Abrupt Decrease Research Articles

Canaries' Microbiota: The Gut Bacterial Communities along One Female Reproductive Cycle.

Investigations of bacterial communities are on the rise both in human and veterinary medicine. Their role in health maintenance and pathogenic mechanisms is in the limelight of infectious, metabolic, and cancer research. Among the most considered, gut bacterial communities take the cake. Their part in animals was assessed mainly to improve animal production, public health, and pet management. In this regard, canaries deserve attention, being a popular pet and source of economic income for bird-keepers, for whom breeding represents a pivotal point. Thus, the present work aimed to follow gut bacterial communities' evolution along on whole reproductive cycle of 12 healthy female canaries. Feces were collected during parental care, molting, and resting phase, and submitted for 16S rRNA sequencing. Data were analyzed and a substantial presence of Lactobacillus aviarius along all the phases, and a relevant shift of microbiota during molting and rest due to an abrupt decrease of the Vermiphilaceae family were detected. Although the meaning of such change is not clear, future research may highlight unforeseen scenarios. Moreover, Lactobacillus aviarius may be deemed for normal bacteria flora restoration in debilitated birds, perhaps improving their health and productivity.

New particle formation in the tropical free troposphere during CAMP2Ex: statistics and impact of emission sources, convective activity, and synoptic conditions

Abstract. Nucleation in the free troposphere (FT) and subsequent growth of new particles represent a globally important source of cloud condensation nuclei (CCN). Whereas new particle formation (NPF) has been shown to occur frequently in the upper troposphere over tropical oceans, there have been few studies of NPF at lower altitudes. In addition, the impact of urban emissions and biomass burning on the NPF in tropical marine FT remains poorly understood. In this study, we examine NPF in the lower and mid-troposphere (3–8.5 km) over the tropical ocean and coastal region using airborne measurements during the recent Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP2Ex). NPF was mostly observed above 5.5 km and coincided with elevated relative humidity (RH) and reduced condensation sink (CS), suggesting that NPF occurs in convective cloud outflow. The frequency of NPF increases with altitude, reaching ∼ 50 % above 8 km. An abrupt decrease in NPF frequency coincides with early monsoon transition and is attributed to increased CS resulting from reduced convective activity and more frequent transport of aged urban plumes. Surprisingly, a large fraction of NPF events in background air were observed in the early morning, and the NPF is likely made possible by very low CS despite low actinic flux. Convectively detrained biomass-burning plumes and fresh urban emissions enhance NPF as a result of elevated precursor concentrations and scavenging of pre-existing particles. In contrast, NPF is suppressed in aged urban plumes where the reactive precursors are mostly consumed, while CS remains relatively high. This study shows a strong impact of urban and biomass-burning emissions on the NPF in tropical marine FT. The results also illustrate the competing influences of different variables and interactions among anthropogenic emissions, convective clouds, and meteorology, which lead to NPF under a variety of conditions in tropical marine environments.

Prediction of nodal-line fermion and phonon-mediated superconductivity in bilayer α-borophene

The electron deficiency of boron allows the formation of a variety of monolayer or few-layer two-dimensional structures (borophenes) with interesting physical properties. Recent experiments have also confirmed that interlayer covalent bonding makes the bilayer structure more stable than the monolayer. In this work based on α-borophene, we propose three free-stranding bilayer structures with dynamic stability. In these three metallic structures, the electronic band crossings around Fermi level form nodal lines. All these structures also exhibit strong electron-phonon couplings. The Bardeen–Cooper–Schrieffer superconducting critical temperature T c of the type-II structure went as high as 28.2 K, which was further improved to 32.0 K by the enhancement effect of Li adatom at the Debye frequency. However, no increase in critical temperature was observed in other Li-doping cases. Specifically, Li intercalation inside the bilayer causes a significant abrupt decrease in the critical temperature of type-I structure. Our results indicated that the bilayer borophene would be an ideal platform for the coexistence of topological electronic states and superconducting states.

Updated COMAGMAT-5: Modeling the Effects of Sulfide Precipitation in Parallel to Crystallization Of Alumino-Chromian Spinel

An updated version of the COMAGMAT-5.3 program is presented, which enables simulations of the silicate-sulfide immiscibility in parallel to crystallization of Al-Cr spinel and other rock-forming minerals. Main changes include a completed recalibration of the previous Fe-Ni sulfide solubility model (Ariskin et al., 2013) and incorporation of equations describing spinel-melt equilibria in a wide range of magmatic systems (Nikolaev et al., 2018а, 2018b). This allowed us to specify more accurately the link between compositions of immiscible sulfides and magma crystallization temperatures, as well as to correct partitioning of alumina between the model spinel and crystallizing melt. The updated COMAGMAT-5.3 can be used for calculations of the crystallization of basaltic to komatiitic magmas, as well as the history of solidification of mafic to ultramafic cumulates, including relative proportions of Al-Cr spinel and immiscible sulfides. Application example includes solidification of sulfide-bearing primitive olivine cumulate from the endocontact of the Yoko-Dovyren intrusion in Northern Transbaikalia (Russia). It is established that maximum crystallization proportions of Al-Cr spinel as much as 3.5 wt % are observed at Ol-Spl cotectic, following an abrupt decrease to slightly negative values during crystallization of plagioclase-bearing assemblages. This results in the inflection point on the trend of evolution of the spinel compositions, which changes from descending the Cr/Al ratio in the field of olivine to its increase when plagioclase starts to crystallize. As compared to previous version COMAGMAT-5.2, the updated model predicts somewhat higher proportions of precipitated sulfides.

Paleomagnetic constraints on neotectonic deformation within the Southern Tian Shan piedmont and implications for the latest Miocene enhanced aridification in the Tarim Basin

The India-Eurasia collision reactivated the Tian Shan belt of Central Asia and led to crustal shortening which has been accommodated by fold-and-thrust belts on both flanks of the orogen. Southward propagation into the Tarim Basin has been accommodated by the Kuqa fold-and-thrust belts which record a range of well-preserved syntectonic continental sequences. Using existing magnetostratigraphic age constraints, we have conducted an in-depth paleomagnetic and rock magnetic investigation of this fold-and-thrust belt with the aim of linking the neotectonic deformation to the uplift of the Tian Shan orogen to the north. Anisotropy of magnetic susceptibility (AMS) shows “pencil structure” fabrics between levels dated 31.0 and 5.5 Ma. These are succeeded by incipient deformation fabrics at ~5.3 Ma, which dates an abrupt decrease in shortening by synsedimentary strain. This change coincides with the timing of initial syntectonic growth strata in the foreland basin of the Southern Tian Shan and contemporaneous vertical-axis rotations in the Yaha section. Collectively this evidence implies that the Southern Tian Shan piedmont underwent transpressional deformation with rotation accompanying strain partitioning during a regional sinistral shear. The extreme aridification which has occurred in the Tarim Basin since the latest Miocene is interpreted in terms of the deflection of the ambient westerly airstream away from this region due to the growth of the Tian Shan and its final collision with the Pamir.

Anomalous temperature dependence of energy levels of electrons on helium

We report on magnetoconductivity measurements of electrons on helium exposed to resonant microwave irradiation within the temperature range associated with electron-ripplon scattering. Our findings reveal a non-monotonic temperature dependence of the intersubband frequency, with an abrupt decrease observed at temperatures below 0.3 K. We attribute this unexpected energy levels shift to the adsorption of 3He impurities near the liquid helium surface at low temperatures and such behavior is consistent with recent theoretical calculations of the surface electron energy spectra on 3He–4He mixtures.

First-principles study of electronic structure and metallization of Mg2Pb under high pressure

The high-pressure electronic structure and electrical properties of Mg2Pb are investigated from ambient pressure to 42 GPa by first-principles calculation. Mg2Pb undergoes reversible structural transitions from Fm3‾m structure to Pnma structure and then to P63/mmc structure. The structural phase transitions are determined respectively at around 6 GPa and 28 GPa using pressure-dependent enthalpy calculations, which are also reflected from the cell volume collapse and discontinuous axial ratios of lattice constants. The sliding of Mg and Pb atomic layers is revealed via the Mg1–Pb–Mg2 atom pair during structural phase transitions, corresponding to abrupt decrease of c/b and a/b. The semimetal-to-metal transition is also observed at approximately 28 GPa owing to energy-band closure, whilst metallic character is strengthened with increasing pressure. The paper is prone to theoretically explore the structural phase transition and metallization of Mg2Pb-type family under extreme conditions.

Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials.

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study.

Highly efficient removal of endocrine disrupting pesticides by metal ferrites loaded Guar gum based green nanomaterials

Numerous persistent and inexpensive pesticides are needed for industrial, domestic, and agricultural uses. Toxicity and bioaccumulation of pesticides have raised concerns for environment and demanding the efficient removal methods based on green nanomaterials. To substantiate this, the crystalline CdMgFe2O4@TiO2 nanocomposite incorporated in guar gum (GG) polymeric matrix (GG-CdMgFe2O4@TiO2) were employed to remove hazardous pesticides. Characterization showed that hybrid nanoparticles with polymer coating (particle size less than 100 nm) were successfully formed. PXRD revealed semi-crystalline nature and microscopic studies confirmed the wrapping of CdMgFe2O4@TiO2 with sheet like structure having size less than 100 nm. At optimum amount of GG-CdMgFe2O4@TiO2 (20 mg), Endosulfan (ES) (94%) and DDE (88%) degraded at neutral pH under sunlight. Both adsorption (GG-polymeric matrix) and photocatalytic degradation (CdMgFe2O4@TiO2) phenomenon followed for removal of target pesticides. Larger surface area (110 m2 g−1) and narrow band gap (1.9 eV) are evident for maximum eradication of pesticides by polymeric nanocomposites supports their excellent efficiency in terms of interactive and semiconducting feature. Removal phenomenon of pesticides followed Ist order kinetics and Langmuir adsorption was evident from the abrupt decrease in pesticides concentration followed by a steady reduction. Radical-scavenger analysis was used to investigate photo-catalytic reduction. LC-MS analysis proved that GG-CdMgFe2O4@TiO2 break down toxic pesticides into safer metabolites in presence of sunlight. In conclusion, polymeric GG-CdMgFe2O4@TiO2 nanocomposite may prove to be highly effective catalyst for industrial applications due to its high reusability (n = 9), higher charge separation, stability and high surface activity.

Beryllium mineralisation in high-sulphur-fugacity fluids in the Dawan Be (Mo) deposit, Southeast China

Beryllium mobilisation, transfer, and enrichment in volcanogenic Be deposits are presumably controlled by F-bearing hydrothermal fluids. However, the stability of Be-bearing species, evolution of Be-bearing minerals, nature of Be deposits, and controls of sulphur fugacity (ƒS2) and alkalinity in such hydrothermal systems are not fully understood. We conducted a detailed petrographic, mineralogical, and geochemical study of the Dawan Be (Mo) deposit in Xiapu County, Fujian Province, China, to investigate Be mineralisation from hydrothermal fluids with high S fugacity and low Al concentrations. The Dawan Be (Mo) deposit occurs in greisen and pyritized zones, hornfels, and quartz veins, which are typically hosted by volcanic rocks (i.e., tuffs). The main Be ore minerals are helvine ((Mn)4Be3(SiO4)3S) and beryl. Helvine occurs mainly in proximal quartz veins, while beryl is found in distal quartz veins. The crystallisation of helvine indicates high-ƒS2 and low-ƒO2 conditions, but danalite is absent, suggesting the hydrothermal fluids had a relatively high ƒS2 and ƒO2. The change in crystallisation from helvine to beryl was mainly due to variations in ƒS2 and ƒO2 in the ore-forming fluids. The abrupt decrease in ƒS2 associated with the formation of sulphides (e.g., pyrite, helvine, and molybdenite) led to the crystallisation of beryl in the distal quartz veins. Bertrandite is one of the alteration products of helvine. Sulfidation, along with redox conditions, SiAl activity, P-T conditions, and fluid F contents, controlled the transport, enrichment, and crystallisation of Be in the Dawan Be (Mo) deposit. In situ U-Th-Pb dating of monazite indicates that the Dawan Be (Mo) deposit formed at between 92‐ 94 Ma, which is similar to the intrusion age of the associated granite. The geological features and similar Pb isotope ratios of pyrite and the granite suggest that Be in the Dawan Be (Mo) deposit was derived from the granite, but the surrounding tuff may have been another source of Be. The mineralogical and geochemical features of the Dawan Be (Mo) deposit reveal that mobilisation, transfer, and enrichment of Be occur in high-ƒS2 fluids, and further exploration of potential Be deposits containing helvine is warranted.

Role of cardiopulmonary interactions in development of ventilator-induced lung injury-Experimental evidence and clinical Implications.

Ventilator-induced lung injury (VILI) impacts outcomes in ARDS and optimization of ventilatory strategies improves survival. Decades of research has identified various mechanisms of VILI, largely focusing on airspace forces of plateau pressure, tidal volume and driving pressure. Experimental evidence indicates the role of adverse cardiopulmonary interaction during mechanical ventilation, contributing to VILI genesis mostly by modulating pulmonary vascular dynamics. Under passive mechanical ventilation, high transpulmonary pressure increases afterload on right heart while high pleural pressure reduces the RV preload. Together, they can result in swings of pulmonary vascular flow and pressure. Altered vascular flow and pressure result in increased vascular shearing and wall tension, in turn causing direct microvascular injury accompanied with permeability to water, proteins and cells. Moreover, abrupt decreases in airway pressure, may result in sudden overperfusion of the lung and result in similar microvascular injury, especially when the endothelium is stretched or primed at high positive end-expiratory pressure. Microvascular injury is universal in VILI models and presumed in the diagnosis of ARDS; preventing such microvascular injury can reduce VILI and impact outcomes in ARDS. Consequently, developing cardiovascular targets to reduce macro and microvascular stressors in the pulmonary circulation can potentially reduce VILI. This paper reviews the role of cardiopulmonary interaction in VILI genesis.

Fluvial-style migration controls autogenic aggradation in submarine channels: Joshua Channel, eastern Gulf of Mexico

Abstract There has been debate over the processes acting on deep-water channels, with comparisons made to the evolution of meandering fluvial systems. We characterized a three-dimensional seismic-reflection dataset of the Joshua deep-water channel–levee system located in the eastern Gulf of Mexico and interpreted 13 horizons showing its kinematic evolution over a 25 km reach. Over this reach, we documented channel migration through systematic bend expansion and downstream translation, which was sustained through channel aggradation as sinuosity increased from 1.25 to 2.3 at abandonment. An abrupt decrease in sinuosity was associated with a neck cutoff, which changed the subsequent migration direction of the channel in that locality. These processes are analogous to the evolution of meandering fluvial systems. We show that increasing channel sinuosity correlates to a reduction in channel slope and hypothesize that this promoted increasingly depositional turbidity currents that led to channel aggradation. Using a simple forward stratigraphic model in which vertical movements of the channel are governed by a stream power law, we show how aggradation can be driven autogenically. Trends in sinuosity, aggradation and slope are in broad agreement between the Joshua Channel and the model. This highlights the potential importance of intrinsic channel processes as a control on system evolution.

Oscillatory Zoned Liddicoatite from Anjanabonoina, Central Madagascar. III. Trace Elements

Abstract Large crystals of liddicoatite (tourmaline) from the Anjanabonoina Pegmatite of Central Madagascar are well-known for their distinct patterns of oscillatory zoning. This study follows two previous investigations, in which the crystal chemistry (Lussier et al. 2011a) and variations of major chemical constituents (Lussier & Hawthorne 2011) were characterized in detail. Here, the variations of elements present only at the trace level are investigated. The measurement by laser ablation inductively coupled plasma mass spectrometry of 26 trace elements, with abundances spanning four orders of magnitude (∼10−1 to 103 ppm) is reported. Trace elements were analyzed along continuous analytical traverses from the core to the rim of the crystal. Abundance profiles for most of the trace elements quantified (21 of 26) show clear oscillations that coincide with optical oscillatory zoning features. Throughout the crystal, the occurrence of compositional oscillation is independent of trace-element abundance; even where mean abundance is low, ∼1 ppm (e.g., V3+, Y3+, Th4+), oscillatory behavior is clear. Conversely, the magnitude of the oscillatory amplitude shows a strong near-linear dependence on element abundance. Within individual oscillatory zones, four unique line-shapes are observed, each differentiated by (1) the direction of a compositional discontinuity at the zone limits and (2) the orientation of the nonlinear curvature across the zone. For any individual zone, the variation in element concentration, C, can be fitted to the equation C = ±Aeλ(x−Φ)+ Δ where A is the zone amplitude; Φ is a reference position, and λi and Δi are fitted parameters. Comparison of the fitted equations shows that linear correlation between element pairs is common, occurring between pairs consisting of trace–trace, trace–major, and major–major elements. The oscillatory behavior of constituent elements is related to the location of the trace element in the tourmaline structure, with elements at the X- and Y-sites typically showing increases and decreases in abundance over single oscillatory zones. Throughout each zone, Mg has high abundance (∼104 ppm) at the start of each zone, followed by an extremely abrupt decrease in abundance, typically over a distance of <1 mm, making its behavior different to that of other elements (both trace and major). Finally, there are systematic differences in trace-element abundances between pyramid {201} and prism {100} sectors of the crystal, echoing the differences observed for major elements between these two sectors and consistent with face-dependent differences in element uptake.

Kratkoročna prognoza vidljivosti određena metodom slučajne šume

Accurate visibility forecasting is essential for safe aircraft operations. This study examines how various configurations of the Random Forest model can enhance visibility predictions. Preprocessing techniques are employed, including correlation analysis to identify fundamental relationships in weather observations. Time-series data is transformed into a regular Data Frame to facilitate analysis. This study proposes a classification framework for organizing visibility data and phenomena, which is then used to develop a visibility forecast using the Random Forest method. The study also presents procedures for hyperparameter tuning, feature selection, data balancing, and accuracy evaluation for this dataset. The main outcomes are the Random Forest model parameters for a three-hour visibility forecast, along with an analysis of errors in low visibility forecasts. Additionally, models for one-hour forecasts and visibility forecasting under precipitation are also examined. The resulting models demonstrate a deterministic forecast accuracy of approximately 78%, with a false alarm rate of around 6%, providing a comprehensive overview of the capabilities of the Random Forest model for visibility forecasting. As anticipated, the model demonstrated limitations in accurately simulating fast radiative cooling or abrupt decreases in visibility caused by precipitation. Specifically, in relation to precipitation, the model achieved an accuracy of 79%, yet exhibited a false alarm rate of 19%. Additionally, this method sets a foundation for enhancing prediction accuracy through the inclusion of supplementary forecast data, while its implementation on real-world datasets expands the reach of machine learning techniques to the members of the meteorological community.

A high time-resolution analysis of the Ground-Level Enhancement (GLE) of 23 February 1956 in terms of the CSHKP standard flare model

The original real-time analog heritage data from the Huancayo recording ionization chamber is differentiated to yield 15–60 s resolution of the first 15 min of the cosmic ray Ground-Level Event (GLE) of 23 February 1956. The initial High-Energy Impulsive (HEI) event of >12.5–20 GeV solar cosmic rays has a rise time of 2 min 15 s with an exponential rise time constant of 49 s, a fluctuating peak pulse of duration 5–7 min, followed by an abrupt decrease of <1 min duration to ∼33% of the peak flux. Detailed analysis of these data shows close consistency with the Carmichael-Sturrock-Hirayama-Kopp-Pneuman (CSHKP) standard flare model. The <49-second acceleration time to >12.5 GeV is explicable in terms of any one of three separate mechanisms: super-Dreier electric acceleration, statistical (Fermi first order), and shock acceleration deep in the corona. The fluctuating solar cosmic ray flux, the abrupt cessation, and the strong cosmic ray anisotropy on arrival at Earth are consistent with the acceleration event consisting of a sequence of short-lived reconnection events within the parent active center. In addition, the HEI event had a duration and time domain profile similar to the gyro-synchrotron emission from electrons associated with the initial acceleration event in the CSHKP model, and the observation of a white light flare towards the end of the microwave pulse. The properties of the GLE-5 HEI event are similar to those accompanying ten other previously studied large GLEs to the west of 240 West on the solar disk. We conclude that the historic high-resolution data from the GLE on 23 February 1956 demonstrate previously unknown properties of the HEI event that are all consistent with cosmic ray acceleration to 25 GeV by the CSHKP and similar flare magnetic reconnection models. A slowly varying and smaller increase commenced 6 min after the commencement of the HEI event and rose steadily to a maximum ∼40 min later. This is consistent with several models of acceleration in association with the coronal mass ejection generated by the flare.

Unexpected epileptogenic effect of lethal doses of pentobarbital: a case report

Background: Barbiturate poisoning is rare but potentially fatal. Case Report: We reported a case of barbiturate poisoning in a 28-year-old woman who recovered from lethal pentobarbital deliberate self-poisoning. The initial blood pentobarbital concentration was 61 mg/L, corresponding to a potentially lethal dose. Despite the ingestion of a high dose of pentobarbital, the electroencephalogram revealed an unattended pattern compatible with possible nonconvulsive status epilepticus. Following resuscitation maneuvers, appropriate care, and antiseizure medication, the patient awakened after 7 days. The evolution was excellent without neurological deficits at 2 months.Conclusion: Despite the expected and known effects of high-dose pentobarbital in reducing and suppressing cortical activity in the brain, the present case demonstrates that lethal dose of pentobarbital may have an epileptogenic effect. Our hypothesis was that the mechanism of the origin of such a picture is a relatively abrupt decrease in toxic doses of pentobarbital, resulting in a withdrawal phenomenon.

Nitrogen storage capacity of phengitic muscovite and K-cymrite under the conditions of hot subduction and ultra high pressure metamorphism

Nitrogen storage capacity and partitioning between main N hosts have been investigated in N-bearing Al-rich natural pelite at 3.0–7.8 GPa, 825–1070 °C and oxygen fugacity (fO2) from NNO (Ni-NiO buffer)+0.3 to NNO-4.1 log units. Under the conditions of hot subduction, pelite converts into a phase assemblage typical of ultrahigh-pressure (UHP) eclogites. Phengitic muscovite in this assemblage is in equilibrium with a volatile-rich granite-like melt at 3.0 GPa and with supercritical fluid at 5.5–7.8 GPa, and contains, respectively, 115–135 and 759–962 wt ppm NH4+ at fO2 values close to NNO. Both melt and supercritical fluid have H2O and CO2 as predominant volatiles and the NH3/(NH3 + N2) ratio from 0.04 to 0.12. The pattern of nitrogen partitioning between its main hosts in pelite (DNH4Ms-Melt = 0.41–0.58 and DNH4Ms-Fluid = 0.63–2.4) proves that the ammonium exhibits moderately incompatible to compatible behavior within a hot oxidized slab in the pressure range from 3.0 GPa to 7.8 GPa. Therefore, even relatively oxidized sediments containing phengitic muscovite can efficiently transport nitrogen to the mantle at sub-arc depths under the hot subduction conditions. At the same time, the changeover of the N host from biotite to muscovite at the arc depths in combination with subsequent pelite melting and an abrupt decrease in phengitic muscovite abundance in pelite may lead to an avalanche-like N outgassing of the slab. The incorporation of an additional nitrogen source of (NH3 + N2) into pelite reduces fO2 to NNO-3.1 – NNO-4.1 log units and increases both the NH3/(NH3 + N2) ratio in the fluid (up to 0.44–0.86) and the NH4+ concentration in phengitic muscovite (up to 3750–3820 wt ppm). K-cymrite was produced in pelite at P ≥ 6.3 GPa and the bulk nitrogen content 3.2–5.9 wt%. K-cymrite possesses exceptional nitrogen storage capacity: it hosts 1.4–1.6 wt% NH4+, up to 0.5 wt% NH3, and 4–6 wt% N2. The DN-NH4Cym-Ms coefficient is as high as 20. Being stable in sediments subducted to mantle depths, K-cymrite, with its extremely high storage capacity, can act as a huge hidden redox-insensitive nitrogen reservoir in the mantle and thus can be involved in the deep nitrogen cycle.

The spatio-temporal pattern of Asian summer monsoon during glacial Termination II recorded by Chinese stalagmite δ18O

The difficulty in constraining the large-scale Asian summer monsoon (ASM) variability in the Chinese monsoon region (CMR) during glacial Termination II lies in our limited knowledge of the western part, primarily due to sparse paleoclimate records. To get a better picture of the ASM during Termination II, we examined a precisely dated stalagmite δ18O record between 133.1 and 127.0 kyr B.P. from Wanxiang Cave located at the ASM's northern edge in western China. In combination with published δ18O data from this cave, we have identified the ‘Weak Monsoon Interval’ (WMI) in the Wanxiang δ18O record and confirmed that the Heinrich 11 cold event in the North Atlantic caused the weakened ASM over the CMR via reorganization of the large-scale ocean-atmospheric circulation. However, the post-WMI change in δ18O is gradual, in contrast with the abrupt shift shown in the other cave records from southern and northeastern China. The rapid northward migration of the westerly jet relative to the Qinghai-Tibet Plateau is probably responsible for this discrepancy. This northward-positioned westerly jet prevented the more 18O-depleted moisture from the Indian Ocean from reaching the study site. Simultaneously, it facilitated the earlier northward movement of the East Asian summer monsoon (EASM) rainband that carries positive precipitation δ18O to obscure the abrupt decrease in our δ18O record. After the onset of the last interglacial, no obvious Younger Dryas (YD)-like event was recorded in Wanxiang Cave. This result is consistent with most stalagmite δ18O records in the CMR and further suggests a minimal impact of the YD-like event on ASM variabilities. The relatively large amplitude of δ18O variations observed in Wanxiang Cave between the late penultimate glacial and the last interglacial corresponds to a dominant control of the Indian summer monsoon (ISM), whereas smaller δ18O amplitudes were recorded in cave sites mainly under the influence of both ISM and EASM. Therefore, we posit that the heterogeneity of the hydroclimate in the CMR during Termination II resulted from a combination of multiple processes, that is, the westerly jet, ISM and EASM, rather than a single one.

Linking the uptake of best management practices on dairy farms to catchment water quality improvement over a 20-year period

Intensive land use, such as dairying, can impair water quality. Although many guidelines exist on how to mitigate the loss of dairy-associated contaminants from land to water through best management practices (BMPs), few datasets exist on the success of implementation on-farm. Five dairy-dominated catchments (from 598 to 2480 ha) in New Zealand were studied from 2001 to 2020. The first period, from 2001 to 2010, involved comprehensive “extension” advice to farmers consisting of workshops, stream water quality and flow monitoring, farm practice surveys, and identified solutions to address site-specific contaminant losses. In the second period (2011−2020), termed “post-extension”, only water quality monitoring and farm practice surveys were continued. Of the water quality contaminants (including dissolved reactive phosphorus (DRP), total phosphorus (TP), ammoniacal-nitrogen, nitrate-nitrite-nitrogen [NNN], suspended sediment and E. coli), 83 % of water quality trend directions were either improving (n = 16) or showed no change (n = 9) during the extension period. Over the 20-year dataset, which included the post-extension period, 20 out of 30 contaminant-catchment combinations (67 %) were improving, but nine were degrading, dominated by NNN (n = 4), DRP (n = 2) and E. coli (n = 2). Abrupt decreases in contaminant concentrations, were correlated with on-farm practice changes mainly associated with transition from direct discharge of farm dairy shed effluent to waterways to land application, and the capture of effluent from off-paddock facilities (like stand off or feed pads). Best management practices reduced phosphorus (P) forms, E. coli and sediment concentrations. Increase in NNN concentrations was caused by transitioning from flood to spray irrigation and a commensurate increase in cow numbers and NNN leaching. These data indicate that extension advice and on-farm practice change have helped to improve overall water quality over time. Nevertheless, recent regulatory threshold values for some contaminant concentrations are not being met, meaning that more actions are required, over and above the BMPs implemented.

On the effectiveness of mitigation strategies for cryogenic applications

The need for sustainable energy sources, as well as the current energetic crisis involving the majority of markets, has promoted the use of cryogenic liquefaction for the transportation and storage of natural gas (i.e., LNG). To guarantee the development of a robust and safe infrastructure, a complete understanding of the main phenomena occurring at low temperatures is paramount. In this sense, the largest grey areas are the characterization of the combustion at low-initial temperature and the interactions between water and cryogenic liquid. For these reasons, this work presents an experimental campaign on the possible mitigation strategies for the mitigation of consequences related to the accidental release of LNG. Particular emphasis was posed on the direct and indirect effects of water on cryogenic pool fire. The former resulted in a significant increase in the dimensions of fire (∼+50%) and burning rate (∼300%) with respect to the case with no direct contact between water and LNG, whereas the latter generated an abrupt decrease in the measured temperatures (<100 °C). The use of an emergency flare to empty an LNG tank was tested, as well. The spatial distribution of temperature was monitored along with the time to guarantee the safe operability of this equipment in the case of LNG combustion. The explanations for the observed phenomena and trends were provided, allowing for the development of safe procedures for the emergency response related to cryogenic fuels.