Search

Hydrodynamics and water-column properties were investigated off west-central Guam from July 2007 through January 2008. Rapid fluctuations, on time scales of 10s of min, in currents, temperature, salinity, and acoustic backscatter were observed to occur on sub-diurnal frequencies along more than 2 km of the fore reef but not at the reef crest. During periods characterized by higher sea-surface temperatures (SSTs), weaker wind forcing, smaller ocean surface waves, and greater thermal stratification, rapid decreases in temperature and concurrent rapid increases in salinity and acoustic backscatter coincided with onshore-directed near-bed currents and offshore-directed near-surface currents. During the study, these cool-water events, on average, lasted 2.3 h and decreased the water temperature 0.57 °C, increased the salinity 0.25 PSU, and were two orders of magnitude more prevalent during the summer season than the winter. During the summer season when the average satellite-derived SST anomaly was +0.63 °C, these cooling events, on average, lowered the temperature 1.14 °C along the fore reef but only 0.11 °C along the reef crest. The rapid shifts appear to be the result of internal tidal bores pumping cooler, more saline, higher-backscatter oceanic water from depths >50 m over cross-shore distances of 100 s of m into the warmer, less saline waters at depths of 20 m and shallower. Such internal bores appear to have the potential to buffer shallow coral reefs from predicted increases in SSTs by bringing cool, offshore water to shallow coral environments. These cooling internal bores may also provide additional benefits to offset stress such as supplying food to thermally stressed corals, reducing stress due to ultraviolet radiation and/or low salinity, and delivering coral larvae from deeper reefs not impacted by surface thermal stress. Thus, the presence of internal bores might be an important factor locally in the resilience of select coral reefs facing increased thermal stress. [ABSTRACT FROM AUTHOR]

Most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100; it is not clear, however, how fluid flow and sediment dynamics on exposed fringing reefs might change in response to this rapid sea-level rise. Coupled hydrodynamic and sediment-transport numerical modeling is consistent with recent published results that suggest that an increase in water depth on the order of 0.5-1.0 m on a 1-2 m deep exposed fringing reef flat would result in larger significant wave heights and setup, further elevating water depths on the reef flat. Larger waves would generate higher near-bed shear stresses, which, in turn, would result in an increase in both the size and the quantity of sediment that can be resuspended from the seabed or eroded from adjacent coastal plain deposits. Greater wave- and wind-driven currents would develop with increasing water depth, increasing the alongshore and offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest. Sediment residence time on the fringing reef flat was modeled to decrease exponentially with increasing sea-level rise as the magnitude of sea-level rise approached the mean water depth over the reef flat. The model results presented here suggest that a 0.5-1.0 m rise in sea level will likely increase coastal erosion, mixing and circulation, the amount of sediment resuspended, and the duration of high turbidity on exposed reef flats, resulting in decreased light availability for photosynthesis, increased sediment-induced stress on the reef ecosystem, and potentially affecting a number of other ecological processes. [ABSTRACT FROM AUTHOR]

Sediment traps are commonly used as standard tools for monitoring 'sedimentation' in coral reef environments. In much of the literature where sediment traps were used to measure the effects of 'sedimentation' on corals, it is clear from deployment descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted or misapplied. Despite their widespread use in this setting, sediment traps do not provide quantitative information about 'sedimentation' on coral surfaces. Traps can provide useful information about the relative magnitude of sediment dynamics if trap deployment standards are used. This conclusion is based first on a brief review of the state of knowledge of sediment trap dynamics, which has primarily focused on traps deployed high above the seabed in relatively deep water, followed by our understanding of near-bed sediment dynamics in shallow-water environments that characterize coral reefs. This overview is followed by the first synthesis of near-bed sediment trap data collected with concurrent hydrodynamic information in coral reef environments. This collective information is utilized to develop nine protocols for using sediment traps in coral reef environments, which focus on trap parameters that researchers can control such as trap height ( H), trap mouth diameter ( D), the height of the trap mouth above the substrate ( z), and the spacing between traps. The hydrodynamic behavior of sediment traps and the limitations of data derived from these traps should be forefront when interpreting sediment trap data to infer sediment transport processes in coral reef environments. [ABSTRACT FROM AUTHOR]

An experiment was conducted along the reefs off west Maui, Hawaii, during the summer of 2003 to monitor the spawning of the reef-building coral Montipora capitata and to determine the role of ocean currents in dispersing the larvae from the natal reef. Instruments documented the environmental forcing during the coral spawning season; drifters were deployed on three successive nights following direct observations of coral spawning. Both the timing and relative magnitude of the coral spawning were identifiable in acoustic backscatter data and correlated to plankton tow data. Each drifter track showed that the surface water containing coral eggs and planula larvae were transported rapidly off- shore and not locally retained. Wind and current patterns during the previous year and during subsequent coral spawning events later in the summer were similar to those observed during the drifter releases. This suggests that the trajectories observed during the focused experiment are representative of the general pattern of larval dispersal off west Maui. These findings demonstrate the application of acoustic profilers for remotely imaging coral spawning and predicting their initial dispersal patterns. [ABSTRACT FROM AUTHOR]

Chandarpur–Raipur sequence in Chattisgarh basin is represented as siliciclastic-dominated Chandarpur Group and carbonate-dominated Raipur Group. Here, we introduce 'Devsagar Sandstone Member', the only sandstone-dominated member in the carbonate-dominated Charmuria Formation of Raipur Group, that marks a period of rapid siliciclastic deposition identifying a phase of forced regression between two carbonate platforms of Charmuria–Chandi formations, thereby indicating a drastic change in palaeogeography of Raipur Group. In addition, this study revised the litho-stratigraphy of Mesoproterozoic Chattisgarh basin to clarify the confusion raised due to the existence of different stratigraphy in different basinal parts and different nomenclature for the same lithologic units. Detailed geological mapping with facies analysis in the eastern part of the basin manifests the entire basin-fill succession as part of the Chattisgarh basin itself, rather than sub-dividing some parts as Baradwar sub-basin and Singhora proto-basin. Singhora Group deposited in Singhora proto-basin has already been presented as equivalent of Chandarpur Group. Here we propose, Bamandihi–Saradih–Raigarh formations of Raipur Group in Baradwar sub-basin, as lateral equivalent of Gunderdehi–Chandi–Tarenga formations of Raipur Group and Sarnadih–Nandeli formations of Kharsiya Group in Chattisgarh basin. Inferred depositional environment and tectonic setting of Chattisgarh basin support the lithostratigraphic revision, which will help in basin analysis as well as intrabasinal–interbasinal correlation in regional and global contexts. Research highlights: Devsagar Sandstone Member introduced as the only sandstone-dominated member in carbonate-dominated Charmuria Formation of Raipur Group. Devsagar Sandstone Member represents a tidal shelf in between two carbonate ramp platforms (Charmuria and Chandi), marking a period of rapid siliciclastic deposition and the only phase of forced regression in overall sea-level rising scenario of the carbonate-dominated Raipur Group. Stratigraphy of Chattisgarh basin revised. The entire Chattisgarh succession is represented as deposits of Chattisgarh basin only, without further subdivision into sub-basin and/or proto-basin, thus resolving the stratigraphic and basinal correlation problem. [ABSTRACT FROM AUTHOR]

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment. [ABSTRACT FROM AUTHOR]

In this paper, detailed studies of structural, micro-structural, dielectric, electrical and magneto-electric characteristics of chemically synthesized a new double perovskite, BiSrFeCeO6 (strontium cerate-modified bismuth ferrite), are reported. The basic crystal data (unit cell dimension and orthorhombic crystal system) of the compound were obtained by analysing the room temperature X-ray powder diffraction data. Study of the surface microstructure of a sintered pellet sample, recorded by scanning electron microscope at room temperature, reveals the formation of high-density sample with the homogeneously and uniformly distributed grains of different size and shape. Analysis of frequency-temperature dependence of dielectric parameters and nature of hysteresis loop has exhibited the ferroelectric characteristics of the material. Studies of complex impedance and modulus components at different temperatures and frequencies have provided electrical characteristics of grains and grain boundaries present in the material, which are closely related to its microstructure. Thus, the correlation between the crystal structure with electrical properties and relaxation mechanism of the prepared sample has been established. The type of dielectric relaxation process and mechanism occurred in the compound have also been studied not only by analysis of the dielectric properties (εr, tan δ) and impedance parameters, but also from the study of frequency-temperature conductivity. The existence of negative temperature coefficient of resistance (NTCR) characteristics in the material has been confirmed from the temperature and dc conductivity analysis. Similarly, the frequency and ac conductivity analysis show that the studied compound follows Jonscher's universal power law. Based on the structural, ferroelectric, magnetic and magneto-electric characteristics, multiferroism in the new composition of bismuth ferrite has been established. [ABSTRACT FROM AUTHOR]

G protein-coupled receptors (GPCRs) are an important family of membrane proteins responsible for many physiological functions in human body. High resolution GPCR structures are required to understand their molecular mechanisms and perform rational drug design, as GPCRs play a crucial role in a variety of diseases. That is difficult to obtain for the wild-type proteins because of their low stability. In this review, we discuss how this problem can be solved by using protein design strategies developed to obtain homogeneous stabilized GPCR samples for crystallization and cryoelectron microscopy. [ABSTRACT FROM AUTHOR]

In this paper we consider an Euler fluid coupled to external electromagnetism. We prove that the Hopfion fluid-electromagnetic knot, carrying fluid and electromagnetic (EM) helicities, solves the fluid dynamical equations as well as the Abanov Wiegmann (AW) equations for helicities, which are inspired by the axial-current anomaly of a Dirac fermion. We also find a nontrivial knot solution with truly interacting fluid and electromagnetic fields. The key ingredients of these phenomena are the EM and fluid helicities. An EM dual system, with a magnetically charged fluid, is proposed and the analogs of the AW equations are written down. We consider a fluid coupled to a nonlinear generalizations for electromagnetism. The Hopfions are shown to be solutions of the generalized equations. We write down the formalism of fluids in 2+1 dimensions, and we dimensionally reduce the 3+1 dimensional solutions. We determine the EM knotted solutions, from which we derive the fluid knots, by applying special conformal transformations with imaginary parameters on un-knotted null constant EM fields. [ABSTRACT FROM AUTHOR]

Due to isolation from the environment with the protection of the full electronic shells, nuclear spins of noble gas typically feature extraordinary long coherence times, high polarization and good chemical inertness, which makes themselves attractive in extensive scientific applications. Recently, the noble-gas spin amplification via the spin-exchange collisions between overlapping noble-gas spins and alkali-atom spins has been theoretically and experimentally demonstrated in various quantum techniques including maser, Floquet maser, spin-based amplifier, and Floquet spin amplifier. The noble-gas spin amplification can enhance the external oscillating magnetic field by a factor of more than 100 and realize ultrasensitive magnetometry, which is important for the detection of weak electromagnetic fields and hypothetical particles. Based on the spin amplification, experiments have been conducted to search for axion-like dark matter and exotic spin-dependent forces and new constraints have been established. This review summarizes the recent progress on noble-gas spin amplification, including the basic principles, methods, different types, the related applications ranging from magnetic-field sensing to searches for new physics, and prospects for further improvements. [ABSTRACT FROM AUTHOR]

The canyon system, including 17 small slope-confined canyons in the Shenhu area, northern South China Sea, is significantly characterized by mounded or undulating features on the canyon flanks and canyon heads. However, the mechanism underlying the formation of these features has yet to be elucidated. In previous studies, most of them were interpreted as sediment deformation on the exploration seismic profiles. In this paper, we collected high-resolution bathymetric data, chirp profiles and geotechnical test data to investigate their detailed morphology, internal structures, and origin. The bathymetric data indicated that most mounded seismic units have smooth seafloors and are separated by grooves or depressions. The distance between two adjacent mounded units is only hundreds of meters. On chirp profiles, mounded seismic units usually exhibit chaotic reflections and wavy reflections, of which the crests migrate upslope. The slope stability analysis results revealed that the critical angle of the soil layers in the study area tends to be 9°, indicating that most mounded seismic units on the canyon flanks and heads are stable at present. The terrain characteristics and seismic configurations combined with the slope stability analysis results indicated that most mounded seismic units are not sediment deformation but depositional structures or mixed systems composed of deformation and depositional structures. [ABSTRACT FROM AUTHOR]

Polycrystalline Y-type hexagonal ferrite sample with composition Ba2−xPbxCo1.5Zn0.5Fe12O22 (0 < x < 0.4) have been prepared via sol–gel auto-combustion method with citric acid as a chelating agent. The synthesized samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometry, and P–E loop tracer. Single-phase of Y-type hexaferrite has been confirmed by XRD. The crystalline nature with hexagonal platelet-like morphology was confirmed by structural and morphological analysis. The dielectric constant (ε′) increases with Pb concentration and maximum dispersion is obtained for x = 0.3 sample. The power law dependence of ac conductivity with exponent (n) value about 0.229 to 0.285, suggests the conduction mechanism via polaron hooping. P–E loop analysis demonstrated the increase in remnant polarization, saturation polarization value with increase of Pb (up to x = 0.2) and shows a decreasing trend for higher Pb content. M–H curves reveal the soft magnetic behavior of the prepared samples. The coercivity (Hc) increases with an increase of Pb content and x = 0.3 sample exhibits the maximum value of coercivity of about ~ 107 Oe. The room temperature magnetoelectric coupling is evidenced with a second-order coupling coefficient (β) of 4.3 × 10−6 μV/cm-Oe2 for x = 0.3 sample, which endorses this material as a potential candidate for multistate memory devices. [ABSTRACT FROM AUTHOR]

The windward-leeward dichotomy is an important biogeographical distinction when investigating prehistoric island colonisation, settlement patterns, site use, and subsistence regimes. We analysed the mollusc remains from late prehistoric windward and leeward coastal midden sites from Moloka'i, Hawaiian Islands, to understand exploitation strategies in differing environmental contexts. Analysis of molluscan remains and their associated habitats, through a patch-choice framework, indicated that, instead of practicing different foraging regimes relative to their location, windward and leeward groups targeted small Neritidae gastropods from habitats adjacent to their home site. Despite the broad environmental differences, similar subsistence strategies may have been adopted for multiple reasons. In our windward-leeward assemblages, we suggest that mollusc size is not the paramount driver of forager decision making. Through a foraging theory lens, mollusc rank is reinterpreted beyond body size in response to prey-specific biological and ecological factors, such as aggregation and predictability. We also consider that targeted exploitation of stable, reliable, and resilient prey populations may instead be indicative of a risk management strategy in marginal, high variance environments. The best explanation may be a combination of both interpretations–where the risk sensitive forager ranks prey by a different set of optimality criteria that includes targeting high-density clusters of small gastropods. [ABSTRACT FROM AUTHOR]

The paper presents the results of experiments with the compression of the plasma of double multiwire arrays of mixed composition and the generation of powerful soft X-ray radiation (SXR) pulses carried out on the powerful electrophysical facility Angara-5-1 at a discharge current of up to 3 MA. Based on the latest experimental data on the production rate of different plasmas (in μg/(cm2 ns)) [1] and on specificities of the dynamics of plasma compression in nested arrays [2], a nested array was designed, which makes it possible to obtain a high SXR peak power in comparison with the optimal (in terms of radiation power) designs of single and nested tungsten wire arrays. By selecting substances with different plasma production rates, it was possible to reduce the level of magnetohydrodynamic instabilities at the final stage of compression of the inner array. This made it possible to reduce the radiation pulse duration and increase the SXR power. Using implosion of nested arrays of mixed composition, consisting of plastic fibers and tungsten wires, shorter and more powerful SXR pulses with a maximum peak power ~10 TW with a pulse duration FWHM ~ 5 ns were obtained, compared to the parameters of SXR pulses upon compression of single tungsten arrays: ~ 5 TW and FWHM ~ 10 ns. Thus, we have shown the possibility of a twofold increase in the peak SXR power during compression of nested arrays under the conditions of our experiments by optimizing their design. One of the results of this work was finding the optimal parameters of the nested arrays and the prediction of the peak SXR power for experiments at powerful electrophysical facilities, differing from with substantially different levels of discharge current, 4–26 MA (Angara-5-1, Julong-1, and ZR). [ABSTRACT FROM AUTHOR]

Although some co-risk factors and hemodynamic alterations are involved in hypertension progression, their direct biomechanical effects are unclear. Here, we constructed a high-hydrostatic-pressure cell-culture system to imitate constant hypertension and identified novel molecular classifications of human aortic smooth muscle cells (HASMCs) by single-cell transcriptome analysis. Under 100-mmHg (analogous to healthy human blood pressure) or 200-mmHg (analogous to hypertension) hydrostatic pressure for 48 h, HASMCs showed six distinct vascular SMC (VSMC) clusters according to differential gene expression and gene ontology enrichment analysis. Especially, two novel HASMC subsets were identified, named the inflammatory subset, with CXCL2, CXCL3 and CCL2 as markers, and the endothelial-function inhibitory subset, with AKR1C2, AKR1C3, SERPINF1 as markers. The inflammatory subset promoted CXCL2&3 and CCL2 chemokine expression and secretion, triggering monocyte migration; the endothelial-function inhibitory subset secreted SERPINF1 and accelerated prostaglandin F2α generation to inhibit angiogenesis. The expression of the two VSMC subsets was greatly increased in arterial media from patients with hypertension and experimental animal models of hypertension. Collectively, we identified high hydrostatic pressure directly driving VSMCs into two new subsets, promoting or exacerbating endothelial dysfunction, thereby contributing to the pathogenesis of cardiovascular diseases. [ABSTRACT FROM AUTHOR]

In a study on CH emission from flooded rice fields under irrigated conditions, fields planted with rice emitted more methane than unplanted fields. The CH efflux in planted plots varied with the rice variety and growth stage and ranged from 4 to 26 mg hm. During the reproductive stage of the rice plants, CH emission was high and the oxidation power of rice roots, in terms of α-naphthylamine oxidation, was very low. The CH emission reached a maximum at midday and declined to minimum levels at midnight, irrespective of the rice variety. The peak CH emission at midday was associated with higher solar radiation and higher soil/water temperature. [ABSTRACT FROM AUTHOR]

During the recent 1983 eruption of Kilauea Volcano in Hawaii, a field measurement of electrical resistivity was made in an 1118°C molten lava flow. A probe containing a four electrode. Wenner aray was inserted into the molten basaltic lava flow at a point about 100 m from the erupting vent. The probe indicated an electrical resistivity of approximately 40 ohm-m for the freshly-erupted molten lava. This value is consistent with existing, but sparce, laboratory data for molten rock in this temperature range. [ABSTRACT FROM AUTHOR]

Using the self-consistent field method in the full active space (SCF FAS) and the Gaussian basis we calculate 11 lowest electronic states of the TiF molecule, which has been little studied experimentally. We show that the lΔ state lies higher than the ground XΦ state by no more than 4000 cm. [ABSTRACT FROM AUTHOR]

The QCD axion or axion-like particles are candidates of dark matter of the universe. On the other hand, axion-like excitations exist in certain condensed matter systems, which implies that there can be interactions of dark matter particles with condensed matter axions. We discuss the relationship between the condensed matter axion and a collective spin-wave excitation in an anti-ferromagnetic insulator at the quantum level. The conversion rate of the light dark matter, such as the elementary particle axion or hidden photon, into the condensed matter axion is estimated for the discovery of the dark matter signals. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is common, yet there is no preventive therapy for AF. We tested the efficacy of AMP-activated protein kinase (AMPK) activators, metformin, and aspirin, in primary prevention of AF in cardiac-specific liver kinase B1 (LKB1) knockout (KO) mouse model of AF. Incidence of spontaneous AF was significantly reduced in treated KO mice with metformin (10 mg/kg/day) (8.3% in male and 10.3% in female) and aspirin (20 mg/kg/day) (29.4% in male and 21.4% in female) compared with untreated littermates (81% in male and 67% in female) at 8 weeks (p < 0.05). Prevention of AF was associated with activation of AMPK in treated mice and thereby improvement of mitochondrial function, gap junction proteins (connexin 40/43), and intra- and inter-cellular ultrastructure in atrial myocardium. Fibrosis was significantly less in treated mice atria. Pharmacological activation of AMPK is an effective upstream therapy for the primary prevention of AF in susceptible heart. [ABSTRACT FROM AUTHOR]

We construct a pseudo-Lagrangian that is invariant under rigid E11 and transforms as a density under E11 generalised diffeomorphisms. The gauge-invariance requires the use of a section condition studied in previous work on E11 exceptional field theory and the inclusion of constrained fields that transform in an indecomposable E11-representation together with the E11 coset fields. We show that, in combination with gauge-invariant and E11-invariant duality equations, this pseudo-Lagrangian reduces to the bosonic sector of non-linear eleven-dimensional supergravity for one choice of solution to the section condi- tion. For another choice, we reobtain the E8 exceptional field theory and conjecture that our pseudo-Lagrangian and duality equations produce all exceptional field theories with maximal supersymmetry in any dimension. We also describe how the theory entails non-linear equations for higher dual fields, including the dual graviton in eleven dimensions. Furthermore, we speculate on the relation to the E10 sigma model. [ABSTRACT FROM AUTHOR]

Corals in nearshore marine environments are increasingly exposed to reduced water quality, which is the primary local threat to Hawaiian coral reefs. It is unclear if corals surviving in such conditions have adapted to withstand sedimentation, pollutants, and other environmental stressors. Lobe coral populations from Maunalua Bay, Hawaii showed clear genetic differentiation between the 'polluted, high-stress' nearshore site and the 'less polluted, lower-stress' offshore site. To understand the driving force of the observed genetic partitioning, reciprocal transplant and common-garden experiments were conducted to assess phenotypic differences between these two populations. Physiological responses differed significantly between the populations, revealing more stress-resilient traits in the nearshore corals. Changes in protein profiles highlighted the inherent differences in the cellular metabolic processes and activities between the two; nearshore corals did not significantly alter their proteome between the sites, while offshore corals responded to nearshore transplantation with increased abundances of proteins associated with detoxification, antioxidant defense, and regulation of cellular metabolic processes. The response differences across multiple phenotypes between the populations suggest local adaptation of nearshore corals to reduced water quality. Our results provide insight into coral's adaptive potential and its underlying processes, and reveal potential protein biomarkers that could be used to predict resiliency. [ABSTRACT FROM AUTHOR]

Topographic/bathymetric conditions of the continental shelf can significantly influence the long-term growth of river deltas. In particular, these conditions constrain the accommodation space for sedimentation in the deltaic areas. In this study, we use a conceptual geometric model to evaluate the role played by this factor, on the basis of the principle of mass conservation. The Ganges-Brahmaputra, Mekong and Nile deltas are examined as three typical examples, in terms of their different original seabed morphologies. The control variate method is applied to eliminate the effect of the difference in model input variables. The results show that, assuming a constant sediment load, the delta growth rate will decrease with time; a higher value of the original seabed slope leads to a lower shoreline progradation rate for the subaerial delta and a higher growth rate for the subaqueous delta. Thus, the original seabed morphology represented by slope is a critical factor affecting the evolution of Holocene large-river deltas. These results explain the interrelationships between sediment load, deltaic plain area, and the original seabed slopes for the 27 large-river deltas worldwide, located in the middle/low latitudes, with different tectonic backgrounds. In the future, the conceptual geometric model may be combined with sediment dynamic modeling to identify more details of the evolution of these deltas. [ABSTRACT FROM AUTHOR]

Let (M , ⟨ , ⟩ TM) be a Riemannian manifold. It is well known that the Sasaki metric on TM is very rigid, but it has nice properties when restricted to T (r) M = { u ∈ T M , | u | = r } . In this paper, we consider a general situation where we replace TM by a vector bundle E ⟶ M endowed with a Euclidean product ⟨ , ⟩ E and a connection ∇ E which preserves ⟨ , ⟩ E . We define the Sasaki metric on E and we consider its restriction h to E (r) = { a ∈ E , ⟨ a , a ⟩ E = r 2 } . We study the Riemannian geometry of (E (r) , h) generalizing many results first obtained on T (r) M and establishing new ones. We apply the results obtained in this general setting to the class of Euclidean Atiyah vector bundles introduced by the authors in Boucetta and Essoufi J Geom Phys 140:161–177, 2019). Finally, we prove that any unimodular three dimensional Lie group G carries a left invariant Riemannian metric, such that (T (1) G , h) has a positive scalar curvature. [ABSTRACT FROM AUTHOR]

This paper is a review of current concepts concerning the seismotectonics and seismicity in the Laptev Sea region. The chief feature of the region is a rift system extending in the shelf from the continental slope with the adjacent Gakkel Ridge to the mainland coast. There are several models to describe the present-day evolution of the region, but no one of these is preferable because of the lack of local instrumental observations of shelf microseismicity, while such microseismicity is characteristic of rift zones. One alternative approach consists in the installation of ocean bottom seismometers on the shelf itself. During the 73rd cruise of the R/V Akademik Mstislav Keldysh, a temporary network was deployed consisting of 7 broadband bottom seismic stations on the Laptev Sea shelf. Comparative analysis of noise spectra based on records of a hydrophone, a bottom seismograph, and a wavegauge, showed that the noise amplitude strongly depends on wind waves, which is in turn dependent on marine ice cover, so that the recording potential of a local network of bottom seismographs is restricted to the winter period of observation. [ABSTRACT FROM AUTHOR]

Infrared spectra are computed for neutral and cationic clusters of Polycyclic Aromatic Hydrocarbon molecules, namely (C 16 H 10) n = 1,4 (0 / +) , using the Density Functional based Tight Binding scheme combined with a Configuration Interaction (DFTB-CI) in the double harmonic approximation. Cross-comparison is carried out with DFT and simple DFTB. Similarly to the monomer cation, the IR spectra of cluster cations are characterized by a depletion of the intensity of the CH stretch modes around 3000 cm−1, with a weak revival for n = 3 and 4. The in-plane CCC modes in the region 1400–2000 cm−1 are enhanced while the CH bending modes in the range 700–1000 cm−1 are significantly weakened with respect to the monomer cation, in particular for n = 2. Finally, soft modes corresponding to diedral fluctuations of the monomers within the central stack of the ion structure, possibly mixed with monomer folding, are also observed in the region 70–120 cm−1. [ABSTRACT FROM AUTHOR]

Oceanography and marine geosciences are closely related subjects, though they have had differing influences. The UK, which has experienced the financial benefits of North Sea oil and gas, while also having an extensive fishing industry and a science base linked to other English-speaking countries and European countries, potentially illustrates some changing influences and collaborative tendencies well. In this article, differences in article publication rates and collaborative tendencies, both globally and for the UK, are examined using the Web of Science™, Scopus™ and Georef™ for the period 1946–2018. The results show that publication rates of global oceanography articles rose exponentially faster than all global scientific publishing from the mid-1960s to 1980. Subsequently, the exponential rate of increase slowed though has remained faster than global science publishing. Global Marine Geoscience publication rates increased into the late 1980s, but have since declined. UK oceanography has roughly followed global trends, though its share of global oceanographic publishing declined from 28% in the 1950s to 8% in 2018. UK Marine Geoscience publishing has also generally followed global trends for that field. However, its share of global publications abruptly increased from 4.9% (average 1960–1980) to 13.2% by 1990, largely due to articles arising from UK participation in the Deep-Sea Drilling Project and Ocean Drilling Program. Oceanography and marine geoscience have also experienced strongly differing histories of collaborative articles over the last four decades. While oceanographic articles co-authored with researchers in other countries have been steadily increasing as a share of total UK Oceanography articles, those of marine geoscience peaked in 1990 and have since declined, though remained at high levels similar to those experienced by 2018 in Oceanography. Comparing global publication rates in both fields with measures of data and sample collection at sea suggests fundamental changes occurred in the way research was carried out. For example, Marine Geoscience publication rates were strongly correlated with geophysical track-line distances for the decade until ~1970, but were inversely correlated for the decade after then. This reflects, for example, the development of plate tectonics, which partly involved analysis of existing marine geophysical data, improved equipment capabilities and the increased role of scientific drilling. [ABSTRACT FROM AUTHOR]

It is known that irreducible noncommutative differential structures over F p [ x ] are classified by irreducible monics m. We show that the cohomology H dR 0 (F p [ x ] ; m) = F p [ g d ] if and only if Trace(m)≠ 0, where g d = x p d − x and d is the degree of m. This implies that there are p − 1 pd ∑ k | d , p ∤ k μ M (k) p d k such noncommutative differential structures (μM the Möbius function). Motivated by killing this zero'th cohomology, we consider the directed system of finite-dimensional Hopf algebras A d = F p [ x ] / (g d) as well as their inherited bicovariant differential calculi Ω(Ad;m). We show that Ad = Cd ⊗χA1 is a cocycle extension where C d = A d ψ is the subalgebra of elements fixed under ψ(x) = x + 1. We also have a Frobenius-fixed subalgebra Bd of dimension 1 d ∑ k | d ϕ (k) p d k (ϕ the Euler totient function), generalising Boolean algebras when p = 2. As special cases, A 1 ≅ F p (ℤ / pℤ) , the algebra of functions on the finite group ℤ / pℤ , and we show dually that F p ℤ / pℤ ≅ F p [ L ] / (L p) for a 'Lie algebra' generator L with eL group-like, using a truncated exponential. By contrast, A2 over F 2 is a cocycle modification of F 2 ((ℤ / 2 ℤ) 2) and is a 1-dimensional extension of the Boolean algebra on 3 elements. In both cases we compute the Fourier theory, the invariant metrics and the Levi-Civita connections within bimodule noncommutative geometry. [ABSTRACT FROM AUTHOR]

The Liaodong Shoal is a group of linear sand ridges located in the east Bohai Sea of China. In this study, 54 surface sediment samples have been collected, current measurements at 4 stations have been carried out and bathymetric data were obtained. The current directions are rightward deflected relative to the strikes of the sand ridges. Affected by the narrowing effect of the ridge, the current velocities exhibited an anti-'C' type vertical profile. The velocities of the lower currents linearly correlate with the water depths. The near-bed current velocities over the troughs are estimated to be higher than those over the ridges, and this feature could be explained by the loss of kinetic energy together with the conversion between kinetic energy and gravitational potential energy. The sedimentary characteristics that are compatible with the tidal dynamics are developed across the ridges and troughs, including grain size compositions, grain size parameters, mineral compositions and Dhm indexes. The existence of the angles between the current directions and the strikes of the sand ridges is the key factor for the growth of the sand ridges. The asymmetric hydrodynamic features between the flood and ebb currents lead to the differences in the topographical and sedimentary characteristics on both sides of a sand ridge. Insufficient material supply led to the degradation of the sand ridges, and the reduction of the tidal current intensity has led to the development of the subordinate sand ridges in the troughs. Sand ridges are migrating. [ABSTRACT FROM AUTHOR]

Purpose: To study the ability of a novel bovine serum albumin-angiotensin II (BSA-Ang II) conjugate to effect responses of the AT1 angiotensin II receptor subtype mediated by the G-protein-coupled and the beta-arrestin pathways. Methods: Angiotensin II (Ang II) was conjugated with bovine serum albumin and compared with Ang II for competition binding to AT1 receptors, to stimulate aldosterone release from adrenocortical cells, to promote beta-arrestin binding to AT1 receptors, to promote calcium mobilization, and stimulate drinking of water and saline by rats. Results: The BSA-Ang II conjugate was less potent competing for AT1R binding, but was equally efficacious at stimulating aldosterone release from H295R adrenocortical cells. Both BSA-Ang II and Ang II stimulated calcium mobilization and beta-arrestin binding to AT1 receptors. BSA-Ang II and Ang II stimulated water appetite equivalently but BSA-Ang II stimulated saline appetite more than Ang II. Both BSA-Ang II and Ang II were considerably more potent at causing calcium mobilization than β-arrestin binding. Conclusions: Addition of a high molecular weight molecule to Ang II reduced its AT1 receptor binding affinity, but did not significantly alter stimulation of aldosterone release or water consumption. The BSA-Ang II conjugate caused a greater saline appetite than Ang II suggesting that it may be a more efficacious agonist of this beta-arrestin-mediated response than Ang II. The higher potency calcium signaling response suggests that the G-protein-coupled responses predominate at physiological concentrations of Ang II, while the beta-arrestin response requires pathophysiological or pharmacological concentrations of Ang II to occur. [ABSTRACT FROM AUTHOR]

A soot coating was treated with NO3 radicals using a flow reactor having a movable insert and coupled to a mass spectrometer for kinetic studies; the treatment was performed until the surface completely stopped to trap the radicals. The chromatographic and mass spectrometry analyses of the composition of the original methane soot and the solid products of its reaction with the gas-phase NO3 oxidant showed that the main products of this heterogeneous reaction were phthalic acid derivatives, paraffins, and acetophenones. The untreated soot contained arenes (up to four-membered aromatic molecules). The nitro compounds were not detected in the original soot and the products of its treatment with NO3 radicals. [ABSTRACT FROM AUTHOR]

Abstract: A study was done of soils in the Moscow, Omsk, and Samara oblasts subjected to hydrocarbon pollutant fluxes from industrial enterprises of the same production profile (carbon black plants) differing in (a) the type and environmental safety of production technologies, (b) the time of operation, and (c) the spatial location with respect to other possible sources of technogenic hydrocarbons. Polyarene and bitumoid geochemical fields in the impact zones of the enterprises were identified and investigated, and power functions reflecting the decrease in pollutant concentrations with increasing distance from the enterprises were determined. From the obtained functions, which are mathematical expressions for the generalizing vectors of hydrocarbon fields, their degrees of gradients were estimated. Polyarene associations and their localizations were determined using cluster analysis, and relationships of associations with the distance from the pollutant sources, the technological specialization of the enterprises, and the local factors of pollutant redistribution and transformation were revealed. [ABSTRACT FROM AUTHOR]

Analysis of modern paleontological, isotope-geochemical, and paleotectonic data on Vendian rocks in the Patom Basin (Siberia) is presented. The paper discusses depositional settings and features of the specifics of sedimentogenesis of the Barakun carbonate-terrigenous formation, which matches the lower strata of postglacial deposits of the Dal’nyaya Taiga Group. It is shown that formation of the transgressive Barakun Formation was governed by relatively deep-water (below the storm wave base) distal settings of a low-angle (about 1°) homoclinal ramp. Its formation was related to a more intense sagging of the northeastern part of the Ura Uplift. The formation of breccias and intrusions was fostered by high seismic activity of the paleobasin recorded in plastic deformations along with liquefaction and fluidization of sedimentary beds. The constant seismic destabilization of bottom beds provoked small but frequent landslides without the formation of turbidite flows. The continuous dislocation of sediments toward the depocenter actively governed specifics of the ramp architecture. The unusual behavior of sediments during their long-term thixotropic residence could be related to a high content of organic matter, processes of methanogenesis and, probably, dissemination of gas hydrate compounds. [ABSTRACT FROM AUTHOR]

Seafloor elongated depressions are indicators of gas seepage or slope instability. Here we report a sequence of slopeparallel elongated depressions that link to headwalls of sediment slides on upper slope. The depressions of about 250 m in width and several kilometers in length are areas of focused gas discharge indicated by bubble-release into the water column and methane enriched pore waters. Sparker seismic profiles running perpendicular and parallel to the coast, show gas migration pathways and trapped gas underneath these depressions with bright spots and seismic blanking. The data indicate that upward gas migration is the initial reason for fracturing sedimentary layers. In the top sediment where two young stages of landslides can be detected, the slopeparallel sediment weakening lengthens and deepens the surficial fractures, creating the elongated depressions in the seafloor supported by sediment erosion due to slope-parallel water currents. [ABSTRACT FROM AUTHOR]

The uptake of NO3 on a pyrene coating at [NO3] = 2.5 × 1012-1.2 × 1013 cm−3 is studied using a coated-insert flow tube reactor coupled to a mass spectrometer. It is established that, in this concentration range, the uptake occurs by the impact recombination mechanism, whereas the consumption of surface sites involves the unimolecular decomposition of stabilized surface complexes. Several hundreds of NO3 radicals are consumed per surface site destroyed. The uptake coefficient depends on the exposure time, being described by the expression γ(t) = γ0exp(−t/τ), where γ0 and τ are parameters dependent on the NO3 concentration. Based on the Langmuir adsorption concept, the following elementary parameters determining the uptake process are estimated: the Langmuir coefficient, KL = 7.1 × 10−13 cm3; the desorption rate constant, kd = 44 s−1; and the rate constant for the unimolecular heterogeneous conversion of surface complexes, kr = 6.6 × 10−2 s−1. Gas chromatography-mass spectrometry measurements showed that the main products of the reaction are phthalates. The nitropyrene yield is found to be ~0.6%. [ABSTRACT FROM AUTHOR]

Sea-level rise and climatic change threaten the existence of atoll nations. Inundation and erosion are expected to render islands uninhabitable over the next century, forcing human migration. Here we present analysis of shoreline change in all 101 islands in the Pacific atoll nation of Tuvalu. Using remotely sensed data, change is analysed over the past four decades, a period when local sea level has risen at twice the global average (~3.90 ± 0.4 mm.yr-1). Results highlight a net increase in land area in Tuvalu of 73.5 ha (2.9%), despite sea-level rise, and land area increase in eight of nine atolls. Island change has lacked uniformity with 74% increasing and 27% decreasing in size. Results challenge perceptions of island loss, showing islands are dynamic features that will persist as sites for habitation over the next century, presenting alternate opportunities for adaptation that embrace the heterogeneity of island types and their dynamics. [ABSTRACT FROM AUTHOR]

Results from experimental studies of implosion of nested wire and fiber arrays at currents of up to 4 MA at the Angara-5-1 facility are presented. Depending on the ratio between the radii of the inner and outer arrays, different modes of the plasma flow in the space between the inner and outer arrays were implemented: the sub-Alfvénic (Vr < VA) and super-Alfvénic (Vr > VA) modes and a mode with the formation of the transition shock wave (SW) region between the cascades. By varying the material of the outer array (tungsten wires or kapron fibers), it is shown that the plasma flow mode between the inner and outer arrays depends on the ratio between the plasma production rates min/mout in the inner and outer arrays. The obtained experimental results are compared with the results of one-dimensional MHD simulation of the plasma flow between the arrays. Stable implosion of the inner array plasma was observed in experiments with combined nested arrays consisting of a fiber outer array and a tungsten inner array. The growth rates of magnetic Rayleigh-Taylor (MRT) instability in the inner array plasma at different numbers of fibers in the outer array and different ratios between the radii of the inner and outer arrays are compared. Suppression of MRT instability during the implosion of the inner array plasma results in the formation of a stable compact Z-pinch and generation of a soft X-ray pulse. A possible scenario of interaction between the plasmas of the inner and outer arrays is offered. The stability of the inner array plasma in the stage of final compression depends on the character of interaction of plasma jets from the outer array with the magnetic field of the inner array. [ABSTRACT FROM AUTHOR]

Results are presented from experimental studies of the implosion of twisted nested arrays in which the wires of the outer and inner arrays are twisted about the array axis in opposite directions (clockwise and counterclockwise). Experiments with twisted arrays were carried out at the Angara-5-1 facility at currents of up to 4 MA. The currents through the arrays were switched either simultaneously or the current pulse through the outer array was delayed by 10-15 ns with the help of an anode spark gap. It is shown that, in such arrays, the currents flow along the inclined wires and, accordingly, there are both the azimuthal and axial components of the discharge current. The process of plasma implosion in twisted arrays depends substantially on the value of the axial (longitudinal) magnetic field generated inside the array by the azimuthal currents. Twodimensional simulations of the magnetic field in twisted nested arrays were performed in the (r, z) geometry with allowance for the skin effect in the discharge electrodes. It is shown that, depending on the geometry of the discharge electrodes, different configurations of the magnetic field can be implemented inside twisted nested arrays. The calculated magnetic configurations are compared with the results of measurements of the magnetic field inside such arrays. It is shown that the configuration of the axial magnetic field inside a twisted nested array depends substantially on the distribution of the azimuthal currents between the inner and outer arrays. [ABSTRACT FROM AUTHOR]

This paper is a review of stratigraphic architectures and evolution history of late Pleistocene lowstand deposits on the outer shelf of Korea Strait. Located between the southeastern tip of the Korean Peninsula and the Tsushima Island, the Korea Strait is a seaway connecting the East Sea with the East China Sea. Detailed analysis of high-resolution seismic profiles and sediment data give a good evidence for the existence of three superimposed wedge-shaped sedimentary units that thicken seaward. The individual sedimentary wedges are characterized by seaward dipping and complex sigmoid-oblique prograding reflection configurations with some chaotic or hummocky reflectors. On the basis of distribution and external geometry, these sedimentary wedges are interpreted as a 'shelf-margin or shelf-edge delta', mainly related to falling and lowstand sea level. Occurrence of this delta type is a common constitute of the Quaternary shelf in the Korea Strait. Although the entire units have not been fully dated, it is believed that these wedges were deposited during late Pleistocene sea-level lowstands. Repeated falls and lowstands of sea level (isotopic stages 8, 6 and 2/4) resulted in the formation of lowstand prograding wedges along the present shelf margin and trough region, having been separated from the inner shelf deposits. During subsequent episodes of sea-level rise (isotopic stages 8/7, 6/5, and 2/1), the upper part of sedimentary wedges was eroded, and thin covered by thin transgressive sands. Consequently, the late Pleistocene sequences on the shelf margin and trough region in this area mainly consist of a succession of stacked lowstand prograding wedges formed during the regression and lowstand of sea level. [ABSTRACT FROM AUTHOR]

New experimental data on the implosion of plasma of nested kapron−tungsten arrays are obtained at the Angara-5-1 facility. The mode of plasma implosion is implemented in which a shock wave region forms in the space between the inner and outer arrays where a transition from the super-Alfvénic ( V > V ) to sub-Alfvénic ( V < V ) plasma flow takes place. Specific features of the formation and decay of the shock region are studied using laser shadow imaging and X-ray frame photography. The plasma density in the transition region is estimated. By comparing the experimental data with the results of simulations of quasi-steady implosion of a nested array with allowance for extended plasma production, the physical conditions are determined at which the implosion mode with the formation the shock region takes place. Stable compression of the plasma of the inner array was observed during the implosion of combined nested arrays with a fiber outer array and tungsten inner array. Suppression of magnetic Rayleigh-Taylor instability during the compression of the inner array plasma results in the formation of a compact radiating Z-pinch and generation of a soft X-ray pulse with a peak power of 4 TW and duration of about 5 ns. [ABSTRACT FROM AUTHOR]

Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set (1902 to 2005), the annual variations in Ba/Ca and Mn/Ca ratios of Porites lutea skeletons at an eastern offshore area of Hainan Island (19°12´28.4´´N, 110°37´38.8´´E) were analyzed using inductively coupled plasma-optic emission spectrometry (ICP-OES). The analysis results showed that Ba/Ca ratios varied from a minimum of 3.120 μmol mol in 1903 to a maximum of 10.064 μmol mol in 1944, with an average of 5.256 μmol mol. Mn/Ca ratios varied from 0.206 to 5.708 μmol mol with an annual average of 1.234 μmol mol, with peak values in 2001, 1964 and 1932, that correlated with strong rainfall events caused by typhoons. Variation in Ba/Ca and Mn/Ca ratios were compared with available river discharge and precipitation records, providing insight into past climatological events. Human activities and their indirect effects could impact the strength of the relationship between Ba/Ca and Mn/Ca ratios and observed precipitation and terrestrial input in the future. [ABSTRACT FROM AUTHOR]

Comprehensive qualitative and semi-quantitative seismic analysis was carried out on 3-dimensional seismic data acquired in the deepwater compressional and shale diapiric zone of the Niger Delta Basin using an advanced seismic imaging tool. The main aim of this work is to obtain an understanding of the forming mechanism of the gas hydrate system, and the fluid migration paths associated with this part of the basin. The results showed the presence of pockmarks on the seafloor and bottom simulating reflectors (BSRs) in the field, indicating the active fluid flux and existence of gas hydrate system in the area. In the area of approximately 195 km occupying nearly 24% of the entire study field, three major zones with continuous or discontinuous BSRs of 3 to 7 km in length which are in the northeastern, southern and eastern part of the field respectively were delineated. The BSR is interpreted to be the transition between the free gas zone and the gas hydrate zone. The geologic structures including faults (strike-slip and normal faults), chimneys and diapirs were deduced to be the main conduits for gas migration. It is concluded that the biogenic gases generated in the basin were possibly transported via faults and chimneys by advection processes and subsequently accumulated under low temperature and high pressure conditions in the free gas zone below the BSR forming gas hydrate. A plausible explanation for the presence of the ubiquitous pockmarks of different diameters and sizes in the area is the transportation of the excessive gas to the seafloor through these mapped geologic structures. [ABSTRACT FROM AUTHOR]

In a superconductor placed in an external magnetic field, surface currents are produced and then distributed in a thin layer treated as the magnetic-field penetration depth. The constant current in a conductor of any type, together with the magnetic field, is forced out to the surface, which leads to the appearance of a so-called surface current. It is proposed that this current be considered as a bulk current flowing, however, in a thin layer. Since the layer thickness is independent of the material and the nature of the conductor, it is possible to assume that it corresponds to the depth of magnetic-field penetration into the superconductor in accordance with London's theory. The boundary conditions for the magnetic induction vector at the flat superconductor--free space interface are written taking this assumption into account. The magnetic induction and the current density experience a jump at the boundary. The obtained result makes it possible to calculate the surface superconductor energy, which turns out to be negative. [ABSTRACT FROM AUTHOR]

To evaluate the effects of pre- and post-conception undernutrition (UN) on fetal and placental development at mid-gestation, 28 Katahdin × Pelibuey multiparous ewes were blocked by weight and assigned to the following four dietary treatments ( n = 7 each): ewes fed 100% (control) or 60% of their nutritional requirements 30 days before mating (UNPre), 50 days after mating (UNPost) or during both periods (UNB). Four twin-bearing ewes were selected per treatment at day 50 post-conception and then slaughtered at day 75 of gestation to analyze their fetuses. Control fetuses were heavier ( P < 0.05) than UNPost and UNB fetuses in 14.6 and 9.4%, respectively. Organ weights as percentage of the fetal weight (except for liver) and morphometric measurements (except for abdominal girth) were similar between control and UN fetuses (UNPre, UNPost, and UNB). Placental mass was heavier ( P < 0.05) in control ewes than UNB ewes, but not relative to ewes of other treatments. The number of placentomes per ewe and placental efficiency were unaffected by UN treatments. Compared to control, only UNB ewes exhibited variations ( P < 0.05) in the proportion of placentomes, specifically for type A (+13.8%) and B (−12.6%). Placentomes of type A and B had lower weight, length, and width of placentas in UNPost and UNB ewes than placentas of control ewes ( P < 0.05). Overall results indicate that fetal and placental development of ewes carrying twins is mainly altered when nutritional restriction occurs simultaneously before conception and during the first third of pregnancy. [ABSTRACT FROM AUTHOR]

The implosion of nested fiber/wire arrays was studied experimentally at the Angara-5-1 facility. The outer array consisted of kapron fibers, while the inner array was made of tungsten wires. The experiments were carried out at a discharge current of 3 MA. Stable compression of the inner array plasma was achieved by increasing the number of fibers in the outer array. In this case, a compact Z-pinch formed at the array axis. Near the pinch, no trailing plasma produced from the high-Z material of the inner array and capable of scattering and reradiating X-ray photons was observed. The trailing edge of the X-ray pulse was found to shorten in the absence of the trailing plasma around the pinch. [ABSTRACT FROM AUTHOR]

The Global Fund raises and invests nearly US$4 billion a year to support programs run in more than 140 countries. The Global Fund strategy 2012-2016 is focused on 'Investing for Impact'. In order to accomplish this, timely and accurate data are needed to inform strategies and prioritize activities to achieve greater coverage with quality services. Monitoring and evaluation is intrinsic to the Global Fund's system of performance-based funding. The Global Fund invests in strengthening measurement and reporting of results at all stages of the grant cycle. The Global Fund approach to measurement is based on three key principles-(1) simplified reporting: the Global Fund has updated its measurement guidance to focus on impact, coverage and quality with the use of a harmonized set of indicators. (2) Supporting data systems-based on a common framework developed and supported by partners, it promotes investment in five common data systems: routine reporting including HMIS; Surveys-population based and risk group surveys; Analysis, reviews and transparency; Administrative and financial data sources; and, Vital registration systems. (3) Strengthen data use: the Global Fund funding encourages use of data at all levels-national, subnational and site level. Countries do not automatically prioritize M&E but when guidance, tools and investments are available, there is high level utilization of M&E systems in program design, planning, implementation, and results reporting. An in-depth analysis of the available data helps the Global Fund and countries to direct investments towards interventions where impact could be achieved and focus on target population groups and geographic areas that are most affected. [ABSTRACT FROM AUTHOR]

Coral reefs in the Xisha Islands (also known as the Paracel Islands in English), South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef flat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health (live versus dead cover) for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was <10%. The total Xisha reef system was estimated to cover 1 060 km, and the emergent reefs covered ~787 m. Hard corals of emergent reefs were considered to cover 97 km. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems. [ABSTRACT FROM AUTHOR]

Submarine sand waves, vital to seabed stability, are an important consideration for oceanic engineering projects such as oil pipe lines and submarine cables. The properties of surface sediment and the evolvement of submarine sand waves in a specified area in the South China Sea are studied using both a hydrological model and field observational data. The bottom flow field data between 2010 and 2011 in the study area are simulated by the Regional Ocean Model System (ROMS). The migration of submarine sand waves is calculated using Rubin's formula along with typhoon data and bottom flow field data, which allows for the analysis of sand wave response under the influence of typhoons. The migration direction calculated by Rubin's formula and bottom flow are very similar to collected data. The migration distance of different positions is between 0.0 m and 21.8 m, which reciprocates cumulatively. This shows that Rubin's formula can predict the progress of submarine sand waves with the bottom flow simulated by ROMS. The migration distances of 2 sites in the study area are 2.0 m and 2.9 m during the typhoon 'Fanapi'. The proportion of the calculated migration distance by the typhoon is 9.17% and 26.36% of the annual migration distance, respectively, which proves that the typhoon can make a significant impact on submarine sand waves. [ABSTRACT FROM AUTHOR]