (10 keV) X-ray band.
Time-resolved spectroscopy reveals that the excess can be attributed to an
enhanced pre-burst/persistent emission or the Comptonization of the burst
emission by the corona/boundary-layer. We find, the burst emission shows a rise
until the photosphere touches down to the NS surface rather than the
theoretical predicted constant Eddington luminosity.
The shortage of the burst emission in the early rising phase is beyond the
occlusion by the disk. We speculate that the findings above correspond to that
the obscured part (not only the lower part) of the NS surface is exposed to the
line of sight due to the evaporation of the obscured material by the burst
emission, or the burst emission is anisotropic () in the burst early
phase. In addition, based on the average flux of PRE bursts at their touch-down
time, we derive a distance estimation as 10.4 kpc.Comment: arXiv admin note: substantial text overlap with arXiv:2208.13556;
text overlap with arXiv:2208.1212
Trace the Accretion Geometry of H 1743--322 with Type C Quasi-periodic Oscillations in Multiple Outbursts
We present a systematic analysis of type C quasi-periodic oscillation (QPO)
observations of H 1743--322 throughout the Rossi X-ray Timing Explorer (RXTE)
era. We find that, while different outbursts have significant flux differences,
they show consistent positive correlations between the QPO fractional
root-mean-square (rms) amplitude and non-thermal fraction of the emission,
which indicate an independence of the intrinsic QPO rms on individual outburst
brightness in H 1743--322. However, the dependence of the QPO rms on frequency
is different between the outburst rise and decay phases, where QPO fractional
rms of the decay phase is significantly lower than that of the rise phase at
low frequencies. The spectral analysis also reveals different ranges of coronal
temperature between the two outburst stages. A semi-quantitative analysis shows
that the Lense-Thirring precession model could be responsible for the QPO rms
differences, requiring a variable coronal geometric shape. However, the
variable-Comptonization model could also account for the findings. The fact
that the rms differences and the hysteresis traces in the hardness-intensity
diagram (HID) accompany each other indicates a connection between the two
phenomena. By correlating the findings with QPO phase lags and the
quasi-simultaneous radio flux previously published, we propose there could be
corona-jet transitions in H 1743--322 similar to those that have been recently
reported in GRS 1915+105.Comment: 21 pages, 12 figure
Cation binding to 15-TBA quadruplex DNA is a multiple-pathway cation-dependent process
A combination of explicit solvent molecular dynamics simulation (30 simulations reaching 4 µs in total), hybrid quantum mechanics/molecular mechanics approach and isothermal titration calorimetry was used to investigate the atomistic picture of ion binding to 15-mer thrombin-binding quadruplex DNA (G-DNA) aptamer. Binding of ions to G-DNA is complex multiple pathway process, which is strongly affected by the type of the cation. The individual ion-binding events are substantially modulated by the connecting loops of the aptamer, which play several roles. They stabilize the molecule during time periods when the bound ions are not present, they modulate the route of the ion into the stem and they also stabilize the internal ions by closing the gates through which the ions enter the quadruplex. Using our extensive simulations, we for the first time observed full spontaneous exchange of internal cation between quadruplex molecule and bulk solvent at atomistic resolution. The simulation suggests that expulsion of the internally bound ion is correlated with initial binding of the incoming ion. The incoming ion then readily replaces the bound ion while minimizing any destabilization of the solute molecule during the exchange
Two colistin resistance-producing Aeromonas strains, isolated from coastal waters in Zhejiang, China: characteristics, multi-drug resistance and pathogenicity
IntroductionAeromonas spp. are ubiquitous inhabitants of ecosystems, and many species are opportunistically pathogenic to humans and animals. Multidrug-resistant (MDR) Aeromonas species have been widely detected in hospitals, urban rivers, livestock, and aquatic animals.ResultsIn this study, we identified two Aeromonas isolates, namely Aeromonas veronii 0728Q8Av and Aeromonas caviae 1029Y16Ac, from coastal waters in Zhejiang, China. Both isolates exhibited typical biochemical characteristics and conferred MDR to 11 kinds of antibiotics, remaining susceptible to ceftazidime. Whole-genome sequencing revealed that both isolates harbored multiple antibiotic resistance genes (ARGs) and several mobile genetic elements (MGEs) on the chromosomes, each containing a resistance genomic island (GI), a typical class 1 integron, a transposon, and various insertion sequences (ISs). Most ARGs were situated within the multiple resistance GI, which contained a class 1 integron and a transposon in both Aeromonas isolates. Furthermore, a chromosomal mcr-3.16 gene was identified in A. veronii 0728Q8Av, while a chromosomal mcr-3.3 was found in A. caviae 1029Y16Ac. Both mcr-3 variants were not located within but were distanced from the multidrug resistance GI on the chromosome, flanking by multiple ISs. In addition, a mcr-3-like was found adjacent to mcr-3.16 to form a tandem mcr-3.16-mcr-3-like-dgkA structure; yet, Escherichia coli carrying the recombinants of mcr-3-like did not exhibit resistance to colistin. And an incomplete mcr-3-like was found adjacent to mcr-3.3 in A. caviae 1029Y16Ac, suggesting the possibility that mcr-3 variants originated from Aeromonas species. In vivo bacterial pathogenicity test indicated that A. veronii 0728Q8Av exhibited moderate pathogenicity towards infected ayu, while A. caviae 1029Y16Ac was non-virulent.DiscussionThus, both Aeromonas species deserve further attention regarding their antimicrobial resistance and pathogenicity
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
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