Vertical distribution and respiration rates of benthic foraminifera: Contribution to aerobic remineralization in intertidal mudflats covered by Zostera noltei meadows

The present study investigates the influence of seagrass root systems on benthic hard-shelled meiofauna (foraminifera). In February and July 2011, sediment cores were collected at low tide at two sites in Arcachon lagoon, a vegetated site with Zostera noltei and a second site with bare sediments. We used the highly discriminative CellTracker™ Green fluorogenic probe technique to recognize living foraminifera and to describe foraminiferal density and diversity. Three dominant species of foraminifera were observed: Ammonia tepida, Haynesina germanica and Eggerella scabra. The two calcareous species, A. tepida and H. germanica, were preferentially found in the upper half to 1 cm of the sediment. At the vegetated site, these two species had a slightly deeper microhabitat. In the literature, both species have been described alive in much deeper sediment layers, possibly due to false positives from the Rose Bengal staining method. These two species also showed 1) higher densities at the site with Z. noltei, 2) a higher density in February when conditions were supposed optimal due to a microphytobenthos bloom, and 3) dissolved calcitic shells in July, probably resulting from a lower pH. The agglutinated species E. scabra was present alive down to at least 7 cm depth. E. scabra showed high densities in the anoxic part of the sediment at both the vegetated and bare sites, with a substantially higher density in summer at the site with bare sediments. Its presence at depth may be related to its trophic requirements; this species could be less dependent on labile organic matter than A. tepida and H. germanica. On this intertidal mudflat, the foraminiferal contribution to aerobic carbon remineralization, based on respiration rate measurements, can account for up to 7% of the diffusive oxygen uptake, almost five times more than the maximum contribution recorded in open marine environments (300 m depth) in the Bay of Biscay

Benthic oxygen exchange over a heterogeneous Zostera noltei meadow in a temperate coastal ecosystem

Seagrass meadows support intense but highly variable benthic metabolic rates that still need to be better evaluated to determine an accurate trophic status. The present study assessed how seagrasses and associated benthic macrofauna control spatiotemporal changes in benthic oxygen exchanges within a temperate bay. Based on seasonal sampling over a complete year cycle, the diffusive oxygen uptake (DOU), community respiration (CR) and gross primary production (GPP) were measured in a Zostera noltei meadow within Arcachon Bay, taking into account its spatial heterogeneity. Oxygen fluxes were assessed in sediment cores, within which benthic macrofauna and seagrass abundances and biomasses were quantified. The presence of Z. noltei did not significantly affect the DOU. Seasonal changes in CR and GPP correlated strongly with temperature in the presence of Z. noltei. The characteristics of benthic macrofauna associated with Z. noltei only weakly affected seasonal changes in CR. High spatial changes in both GPP and CR were mainly driven by the aboveground biomass of Z. noltei. When extrapolated to the whole intertidal area of the bay, in spite of limitations, our results suggest (1) overall higher contributions to CR and GPP from the seagrass meadow than from bare sediments, even though alternative primary producers in bare sediments (likely microphytobenthos) contributed significantly during winter; (2) an annual decrease in CR and GPP of 35 and 41%, respectively, resulting from the decline in Z. noltei of 25% between 2005 and 2007; and (3) a strong seasonality in the magnitude of this decrease, which was high during autumn and low during winter.

Cultural and Family Challenges to Managing Type 2 Diabetes in Immigrant Chinese Americans

OBJECTIVE— Although Asians demonstrate elevated levels of type 2 diabetes, little attention has been directed to their unique cultural beliefs and practices regarding diabetes. We describe cultural and family challenges to illness management in foreign-born Chinese American patients with type 2 diabetes and their spouses. RESEARCH DESIGN AND METHODS— This was an interpretive comparative interview study with 20 foreign-born Chinese American couples (n = 40) living with type 2 diabetes. Multiple (six to seven) semistructured interviews with each couple in individual, group, and couple settings elicited beliefs about diabetes and narratives of care within the family and community. Interpretive narrative and thematic analysis were completed. A separate respondent group of 19 patients and spouses who met the RESULTS— Cultural and family challenges to diabetes management within foreign-born Chinese American families included how 1) diabetes symptoms challenged family harmony, 2) dietary prescriptions challenged food beliefs and practices, and 3) disease management requirements challenged established family role responsibilities. CONCLUSIONS— Culturally nuanced care with immigrant Chinese Americans requires attentiveness to the social context of disease management. Patients’ and families’ disease management decisions are seldom made independent of their concerns for family well-being, family face, and the reciprocal responsibilities required by varied family roles. Framing disease recommendations to include cultural concerns for balance and significant food rituals are warranted

Live (stained) benthic foraminifera from the Cap-Ferret Canyon (Bay of Biscay, NE Atlantic): A comparison between the canyon axis and the surrounding areas

Living (Rose Bengal stained) benthic foraminiferal faunas were investigated at 13 deep-sea stations sampled in the Cap-Ferret Canyon area (NE Atlantic). One station (151 m) is located on the continental shelf close to the canyon head. All other stations are located along 2 bathymetric transects: 7 sites along the canyon axis with depths ranging from 300 to 3000 m and 5 stations along the adjacent flank with depths ranging from 300 m to 2000 m. Sedimentological analyses indicate that the Cap-Ferret Canyon is at present inactive in terms of sediment gravity flow. Compared to stations on the adjacent flank, canyon-axis stations are generally characterised by shallow oxygen penetration depths, high diffusive oxygen uptakes (DOU) and high lipid contents. Higher mineralisation rates recorded in the canyon axis are likely due to a preferential focusing of labile organic matter in the canyon axis. Foraminiferal standing stocks do not exhibit any straightforward correlation with the different descriptors of organic matter available in the sediment. However, foraminiferal standing stock and diversity along the canyon axis are generally higher than on the adjacent flank. Canyon axis sites yield dominant species that are similar to those at adjacent flank and open slope stations located at comparable water depths. However, intermediate and deep infaunal species were only recorded in the lower canyon axis, where high amounts of organic matter were observed in deeper sediment layers. Finally, the faunal composition in the Cap-Ferret Canyon is different compared to the nearby Cap-Breton Canyon, where sediment gravity flows are active. The absence of pioneer species and the occurrence of highly specialized taxa are both consistent with the much more stable conditions in terms of hydro-sedimentary conditions prevailing in the Cap-Ferret Canyon

Loop quantum gravity and light propagation

Within loop quantum gravity we construct a coarse-grained approximation for the Einstein-Maxwell theory that yields effective Maxwell equations in flat spacetime comprising Planck scale corrections. The corresponding Hamiltonian is defined as the expectation value of the electromagnetic term in the Einstein-Maxwell Hamiltonian constraint, regularized a la Thiemann, with respect to a would-be semiclassical state. The resulting energy dispersion relations entail Planck scale corrections to those in flat spacetime. Both the helicity dependent contribution of Gambini and Pullin [GP] and, for a value of a parameter of our approximation, that of Ellis et. al. [ELLISETAL] are recovered. The electric/magnetic asymmetry in the regularization procedure yields nonlinearities only in the magnetic sector which are briefly discussed. Observations of cosmological Gamma Ray Bursts might eventually lead to the needed accuracy to study some of these quantum gravity effects.Comment: Latex, 45 pages, shorter abstract, additional reference

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

The second-order Fourier coefficients (υ$_{2}$) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the υ$_{2}$ coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p$_{T}$ < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ$_{2}$ values for the Υ mesons are found to be consistent with zero

Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 10$^{34}$ cm$^{-2}$s$^{-1}$, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals

Measurement of the Y(1S) pair production cross section and search for resonances decaying to Y(1S)μ⁺μ⁻ in proton-proton collisions at √s = 13 TeV

The fiducial cross section for Y(1S)pair production in proton-proton collisions at a center-of-mass energy of 13TeVin the region where both Y(1S)mesons have an absolute rapidity below 2.0 is measured to be 79 ± 11 (stat) ±6 (syst) ±3 (B)pbassuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the Y(1S)meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9fb$^{-1}$. This process serves as a standard model reference in a search for narrow resonances decaying to Y(1S)μ$^{+}$μ$^{-}$ in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two bquarks and two b̅ antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5GeV, while a generic search for other resonances is performed for masses between 16.5 and 27GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate Y(1S)resonance are set as a function of the resonance mass