A sensitive method for the detection of legacy and emerging per- and polyfluorinated alkyl substances (PFAS) in dairy milk

There is widespread contamination by per- and polyfluoroalkyl substances (PFAS) across the globe, with adverse effects on human and environmental health. For human exposure, drinking water and dietary exposure have been recognized as important PFAS exposure pathway for the general population. Several documented cases of dairy milk contamination by PFAS have raised concerns over this exposure pathway in general. A sensitive method for determination of 27 PFAS in milk was hence modified and applied on raw and processed milk samples from 13 farms across the United States (U.S.). A combination of acid and basic extraction method and ENVI-Carb clean-up achieved recoveries of targeted PFAS between 70 and 141%. The method detection limits (MDL) ranged from 0.8 to 22 ng/L (for 26 PFAS) and 144 ng/L for perfluorobutanoic acid (PFBA). The uniqueness of this method is considered in the targeted screening of a broad range of legacy PFAS, as well as perfluorinated sulfonamide species and fluorotelomer sulfonates. No legacy PFAS were detected in 13 milk samples from regions of concern given local use of biosolids or proximity to fire training areas. Overall, then, the uptake of perfluoroalkyl acids (PFAA) from dairy milk in the U.S. is considered low

Local moments and symmetry breaking in metallic PrMnSbO

We report a combined experimental and theoretical investigation of the layered antimonide PrMnSbO which is isostructural to the parent phase of the iron pnictide superconductors. We find linear resistivity near room temperature and Fermi liquid-like T^{2} behaviour below 150 K. Neutron powder diffraction shows that unfrustrated C-type Mn magnetic order develops below \sim 230 K, followed by a spin-flop coupled to induced Pr order. At T \sim 35 K, we find a tetragonal to orthorhombic (T-O) transition. First principles calculations show that the large magnetic moments observed in this metallic compound are of local origin. Our results are thus inconsistent with either the itinerant or frustrated models proposed for symmetry breaking in the iron pnictides. We show that PrMnSbO is instead a rare example of a metal where structural distortions are driven by f-electron degrees of freedom

Was ist "Identität"?

´In dem Beitrag wird der Versuch unternommen, die Konzepte "Identität", "Identitätsbewußtsein", "Selbstkonzept" und "Selbstwertgefühl" zu spezifizieren und einen allgemeinen Ansatz zu einer Erklärung des Wandels von Identität zu formulieren. Der Autor geht auf soziologische und sozialpsychologische Identitätstheorien ein (Mead, Goffman, Krappmann), kritisiert diese dem symbolischen Interaktionismus zuzurechnenden Ansätze und stellt Ansätze der Selbstkonzeptforschung vor. Insbesondere Ansätze der Selbstkonzeptforschung, die den Schwerpunkt auf die Informationsverarbeitung legen, sieht er als theoretisch verheißungsvoll an. Nach diesem Überblick entwirft er selbst eine Identitätstheorie unter Bezugnahme auf die Wert-Erwartungs-Theorie (SEU-Theorie). Aus dieser Perspektive werden wiederholt erfolgreiche Sequenzen von Handlungen zu relativ dauerhaften Reaktionsmustern. Diese von den Individuen wahrgenommenen und kategorisierten Reaktionsmuster werden als "Identitäten" bezeichnet. Der Autor zeigt, wie mit dieser Sichtweise verschiedene soziologische Identitäts-Konzepte und sozialpsychologische Annahmen von "habits" und "traits" und "traits" theoretisch integriert werden können. (PF

Performance of ECG-based seizure detection algorithms strongly depends on training and test conditions

Objective To identify non-EEG-based signals and algorithms for detection of motor and non-motor seizures in people lying in bed during video-EEG (VEEG) monitoring and to test whether these algorithms work in freely moving people during mobile EEG recordings. Methods Data of three groups of adult people with epilepsy (PwE) were analyzed. Group 1 underwent VEEG with additional devices (accelerometry, ECG, electrodermal activity); group 2 underwent VEEG; and group 3 underwent mobile EEG recordings both including one-lead ECG. All seizure types were analyzed. Feature extraction and machine-learning techniques were applied to develop seizure detection algorithms. Performance was expressed as sensitivity, precision, F$_{1}$ score, and false positives per 24 hours. Results The algorithms were developed in group 1 (35 PwE, 33 seizures) and achieved best results (F$_{1}$ score 56%, sensitivity 67%, precision 45%, false positives 0.7/24 hours) when ECG features alone were used, with no improvement by including accelerometry and electrodermal activity. In group 2 (97 PwE, 255 seizures), this ECG-based algorithm largely achieved the same performance (F$_{1}$ score 51%, sensitivity 39%, precision 73%, false positives 0.4/24 hours). In group 3 (30 PwE, 51 seizures), the same ECG-based algorithm failed to meet up with the performance in groups 1 and 2 (F$_{1}$ score 27%, sensitivity 31%, precision 23%, false positives 1.2/24 hours). ECG-based algorithms were also separately trained on data of groups 2 and 3 and tested on the data of the other groups, yielding maximal F1 scores between 8% and 26%. Significance Our results suggest that algorithms based on ECG features alone can provide clinically meaningful performance for automatic detection of all seizure types. Our study also underscores that the circumstances under which such algorithms were developed, and the selection of the training and test data sets need to be considered and limit the application of such systems to unseen patient groups behaving in different conditions

Characterizing uncertainty in process-based hydraulic modeling, exemplified in a semiarid Inner Mongolia steppe

Assessing root sources of three uncertainties – parameterization of soil hydraulic characteristics, boundary conditions, and estimation of source/sink terms – is a significant challenge in soil water transport modeling. This study aims to evaluate the uncertainty of three each widely-used parameter estimation methods affecting plot-scale water dynamics. The study employs HYDRUS, a process-based hydrologic model, to incorporate these uncertainties and compare model predictions to measured values in a semiarid Inner Mongolia steppe, China. Soil hydraulic parameters are determined using two direct methods (laboratory-derived approach and evaporation method) and one indirect method (neural network). While each hydraulic parameter method generally simulates soil moisture dynamics, the evaporation method performed better, especially under dry conditions. This suggests that measuring the intensity properties, such as unsaturated hydraulic conductivity, with the evaporation method is crucial for reasonable soil moisture simulation. The study also demonstrates the impact of different applied boundary conditions on simulated soil moisture, specifically the partitioning of reference FAO evapotranspiration via one direct method (soil fraction cover) and two indirect methods (leaf area index and crop height). The partitioning via soil fraction cover reflected a better simulation. Additionally, the study compares the uncertainties of root water uptake function with root growth parameters and constant root depth referenced to grass and pasture, and finds no significant difference among them. Comparing three sources of uncertainty in predicting soil moisture, the study concludes that the input soil hydraulic parameter is more sensitive than evapotranspiration partitioning or representation of root water uptake function. Our study highlights that measuring soil intensity properties can better reflect the effects of land use change, such as compaction, on field water transports

Bioconcentration of per- and polyfluoroalkyl substances and precursors in fathead minnow tissues environmentally exposed to aqueous film-forming foam–contaminated waters

Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with toxicity in wildlife and negative health effects in humans. Decades of fire training activity at Joint Base Cape Cod (MA, USA) incorporated the use of aqueous film-forming foam (AFFF), which resulted in long-term PFAS contamination of sediments, groundwater, and hydrologically connected surface waters. To explore the bioconcentration potential of PFAS in complex environmental mixtures, a mobile laboratory was established to evaluate the bioconcentration of PFAS from AFFF-impacted groundwater by flow-through design. Fathead minnows (n = 24) were exposed to PFAS in groundwater over a 21-day period and tissue-specific PFAS burdens in liver, kidney, and gonad were derived at three different time points. The ∑PFAS concentrations in groundwater increased from approximately 10,000 ng/L at day 1 to 36,000 ng/L at day 21. The relative abundance of PFAS in liver, kidney, and gonad shifted temporally from majority perfluoroalkyl sulfonamides (FASAs) to perfluoroalkyl sulfonates (PFSAs). By day 21, mean ∑PFAS concentrations in tissues displayed a predominance in the order of liver \u3e kidney \u3e gonad. Generally, bioconcentration factors (BCFs) for FASAs, perfluoroalkyl carboxylates (PFCAs), and fluorotelomer sulfonates (FTS) increased with degree of fluorinated carbon chain length, but this was not evident for PFSAs. Perfluorooctane sulfonamide (FOSA) displayed the highest mean BCF (8700 L/kg) in day 21 kidney. Suspect screening results revealed the presence of several perfluoroalkyl sulfinate and FASA compounds present in groundwater and in liver for which pseudo-bioconcentration factors are also reported. The bioconcentration observed for precursor compounds and PFSA derivatives detected suggests alternative pathways for terminal PFAS exposure in aquatic wildlife and humans. Environ Toxicol Chem 2024;00:1–12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC

Ultrahigh energy cosmic rays from dark matter annihilation

Annihilation of clumped superheavy dark matter provides an interesting explanation for the origin of ultrahigh energy cosmic rays. The predicted anisotropy signal provides a unique signature for this scenario.Comment: 4 pages, 2 figures, to appear in the proceedings of Dark Matter 2002: Sources and Detection of Dark Matter and Dark Energy in the Univers

Millimetre observations of a sample of high-redshift obscured quasars

We present observations at 1.2 mm with MAMBO-II of a sample of z>~2 radio-intermediate obscured quasars, as well as CO observations of two sources with the Plateau de Bure Interferometer. Five out of 21 sources (24%) are detected at a significance of >=3sigma. Stacking all sources leads to a statistical detection of = 0.96+-0.11 mJy and stacking only the non-detections also yields a statistical detection, with = 0.51+-0.13 mJy. This corresponds to a typical far-infrared luminosity L_FIR~4x10^12 Lsol. If the far-infrared luminosity is powered entirely by star-formation, and not by AGN-heated dust, then the characteristic inferred star-formation rate is ~700 Msol yr-1. This far-infrared luminosity implies a dust mass of M_dust~3x10^8 Msol. We estimate that such large dust masses on kpc scales can plausibly cause the obscuration of the quasars. We present dust SEDs for our sample and derive a mean SED for our sample. This mean SED is not well fitted by clumpy torus models, unless additional extinction and far-infrared re-emission due to cool dust are included. There is a hint that the host galaxies of obscured quasars must have higher far-infrared luminosities and cool-dust masses and are therefore often found at an earlier evolutionary phase than those of unobscured quasars. For one source at z=2.767, we detect the CO(3-2) transition, with S_CO Delta nu=630+-50 mJy km s-1, corresponding to L_CO(3-2)= 3.2x10^7 Lsol, or L'_CO(3-2)=2.4x10^10 K km s-1 pc2. For another source at z=4.17, the lack of detection of the CO(4-3) line yields a limit of L'_CO(4-3)<1x10^10 K km s-1 pc2. Molecular gas masses, gas depletion timescales and gas-to-dust ratios are estimated (Abridged).Comment: Accepted by ApJ, 25 pages, 11 figures, 4 table

Explicit processing of verbal and spatial features during letter-location binding modulates oscillatory activity of a fronto-parietal network.

The present study investigated the binding of verbal and spatial features in immediate memory. In a recent study, we demonstrated incidental and asymmetrical letter-location binding effects when participants attended to letter features (but not when they attended to location features) that were associated with greater oscillatory activity over prefrontal and posterior regions during the retention period. We were interested to investigate whether the patterns of brain activity associated with the incidental binding of letters and locations observed when only the verbal feature is attended differ from those reflecting the binding resulting from the controlled/explicit processing of both verbal and spatial features. To achieve this, neural activity was recorded using magnetoencephalography (MEG) while participants performed two working memory tasks. Both tasks were identical in terms of their perceptual characteristics and only differed with respect to the task instructions. One of the tasks required participants to process both letters and locations. In the other, participants were instructed to memorize only the letters, regardless of their location. Time–frequency representation of MEG data based on the wavelet transform of the signals was calculated on a single trial basis during the maintenance period of both tasks. Critically, despite equivalent behavioural binding effects in both tasks, single and dual feature encoding relied on different neuroanatomical and neural oscillatory correlates. We propose that enhanced activation of an anterior–posterior dorsal network observed in the task requiring the processing of both features reflects the necessity for allocating greater resources to intentionally process verbal and spatial features in this task