Oxygen isotopic composition of early Eocene fishapatite from hole 913 B, ODP Leg 151: An indicator of the early Norwegian-Greenland Sea paleosalinity

Fish-apatite (teeth and bone fragments) of early Eocene age from Ocean Drilling Program Hole 913B (Greenland Basin) was analyzed, in the absence of biogenic calcite, for stable isotopic (δ1 8θco,2~, δ13C) composition to determine paleosalinity. Comparisons are made with isotopic results for early Eocene fish-apatite from Deep Sea Drilling Project (DSDP) Hole 550 (northeastern Atlantic) and the R0snaεs Clay Formation (Denmark). These two sites represent fully marine and semimarine conditions, respectively. The δ^Ocα,2- values of the fish-apatite from Hole 913B are 4.3%o to 8.1%c more negative than the fish-apatite values from DSDP Hole 550, and 1.9%o to 6.1%o more negative than the values from the R0snses Clay Formation. The results indicate reduced salinity in the early Eocene Greenland Basin relative to the open ocean. Using the present salinity/ δ'8O relationship in the North Atlantic, the salinity in the Greenland Basin was 22 ppt to 28 ppt. The reduced salinity is in agreement with an isolated early Eocene Greenland Basin, as suggested in earlier geophysical and paleontological studies. It is also likely that other parts of the Norwegian-Greenland Sea, such as the Lofoten Basin, exhibited brackish water conditions. Because of similar oxygen-isotopic composition of fish-apatite and excellently preserved foraminifer tests in the samples from the R0snaεs Clay Formation as well as DSDP Hole 550, we consider the fish-apatite δ1 8θco,2 - t o be a reliable instrument for paleosalinity determination. It is possible that the fish-apatite was exposed to diagenesis and isotopic reequilibration shortly after deposition on the seafloor. This should not, however, reduce the possibility of using δ1 8θco,2 - as an indicator of paleosalinity, because both δ1 8θ and salinity usually are very similar in the uppermost pore water and the overlying water mass. The fish-apatite δ13C values may support that early diagenesis has affected the original isotopic signal. The values seem to be related to the organic carbon content of the sediment as the lowest δ13C values, -4.6%c to -10.5%o, are found in the fish-apatite from the very dark sediment of Hole 913B, whereas the highest δ13C values, +0.6‰ to -1.7%o, are found in the pale, oxidized sediment of DSDP Hole 550

Dynamics of cerebrospinal fluid levels of matrix metalloproteinases in human traumatic brain injury

Matrix metalloproteinases (MMPs) are extracellular enzymes involved in the degradation of extracellular matrix (ECM) proteins. Increased expression of MMPs have been described in traumatic brain injury (TBI) and may contribute to additional tissue injury and blood–brain barrier damage. The objectives of this study were to determine longitudinal changes in cerebrospinal fluid (CSF) concentrations of MMPs after acute TBI and in relation to clinical outcomes, with patients with idiopathic normal pressure hydrocephalus (iNPH) serving as a contrast group. The study included 33 TBI patients with ventricular CSF serially sampled, and 38 iNPH patients in the contrast group. Magnetic bead-based immunoassays were utilized to measure the concentrations of eight MMPs in ventricular human CSF. CSF concentrations of MMP-1, MMP-3 and MMP-10 were increased in TBI patients (at baseline) compared with the iNPH group (p < 0.001), while MMP-2, MMP-9 and MMP-12 did not differ between the groups. MMP-1, MMP-3 and MMP-10 concentrations decreased with time after trauma (p = 0.001–0.04). Increased concentrations of MMP-2 and MMP-10 in CSF at baseline were associated with an unfavourable TBI outcome (p = 0.002–0.02). Observed variable pattern of changes in MMP concentrations indicates that specific MMPs serve different roles in the pathophysiology following TBI, and are in turn associated with clinical outcomes

Analytical and clinical validation of a blood progranulin ELISA in frontotemporal dementias

Heterozygous mutations in the granulin (GRN) gene may result in haploinsufficiency of progranulin (PGRN), which might lead to frontotemporal dementia (FTD). In this study, we aimed to perform analytical and clinical validation of a commercial progranulin kit for clinical use. Analytical validation parameters including assay precision, selectivity, measurement range, dilution linearity, interferences and sample stability were tested according to previously described procedures. For clinical validation, PGRN levels were measured in plasma from 32 cognitively healthy individuals, 52 confirmed GRN mutation carriers, 25 C9orf72 mutation carriers and 216 patients with different neurodegenerative diseases of which 70 were confirmed as non-mutation carriers. Among the analytical validation parameters, assay precision and repeatability were very stable (coefficients of variation <7 %). Spike recovery was 96 %, the measurement range was 6.25-400 μg/L and dilution linearity ranged from 1:50-1:200. Hemolysis did not interfere with progranulin levels, and these were resistant to freeze/thaw cycles and storage at different temperatures. For the clinical validation, the assay was capable of distinguishing GRN mutation carriers from controls and non-GRN mutation carriers with very good sensitivity and specificity at a cut-off of 57 μg/L (97 %, 100 %, respectively). In this study, we demonstrate robust analytical and diagnostic performance of this commercial progranulin kit for implementation in clinical laboratory practice. This easy-to-use test allows identification of potential GRN mutation carriers, which may guide further evaluation of the patient. This assay might also be used to evaluate the effect of novel PGRN-targeting drugs and therapies

Gravastar energy conditions revisited

We consider the gravastar model where the vacuum phase transition between the de Sitter interior and the Schwarzschild or Schwarzschild-de Sitter exterior geometries takes place at a single spherical delta-shell. We derive sharp analytic bounds on the surface compactness (2m/r) that follow from the requirement that the dominant energy condition (DEC) holds at the shell. In the case of Schwarzschild exterior, the highest surface compactness is achieved with the stiff shell in the limit of vanishing (dark) energy density in the interior. In the case of Schwarzschild-de Sitter exterior, in addition to the gravastar configurations with the shell under surface pressure, gravastar configurations with vanishing shell pressure (dust shells), as well as configurations with the shell under surface tension, are allowed by the DEC. Respective bounds on the surface compactness are derived for all cases. We also consider the speed of sound on the shell as derived from the requirement that the shell is stable against the radial perturbations. The causality requirement (sound speed not exceeding that of light) further restricts the space of allowed gravastar configurations.Comment: LaTeX/IOP-style, 16 pages, 2 figures, changes wrt v1: motivation for eq. (6) clarified, several referecnes added (to appear in Class. Quantum Grav.

Phonon spectra of pure and acceptor doped BaZrO3 investigated with visible and UV Raman spectroscopy

We report results from visible and UV Raman spectroscopy studies of the phonon spectra of a polycrystalline sample of the prototypical perovskite type oxide BaZrO3 and a 500 nm thick film of its Y-doped, proton conducting, counterpart BaZr0.8Y0.2O2.9. Analysis of the Raman spectra measured using different excitation energies (between 3.44 eV and 5.17 eV) reveals the activation of strong resonance Raman effects involving all lattice vibrational modes. Specifically, two characteristic energies were identified for BaZrO3, one around 5 eV and one at higher energy, respectively, and one for BaZr0.8Y0.2O2.9, above 5 eV. Apart from the large difference in spectral intensity between the non-resonant and resonant conditions, the spectra are overall similar to each other, suggesting that the vibrational spectra of the perovskites are stable when investigated using an UV laser as excitation source. These results encourage further use of UV Raman spectroscopy as a novel approach for the study of lattice vibrational dynamics and local structure in proton conducting perovskites, and open up for, e.g., time-resolved experiments on thin films targeted at understanding the role of lattice vibrations in proton transport in these kinds of materials

Interdisciplinary perspectives on offshore energy system integration in the North Sea: A systematic literature review

To facilitate the rapid and large-scale developments of offshore wind energy, scholars, policymakers and infrastructure developers must start considering its integration into the larger onshore energy system. Such offshore system integration is defined as the coordinated approach to planning and operation of energy generation, transport and storage in the offshore energy system, across multiple energy carriers and sectors. This article conducts a systematic literature review to identify infrastructure components of offshore energy system integration (including alternative cable connections, offshore energy storage, and power-to-hydrogen applications) and barriers to their development. An interdisciplinary perspective is provided where current offshore developments require not only mature and economically feasible technologies, but equally strong legal and governance frameworks. The findings demonstrate that current literature lacks a holistic perspective on the offshore energy system. To date, techno-economic assessments solving challenges of specific infrastructure components prevail over an integrated approach. Nevertheless, permitting issues, gaps in legal frameworks, strict safety and environmental regulations, and spatial competition also emerge as important barriers. Overall, this literature review emphasizes the necessity of aligning various disciplines to provide a fundamental approach for the development of an integrated offshore energy system. More specifically, timely policy and legal developments are key to incentivize technical development and enable economic feasibility of novel components of offshore system integration. Accordingly, to maximize real-world application and policy learning, future research will benefit from an interdisciplinary perspective

The Schro¨\ddot{o}dinger-Poisson equations as the large-N limit of the Newtonian N-body system: applications to the large scale dark matter dynamics

In this paper it is argued how the dynamics of the classical Newtonian N-body system can be described in terms of the Schr$\ddot{o}$dinger-Poisson equations in the large $N$ limit. This result is based on the stochastic quantization introduced by Nelson, and on the Calogero conjecture. According to the Calogero conjecture, the emerging effective Planck constant is computed in terms of the parameters of the N-body system as $\hbar \sim M^{5/3} G^{1/2} (N/)^{1/6}$, where is $G$ the gravitational constant, $N$ and $M$ are the number and the mass of the bodies, and $$ is their average density. The relevance of this result in the context of large scale structure formation is discussed. In particular, this finding gives a further argument in support of the validity of the Schr$\ddot{o}$dinger method as numerical double of the N-body simulations of dark matter dynamics at large cosmological scales.Comment: Accepted for publication in the Euro. Phys. J.

A statistical approach to detect protein complexes at X-ray free electron laser facilities

The Flash X-ray Imaging (FXI) technique, under development at X-ray free electron lasers (XFEL), aims to achieve structure determination based on diffraction from individual macromolecular complexes. We report an FXI study on the first protein complex-RNA polymerase II-ever injected at an XFEL. A successful 3D reconstruction requires a high number of observations of the sample in various orientations. The measured diffraction signal for many shots can be comparable to background. Here we present a robust and highly sensitive hit-identification method based on automated modeling of beamline background through photon statistics. It can operate at controlled false positive hit-rate of 3 x10(-5). We demonstrate its power in determining particle hits and validate our findings against an independent hit-identification approach based on ion time-of-flight spectra. We also validate the advantages of our method over simpler hit-identification schemes via tests on other samples and using computer simulations, showing a doubled hit-identification power

"Yay, Another Lady Starting a Log!": Women's Fitness Doping and the Gendered Space of an Online Doping Forum

This study aims to investigate and dissect the meanings attached to women’s use of performance and image enhancing drugs (PIEDs), how fitness doping can be understood in terms of gender and spatiality, and what implications this has for women’s communicative engagement with one another within an online forum. The study is based on a netnographic and qualitative methodology. Theoretically, it considers a women’s online forum for PIEDs and analyzes it as a community of practice (CofP) and a spatiality in which gender, bodies, and side effects are discussed and negotiated. The results show that although the women’s forum provides a space for women to share their own unique experiences, there is a limit to the extent to which the discussions mirror the experiences and experimentations of women. Instead, discussions are often dominated by men’s voices/experiences. This has two main implications. Firstly, the prevalence of men’s voices can block the development of a women’s CofP. Symbolically, men engage in a sort of cultural manspreading by encroaching on the women’s forum space. Secondly, it has implications for women’s PIED use and use practices. Women seeking out advice or the experiences of other women must navigate through and around men’s contributions