Uptake, distribution and elimination of palladium-doped polystyrene nanoplastics in rainbow trout (Oncorhynchus mykiss) following dietary exposure.

The ingestion of nanoplastics (NPs) by fish has led to concerns regarding fish health and food chain transfer, but analytical constraints have hindered quantitative data collection on their uptake and depuration. We used palladium-doped polystyrene nanoplastics (PS-Pd NPs, ~200 nm) to track particle fate in rainbow trout (Oncorhynchus mykiss) during a week-long dietary exposure and subsequent 7-day depuration period on a control diet (no added PS-Pd NPs). At Day 3 and 7 of the exposure, and after depuration, the mid intestine, hind intestine, liver, gallbladder, kidney, gill and carcass were sampled. All organs and the carcass were analysed for total Pd content by inductively couple plasma mass spectrometry. After 3 days of exposure, the mid (32.5 ± 8.3 ng g-1) and hind (42.3 ± 8.2 ng g-1) intestine had significantly higher total Pd concentrations compared to the liver and carcass (1.3 ± 0.4 and 3.4 ± 1.1 ng g-1, respectively). At Day 7, there was no time-related difference in any organ (or the carcass) total Pd concentrations compared to Day 3. When the total Pd content was expressed as a body distribution based on mass of tissue, the carcass contained the highest fraction with 72.5 ± 5.2 % at Day 7, which could raise concerns over transfer to higher trophic levels. The total number of particles that entered the fish over the 7 days was 94.5 ± 13.5 × 106 particles, representing 0.07 ± 0.01 % of the Pd the fish had been fed. Following depuration, there was no detectable Pd in any organ or the carcass, indicating clearance from the fish. These data indicate that these NPs are taken into the internal organs and carcass of fish, yet removal of the exposure results in substantial excretion to below the limit of detection

Ultrasonic Monitoring of Recrystallization Textures in Aluminum

The present paper is an attempt to use ultrasonic velocity measurements to characterize the texture of an aluminum-magnesium alloy (Al 5xxx) and to compare the results with orientation imaging microscopy (OIM) results. The results are characterized in terms of three orientation distribution coefficients (ODC’s), W400, W420, and W440, each of which describes a particular forming anisotropy, and each of which has significant impact on the final products

Demonstrating the translocation of nanoplastics across the fish intestine using palladium-doped polystyrene in a salmon gut-sac

Fish are widely reported to ingest microplastics with low levels accumulating in the tissues, but owing to analytical constraints, much less is known about the potential accumulation of nanoplastics via the gut. Recently, the labelling of plastics with inorganic metals (e.g., palladium) has allowed measurements of nanoplastic uptake. The aim of the current study was to quantitatively assess the uptake of nanoplastics by the fish gut using palladium-doped nanoplastics (with a mean hydrodynamic radius of 202 ± 7 nm). By using an ex vivo gut sac exposure system, we show that in 4 h between 200 and 700 million nanoplastics (representing 2.5–9.4% of the administered nanoplastics dose) can enter the mucosa and muscularis layers of the intestine of salmon. Of the particles taken up, up to 700,000 (representing 0.6% of that taken into the tissue) of the nanoplastics passed across the gut epithelium of the anterior intestine and exit into the serosal saline. These data, generated in highly controlled conditions provide a proof-of-concept study, suggesting the potential for nanoplastics to distribute throughout the body, indicating the potential for systemic exposure in fish.Demonstrating the translocation of nanoplastics across the fish intestine using palladium-doped polystyrene in a salmon gut-sacpublishedVersio

Synthesis and Anti-Mycobacterium tuberculosis Activity of Imidazo[2,1-b][1,3]oxazine Derivatives against Multidrug-Resistant Strains

The emergence of multidrug-resistant strains of M. tuberculosis has raised concerns due to the greater difficulties in patient treatment and higher mortality rates. Herein, we revisited the 2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine scaffold and identified potent new carbamate derivatives having MIC90 values of 0.18–1.63 μM against Mtb H37Rv. Compounds 47–49, 51–53, and 55 exhibited remarkable activity against a panel of clinical isolates, displaying MIC90 values below 0.5 μM. In Mtb-infected macrophages, several compounds demonstrated a 1-log greater reduction in mycobacterial burden than rifampicin and pretomanid. The compounds tested did not exhibit significant cytotoxicity against three cell lines or any toxicity to Galleria mellonella. Furthermore, the imidazo[2,1-b][1,3]oxazine derivatives did not show substantial activity against other bacteria or fungi. Finally, molecular docking studies revealed that the new compounds could interact with the deazaflavin-dependent nitroreductase (Ddn) in a similar manner to pretomanid. Collectively, our findings highlight the chemical universe of imidazo[2,1-b][1,3]oxazines and their promising potential against MDR-TB

The AIMSS Project – III. The Stellar Populations of Compact Stellar Systems

In recent years, a growing zoo of compact stellar systems (CSSs) have been found whose physical properties (mass, size, velocity dispersion) place them between classical globular clusters (GCs) and true galaxies, leading to debates about their nature. Here we present results using a so far underutilized discriminant, their stellar population properties. Based on new spectroscopy from 8–10m telescopes, we derive ages, metallicities, and [α/Fe] of 29 CSSs. These range from GCs with sizes of merely a few parsec to compact ellipticals (cEs) larger than M32. Together with a literature compilation, this provides a panoramic view of the stellar population characteristics of early-type systems. We find that the CSSs are predominantly more metal rich than typical galaxies at the same stellar mass. At high mass, the cEs depart from the mass–metallicity relation of massive early-type galaxies, which forms a continuous sequence with dwarf galaxies. At lower mass, the metallicity distribution of ultracompact dwarfs (UCDs) changes at a few times 107 M⊙, which roughly coincides with the mass where luminosity function arguments previously suggested the GC population ends. The highest metallicities in CSSs are paralleled only by those of dwarf galaxy nuclei and the central parts of massive early types. These findings can be interpreted as CSSs previously being more massive and undergoing tidal interactions to obtain their current mass and compact size. Such an interpretation is supported by CSSs with direct evidence for tidal stripping, and by an examination of the CSS internal escape velocities

Genomic analysis of male puberty timing highlights shared genetic basis with hair colour and lifespan

The timing of puberty is highly variable and is associated with long-term health outcomes. To date, understanding of the genetic control of puberty timing is based largely on studies in women. Here, we report a multi-trait genome-wide association study for male puberty timing with an effective sample size of 205,354 men. We find moderately strong genomic correlation in puberty timing between sexes (rg = 0.68) and identify 76 independent signals for male puberty timing. Implicated mechanisms include an unexpected link between puberty timing and natural hair colour, possibly reflecting common effects of pituitary hormones on puberty and pigmentation. Earlier male puberty timing is genetically correlated with several adverse health outcomes and Mendelian randomization analyses show a genetic association between male puberty timing and shorter lifespan. These findings highlight the relationships between puberty timing and health outcomes, and demonstrate the value of genetic studies of puberty timing in both sexes

Reporting conditionals with modals

Conditionals and modals work in tandem in some instances of practical reasoning, or decision making. Consider the following example (from Kratzer 2012): a. I want to become a mayor. b. (q) I will become a mayor only if (p) I go to the pub. c. Therefore, I should go to the pub. Given what the cogniser wants (a) and the relevant circumstances (b), the conclusion that the cogniser goes to the pub comes out as necessary. Hence, the presence of the necessity modal should in (c). Indeed, given the context of (a), the necessity modal in (c) is simply a reflection of the necessity of p for q, which is overtly represented by the use of the ‘only if p, q’ construction. This chapter looks into whether indirect reports of conditionals – in particular, indirect reports which involve the use of a modal verb – are sensitive to the necessity of p for q in cases where necessity is not overtly represented in a conditional, as in ‘if p, q’ formulations. We report on two online experiments into the relation between (i) perceived necessity or sufficiency of the truth of a conditional antecedent for the truth of the consequent, and (ii) the formulation of an indirect report of a conditional with necessity or possibility modals (have to, should, could). In Experiment 1, the ‘necessity/sufficiency of p for q’ variable was manipulated by contextually altering the number of alternative antecedents (e.g. Cummins et al. 1991; Thompson 1994; Politzer 2003). It was found that modals used in indirect reports of ‘if p, q’ conditionals co-vary with the number of alternative antecedents in predictable ways. This suggests that modals used in indirect reports of ‘if p, q’ conditionals may be a diagnostic for biconditional versus material interpretations of conditionals. The aim of Experiment 2 was to find out whether the results of Experiment 1 could be replicated in contexts which lower/eliminate the believability of the conditionals. It was found that manipulating the believability variable has no reliable effect on the results

Baryon Washout, Electroweak Phase Transition, and Perturbation Theory

We analyze the conventional perturbative treatment of sphaleron-induced baryon number washout relevant for electroweak baryogenesis and show that it is not gauge-independent due to the failure of consistently implementing the Nielsen identities order-by-order in perturbation theory. We provide a gauge-independent criterion for baryon number preservation in place of the conventional (gauge-dependent) criterion needed for successful electroweak baryogenesis. We also review the arguments leading to the preservation criterion and analyze several sources of theoretical uncertainties in obtaining a numerical bound. In various beyond the standard model scenarios, a realistic perturbative treatment will likely require knowledge of the complete two-loop finite temperature effective potential and the one-loop sphaleron rate.Comment: 25 pages, 9 figures; v2 minor typos correcte