Late Miocene to Quaternary intraplate basaltic volcanism in the Al Ghab and Homs regions, northwestern Syria (the Al Ghab volcanic group and the Homs volcanic group), occurred roughly synchronously ...with the propagation of the Dead Sea Fault System in these regions. Petrographic evidence as well as major and trace element variations suggest that the basalts have undergone varying amounts of crystal fractionation of olivine plus or minus clinopyroxene plus or minus   ; spinel, with feldspar fractionation only in the most evolved samples. The major and trace element chemistry and Nd-Sr-Pb isotopic variations of the basalts reflect both mantle source heterogeneity and relatively minor crustal contamination. Semi-quantitative assimilation-fractional crystallization modelling suggests that some samples may reflect assimilation of no more than 6% of upper continental crust, probably with Late Proterozoic Arabian Shield characteristics. Amongst the least crustally contaminated and relatively primitive samples, basanites are characterized by marked depletion of K, Rb and Zr relative to other neighbouring incompatible elements on primitive mantle normalized trace element diagrams. This, together with their low SiO sub(2) and high TiO sub(2) and Dy/Yb, is consistent with magma genesis involving a large proportion of garnet-bearing hornblendite or similar amphibole-rich metasomatic veins. Associated alkali and tholeiitic basalts with the higher SiO sub(2), lower TiO sub(2), less negative K, Rb and Zr anomalies, and moderately high Dy/Yb are consistent with melt extraction from a largely peridotitic mantle source. It is suggested that the compositional spectrum from basanite via alkali basalt to tholeiitic basalt can be explained by increasing degrees of metasomatic vein-wall-rock interaction, plus asthenospheric melt assimilation. In agreement with this is the identification of three distinct isotopic and chemical characteristics within the spectrum of mafic lavas, each of which can be referred to a unique mantle source (metasomatic vein, lithospheric wall-rock peridotite mantle and asthenospheric peridotite mantle). A decrease in eruption volume and increase in Si-undersaturation of the lavas from south (Homs) to north (Al Ghab) along the northern Dead Sea Fault System from latest Miocene to Quaternary times suggest a diminishing thermal perturbation and increasing importance of the amphibole-rich veins in magma genesis over time. It is proposed that the genesis of the oldest lavas reflects the arrival of asthenospheric melts beneath the Homs region, which with assimilation of lithospheric metasomatic veins and their wall-rocks produced the parental magmas of the Homs volcanic group. Subsequently, upwelling asthenospheric material could have been channelled northwards at the base of the lithosphere, presumably related to the northward propagation of the Dead Sea Fault System in the Pliocene. Cooling of this channelled asthenospheric material, which did not penetrate the lithosphere during this later period of magma genesis, provided the minimal thermal perturbation necessary for melting of amphibole-rich metasomatic veins and wall-rock peridotite within the lithosphere.
We demonstrate scalable and intercompatible multilayer photonic platforms that operate over a multioctave wavelength range from the near-ultraviolet (NUV) into the short-wave infrared (SWIR). We ...demonstrate low-loss waveguides (<inline-formula><tex-math notation="LaTeX">\leq</tex-math></inline-formula>3 dB/cm above 370 nm and <0.3 dB/cm between 633 and 1550 nm for both TE and TM polarizations) and present verified component libraries at several wavelengths within this range. We demonstrate the use of thermo-optic heaters for tuning in the SWIR and show that we can automatically initialize complex optical filters. Our platforms are fabricated in a silicon CMOS foundry operating at a 90 nm node and consist of silicon nitride (SiN) and amorphous aluminum oxide (alumina, Al 2 O 3 ) optical waveguides cladd with silicon dioxide (SiO 2 ). They can be combined in multilayer stacks to enable complex routing of multiple wavelengths, making them useful for applications ranging from atomic-molecular-optical applications to biophotonics to integrated microwave photonics.
We present a low-loss integrated photonics platform in the visible and near ultraviolet (UV) regime. Fully etched waveguides based on atomic layer deposition (ALD) of aluminum oxide operate in a ...single transverse mode with <3 dB/cm propagation loss at a wavelength of 371 nm. Ring resonators with intrinsic quality factors exceeding 470 000 are demonstrated at 405 nm, and the thermo-optic coefficient of ALD aluminum oxide is estimated to be 2.75 × 10−5 (RIU/°C). Absorption loss is sufficiently low to allow on-resonance operation with intra-cavity powers up to at least 12.5 mW, limited by available laser power. Experimental and simulated data indicate that the propagation loss is dominated by sidewall roughness, suggesting that lower loss in the blue and UV is achievable.
Cannabis use during pregnancy has increased over the past few decades, with recent data indicating that, in youth and young adults especially, up to 22% of people report using cannabis during ...pregnancy. Animal models provide the ability to study prenatal cannabis exposure (PCE) with control over timing and dosage; however, these studies utilize both injection and inhalation approaches. While it is known that Δ9‐tetrahydrocannabinol (THC; primary psychoactive component of cannabis) can cross the placenta, examination of the transmission and concentration of THC and its metabolites from maternal blood into the placenta and fetal brain remains relatively unknown, and the influence of route of administration has never been examined. Pregnant female rats were exposed to either vaporized THC‐dominant cannabis extract for pulmonary consumption or subcutaneous injection of THC repeatedly during the gestational period. Maternal blood, placenta, and fetal brains were collected following the final administration of THC for analysis of THC and its metabolites, as well as endocannabinoid concentrations, through mass spectrometry. Both routes of administration resulted in the transmission of THC and its metabolites in placenta and fetal brain. Repeated exposure to inhaled THC vapor resulted in fetal brain THC concentrations that were about 30% of those seen in maternal blood, whereas repeated injections resulted in roughly equivalent concentrations of THC in maternal blood and fetal brain. Neither inhalation nor injection of THC during pregnancy altered fetal brain endocannabinoid concentrations. Our data provide the first characterization of maternal‐fetal transmission of THC and its metabolites following both vaporized delivery and injection routes of administration. These data are important to establish the maternal‐fetal transmission in preclinical injection and inhalation models of PCE and may provide insight into predicting fetal exposure in human studies.
Animal models provide the ability to study prenatal cannabis exposure with control over timing and dosage but employ both injection and inhalation approaches; however, the degree of transmission of THC through placenta to fetal brain within these models is unknown. Here we show differences in THC and metabolite distribution following injection versus inhalation.
Abstract Patients with B-cell lymphomas have altered cellular components of vaccine responses due to malignancy and therapy, and the optimal timing of vaccination relative to therapy remains unknown. ...Severe acute respiratory syndrome coronavirus 2 vaccines created an opportunity for new insights in vaccine timing because patients were challenged with a novel antigen across multiple phases of treatment. We studied serologic messenger RNA vaccine response in retrospective and prospective cohorts with lymphoma and chronic lymphocytic leukemia, paired with clinical and research immune parameters. Reduced serologic response was observed more frequently during active treatment, but nonresponse was also common within observation and posttreatment groups. Total immunoglobulin A and immunoglobulin M correlated with successful vaccine response. In individuals treated with anti-CD19–directed chimeric antigen receptor–modified T cells, nonresponse was associated with reduced B and T follicular helper cells. Predictors of vaccine response varied by disease and therapeutic group, and therefore further studies of immune health during and after cancer therapies are needed to individualize vaccine timing.
Dissolved organic nitrogen (DON) can comprise up to 80% of the dissolved N pool in riverine ecosystems, but concentration and compositional responses to catchment conditions has received limited ...attention. We examined the suite of nitrogenous nutrients along the length of the Ovens River, Victoria, Australia, a river with identifiable regions of native vegetation, agricultural activity and floodplain forest connection, carrying out longitudinal surveys in winter during a period of high flow and in summer during a period of stable base flow. We examined: the concentrations of DON, the proportion of DON that occurs as dissolved combined amino acids (DCAAs), whether concentration and DCAA composition varied between flow and whether land-use and tributaries have an impact upon nutrient concentration and DON composition. DON concentrations were greater than dissolved inorganic nitrogen under both base flow and high flow conditions. Under base flow DON exhibited a continuous increase in concentration downstream (ranging from 50 to 300 μg/L), compared to a much larger increase under high flow (150–600 μg/L) coupled with a major discrete increase of ~ 350 μg/L at a tributary input (King River). Concentrations of NOₓ (oxides of nitrogen) species were much higher under high flow conditions (range 50–250 μg/L) compared to 0–50 μg/L at base flow, and showed a significant increase in concentration with distance downstream. A discrete change in NOₓ concentrations was also observed at the King River confluence under high flow, although in this case causing a decrease in concentration of ~ 100 μg/L. DCAA concentrations varied little along the length of the river at base flow but increased with distance downstream at high flow. The DCAA concentrations were of the same order of magnitude as ammonium at both base and high flows and nitrate concentrations at base flow. The proportion of DON that was in the form of DCAA was reasonably uniform during high flow (3–6%), but highly variable at base flow (5–44%). The amino acid (AA) composition of the DCAA varied along the river and differed between flow regimes (except below the confluence with the King River where AA composition under the two flow conditions converged) suggesting a strong influence of land use. We show that DON is potentially a large component (4–81%) of the total N budget and given that 5–23% is in the form of peptide/protein, represents an important source of N. DON and more specifically DCAAs should therefore be considered both when constructing N budgets and monitoring levels of in-stream nitrogen.
The aim of this study was to compare the efficacy of fascia iliaca block, performed by loss of resistance and ultrasound guidance techniques.
Eighty patients undergoing either unilateral hip or knee ...joint replacement surgery were randomly assigned to undergo fascia iliaca compartment block by either loss of resistance or ultrasound guidance. Sensation in the anterior (femoral nerve), lateral (lateral cutaneous nerve) and medial (femoral and variable contribution from obturator nerve) aspects of the thigh were assessed prior to block placement. Femoral motor block (knee extension) was also evaluated. Obturator motor block (hip adduction) was measured using a sphygmomanometer. Sensation and motor function were reassessed after block placement.
Using ultrasound guidance, there was a statistically significant increase in the incidence of sensory loss in the medial aspect of the thigh from 60% to 95% (P = .001). Complete loss of sensation in the anterior, medial, and lateral aspects of the thigh increased from 47% to 82% of patients using ultrasound (P = .001). Ultrasound-guided fascia iliaca block resulted in a statistically significant increase in the incidence of femoral (P = .006) and obturator (P = .033) nerve motor block.
Ultrasound-guided fascia iliaca block increased the frequency of sensory loss in the medial aspect of the thigh. Ultrasound guidance also increased the frequency of femoral and obturator motor block.
The aim of this study was to compare the accuracy of local anesthetic placement in the rectus sheath block when performed by trainee anesthetists using loss of resistance (LOR) or ultrasound ...guidance.
Eighty-one patients undergoing laparoscopic surgery were randomly assigned to undergo rectus sheath block by either LOR or ultrasound guidance. Trainee anesthesiologists were also randomly assigned to provide the rectus sheath block by LOR or by using ultrasound. The placement of local anesthetic was recorded using ultrasound.
The placement of local anesthetic by LOR was accurate in 45% of attempts but was superficial and deep to the rectus sheath in 34% and 21% of punctures, respectively. Accurate placement of local anesthetic within the rectus sheath decreased significantly as body mass index increased. Ultrasound guidance significantly improved the accuracy of needle placement, with 89% of abdominal punctures being correctly placed at the time of first injection of local anesthetic. An additional fascial plane lying at variable distance above the anterior layer of the rectus sheath was commonly observed.
Ultrasound guidance improves the accuracy of local anesthetic placement when undertaking the rectus sheath block. An additional fascial plane above the anterior layer of the rectus sheath may be wrongly perceived as the anterior layer of the rectus sheath when the block is undertaken without the aid of ultrasound.
The acid generation mechanisms and neutralizing capacities of sulfidic sediments from two inland wetlands have been studied in order to understand the response of these types of systems to drying ...events. The two systems show vastly different responses to oxidation, with one (Bottle Bend (BB) lagoon) having virtually no acid neutralizing capacity (ANC) and the other (Psyche Bend (PB) lagoon) an ANC that is an order of magnitude greater than the acid generation potential. While BB strongly acidifies during oxidation the free acid generation is less than that expected from the measured proton production and consumption processes, with additional proton consumption attributed to the formation of an acid-anion (chloride) FeIII (oxyhydr)oxide product, similar to akaganéite (Fe(OH)2.7Cl0.3). While such products can partially attenuate the acidification of these systems, resilience to acidification is primarily imparted by sediment ANC.
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•Dissolved combined amino acids (DCAAs) have been measured in peatland stream waters during a storm event.•DCAAs account for 5 – 15% of dissolved organic nitrogen (DON) across the ...event.•Dissolved organic carbon (DOC) enriched in DCAAs appears in the rising limb of the storm pulse.•Temporal referencing of DOC and DON to DCAAs reveals both ‘fast’ and ‘slow’ DOC(N) components.
The export of fixed carbon from peatlands is likely important in driving freshwater ecosystem productivity in head water streams. Here we studied the stream composition from three peatlands, and the sub-catchment containing these peatlands, in response to a natural storm event. We investigated the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) mobilised by this event as well as the dissolved combined amino acids (DCAAs; proteins, peptides and free AAs) component of the DOC/DON. The storm pulse was characterised by a strong DOC/DON/DCAA pulse reflecting the mobilisation of materials from the peat profile. Through the storm cycle a transient increase in the C:N ratio of the DOC was observed (ranging over 20 – 50 across the four sites), likely reflecting the mobilisation of less decomposed material from higher in the peat soil profile. By comparing the DCAA and DON dynamics we show that a DCAA-rich component (fast-DCAA) is mobilised earlier in the storm cycle, likely reflecting a higher mobility in the peat soil. Similarly, comparison of the DCAA and DOC dynamics suggests that at least part of the DOC is mobilised more rapidly than fast-DCAA (fast-DOC). While we may not expect the composition of a storm pulse to be uniform through the cycle, this study shows that within the DOC and DON pools there is spatial and temporal separation of molecular groups. Proteins (in principal) represent both highly bioavailable N-sources as well as potential biological trigger molecules, so our work shows that these compounds are more dominant in the early part (rising limb) of the storm pulse. This understanding of the changing composition of DOC through a storm peak also provides greater insight into the concentration-discharge (C-Q) response of peatlands; our work shows that the activation of water paths higher in the peat profile at high flows leads to the mobilisation of different pools of DOC such that the molecular characteristics of DOC change through the storm cycle.
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