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Doctoral journeys-beyond the Doctorate:Sin-Wang Chong (Part 2)
No full textDoctoral Journeys-Beyond the Doctorate is a podcast and academic blog series
Scalable and robust multiband modeling of AGN light curves in Rubin-LSST
No full textThe Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will monitor tens of millions of active galactic nuclei (AGNs) for a period of 10 yr with an average cadence of 3 days in six broad photometric bands. This unprecedented data set will enable robust characterizations of AGN UV/optical variability across a wide range of AGN physical properties. However, existing tools for modeling AGN light curves are not yet capable of fully leveraging the volume, cadence, and multiband nature of LSST data. We present EzTaoX, a scalable light-curve modeling tool designed to take advantage of LSST’s multiband observations to simultaneously characterize AGN UV/optical stochastic variability and measure interband time delays. EzTaoX achieves a speed increase of ∼102–104× on CPUs over current tools with similar capabilities, while maintaining equal or better accuracy in recovering simulated variability properties. This performance gain enables continuum time-delay measurements for all AGNs discovered by LSST—both in the Wide Fast Deep survey and the Deep Drilling Fields—thereby opening new opportunities to probe AGN accretion-flow geometries. In addition, EzTaoX’s multiband capability allows for robust characterization of AGN stochastic variability down to hourly timescales, facilitating the identification of accreting low-mass AGNs—such as those residing in dwarf galaxies—through their distinctive variability signatures
Biofilter performance, water quality, and microbial dynamics in RAS operated under high or low suspended solids load
No full textAccumulation of total suspended solids (TSS) in recirculating aquaculture systems (RAS) may be harmful to fish and biofilter functionality, and there is a link between particulate organic matter and heterotrophic bacteria proliferation in RAS. In this study, the chronic effects of high total suspended solids (HTSS, n = 3) in RAS were assessed on water quality, biofilter performance, and microbiota, compared to RAS with low levels of suspended solids (LTSS, n = 3), during a 128 day-trial following smoltification procedures on Atlantic salmon.Higher TSS concentration (1 vs 7 mg/L) was accompanied by increased organic matter, particle concentration, surface area, and volume, and bacterial concentration and activity in the water and the biofilter. Furthermore, high TSS systems exhibited higher mean levels of ammonia and nitrite, and lower levels of nitrate. Fish biomass increase after 128 days was 14 % lower in HTSS systems. The microbiota composition in the water and biofilter-biofilm was altered by TSS load, and competition from heterotrophic bacteria may have reduced the nitrifying capacity of the biofilter.A combined nutritional-hydrobiological model was developed to assess the effect of commercially-relevant C/N ratios on biofilter performance. Nitrification was not affected by calculated C/N ratios between 4.0 and 5.4, but the dynamics of nitrification were influenced by nitrogen load and source (fish or bacteria). This model is a promising tool for biofilter assessment studies in commercially-relevant scenarios but requires further development and validation.The results indicate the potential impacts of accumulating organic matter on RAS water quality, microbiota, and fish performance
King Eysteinn's raid on Aberdeen and the Scottish Kingdom in the mid-twelfth century
No full textIn the early 1150s King Eysteinn of Norway led an expedition to northern Britain and among other targets attacked the newly founded burgh of Aberdeen. The paper examines the context and ramifications of this attack
Timing matters:early administration of a high-affinity antibody targeting the tau repeat domain prevents aggregation in a mouse tauopathy model
No full textIntroduction: Immunotherapy is an attractive proposition for preventing the spread of pathologic tau in Alzheimer’s disease and other tauopathies. Given that tau is heavily truncated in tauopathies, it is hypothesised that directly targeting the repeat domain which forms the core of pathological filaments will improve the likelihood of success. S1D12, a chimeric IgG2a isolated via phage display, recognises 2N4R tau341-353 with high affinity (200 pM) and has previously been shown to prevent tau aggregation and propagation in vitro. We further explored the pharmacokinetics and biodistribution of S1D12 as well as its efficacy in a tauopathy mouse model. We also verified its efficacy in vitro against tau seeding species from multiple human tauopathies.Methods: Single dose S1D12 intraperitoneal injections (30 mg/kg) were performed in wild-type mice followed by tissue harvest at multiple time points. For efficacy studies, four-weekly doses followed by four-fortnightly doses of S1D12 (30 mg/kg) or negative control antibody were administered intraperitoneally to Line 66 tau transgenic mice. Two cohorts, beginning from 2 months and 4.5 months of age were utilised. Endpoints included quantification of aggregated tau, seed-competent tau and insoluble phosphorylated tau in brain homogenates, as well as neurofilament light (NfL), tau phosphorylated at Thr-217 (pTau217) and core tau in plasma.Results: S1D12 was detected in plasma and in brain with a tmax of 24/48 h respectively, and a slow washout over 7 days (t1/2 > 230 h), with 0.35% CNS bioavailability. S1D12 inhibited the generation of aggregated tau, seed-competent tau and insoluble phosphorylated tau in transgenic mice. This was associated with a reduction in NfL and pTau217, and an increase in core tau in plasma. In the 4.5-month cohort, S1D12 did not remove already established tau aggregates below baseline. Additionally, S1D12 inhibited seeding tau species from different tauopathies to a similar degree, independent of structural diversity.Conclusions: S1D12, a high-affinity antibody targeting the R4 repeat domain of tau offers potential for halting progression of tau pathology through inhibition of tau aggregation rather than removal of established aggregates. These findings support the notion that both early diagnosis and intervention are key for the treatment of AD and other tauopathies
Diplomacy, security and economic development in China-Afghanistan relations
No full textIn this contribution I examine the challenges and opportunities in the relations between Afghanistan and China from the vantage point of three connectivity projects: the Mes Aynak copper mine, the Amu Darya oil field and the Wakhan road project. Taken together, these three projects, while not exhaustive of the entirety of the bilateral relationship, offer a nuanced picture of the promise and perils accompanying Chinese efforts to invest in Afghanistan
The sedimentary geochemistry and paleoenvironments project phase 2 data release:an open data resource for the study of Earth's environmental history
No full textMultiple convolutions and multilinear fractal Fourier extension estimates
No full textThe classical Stein--Tomas theorem extends the theory of linear Fourier restriction estimates from smooth manifolds to fractal measures exhibiting Fourier decay. In the multilinear setting, transversality allows for Fourier extension estimates that go beyond those implied by the linear theory to hold. We establish a multilinear Fourier extension estimate for measures whose convolution belongs to an space, applicable to known results by Shmerkin and Solomyak that exploit `transversality' between self-similar measures. Moreover, we generalise work by Hambrook--Łaba and Chen from the linear setting to obtain Knapp-type examples for multilinear estimates; we obtain two necessary conditions: one in terms of the upper box dimension of the measures' supports, and another one in terms of their Fourier decay and a ball condition. In particular, these conditions give a more restrictive range compared with previously known results whenever the convolution of the measures at play is singular
Transcriptomic responses to <i>Marteilia sydneyi</i> infection in the Sydney rock oyster <i>Saccostrea glomerata</i>
No full textMarteilia sydneyi, an ascetosporean parasite, is the causative agent of Queensland Unknown (QX) disease in Saccostrea glomerata. QX disease outbreaks often lead to high mortality rates and considerable population losses. Investigating molecular host/parasite interactions is imperative to better understand how S. glomerata mounts immune defences and to explore whether M. sydneyi evades host responses. This study aims to investigate S. glomerata's response to M. sydneyi infection through differential gene expression analysis to uncover immune mechanisms and potential markers for resistance. RNA sequencing and differential gene expression analysis revealed widespread transcriptional changes between infected and non-infected oysters. Genes involved in pathogen recognition and immune response signalling, such as galectin-4-like and G-protein coupled receptors, were significantly differentially expressed in infected S. glomerata, suggesting involvement in the host's immune responses. The upregulation of cytochrome P450 family genes indicates an enhanced detoxification response to infection-induced stress. However, extracellular superoxide dismutase, a gene previously implicated in the oxidative stress response to pathogens, was significantly downregulated, suggesting potential suppression of oxidative burst defence mechanisms. These results reveal the complex nature of S. glomerata's response to M. sydneyi infection, and possible suppression or evasion of host defences by the parasite. The study also identifies multiple genes that likely play crucial roles in the molecular responses and defence mechanisms of S. glomerata to M. sydneyi infection. The identification of these genes provides potential target genes for future studies and possible biomarkers for breeding QX-resistant oyster lines
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