Unusual Composition Research Articles

The applicability of prompt-gamma activation analysis to obsidian provenance studies—The case of a strange find: a blade from Csongrád (South-East Hungary)

In the last twenty years, prompt-gamma activation analysis (PGAA) turned out to be successful in provenance research of obsidians, i.e. in the identification of possible raw material sources of various archaeological objects. Since the early 2000s, a significant database has been built at the Budapest Neutron Centre, which includes compositional data of about 500 geological and archaeological obsidian items, representing the major European and Mediterranean sources. Besides the straightforward cases of provenance studies, however, there are still a few difficult questions to answer. During the excavations of a unique grave at Csongrád (SE Hungary), a long transparent obsidian blade was found together with other objects. The grave was dated to 4370–4239 (1σ, 68.2%) cal. BC, belonging to the first wave of the ‘Pit Grave’ culture and having strong eastern contacts. Following the first energy dispersive X-ray spectroscopy (EDS) measurement in 1983, the blade was compared to the Carpathian 1 (Slovakian) type raw material. In 2019, PGAA and portable X-Ray Fluorescence analysis have been done on the same piece. Based on the first results, the Csongrád specimen, unlike other archaeological samples studied so far, was not possible to unambiguously associate with any of the known obsidian types. In order to clarify the provenance of the Csongrád blade, we have extended our database with more geological reference data from both sides of the Caucasus (i.e. from Armenia and Georgia), which are the closest outcrops to the main distribution region of the Pit Grave Culture in the NE part of the Black Sea. Until now, still no reassuring explanation is available concerning the provenance of the object with unusual composition.

Faunal Composition of the Sumisu Caldera Hydrothermal Vent Field as a Key Baseline for Conservation in Light of Deep‐Sea Mining

ABSTRACTHydrothermal vents are biodiversity hotspots on the deep seafloor powered by chemosynthetic primary production, inhabited by a specially adapted fauna whose composition varies between regions. Sumisu Caldera, located approximately 500 km south of Tokyo, hosts a hot vent with an unusual species composition among the Izu–Ogasawara Arc sites and has been suggested as a priority site for conservation in light of upcoming deep‐sea mining for massive sulfides. However, this was based on just five species serendipitously recorded from geological surveys. Here, we carried out the first comprehensive biological sampling of Sumisu using two dives of the human‐occupied vehicle Shinkai 6500. Together with literature records, we count a total of 54 animal species of which at least 25 are endemic to chemosynthetic ecosystems, drastically increasing the known faunal diversity—including three sponges, one cnidarian, 12 molluscs, 23 annelids, 13 arthropods, one echinoderm, and one fish. The presence of sediments facilitating the occurrence of burrowing species and three non‐endemic predators contribute to the high species richness. Our findings make Sumisu the most species‐rich vent community in the entire northwestern Pacific and our work serves as a prime example for detailed faunal surveys to obtain key piece of baseline data for future environmental assessments. Although the apparent lack of massive sulfide deposits means Sumisu is unlikely to be an immediate target of mining, its close distance to Bayonnaise Knoll with a major deposit and the possibility that it acts as a critical stepping‐stone population for many species, as well as the presence of several endangered ones, presents a case for its protection.

Unusual Composition of the Sarezzano Reliquary Busts

The interdisciplinary study of two reliquary busts from Sarezzano (Piedmont, Italy) is a perfect example of the necessity to provide for material characterisation as a recurring common practice in historical studies and a mandatory step in conservation assessment. Furthermore, the diagnostics of cultural heritage play a crucial role in art historical research, providing relevant information on artefacts’ genesis, production technology, and conservation history. The study of the materials of the reliquary busts was performed by non-invasive (portable X-ray fluorescence spectrometry) and micro-invasive (stereomicroscope, attenuated total reflection Fourier transform infrared spectroscopy and powder X-ray diffraction analysis) methods. According to the results, the busts were found to be made of a tin–lead alloy, a rather unusual material for mediaeval reliquary busts. Moreover, the outcome suggests that the busts were originally silvered, except for the hair and beard which are still gilded. The analysis reveals the use of colophony as an adhesive buffer layer on the busts’ alloy, as well as inside them, to favour the metal working process, since it is found as degraded residue. Finally, even the typology of alloy decay is defined. All this information has enabled us to determine the artistic technique and estimate the value and quality of the material employed. In addition, it has led to the correct choice of materials and methods to be adopted during the restoration, and therefore the usage of more suitable solvents and tools.

Lavender essential oil market integrity: A comprehensive study of commercial Lavandula angustifolia essential oils adulteration and assessment of industrial standards

Adulteration of essential oils (EOs) is a common and unethical practice that affects both consumers and honest suppliers and harms market integrity. Despite the awareness of this problem, scarce scientific studies are described in the scientific literature. Therefore, 55 samples of lavender EOs were purchased and extensively analyzed to the trace levels, including chromatographic profile, quantitative analysis, and chiral profile. Of the 51 samples labeled as Lavandula angustifolia, 51 % were genuine, 6 % were cheaper lavandin EO, 14 % were fortified with synthetic additives and over 29 % of the samples were adulterated with both lavandin EO and synthetics. Usually, adulterated EOs were cheaper than genuine products, still some expensive products were also falsified. The most common synthetic adulterants were synthetic linalool and linalyl acetate, 3,5,5-trimethylhexyl acetate, α-terpinyl acetate, and dipropylene glycol. Only four of the studied samples were diluted with a medium not fully visible in the recorded GC profile. Industry standards were assessed to eliminate adulterated EOs and ISO 3515 was found to be impractical and too strict, but Ph. Eur. demonstrated its efficiency in eliminating adulterated samples without rejecting many genuine ones.PCA enabled the differentiation of lavender EOs containing synthetics from those of purely natural origin, and in the latter group, to distinguish L. angustifolia from lavandin. Some samples had an unusual composition suggesting that they were artificial blends of synthetics and some terpene fractions of non-lavender origin.This is the first such extensive study of adulteration of lavender EOs, regarding both the number of commercial samples as well as implications on their biological activity. The adulteration via dilution influenced the antimicrobial activity of the essential oils. In conclusion, adulteration is a significant problem in the market, and a large share of products on the market is somehow counterfeited, not only the cheapest products.

Geochemical and Sr-Nd isotopic implications for the petrogenesis of the late Silurian Shitoukengde mafic–ultramafic intrusion in the East Kunlun Orogen, NW China

The Shitoukengde mafic–ultramafic intrusion is the host of the second-largest sulfide deposit after the Xiarihamu Ni-Co deposit in the East Kunlun Orogenic Belt (EKOB), northern Tibet Plateau, China. Despite several studies, the age, petrogenesis, and the cause of low Ni-tenor for this intrusion remain poorly constrained. In this study, zircons separated from the pyroxenite at Shitoukengde yield a SHRIMP U-Pb age of 418.9 ± 3.1 Ma, corresponding to the widespread magmatism of the late Silurian to early Devonian in the EKOB. Whole-rock major and trace element compositions indicate that fractional crystallization played a key role in controlling the magma composition and element distribution within the intrusion. Mafic-ultramafic rocks of the intrusion, particularly peridotite, have highly variable and exceptionally elevated (87Sr/86Sr)i and negative ɛNd(t) values. Some samples from the Shitoukengde intrusion exhibit initial Sr-Nd isotope ratios that overlap with those from the Xiarihamu intrusion, while others (e.g., peridotite) display higher (87Sr/86Sr)i values than those observed in the latter. The unusual Sr-Nd isotopic compositions of the Shitoukengde intrusion could be attributed to the assimilation of Mg-rich carbonate within a deep-seated magma chamber. This contamination process facilitates the crystallization of olivine, consequently reducing Ni content in residual magma. Furthermore, the contamination of Mg-rich carbonate may promote oxygen fugacity and thus enhance the solubility of sulfur while restricting the sulfide saturation in the magma. We thus propose that the extensive contamination of Mg-rich carbonate is a key factor contributing to the relatively low Ni-tenor observed at Shitoukengde.

High-resolution Elemental Abundance Measurements of Cool JWST Planet Hosts Using AutoSpecFit: An Application to the Sub-Neptune K2-18b’s Host M Dwarf

We present an in-depth, high-resolution spectroscopic analysis of the M dwarf K2-18, which hosts a sub-Neptune exoplanet in its habitable zone. We show our technique to accurately normalize the observed spectrum, which is crucial for a proper spectral fitting. We also introduce a new automatic, line-by-line, model-fitting code, AutoSpecFit, which performs an iterative χ 2 minimization process to measure individual elemental abundances of cool dwarfs. We apply this code to the star K2-18, and measure the abundance of 10 elements: C, O, Na, Mg, Al, K, Ca, Sc, Ti, and Fe. We find these abundances to be moderately supersolar, except for Fe, with a slightly subsolar abundance. The accuracy of the inferred abundances is limited by the systematic errors due to uncertain stellar parameters. We also derive the abundance ratios associated with several planet-building elements such as Al/Mg, Ca/Mg, Fe/Mg, and (a solar-like) C/O = 0.568 ± 0.026, which can be used to constrain the chemical composition and the formation location of the exoplanet. On the other hand, the planet K2-18 b has attracted considerable interest, given the JWST measurements of its atmospheric composition. Early JWST studies reveal an unusual chemistry for the atmosphere of this planet, which is unlikely to be driven by formation in a disk of unusual composition. The comparison between the chemical abundances of K2-18 b from future JWST analyses and those of the host star can provide fundamental insights into the formation of this planetary system.

Sampling of Culicoides with nontraditional methods provides unusual species composition and new records for southern Spain

BackgroundCulicoides midges have been well-studied in Spain, particularly over the last 20 years, mainly because of their role as vectors of arboviral diseases that affect livestock. Most studies on Culicoides are conducted using suction light traps in farmed environments, but studies employing alternative trapping techniques or focusing on natural habitats are scarce.MethodsIn the present study, we analyze Culicoides captured in 2023 at 476 sites in western Andalusia (southern Spain) using carbon dioxide-baited Biogents (BG)-sentinel traps across different ecosystems.ResultsWe collected 3,084 Culicoides midges (3060 females and 24 males) belonging to 23 species, including the new species Culicoides grandifovea sp. nov. and the first record of Culicoides pseudolangeroni for Europe. Both species were described with morphological and molecular methods and detailed data on spatial distribution was also recorded. The new species showed close phylogenetic relations with sequences from an unidentified Culicoides from Morocco (92.6% similarity) and with Culicoides kurensis. Culicoides imicola was the most abundant species (17.4%), followed by Culicoides grandifovea sp. nov. (14.6%) and Culicoides kurensis (11.9%). Interestingly, Culicoides montanus was the only species of the obsoletus and pulicaris species complexes captured, representing the first record of this species in southern Spain. A total of 53 valid Culicoides species have been reported in the area, with 48 already reported in literature records and 5 more added in the present study. Information on the flight period for the most common Culicoides species is also provided.ConclusionsTo the best of our knowledge, our study represents the most comprehensive effort ever done on nonfarmland habitats using carbon-dioxide baited suction traps for collecting Culicoides. Our data suggests that using carbon dioxide traps offers a completely different perspective on Culicoides communities compared with routinely used light traps, including the discovery of previously unrecorded species.Graphical

Kyanite and Cordierite‐Andalusite occurrences in parts of Barrow's Staurolite zones – The effects of high ferric iron

AbstractGeorge Barrow's maps (1893, 1912) of the metamorphic zones named after him in the south‐eastern Scottish Highlands, show a prominent staurolite zone running from the west of Glen Clova to the North Sea coast near Stonehaven in the east. Pelitic mica schists throughout this zone commonly show principal mineral assemblages of staurolite+biotite+garnet+muscovite +quartz (St + Bt + Grt), with sodic plagioclase, ilmenite and sometimes magnetite as common accessories; these schists have bulk compositions corresponding with those of common Dalradian metasediments. However, the mineral assemblages on the low‐ and high‐grade margins of the staurolite zone show evidence of changes from west to east. Lower grade assemblages near Stonehaven include chloritoid+biotite, which has not been found further west in the classic ‘Barrovian’ sequence; whilst the higher grade assemblages near Stonehaven lack kyanite, which is widely seen further west. The Stonehaven area has been suggested to have under gone metamorphism at lower pressure (P) than the classic region of the ‘Glens’ inland to the west.This paper describes the occurrence at middle grade in the broad staurolite zone, of unusual bulk rock compositions showing high ratios of Fe2O3/(Fe2O3 + FeO) and MgO/(MgO + FeO) (abbreviated to M/FM). The high M/FM assemblages are distinct from those of the common St‐Bt‐Grt schists. The high ratios of ferric to ferrous iron are thought to result from original sedimentary protolith compositions, that led to metamorphism at relatively high conditions of oxygen fugacity (ƒo2), and resulted in the formation of haematite‐bearing assemblages, rather than ones carrying accessory ilmenite and magnetite as in the common St + Bt + Grt rocks.In the west (Glen Lethnot), the haematite‐bearing pelites show the occurrence of kyanite at a distinctly lower grade than the common (haematite‐free) pelites, and a transition from staurolite‐biotite (St + Bt) through staurolite–kyanite‐biotite (St + Ky + Bt) to kyanite‐biotite (Ky‐Bt) assemblages occurs with increasing abundance of haematite and higher bulk M/FM values. In all bulk compositions, the upgrade formation of kyanite may be associated with the movement of the St + Ky + Bt assemblage to lower M/FM bulk compositions with increasing temperature (T). The difference in the temperature of lowest‐grade kyanite formation in haematite‐rich schists, compared with that in common haematite‐free schists may approach 50°C.In the east (Stonehaven section), the haematite‐bearing assemblages are much rarer than in Glen Lethnot, but those found so far are very distinctive in showing large porphyroblasts of probable cordierite (typically altered to chlorite and sericite). Occasional assemblages of andalusite‐cordierite‐biotite (And‐Crd‐Bt) also occur in the haematite‐bearing rocks and confirm lower pressures of metamorphism near Stonehaven than those seen further west in Glens Clova, Lethnot and Esk.

New archosauromorph remains provide data on the age of a unique Late Triassic assemblage from southern Brazil

The Santa Maria Supersequence, an important stratigraphic unit in the Paraná Basin, yielded a diverse range of Triassic tetrapod assemblages, providing valuable insights into the evolutionary history of southwestern Pangea. This study focuses on the Candelária Sequence of the Santa Maria Supersequence, which includes the Hyperodapedon Assemblage Zone (AZ) and the Riograndia AZ. The Hyperodapedon AZ is characterized by the presence of Hyperodapedon rhynchosaurs alongside a diverse array of other taxa, including dinosaurs, pseudosuchians, and cynodonts. In contrast, the Riograndia AZ preserves mostly small cynodonts, lepidosauromorphs, and sauropodomorph dinosaurs. Whereas biostratigraphic correlations between several localities of the Candelária Sequence have been firmly established, certain sites, like the Niemeyer complex in the Agudo municipality of southern Brazil, present challenges because of their unusual assemblage composition, which result in ambiguous depositional ages. Despite yielding thousands of fossil specimens, the Niemeyer complex lacks index fossils typical of the known Brazilian AZs, making reliable correlation with other sites challenging. This study presents and describes new archosauromorph specimens discovered at the upper portion of the Niemeyer complex. The new materials include a rhynchosaur, a saurischian dinosaur, and a possible silesaurid, which represent the first record of these groups for the site. A phylogenetic analysis of the rhynchosaur material provides insights into its taxonomic affinities, offering valuable data for biostratigraphic comparisons. The new data reinforces an age (early Norian?) that is younger than that of the typical outcrops assigned to the Hyperodapedon AZ. Furthermore, these new specimens contribute to the unique assemblage of the Niemeyer complex, shedding light on its significance within the context of the Santa Maria Supersequence and the broader landscape of southern Brazil during the Triassic Period.

Antarctic Polar Stratospheric Cloud Analysis of ACE‐FTS Data From 2005 to 2023

AbstractWe present an analysis of Antarctic polar winters from 2005 to 2023 as observed by the Atmospheric Chemistry Experiment (ACE). The unique broad band infrared spectral features in ACE “residual” spectra are used to classify the spectra of polar aerosols by composition into polar stratospheric clouds (PSCs) and sulfate aerosols. The spectra of PSCs are further classified into nitric acid trihydrate, supercooled ternary solutions, supercooled nitric acid, ice‐mix, and mixtures of PSCs. A breakdown of PSC composition is presented for each year. Antarctic winter seasons with unusual compositions are: 2011, in which volcanic ash mixed with PSCs was observed from July to August; 2019, which experienced a stratospheric warming event; 2020, the PSC season following the Australian Black Summer pyrocumulonimbus event; and 2023, which had unusually large sulfate aerosols following the Honga‐Tonga Honga Ha'apai eruption of 2022.

Interstellar meteors from the tidal disruption of rocky planets on eccentric orbits around M dwarfs

Context. Low-mass stars appear to frequently host planetary systems. When these rocky planets develop high eccentricities as a result of secular torques or dynamical scatterings, they occasionally pass close to the host star. In these close passages, the planets can be tidally disrupted, and sheared into bound and unbound debris tails. To suffer such a disruption, the stellar density must be higher than the planetary density. Aims. This condition is met for the most common star and planet systems, M dwarf stars hosting rocky planets. We describe the dynamics of a tidal disruption, and estimate the typical velocities of unbound ejecta. Methods. We simulate the gas dynamics of a planetary tidal disruption, and show that disruptions preserve the layered structure of a rocky body, with the outermost layers flung into interstellar space with the highest velocities. Results. We compare these properties to those of the candidate interstellar meteoroid CNEOS-2014-01-08 (IM1). IM1's approximately 60 km s−1 excess speed relative to the local standard of rest is naturally reproduced by the unbound debris of the disruption of an Earth-like planet around an M dwarf star. We suggest that such an encounter might explain the interstellar kinematics of IM1, and its unusual composition, especially if it originated in the fastest-expelled crust of a differentiated rocky planet. Finally, we estimate that the disruption of ~10 M⊕ reservoirs of rocky planets per M dwarf are needed to reproduce the inferred rate of IM1-like objects.

Monet’s Unified View: The Fusion of Eastern and Western Cultures

When Japan opened its borders in the 1850s, citizens, especially those from France, were awed by the different styles of art the Japanese had compared to the West. As this interest in Japanese culture grew, more and more people collected Japanese prints, books, and other goods. Many artists took inspiration from the Japanese art style, such as the use of bright colors, unusual compositions, and flat, unrealistic perspectives. This eventually led to the creation of a new art movement called Japonisme. One major artist within the movement was Claude Monet, who fell in love with Japan’s style of art and admired nature's role within it. Inspiration from the culture can clearly be seen in his Japanese-styled garden at Giverny but also in the painting La Japoinaise (1876), which allowed him to critique fellow French artists who embraced the Japonisme movement for its exoticism. He instead relied on Japanese forms and color to create his own style of art. While most scholars agree that Monet was trying to criticize Japonisme, they mainly focus on identifying elements of Japanese culture in the painting, without fully addressing why and how Monet utilized these stylistic traits. Rather than focusing solely on aspects of Japanese culture in the painting, my paper positions Monet as a critic of those who denigrated Japanese art by analyzing how he unifies Japanese and French culture in La Japonaise, mainly through examination of the Japanese story depicted on the woman’s kimono. Within this painting, Monet, thus, simultaneously critiques the French appropriation of Japanese culture for its exoticism while melding Japanese literary and artistic traditions with Western ones to showcase to the rest of the art world his specific vision of the unification of the two cultures.

Lithium Cepheid V708 Car with an unusual chemical composition

Aims. The purpose of this work is to spectroscopically analyse the classical Cepheid V708 Car. A preliminary check of the spectrum of V708 Car showed that this is a lithium-rich supergiant. We also found that V708 Car has an unusual chemical composition in that the abundances of various elements correlate with their condensation temperatures. We tried to find an explanation of this feature, which is unusual for classical Cepheids. Methods. For the spectroscopic analysis, we used methods based on the assumption of local and non-local thermodynamic equilibrium. Results. We determined the fundamental parameters of our program star V708 Car. This long-period Cepheid has a mass of about 12 M⊙. We derived the abundances of 27 chemical elements in this star. They are clearly correlated with their condensation temperature: the higher the condensation temperature, the lower the abundance (there are exceptions for sodium and barium, however). We explain this peculiar chemical composition of the V708 Car atmosphere by the gas–dust separation in the envelope of this star. A similar mechanism leads to the observed peculiarities of the chemical composition of λ Boo, W Vir, and asymptotic giant branch stars.

Natural history of pollination of an Asian bignoniaceous tree: The long-tubed flower and the not-so-long bird bill

Bird pollination is well-established in New World Bignoniaceae, but studies of species with floral traits suggestive of bird pollination in the Old World are lacking. Here we studied the pollination ecology of Mayodendron igneum to test the prediction of pollination by specialist flower-visiting birds. Observations from multiple sites showed that both the Streaked Spiderhunter (Arachnothera magna) and pollen-collecting bees were floral visitors. However, almost no fruit was produced if birds were excluded, suggesting that bees do not play a role in pollination, and that pollination is performed almost exclusively by birds in this self-incompatible tree. Measurements of floral traits revealed a typical bird pollination syndrome, and the nectar concentration and volume were both within the proposed ranges based on other flowers pollinated by specialist birds. However, the rather low level of sucrose (less than 2 %) in nectar sugar contradicts the expectation for nectar of flowers pollinated by specialist nectar-feeding birds. Although the Streaked Spiderhunter is among the longest-billed flower-visiting birds in Asia, its bill is only 2/3 of the corolla tube in length, suggesting that the bird can extend the tongue to access nectar. This study is the first to experimentally confirm bird pollination in the Old World Bignoniaceae. It also indicates aspects that are possibly characteristic of spiderhunter pollination systems, i.e. high degrees of specialization, unusual nectar sugar composition, and floral tubes much longer than bird bills.

Reduced 2,2’‐Bipyridine Lanthanide Metallocenes Provide Access to Mono‐C5Me5 and Polyazide Complexes

AbstractExploration of the reduction chemistry of the 2,2’‐bipyridine (bipy) lanthanide metallocene complexes Cp*2LnCl(bipy) and Cp*2Ln(bipy) (Cp* = C5Me5) resulted in the isolation of a series of complexes with unusual composition and structure including complexes with a single Cp* ligand, multiple azide ligands, and bipy ligands with close parallel orientations. These results not only reveal new structural types, but they also show the diverse chemistry displayed by this redox‐active platform. Treatment of Cp*2NdCl(bipy) with excess KC8 resulted in the formation of the mono‐Cp* Nd(III) complex, [K(crypt)]2[Cp*Nd(bipy)2], 1, as well as [K(crypt)][Cp*2NdCl2], 2, and the previously reported [K(crypt)][Cp*2Nd(bipy)]. A mono‐Cp* Lu(III) complex, Cp*Lu(bipy)2, 3, was also found in an attempt to make Cp*2Lu(bipy) from LuCl3, 2 equiv. of KCp*, bipy, and K/KI. Surprisingly, the (bipy)1− ligands in neighboring molecules in the structure of 3 are oriented in a parallel fashion with intermolecular C⋅⋅⋅C distances of 3.289(4) Å, which are shorter than the sum of van der Waals radii of two carbon atoms, 3.4 Å. Another product with one Cp* ligand per lanthanide was isolated from the reaction of [K(crypt)][Cp*2Eu(bipy)] with azobenzene, which afforded the dimeric Eu(II) complex, [K(crypt)]2[Cp*Eu(THF)(PhNNPh)]2, 4. Attempts to make 4 from the reaction between Cp*2Eu(THF)2 and a reduced azobenzene anion generated instead the mixed‐valent Eu(III)/Eu(II) complex, [K(crypt)][Cp*Eu(THF)(PhNNPh)]2, 5, which allows direct comparison with the bimetallic Eu(II) complex 4. Mono‐Cp* complexes of Yb(III) are obtained from reactions of the Yb(II) complex, [K(crypt)][Cp*2Yb(bipy)], with trimethylsilylazide, which afforded the tetra‐azido [K(crypt)]2[Cp*Yb(N3)4], 6, or the di‐azido complex [K(crypt)]2[Cp*Yb(N3)2(bipy)], 7 a, depending on the reaction stoichiometry. A mono‐Cp* Yb(III) complex is also isolated from reaction of [K(crypt)][Cp*2Yb(bipy)] with elemental sulfur which forms the mixed polysulfido Yb(III) complex [K(crypt)]2[Cp*Yb(S4)(S5)], 8 a. In contrast to these reactions that form mono‐Cp* products, reduction of Cp*2Yb(bipy) with 1 equiv. of KC8 in the presence of 18‐crown‐6 resulted in the complete loss of Cp* ligands and the formation of [K(18‐c‐6)(THF)][Yb(bipy)4], 9. The (bipy)1− ligands of 9 are arranged in a parallel orientation, as observed in the structure of 3, except in this case this interaction is intramolecular and involves pairs of ligands bound to the same Yb atom. Attempts to reduce further the Sm(II) (bipy)1− complex, Cp*2Sm(bipy) with 2 equiv. of KC8 in the presence of excess 18‐crown‐6 led to the isolation of a Sm(III) salt of (bipy)2− with an inverse sandwich Cp* counter‐cation and a co‐crystallized K(18‐c‐6)Cp* unit, [K2(18‐c‐6)2Cp*]2[Cp*2Sm(bipy)]2 ⋅ [K(18‐c‐6)Cp*], 10.

Dynamics of diabatically forced anticyclonic plumes in the stratosphere

AbstractA new class of vortices has been observed in the stratosphere following extreme wildfires (Canada 2017, Australia 2020) and volcanic eruptions (Raikoke 2019). These vortices are long‐lived mesoscale anticyclones (hundreds to 1,000 km in diameter) trapping plumes of aerosols and combustion/volcanic compounds. Owing to their unusual composition, these anticyclonically trapped plumes (ATPs) are associated with a significant radiative heating, which fuels their ascent through the stratosphere. This article investigates the dynamics of ATPs using two complementary approaches: analytically, in a potential vorticity (PV) perspective, and through idealised numerical simulations with the Weather Research and Forecasting (WRF) model. In both cases, we consider the vortical flow forced by a heating Lagrangian tracer. By reformulating the problem in the potential radius–potential temperature coordinate system introduced for tropical cyclones, we first clarify that ATP formation is concomitant with the injection of air into the stratosphere at extratropical latitudes. Then, we derive a set of simplified one‐dimensional equations describing the subsequent evolution of the flow after the injection. The equation obtained for the tracer is a variant of the classical Burgers' equation. In qualitative agreement with the three‐dimensional WRF simulations, this theoretical model predicts that ATPs develop an upper tracer front associated with sustained near‐zero anticyclonic PV, followed by a smooth tracer tail of cyclonic PV. Radiative relaxation of the temperature perturbations induced by the anticyclone and the presence of an initial PV anomaly tend to stabilise ATPs during their ascent. Finally, we note that the theory predicts a similar relationship between the plume and anticyclonic PV for cooled ATPs, which is supported by three‐dimensional simulations and may apply to the 2022 Hunga volcanic plume.

A naturally occurring Al-Cu-Fe-Si quasicrystal in a micrometeorite from southern Italy

Quasicrystals, solids with rotational symmetries forbidden for crystals, are usually synthesized in the laboratory by mixing specific ratios of selected elemental components in the liquid and quenching under strictly controlled protocols. Nevertheless, the discovery of Al-Cu-Fe natural quasicrystals in the Khatyrka meteorite showed that these exotic phases could also form in high-velocity impact-induced shock events introducing an endeavour to search them in cosmic material. Here we report the discovery of an extraterrestrial icosahedral quasicrystal with an unusual composition Al51.7(6)Cu30.8(9)Fe10.3(4)Si7.2(9), ideally Al52Cu31Fe10Si7, found in a scoriaceous micrometeorite, named FB-A1, recovered at the top of Mt. Gariglione (Italy). The chemistry of the icosahedral phase was characterized by electron microprobe, and the rotational symmetry was confirmed by means of electron backscatter diffraction. The FB-A1 micrometeorite represents the third independent discovery of naturally occurring intermetallic Al-Cu-Fe-(Si) alloys in extraterrestrial bodies and the second case of extraterrestrial material containing a natural quasicrystal, after Khatyrka meteorite.

The Eastern Bandy Bandy Vermicella annulata, expresses high abundance of SVMP, CRiSP and Kunitz protein families in its venom proteome

The Australian elapid snake radiation (Hydrophiinae) has evolved in the absence of competition from other advanced snakes. This has resulted in ecological specialisation in Australian elapids and the potential for venom proteomes divergent to other elapids. We characterised the venom of the Australian elapid Vermicella annulata (eastern bandy bandy). The venom was analysed using a two-dimensional fractionation process consisting of reverse-phase high-performance liquid chromatography then sodium dodecyl sulphate polyacrylamide gel electrophoresis, followed by bottom-up proteomics. Resulting peptides were matched to a species-specific transcriptome and 87% of the venom was characterised. We identified 11 toxins in the venom from six families: snake venom metalloproteinases (SVMP; 24.2%; two toxins) that are class P-III SVMPs containing a disintegrin-like domain, three-finger toxins (3FTx; 21.6%; five toxins), kunitz peptides (KUN; 19.5%; one toxin), cysteine-rich secretory proteins (CRiSP; 18%; one toxin), and phospholipase A2 (PLA2; 4%; two toxins). The venom had low toxin diversity with five protein families having one or two toxins, except for 3FTx with five different toxins. V. annulata expresses an unusual venom proteome, with high abundances of CRiSP, KUN and SVMP, which are not normally highly expressed in elapid venoms. This unusual venom composition could be an adaptation to its specialised diet. Biological significanceAlthough the Australian elapid radiation represents the most extensive speciation event of elapids on any continent, with 100 terrestrial species, the venom composition of these snakes has rarely been investigated, with only five species currently characterised. Here we provide the venom proteome of a sixth species, Vermicella annulata. The venom of this species could be particularly informative from an evolutionary perspective, as it is an extreme dietary specialist, only preying on blind snakes (Typhlopidae). We show that V. annulata expresses a highly unusual venom for an elapid, due to the high abundance of the protein families SVMP, CRiSP, and KUN, which together make up 61% of the venom. When averaged across all species, a typical elapid venom is 82% PLA2 and 3FTx. This is the second recorded instance of an Australian elapid having evolved highly divergent venom expression.

Unusual vitamin E profile in the oil of a wild African oil palm tree (Elaeis guineensis Jacq.) enhances oxidative stability of provitamin A.

The African oil palm (Elaeis guineensis Jacq.) is the predominant oil crop in the world. In addition to triacylglycerols, crude palm oil (CPO) extracted from the mesocarp of the fruits, contains high amounts of provitamin A (carotenes) and vitamin E (tocochromanols). Because of their unsaturated nature, the carotenes are prone to oxidation and therefore are in part limiting for the shelf life of CPO. A tree with unusual toochromanol composition was identified by HPLC screening of the mesocarp of wild trees. Polymorphisms in a candidate gene were identified by DNA sequencing. The candidate protein was heterologously expressed in Escherichia coli coli and Arabidopsis thaliana to test for enzyme activity. Oxidative stability of the CPO was studied by following carotene degradation over time. In the present study, a wild Oil Palm tree (C59) from Cameroon was identified that lacks α-tocopherol and α-tocotrienol and instead accumulates the respective γ forms, suggesting that the activity of γ-tocopherol methyltransferase (VTE4) was affected. Sequencing of the VTE4 locus in the genome of plant C59 identified a G/C polymorphism that causes the exchange of a highly conserved tryptophan at position 290 with serine. The W290S exchange renders the VTE4 enzyme inactive, as shown after expression in Escherichia coli and Arabidopsis thaliana. The oxidative stability of carotenes in the mesocarp of the wild palm C59 was enhanced compared with control accessions. Furthermore, supplementation of commercial palm oil with different tocochromanols showed that γ-tocotrienol exerts a stronger effect during the protection of carotenes against oxidation than α-tocotrienol. Therefore, the introduction of the high γ-tocotrienol trait into elite breeding lines represents a potent strategy to protect carotenes against oxidation and extend the shelf life of CPO, hence allowing the development of a value added high-carotene CPO to be used to fight against vitamin A deficiency.

КИТАЙСКИЙ ИНСТРУМЕНТ ЭРХУ В РОССИИ

The sound of the Chinese folk instrument erhu, which belongs to the ancient string-bow family of the Huqin family, is distinguished by a special timbre resembling a human voice. In the XXth century, especially in its second half, Chinese composers began to willingly include erhu in the orchestra with European instruments, and in various ensembles, namely: erhu — flute, erhu — harp, erhu — piano. In the last century, the tradition of creating solo compositions for the erhu began to take shape, as the blind musician Abing (Hua Yanjun, 1893–1950) wrote pieces for this instrument. He owns one of the most famous compositions for erhu — “Moon Reflected in Two Springs”. Musical pictures for erhu were created by Liu Tianhua (1895–1932, “A Beautiful Night”), Liu Wenjin (1937–2013, “Capriccio in the Sanmen Gorge”). The erhu is not widely known in the world, although it was used by such major American composers as Lou Harrison (1917–2003), Terry Riley (b. 1935), Philip Glass (b. 1937), Chinese composer Tang Dong (1923–2011). This instrument is also little known in Russia. Saint Petersburg composer Viktor Pleshak (b. 1946) was one of the first to address erhu in his vocal and symphonic triptych “Dunhuang — Yesterday, Today, Tomorrow”. Moscow composer Zuo Zhengguan (b. 1945) wrote a chamber piece “Water in the River” for an unusual composition: erhu and vibraphone. The author of the article set out to reveal the prehistory of the folklore source in Chinese art and to consider its new interpretation in Zuo Zhengguan’s composition.