Depletion Patterns Research Articles

Evaluating the Presence and Depletion of Residual Ivermectin in Milk Following Subcutaneous Injections on Lactating Cows

Dairy farming industry in Kenya has experienced significant growth due to the rising consumption of milk and dairy products. Consequently, to improve output,veterinary drugs were administered prophylactically and/or therapeutically to dairy cattle. Commonly used drugs included beta-agonists, anthelmintics, antibiotics, and steroid hormones. Parasitic diseases more so tick infestations hindered production. Chemical methods were primarily used in tick management however, the technique proved expensive and developed resistance. Conversely, ivermectin effectively controlled ecto- and endoparasites in livestock, hence gaining popularity in tick management. Nonetheless, its residues accumulated in animal tissues, rendering it unacceptable on animals that produced milk for human use. Apparently, farmers in tick-infested areas in Nyandarua County, Kenya used ivermectin, but there lacked adequate evidence to show that it occurred in milk. Thus, this study examined the performance of Liquid Chromatography tandem mass spectrometry (LC-MS-MS) in order to analyse the presence and depletion pattern of ivermectin residues after it excreted in cow milk following subcutaneous treatment of dairy cows. Between day 0.5 and day 57 following treatment, 24 milk samples were purposefully collected and stored at -20°C.. The samples were prepared using QuEChERS, a solid-phase extraction technique.Further, positive Electrospray ionization (+ESI) LC-MSMS qualitative analysis identified a precursor ion with the mass number of m/z 897.5 and corresponding product ions—m/z 897.5 > 329, m/z 897.5 > 240, and m/z 897.5 > 183—within a retention time of 8.782-8.858 (mean = 8.362±0.002) minutes. The solvent and matrixmatched calibration curves displayed satisfactory linearity with r=0.998 and 0.993 as their respective correlation coefficients. Additionally, the limit of detection was 2.5 ng/ml and limit of quantification reached 10 ng/ml. The analyte recovery ranged from 74.977% to 101.435%, within satisfactory limits. Hence, ivermectin residues were quantified in milk samples from the 0.5th to 17th day. The highest concentration (60.90±0.98 ng/ml) was observed on 2nd day. No traces of the residue were detected beyond day 18 and as a result, the study recommends a withdrawal period of 18days after subcutaneous ivermectin treatment. It is therefore important to perform further research on other dairy and animal products that people consume.

Geochemical dichotomy of Tethyan oceanic mantle and the supercontinent connection: Insights from Os isotopic signatures of mantle peridotites from Naga Hills ophiolite

Naga Hills Ophiolite (NHO) represents a thrusted section of relict Neo-Tethyan oceanic lithosphere comprising distinct crustal and upper mantle lithologies that preserve imprints of different stages of evolution of ancient ocean basins and subsequent accretion onto continental margins during late Cretaceous-Eocene collision involving Indian and Eurasian Plates. This study presents bulk geochemistry and Re-Os isotopic compositions for the mantle peridotites of NHO to address their petrogenetic aspects, implications for Neo-Tethyan upper mantle heterogeneity and thermo-tectonic evolution of Neo-Tethyan oceanic lithosphere through subduction-accretion-collision processes. Geochemical characteristics of the mantle peridotites, as reflected from their chondrite normalized REE patterns, binary relationship between fractionation depletion indices, low Re/Os, suggest that these are mantle residues resulting from ∼ 5–20 % of melt extraction from a spinel peridotite source that experienced decompression melting in a fore-arc extensional setting in response to subduction initiation. Isotopically, these mantle peridotites are subchondritic with 187Os/188Os (0.1218–0.1266) and γOs values of −3.73 to −0.09 comparable with the depleted MORB source. LILE-LREE enrichment, HFSE depletion, and U-shaped chondrite-normalized REE patterns demonstrated by the studied samples with Re addition collectively corroborate multistage petrogenetic processes in compliance with geodynamic transition from extensional to compressional regime in a suprasubduction zone environment and partial melting of a chemically heterogeneous source mantle. This compositional heterogeneity can be equated with mantle depletion by melt extraction and refertilization by influx of slab-dehydrated fluids and percolation of boninitic melts. The non-radiogenic Os isotope signatures, negative γOs values and wide spectrum of melt extraction ages for these mantle peridotites correspond to (i) multiple melt production and melt extraction events prior to the opening of Neo-Tethyan seaway (ii) detachment and incorporation of ancient, depleted SCLM fragments into oceanic mantle concurrent with subduction driven ocean basin closure-congregation of Gondwana Supercontinent and emergence of Neo-Tethyan embryonic ocean in response to disintegration of Gondwana Supercontinent.

Stellar Outbursts and Chondrite Composition

The temperatures of observed protoplanetary disks are not sufficiently high to produce the accretion rate needed to form stars, nor are they sufficient to explain the volatile depletion patterns in CM, CO, and CV chondrites and terrestrial planets. We revisit the role that stellar outbursts, caused by high-accretion episodes, play in resolving these two issues. These outbursts provide the necessary mass to form the star during the disk lifetime and provide enough heat to vaporize planet-forming materials. We show that these outbursts can reproduce the observed chondrite abundances at distances near 1 au. These outbursts would also affect the growth of calcium-aluminum-rich inclusions and the isotopic compositions of carbonaceous and noncarbonaceous chondrites.

The characteristics of rare earth elements in the main water filling sources of Sunan mining area

This study employs rare earth elements to investigate the features and procedures of water-rock interactions within aquifers of loose strata, sandstone, and limestone in the Sunan mining region of North Anhui, China. Through a comparison of the differential characteristics of rare earth elements across primary water sources, we are able to uncover the influence of water-rock interactions on the transfer and conversion of rare earth elements within various water-sediment systems. Indeed, the normalization of water compositions against host rock concentrations revealed a distinct pattern of rare-earth elements for each group of waters. Not only did the absolute concentrations of the elements in each sampling site change, but also the normalized patterns. In contrast to sediment samples, all water samples exhibit a clear enrichment of MREEs, but they also reveal a trend of HREEs enrichment. This is attributed to the differential adsorption effect of oxides on rare earth elements, which is influenced by pH, and the complexation reactions between rare earth elements and carbonate ions. The significant Ho and Ce anomalies in the water-sediment system are associated with robust water rock interactions, whereas the high Ba content significantly impacts the Eu anomaly. The enrichment of Eu is attributed to the interaction between the water environment and the dissolution of minerals rich in Eu. Furthermore, we utilize decision trees and recursive feature elimination techniques for selecting indices, and create a model that incorporates triangular fuzzy numbers (TFN), CRITIC, D-S evidence theory (DSET), factor space (FS), and set pair cloud model (SPCM) to differentiate, describe, and evaluate three distinct groups of waters with varying hydrofacies. The conclusion drawn is that sandstone and limestone aquifers are the main sources of water inrush, with a mixing ratio exceeding 50%. Moreover, this marks the inaugural attempt to utilize patterns of rare-earth elements for establishing a comparison between various water groups, thereby enabling us to distinguish and differentiate depletion patterns resulting from dilution processes from those resulting from precipitation processes, with the aim of determining the contribution rates of mine water. The findings offer valuable insights for predicting water disasters in the Sunan mining area.

Reverse pH-dependent fluorescence protein visualizes pattern of interfacial proton dynamics during hydrogen evolution reaction

Reverse pH-dependent fluorescent protein, including dKeima, is a type of fluorescent protein in which the chromophore protonation state depends inversely on external pH. The dependence is maintained even when immobilized at the metal-solution interface. But, interestingly, its responses to the hydrogen evolution reaction (HER) at the interface are not reversed: HER rises the pH of the solution around the cathode, but, highly active HER induces chromophore deprotonation regardless of the reverse pH dependence, reflecting an interface-specific deprotonation effect by HER. Here, we exploit this phenomenon to perform scanning-less, real-time visualization of interfacial proton dynamics during HER at a wide field of view. By using dKeima, the HER-driven deprotonation effect was well discriminated from the solution pH effect. In the electrodes of composite structures with a catalyst, dKeima visualized keen dependence of the proton depletion pattern on the electrode configuration. In addition, propagations of optical signals were observed, which seemingly reflect long-range proton hopping confined to the metal-solution interface. Thus, reverse pH-dependent fluorescent proteins provide a unique tool for spatiotemporal analysis of interfacial proton dynamics, which is expected to contribute to a better understanding of the HER process and ultimately to the safe and efficient production of molecular hydrogen.

Outgassing Composition of the Murchison Meteorite: Implications for Volatile Depletion of Planetesimals and Interior-atmosphere Connections for Terrestrial Exoplanets

Outgassing is a central process during the formation and evolution of terrestrial planets and their atmospheres both within and beyond the solar system. Although terrestrial planets’ early atmospheres likely form via outgassing during planetary accretion, the connection between a planet’s bulk composition and its initial atmospheric properties is not well understood. One way to inform this connection is to analyze the outgassing compositions of meteorites, and in particular carbonaceous chondrites, because they are some of the most volatile-rich, primitive materials (in terms of their bulk compositions) that are available for direct study. In addition, they may serve as compositional analogs for the building block materials of terrestrial planets in our solar system and around other Sun-like stars. This study builds upon previous outgassing experiments that monitored the abundances of volatile species (e.g., H2O, CO, and CO2) released from the Murchison meteorite. To gain a more complete understanding of Murchison’s outgassing composition, we perform a series of heating experiments under atmospheric pressure (1 bar) and vacuum (∼10−9 bar) conditions on samples of the Murchison meteorite and subsequent bulk element analysis to inform the outgassing trends of a suite of major elements in Murchison (e.g., Fe, Mg, Zn, and S). Under both pressure conditions, sulfur outgases significantly at the highest temperatures (∼800°C–1000 °C). For the samples heated under vacuum conditions, we also detect outgassing of zinc. Combined with prior outgassing experiments, this study provides important insights into the volatile depletion patterns of undifferentiated planetesimals and the early outgassing compositions of terrestrial exoplanets.

Different Responses of Soil Moisture to Different Artificial Forest Species on the Loess Plateau

The Chinese Loess Plateau has undertaken a large-scale “Grain for Green” project since 1999. Understanding how reforestation affects soil moisture is crucial for ecological construction and the region’s revegetation. In this study, soil sensors were installed to monitor the soil moisture content (SMC) and soil desiccation intensity in a 0–200 cm soil profile online during the growing season, with farmland as a control and Robinia (R.) pseudoacacia L., Pinus (P.) tabulaeformis Carr., Populus (P.) alba L., and Ulmus (U.) pumila L. were selected. The results showed that the SMC increased with soil depth, and the soil moisture storage (SMS) in the 0–200 cm soil profile was ranked as R. pseudoacacia L. (424.3 mm) < farmland (479.8 mm) < U. pumila L. (569.8 mm) < P. alba L. (583.9 mm) < P. tabulaeformis Carr. (589.8 mm). Secondly, the percentages of inefficient water and gravimetric water in soil moisture were ranked as R. pseudoacacia L. (63%) > farmland (49%) > U. pumila L. (43%) > P. alba L. (17%) > P. tabulaeformis Carr. (11%). The soil desiccation intensity of artificial forests was heavy in June, light in April and July, and no desiccation in the other months. Moderate desiccation was discovered in the 0–40 cm soil layer and mild desiccation occurred in the 40–60 cm soil layer. Additionally, the representative soil layer for SMS in farmland for P. tabulaeformis Carr., U. pumila L., and R. pseudoacacia L. was the 90 cm soil layer, and the SMS representative soil layer for P. alba L. was the 70 cm soil layer. In brief, an SMS deficit occurred after the conversion of the farmland to R. pseudoacacia L., but there was an SMS surplus after the conversion of the farmland to P. alba L., U. pumila L., and P. tabulaeformis Carr. This suggests that the artificial forest species could be optimized by introducing P. tabulaeformis Carr. instead of R. pseudoacacia L., and the degradation of R. pseudoacacia L. could be suppressed by the application of a nitrogen fertilizer. Our research demonstrated that soil moisture depletion patterns were closely related to artificial forest species, and attention should be paid to the vegetation restoration and maintenance of afforestation achievements in water-constrained arid regions in the future.

Цитокин-опосредованная дисрегуляция иммунного ответа при инфицировании SARS-CoV-2 (обзор)

This review presents a hypothesis on the formation of cytokine-mediated dysregulation of immune response in humans upon introduction of coronavirus 2 (SARS-CoV-2) into the body. Some morphological features of this virus are highlighted, contributing to its penetration into the body and to the generation of a signal for the activation of antiviral immune defence. It has been determined that interleukins 1, 6 and 10 stimulate systemic inflammation, while interleukins 2, 7 and 15 regulate the adaptive immune responses of CD8+ T cells. The protective effect of interferons λ1–4 has been shown to alter the Th1/Th2 balance and thereby preserve immune homeostasis. However, in patients with COVID-19, CD8+ T cells demonstrate patterns of functional depletion amid an evolving cytokine storm. Nevertheless, with sufficient reserve capabilities of the immune system, an adaptive immune response can develop, potentiated by the body’s interferon, interleukin and humoral-cellular defence against SARS-CoV-2. However, against the background of cytokine-mediated dysregulation of T-cell immunity and progressive hyperinflammation in patients with a severe course of COVID-19, blood tests show pronounced leukopenia, acute-phase proteins, changes in the ratio between certain types of leukocytes, as well as a decrease in the number of T helper and T suppressor cells. The author believes such changes in human immune responses to be a result of an uncontrolled overproduction of cytokines that changed the body’s immune reactivity and resistance as well as caused a subsequently decreased synthesis of specific antibodies and a limited humoral response to the antigen. A conclusion is made that a timely elimination of the dysregulatory immune response is necessary to form an adequate humoral response and maintain high immunoreactivity in human populations, as well as to increase the body’s resistance and form a stable population immunity.

Intestinal microbiota links to allograft stability after lung transplantation: a prospective cohort study

Whether the alternated microbiota in the gut contribute to the risk of allograft rejection (AR) and pulmonary infection (PI) in the setting of lung transplant recipients (LTRs) remains unexplored. A prospective multicenter cohort of LTRs was identified in the four lung transplant centers. Paired fecal and serum specimens were collected and divided into AR, PI, and event-free (EF) groups according to the diagnosis at sampling. Fecal samples were determined by metagenomic sequencing. And metabolites and cytokines were detected in the paired serum to analyze the potential effect of the altered microbiota community. In total, we analyzed 146 paired samples (AR = 25, PI = 43, and EF = 78). Notably, we found that the gut microbiome of AR followed a major depletion pattern with decreased 487 species and compositional diversity. Further multi-omics analysis showed depleted serum metabolites and increased inflammatory cytokines in AR and PI. Bacteroides uniformis, which declined in AR (2.4% vs 0.6%) and was negatively associated with serum IL-1β and IL-12, was identified as a driven specie in the network of gut microbiome of EF. Functionally, the EF specimens were abundant in probiotics related to mannose and cationic antimicrobial peptide metabolism. Furthermore, a support-vector machine classifier based on microbiome, metabolome, and clinical parameters highly predicted AR (AUPRC = 0.801) and PI (AUPRC = 0.855), whereby the microbiome dataset showed a particularly high diagnostic power. In conclusion, a disruptive gut microbiota showed a significant association with allograft rejection and infection and with systemic cytokines and metabolites in LTRs.

Distinct amyloid-dependent patterns of nigra dopamine depletion in Lewy body diseases.

Concomitant amyloid pathology is not uncommon and contributes to the clinical characteristics of Lewy body disease (LBD). We investigated the effect of amyloid on striatal18F-FP-CIT uptake patterns in LBD, including Parkinson's disease (PD) and dementia with Lewy bodies. We enrolled 125 patients with LBD who underwent18F-florbetaben positron emission tomography (PET) and18F-FP-CIT PET. Patients were divided into amyloid-positive and amyloid-negative groups. We investigated the effect of amyloid on striatal dopamine transporter (DAT) availability, depending on the type of LBD, using general linear models with interaction analysis after controlling for age, sex, education, deep white matter hyperintensity (WMH), periventricular WMH, and cognitive status. There was a significant interaction effect between the disease group and the presence of amyloid on DAT availability in the anterior putamen, posterior putamen, caudate, and ventral striatum. In the presence of amyloid, only the PD group exhibited decreased DAT availability in the anterior and posterior putamen. In both groups, the presence of amyloid was not associated with DAT availability in the caudate and ventral striatum. The presence of amyloid was not directly related to the worse parkinsonian motor symptoms in both groups. However, there was a significant indirect effect of amyloid on parkinsonian motor symptoms, which was mediated by anterior and posterior putaminal DAT availability in the PD group alone. This study demonstrates different amyloid-dependent or amyloid-independent18F-FP-CIT PET patterns in patients with LBD, suggesting distinctive interactions between α-synuclein and amyloid pathology based on the type of LBD.

Mapping the path forward: A prospective model of natural resource depletion and sustainable development

This paper introduces a sustainable development model of natural resource depletion that quantifies the optimal relationship between the two. Adopting a nested constant elasticity-of-substitution production function with easy substitution between capital and natural resource depletion, the derived model that was simulated prospectively for the time horizon 2020–2100 reveals a non-linear pattern of natural resource depletion, with a minimum of 0.735 million tons, projected for the year 2100. Sustainable development exhibits a quasi-inverse U shape, raising questions about the long-term sustainability of sustainable development. The model predicts two distinct relationships between sustainable development and natural resource depletion, depending on the existence of a 6 billion tons threshold for natural resource depletion. Supported by the Regression Discontinuity Design, a positive relationship was established below the threshold point in opposition to a negative association above this cutoff level. This model is a valuable tool for policymakers to monitor and inform sustainable development policies with regard to natural resource depletion.

Assessing global trends in Mars magma compositions using ground truth

AbstractGlobal magmatic trends inferred from gamma‐ray, visible/near‐infrared, and thermal infrared spectrometers on Mars‐orbiting spacecraft have been used to constrain planetary petrogenetic processes and global thermal evolution models. Inferred magmatic trends include temporal variations in the relative proportions of low‐Ca and high‐Ca pyroxenes, and in the abundances of potassium (and total alkalis), silica, FeO* (total iron expressed as FeO), and thorium. These patterns are evaluated for consistency with the compositions of surface igneous rocks of different ages analyzed by Mars rovers and of martian meteorites. Trends of decreasing low‐Ca pyroxene/total pyroxene ratios and of decreasing potassium (and total alkalis), with time are generally supported by surface rock analyses. However, significant differences in the GRS‐measured silica in Amazonian volcanoes and in martian meteorites of equivalent age result from contamination by silica‐rich dust and are problematic for a silica trend. Comparison of FeO* in Noachian and Amazonian surface data shows no decrease. An inferred temporal trend in thorium is in conflict with the complex enrichment and depletion patterns of incompatible trace elements in martian meteorites of various ages. A dearth of analyses of Hesperian‐age surface rocks precludes a firm evaluation of inferred Noachian‐Hesperian trends and Hesperian‐Amazonian trends, but abundant Noachian rocks and a few Hesperian rocks at rover sites, and Amazonian martian meteorites, collectively representing at least 16 surface locations, afford useful comparisons with orbital remote‐sensing data.

Continental crustal growth and differentiation in intraoceanic arcs: Insights from plagiogranites in the forearc ophiolite of the southeastern Central Asian Orogenic Belt, China

Oceanic plagiogranites in subduction initiation zones record key information of continental crustal growth and differentiation. However, their petrogenesis remains controversial, due to the lack of complete subduction initiation records in most of ophiolites. In this study, we report a newly recognized plagiogranite suite (including intrusive plagiogranite porphyries and extrusive rhyolites) from the Diyanmiao forearc ophiolite in Inner Mongolia, southeastern section of the Centra Asian Orogenic Belt, where a relatively complete forearc magmatic succession is preserved. In the Diyanmiao suite, the plagiogranite porphyries, occur as small irregular dykes or pods intruding pillowed transitional lavas, and rhyolite lavas within or overlying the upper boninitic lavas, from bottom to top. Zircon UPb dating of two plagiogranite porphyry samples and one rhyolite sample yields mean ages of 322.5 ± 3.6, 319.9 ± 1.9, and 319.6 ± 2.6 Ma respectively. Similar to other oceanic plagiogranites, the plagiogranite porphyries and rhyolites in our study exhibit high SiO2 and Na2O contents and low K2O. They have chondrite-normalized flat to slightly depleted rare earth element patterns, and significantly negative Nb, Ta, and Ti anomalies similar to arc magmatic rocks. They also display high positive εHf(t) values (+12.5 − +18.7) and εNd(t) values (+6.9 − +10.0), comparable to the values of their host rocks. Petrographic characteristics and Rhyolite-MELTS modeling suggest that the plagiogranite porphyries and rhyolites were generated by high degree of crystal fractionation from parent tholeiitic basalt magmas. Our results suggest that melt migration triggered by fractional crystallization of mafic magmas played a vital role in the growth of continental crust in intraoceanic arcs in the southeastern Paleo-Asian Ocean.

Geochemical Characteristics of Garnet from Zinc–Copper Ore Bodies in the Changpo–Tongkeng Deposit and Its Geological Significance

The Changpo–Tongkeng tin polymetallic deposit in Dachang, Guangxi, is a world-class, superlarge, polymetallic tin deposit consisting of lower skarn zinc–copper ore bodies and upper tin polymetallic ore bodies. Garnet is the main gangue mineral in the skarn zinc–copper ore bodies and has a granular texture. Based on hand specimens and microscopic observations, the existing garnet can be divided into two generations: an early generation (Grt I) and a late generation (Grt II). The results of electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) in situ microanalysis show that the contents of SiO2 and CaO in the garnets from the two generations present limited variations, while the FeOT and Al2O3 contents vary significantly, indicating the grossular–andradite solid solution series (Gro29–82And12–69). Compared with Grt I (Gro72And25), Grt II (Gro39And59) is Fe-enriched and oscillatory zoning is developed. The total rare earth element (REE) contents in the two generations of garnet are relatively low, showing light rare earth element (LREE) depletion and heavy rare earth element (HREE) enrichment patterns. Grt II has higher REE content than Grt I and exhibits significant negative Eu anomalies (δEu = 0.18–0.44). The contents and variation characteristics of the major and trace elements in the two generations of garnet suggest that there were variable redox conditions and water/rock ratios in the hydrothermal system during the crystallization process of garnet. In the early stage, skarnization was in a relatively closed and low-oxygen fugacity system, with hydrothermal diffusion metasomatism being dominant, forming homogeneous Grt I lacking well-developed zoning. In the late stage of skarnization, the oxygen fugacity of the ore-forming fluids increased, with infiltration metasomatism being dominant, forming Grt II with well-developed oscillatory zoning. The contents of Sn, As, W, In, and Ge in the garnets are relatively high and increase with the proportion of andradite. Sn in zinc–copper ore bodies mainly exists in the form of isomorphic substitution in garnet, which may be the main reason for the lack of tin ore bodies during the skarn stage. This paper compares the trace element contents in garnets from domestic skarn deposits. The results indicate that the Sn content and δEu in garnet can be used to evaluate the tin-forming potential of skarn deposits.

Effects of aberrations on isoSTED microscopy

Aberrations are inevitable in optical microscopes and affect the image quality. In STED microscopy, the optical resolution is especially dominated by the performance of depletion pattern. To quench fluorescence only in the periphery of the excitation focus, the depletion focus ideally has a zero-intensity point that is surrounded by a high-intensity crest. Otherwise, distortion of the depletion beam causes unwanted fluorescence inhibition. The influence of aberrations on isoSTED microscopy differs from that on STED microscopy because isoSTED microscopy generates a more complicated shape of the depletion focal spot with two opposing objectives which have different focusing properties. We present analysis that elucidates the effects on the shape, the central minimum intensity, and the peak intensity of the isoSTED pattern regarding primary aberrations such as astigmatism, coma, and spherical aberration when those aberrations are added in the shared beam path and each beam path in the 4Pi-cavity. The simulation results demonstrate significant resolution degradation (>160%; defined as the focal volume) for the aberrations with root mean square wavefront errors of 0.5 rad.

Hydrogeochemistry of trace and rare earth elements in the Caviahue-Copahue Volcanic Complex

The Caviahue-Copahue Volcanic Complex is one of the most studied active volcanic systems in the South American Andean range, and yet little research has focused on trace and rare-earth elements of waters, especially during an eruptive cycle. In this study, we sampled and investigated natural waters from 23 sites (involving the crater lake, hot springs, streams, rivers, and bubbling pools) in two campaigns in 2017 and 2018, using physicochemical parameters, major, trace and rare-earth elements concentrations. With this novel dataset, it was possible to identify, characterize and compare three groups of waters with distinctive hydrofacies. Indeed, the normalization of water compositions against host rock concentrations showed a particular trace element pattern for each group of waters. Although the absolute concentrations of the elements in each sampling site changed from 2017 to 2018, the normalized patterns did not. Boron, As, Cd, Tl, Se, and Te, commonly recognized as volatile, are the main trace elements that magmatic gases supply to the system headwaters, whereas elements such as Ca, K, and Ba are affected by precipitation of secondary minerals (gypsum, anhydrite, barite, jarosite, and alunite). Furthermore, the main river draining the summit volcano shows a steep decrease in As, Cr, and V concentrations correlated to the precipitation of Fe and Al hydroxysulfates (schwertmannite and basaluminite, respectively). Moreover, it is the first time that a comparison between the different water groups is made using the patterns of the rare-earth elements, allowing us to identify and separate depletion patterns due to dilution processes from those due to precipitation processes.

Experimental evolution of metabolism under nutrient restriction: enhanced amino acid catabolism and a key role of branched-chain amino acids.

Periodic food shortage is a common ecological stressor for animals, likely to drive physiological and metabolic adaptations to alleviate its consequences, particularly for juveniles that have no option but to continue to grow and develop despite undernutrition. Here we study changes in metabolism associated with adaptation to nutrient shortage, evolved by replicate Drosophila melanogaster populations maintained on a nutrient-poor larval diet for over 240 generations. In a factorial metabolomics experiment we showed that both phenotypic plasticity and genetically-based adaptation to the poor diet involved wide-ranging changes in metabolite abundance; however, the plastic response did not predict the evolutionary change. Compared to nonadapted larvae exposed to the poor diet for the first time, the adapted larvae showed lower levels of multiple free amino acids in their tissues-and yet they grew faster. By quantifying accumulation of the nitrogen stable isotope 15N we show that adaptation to the poor diet led to an increased use of amino acids for energy generation. This apparent "waste" of scarce amino acids likely results from the trade-off between acquisition of dietary amino acids and carbohydrates observed in these populations. The three branched-chain amino acids (leucine, isoleucine, and valine) showed a unique pattern of depletion in adapted larvae raised on the poor diet. A diet supplementation experiment demonstrated that these amino acids are limiting for growth on the poor diet, suggesting that their low levels resulted from their expeditious use for protein synthesis. These results demonstrate that selection driven by nutrient shortage not only promotes improved acquisition of limiting nutrients, but also has wide-ranging effects on how the nutrients are used. They also show that the abundance of free amino acids in the tissues does not, in general, reflect the nutritional condition and growth potential of an animal.

Proximate molecular quasar absorbers

Proximate molecular quasar absorbers (PH2) are an intriguing population of absorption systems that was recently uncovered through strong H2absorption at a small velocity separation from the background quasars. We performed a multi-wavelength spectroscopic follow-up of 13 such systems with VLT/X-shooter. Here, we present the observations and study the overall chemical enrichment measured from the H I, H2, and metal lines. We combined this with an investigation of the neutral gas kinematics with respect to the quasar host. We find gas-phase metallicities in the range 2% to 40% of the solar value, that is, in the upper-half range of H I-selected proximate damped Lyman-αsystems, but similar to what is seen in intervening H2-bearing systems. This is likely driven by similar selection effects that play against the detection of most metal- and molecule-rich systems in absorption. Differences are seen in the abundance of dust (from [Zn/Fe]) and its depletion pattern when compared to intervening systems, however, possibly indicating different dust production or destruction close to the active galactic nucleus. We also note the almost ubiquitous presence of a high-ionisation phase traced by N Vin proximate systems. In spite of the hard UV field from the quasars, we found no strong overall deficit of neutral argon, at least when compared to intervening damped Lyman-αsystems. The reason likely is that argon is mostly neutral in the H2phase, which accounts for a large fraction of the total amount of metals. We measured the quasar systemic redshifts through emission lines from both ionised gas and CO(3–2) emission, the latter being detected in all six cases for which we obtained 3 mm data from complementary NOEMA observations. For the first time, we observe a trend between the line-of-sight velocity with respect to systemic redshift and metallicity of the absorbing gas. This suggests that high-metallicity neutral and molecular gas is more likely to be located in outflows, while low-metallicity gas could be more clustered in velocity space around the quasar host, possibly with an infalling component.

Antibiotic Conditioning Shapes Pseudosterile Mouse Models by Deleting Colonic Microbes Rather than Small Intestinal Microbes.

A simple model of alternative microbiota in the developing intestinal environment has been highly desirable for the study of health and disease in the gut. The pattern of antibiotic depletion of natural gut microbes is necessary for this model. However, the effects and loci of antibiotic deletion of gut microbes remain unclear. In this study, a mixture of three proven broad-spectrum antibiotics was selected to study their effects on microbial deletions in the jejunum, ileum, and colon of mice. The 16S rRNA sequencing results showed that antibiotics significantly reduced colonic microbial diversity, with limited effects on the jejunum and ileum. At the level of microbial genera, only 93.38% of Burkholderia-Caballeronia-Paraburkholderia and 5.89% of Enterorhabdus were present in the colon after antibiotic treatment. However, such changes were not observed in the microbial composition of the jejunum and ileum. Our results suggest that the antibiotics depleted intestinal microorganisms by acting primarily in the colon and not in the small intestine (jejunum and ileum). IMPORTANCE Many studies have applied antibiotics to delete intestinal microbes to shape pseudosterile mouse models and further used for fecal microbial transplantation. However, few studies have explored the spatial location of antibiotic action in the intestine. This study shows that the selected antibiotics effectively deleted microbiota in the colon of mice, with limited effects on microbes in the jejunum and ileum. Our study provides guidance for the application of a mouse model of antibiotic deletion of intestinal microbes.

Uncovering the Depletion Patterns of Inland Water Bodies via Remote Sensing, Data Mining, and Statistical Analysis

Addressing the issue of shrinking saline lakes around the globe has turned into one of the most pressing issues for sustainable water resource management. While it has been established that natural climate variability, human interference, climate change, or a combination of these factors can lead to the depletion of saline lakes, it is crucial to investigate each case and diagnose the potential causes of this devastating phenomenon. On that note, this study aims to promote a comprehensive analytical framework that can reveal any significant depletion patterns in lakes while analyzing the potential reasons behind these observed changes. The methodology used in this study is based on statistical analysis, data mining techniques, and remote sensing-based datasets. To achieve the objective of this study, Maharlou Lake has been selected to demonstrate the application of the proposed framework. The results revealed two types of depletion patterns in the lake’s surface area: a sharp breaking point in 2007/2008 and a gradual negative trend, which was more pronounced in dry seasons and less prominent in wet seasons. Furthermore, the analysis of hydro-climatic variables has indicated the presence of abrupt and gradual changes in these variables’ time series, which could be interpreted as a signal that climate change and anthropogenic drought are changing the basin’s status quo. Lastly, analyzing the statistically significant correlation between hydro-climatic variables and the lake’s surface area showed the potential connection between the observed changing patterns. The results obtained from data mining models suggest that Maharlou Lake has undergone a morphological transformation and is currently adopting these new conditions. If preventive measures are not taken to revive Maharlou Lake, the tipping point might have been reached, and reviving the lake could be improbable, if not impossible.