Meteor

The large Weilasituo Sn-polymetallic deposit is a recent exploration discovery in the southern Great Xing'an Range, northeast China. The ore cluster area shows horizontal mineralization zoning, from the inner granite body outward, consisting of high-T Sn-W-Li mineralization, middle-T Cu-Zn mineralization and peripheral low-T Pb-Zn-Ag mineralization. However, the intrinsic genetic relationship between Sn-W-Li mineralization and peripheral vein-type Pb-Zn-Ag-Cu mineralization, the formation mechanism and the deep geological background are still insufficiently understood...

The high-level nuclear waste, HLW, from Swedish and Finnish reactors will be deposited in crystalline rock at depths around 500 m. The waste is enclosed in steel canisters protected against corrosion by a 5 cm thick copper shell, which ensures a lifetime far longer than 100 000 years. Should some canister be breached any leaking nuclides will have decayed to so low activity that even if they reached the biosphere, they would cause minimal risk to humans. The cost of the copper is significant. The dismantling of the nuclear reactors, with induced activity must also be disposed of and this waste volume is much larger than that of the HLW, which makes it impossible to protect it in the same way...

The Makgadikgadi Salt Pans are the remnants of a mega paleo-lake system in the central Kalahari, Botswana. Today, the Makgadikgadi Basin is an arid to semi-arid area receiving water of meteoric origin during the short, wet season. Large microbial mats, which support primary production, are formed due to desiccation during the dry season. This study aimed to characterise the microbial diversity of the microbial mats and the underlying sediment. The focus was the Ntwetwe Pan, located west of the Makgadikgadi Basin...

Stable isotope ratios of mollusc shell carbonates have long been used to reconstruct past environmental conditions. Although shells also contain organics, they are seldom used in (paleo)climatic studies. Here, we extract the acid-soluble and insoluble fractions of the organic matrix of modern Mytilus galloprovincialis shells from three sites along a coast-to-upper-estuary environmental gradient to measure their hydrogen (δ2 H) and oxygen (δ18 O) isotope compositions. Both organic fractions showed isotopic signatures significantly different from those of carbonate and water at each site, indicating the involvement of different fractionation mechanisms...

Plastids and mitochondria are the only organelles that possess genomes of endosymbiotic origin. In recent decades, advances in sequencing technologies have contributed to a meteoric rise in the number of published organellar genomes, and have revealed greatly divergent evolutionary trajectories. In this review, we quantify the abundance and distribution of sequenced plant organellar genomes across the plant tree of life. We compare numerous genomic features between the two organellar genomes, with an emphasis on evolutionary trajectories, transfers, the current state of organellar genome editing by transcriptional activator-like effector nucleases (TALENs), transcription activator-like effector (TALE)-mediated deaminase, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas), as well as genetic transformation...

Beihai City is a typical coastal city where groundwater provides a strong support for social and economic development. Studies on the hydrochemical characteristics and formation mechanism in Beihai City play an important role in the scientific management of water resources and coastal ecological environment protection. In this study, we revealed the main hydrogeochemical processes controlling groundwater quality by means of groundwater survey and water sample collection in the western region of Hepu Basin, Beihai City, combined with hydrochemistry and isotope theories and methods...

Although positron emission tomography/computed tomography (PET/CT) underwent rapid growth during the last quarter-century, becoming a new standard-of-care for imaging most cancer types, CT and bone scan remained the gold standard for patients with prostate cancer. This occurred as 2-fluorine-18-fluoro-2-deoxy-d-glucose was perceived to have a limited role owing to low sensitivity in many patients. A resurgence of interest occurred with the use of fluorine-18-sodium-fluoride PET/CT as a replacement for bone scintigraphy, and then choline, fluciclovine, and dihydrotestosterone (DHT) PET/CT as prostate "specific" radiotracers...

In Taiwanese volcanic watersheds, we investigated stable water isotopes in meteoric water, plants, and thermal water. Meteoric water exhibited a seasonal cycle, with heavier isotopes in winter and lighter ones in summer, especially in the southern region. The northern monsoon signal lagged the south by two weeks. In the Tatun mountains, young water fractions indicated prevalent old water sources. In the northern watershed, streamwater mainly came from the winter monsoon, while the southern one was influenced by alternating monsoons...

Rate constants and product branching fractions were measured from 300-600 K for Fe n - + O2 ( n = 2-17) and for 300-500 K for Fe x Ni y - + O2 ( x + y = 3-9) using a selected-ion flow tube (SIFT) apparatus. Rate constants for 46 species are reported. All rate constants increased with increasing temperature, and several were in excess of the Langevin-Gioumousis-Stevenson (LGS) capture rate at elevated temperatures. As with previously studied transition metal anion oxidation reactions, the collision limit is treated as the sum of the LGS limit along with a hard-sphere contribution, allowing for determination of activation energies...

High level dissolved B, which poses risks to human health, has been widely observed in geothermal water. In the Guide Basin, NW China, a series of geothermal water samples along a fault show a wide range of B contents ranging from 3.14 to 8.33 mg/L, which are higher than the WHO Guideline value equaling 2.4 mg/L in drinking water. To identify the sources and fate of B, we conduct a comprehensive analysis of hydrochemistry and stable isotopes (D, 18 O and 11 B) of three thermal fields representing three stages of hydrogeochemical evolution (stages I, II and III)...

In situ cryo-electron tomography (cryo-ET) is the most current, state-of-the-art technique to study cell machinery in its hydrated near-native state. The method provides ultrastructural details at sub-nanometer resolution for many components within the cellular context. Making use of recent advances in sample preparation techniques and combining this method with correlative light and electron microscopy (CLEM) approaches have enabled targeted molecular visualization. Nevertheless, the implementation has also added to the complexity of the workflow and introduced new obstacles in the way of streamlining and achieving high throughput, sample yield, and sample quality...

Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide (i.e. meteor) impacts, large igneous province (LIP) eruptions and bioevolutionary events have each triggered one or more of the Phanerozoic Big Five mass extinctions, and that tectono-oceanic changes have triggered some second-order extinction events...

BACKGROUND: To tolerate salt and water-deficit stress, the plant adapts to the adverse environment by regulating its metabolism and expressing certain stress-induced metabolic pathways. This research analyzed the relative expression of four pea genes (P5CR, PAL1, SOD, and POX) in three pea varieties (Climax, Green grass, and Meteor) under different levels of salt and water-deficit stress. METHODS AND RESULTS: The experiments on salt stress and water-deficit stress were carried out within greenhouse settings under controlled environment...

Mesospheric Green emissions from excited Oxygen in Sprite Tops (ghosts) are infrequent and faint greenish transient luminous events that remain for hundreds of milliseconds on top of certain energetic sprites. The main hypothesis to explain this glow persistence is the long lifetime of excited atomic oxygen at 557.73 nm, a well-known emission line in aurora and airglow. However, due to the lack of spectroscopic campaigns to analyse such events to date, the species involved in the process can not yet be identified...

The production of locally atomically ordered FeNi (known by its meteoric mineral name, tetrataenite) is confirmed in bulk samples by simultaneous conversion X-ray and backscattered γ-ray 57 Fe Mössbauer spectroscopy. Up to 22 volume percent of the tetragonal tetrataenite phase is quantified in samples thermally treated under simultaneous magnetic- and stress-field conditions for a period of 6 weeks, with the remainder identified as the cubic FeNi alloy. In contrast, all precursor samples consist only of the cubic FeNi alloy...

Mining waste is an obvious source of environmental pollution due to the presence of heavy metals, which can contaminate soils, water resources, sediments, air, and people living nearby. The F-(Ba-Pb-Zn) deposit of Hammam Zriba located in northeast Tunisia, 8 km southeast of Zaghouan was intensively exploited from 1970 to 1992. More than 250,000 m3 of flotation tailings were produced and stored in the open air in three dumps without any measure of environmental protection. Thus, in this paper, mineralogical and chemical characterization, especially the sulfide and carbonate phases, were carried out to evaluate the potential for acid mining drainage (AMD) and metal leaching (ML)...

UNLABELLED: The outbreak of novel SARS-CoV-2 virion has wreaked havoc with a high prevalence of respiratory illness and high transmission due to a vague understanding of the viral antigenicity, augmenting the dire challenge to public health globally. This viral member necessitates the expansion of diagnostic and therapeutic tools to track its transmission and confront it through vaccine development. Therefore, prophylactic strategies are mandatory. Virulent spike proteins can be the most desirable candidate for the computational design of vaccines targeting SARS-CoV-2, followed by the meteoric development of immune epitopes...

The field of human-computer interaction is expanding, especially within the domain of intelligent technologies. Scene understanding, which entails the generation of advanced semantic descriptions from scene content, is crucial for effective interaction. Despite its importance, it remains a significant challenge. This study introduces RGBD2Cap, an innovative method that uses RGBD images for scene semantic description. We utilize a multimodal fusion module to integrate RGB and Depth information for extracting multi-level features...

The meteoric rise of single-cell genomic technologies, especially of single-cell RNA-sequencing (scRNA-seq), has revolutionized several fields of cellular biology, especially immunology, oncology, neuroscience and developmental biology. While the field of virology has been relatively slow to adopt these technological advances, many works have shed new light on the fascinating interactions of viruses with their hosts using single cell technologies. One clear example is the multitude of studies dissecting viral infections by single-cell sequencing technologies during the recent COVID-19 pandemic...

BACKGROUND: Symptoms of inflammatory myofibroblastic tumor (IMT) are atypical, and histopathological misdiagnosis of IMT is still inevitable. Here we present a pediatric case that an eight-year-old boy with recurrent fever for fifteen months, received anti-tuberculosis therapy for five months and was ultimately confirmed to be IMT. CASE PRESENTATION: An eight-year-old boy experienced a recurrent fever for fifteen months, accompanied by cough, vomiting, meteorism, night sweating, and emaciation...