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Oxygen isotope records from Chinese caves characterize changes in both the Asian monsoon and global climate. Here, using our new speleothem data, we extend the Chinese record to cover the full uranium/thorium dating range, that is, the past 640,000 years. The record’s length and temporal precision allow us to test the idea that insolation changes caused by the Earth’s precession drove the terminations of each of the last seven ice ages as well as the millennia-long intervals of reduced monsoon rainfall associated with each of the terminations. On the basis of our record’s timing, the terminations are separated by four or five precession cycles, supporting the idea that the ‘100,000-year’ ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in both the precession and obliquity bands, and is nearly in anti-phase with summer boreal insolation. These observations indicate that insolation, in part, sets the pace of the occurrence of millennial-scale events, including those associated with terminations and ‘unfinished terminations’. Records of the Asian monsoon have been extended to 640,000 years ago, and confirm both that the 100,000-year ice age cycle results from integral numbers of precessional cycles and that insolation influences the pacing of major millennial-scale climate events. A 640,000-year record of the Asian monsoon Prior records of the Asian monsoon have revealed cyclic variations over hundreds of thousands of years, probably driven by variations in insolation caused by the precession of Earth's orbit. Hai Cheng and colleagues now provide a speleothem record from Chinese cave samples that extends earlier records to 640,000 years ago, close to the maximum age possible with uranium/thorium dating. This spectacular record confirms that the characteristic '100,000-year' ice age cycle corresponds to an integral number (four or five) of precession cycles, and that insolation influences millennial-scale variations in monsoon strength.

Oxygen isotope records derived from stalagmites in the eastern Amazon reveal that rainfall was about half of today’s during the Last Glacial Maximum but half again as much during the mid-Holocene, broadly coinciding with global changes in temperature and carbon dioxide. Amazon Basin resilience to hydroclimate variation The Amazon forest both responds to and drives much of the variability in climate and biogeochemistry from annual to millennial time scales. But highly resolved records of past climate variability in the region are hard to come by, and until now it has not been clear whether the Amazon forest was wetter or drier during the Last Glacial Maximum (LGM). Xianfeng Wang et al . have now collected oxygen isotope data covering the past 45,000 years from stalagmite calcite deposits in the Paraíso Cave in eastern Amazonia. Their data show that rainfall was about half that of today during the LGM (around 21,000 years ago) but was some 50% greater during the mid-Holocene (6,000 years ago), broadly coinciding with global changes in temperature and carbon dioxide. Although the Amazon was drier during the glacial period, the rainforest persisted throughout. Whether or not it can be sustained in the future, however, remains an open question. Reconstructing the history of tropical hydroclimates has been difficult, particularly for the Amazon basin—one of Earth’s major centres of deep atmospheric convection 1 , 2 . For example, whether the Amazon basin was substantially drier 3 , 4 or remained wet 1 , 5 during glacial times has been controversial, largely because most study sites have been located on the periphery of the basin, and because interpretations can be complicated by sediment preservation, uncertainties in chronology, and topographical setting 6 . Here we show that rainfall in the basin responds closely to changes in glacial boundary conditions in terms of temperature and atmospheric concentrations of carbon dioxide 7 . Our results are based on a decadally resolved, uranium/thorium-dated, oxygen isotopic record for much of the past 45,000 years, obtained using speleothems from Paraíso Cave in eastern Amazonia; we interpret the record as being broadly related to precipitation. Relative to modern levels, precipitation in the region was about 58% during the Last Glacial Maximum (around 21,000 years ago) and 142% during the mid-Holocene epoch (about 6,000 years ago). We find that, as compared with cave records from the western edge of the lowlands, the Amazon was widely drier during the last glacial period, with much less recycling of water and probably reduced plant transpiration, although the rainforest persisted throughout this time.

It is generally accepted that supported graphene is hydrophobic and that its water contact angle is similar to that of graphite. Here, we show that the water contact angles of freshly prepared supported graphene and graphite surfaces increase when they are exposed to ambient air. By using infrared spectroscopy and X-ray photoelectron spectroscopy we demonstrate that airborne hydrocarbons adsorb on graphitic surfaces, and that a concurrent decrease in the water contact angle occurs when these contaminants are partially removed by both thermal annealing and controlled ultraviolet–O 3 treatment. Our findings indicate that graphitic surfaces are more hydrophilic than previously believed, and suggest that previously reported data on the wettability of graphitic surfaces may have been affected by unintentional hydrocarbon contamination from ambient air. Contact-angle and spectroscopy experiments on clean supported graphene and graphite show that these surfaces become more hydrophobic as they adsorb airborne hydrocarbons. Furthermore, the water contact angle on these graphitic surfaces decreases if these contaminants are partially removed by both thermal annealing and controlled ultraviolet–ozone treatments, suggesting that graphitic surfaces are more hydrophilic than previously believed.

²³⁰Th-dated oxygen isotope records of stalagmites from Sanbao Cave, China, characterize Asian Monsoon (AM) precipitation through the ends of the third- and fourthmost recent ice ages. As a result, AM records for the past four glacial terminations can now be precisely correlated with those from ice cores and marine sediments, establishing the timing and sequence of major events. In all four cases, observations are consistent with a classic Northern Hemisphere summer insolation intensity trigger for an initial retreat of northern ice sheets. Meltwater and icebergs entering the North Atlantic alter oceanic and atmospheric circulation and associated fluxes of heat and carbon, causing increases in atmospheric CO₂ and Antarctic temperatures that drive the termination in the Southern Hemisphere. Increasing CO₂ and summer insolation drive recession of northern ice sheets, with probable positive feedbacks between sea level and CO₂.

China story Stalactites, stalagmites and the many other forms of mineral deposits found in caves are a mainstay of climate studies, recording oxygen isotope ratios in limestone laid down over time. That pattern links to the water temperature of ancient oceans, and thus to climate. A new oxygen isotope record from Sanbao Cave, central China, tells the story of the region's climate stretching back 200,000 years, filling gaps in the record of a particularly important climate event, the East Asian monsoon. High-resolution speleothem records from China have provided insights into the factors that control the strength of the East Asian monsoon 1 , 2 , 3 , 4 . Our understanding of these factors remains incomplete, however, owing to gaps in the record of monsoon history over the past two interglacial–glacial cycles. In particular, missing sections have hampered our ability to test ideas about orbital-scale controls on the monsoon 5 , 6 , 7 , the causes of millennial-scale events 8 , 9 and relationships between changes in the monsoon and climate in other regions. Here we present an absolute-dated oxygen isotope record from Sanbao cave, central China, that completes a Chinese-cave-based record of the strength of the East Asian monsoon that covers the past 224,000 years. The record is dominated by 23,000-year-long cycles that are synchronous within dating errors with summer insolation at 65° N (ref. 10 ), supporting the idea that tropical/subtropical monsoons respond dominantly and directly to changes in Northern Hemisphere summer insolation on orbital timescales 5 . The cycles are punctuated by millennial-scale strong-summer-monsoon events (Chinese interstadials 1 ), and the new record allows us to identify the complete series of these events over the past two interglacial–glacial cycles. Their duration decreases and their frequency increases during glacial build-up in both the last and penultimate glacial periods, indicating that ice sheet size affects their character and pacing. The ages of the events are exceptionally well constrained and may thus serve as benchmarks for correlating and calibrating climate records.

A record from Wanxiang Cave, China, characterizes Asian Monsoon (AM) history over the past 1810 years. The summer monsoon correlates with solar variability, Northern Hemisphere and Chinese temperature, Alpine glacial retreat, and Chinese cultural changes. It was generally strong during Europe's Medieval Warm Period and weak during Europe's Little Ice Age, as well as during the final decades of the Tang, Yuan, and Ming Dynasties, all times that were characterized by popular unrest. It was strong during the first several decades of the Northern Song Dynasty, a period of increased rice cultivation and dramatic population increase. The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century.

The transcriptome of fowl adenovirus has not been comprehensively revealed. Here, we attempted to analyze the fowl adenovirus 4 (FAdV-4) transcriptome by deep sequencing. RNA samples were extracted from chicken LMH cells at 12, 18 or 26 h post-FAdV-4 infection, and subjected to Illumina strand-specific RNA-seq or nanopore full-length PCR-cDNA sequencing. After removing the reads of host cells, the data of FAdV-4 nanopore full-length cDNAs (transcripts) were corrected with reads from the Illumina RNA-seq, mapped to the viral genome and then used to predict viral open reading frames (ORFs). Other than 42 known ORFs, 39 novel ORFs were annotated to the FAdV-4 genome. Different from human adenovirus 5, one FAdV-4 ORF was often encoded by several transcripts, and more FAdV-4 ORFs were located on two exons. With these data, 18 major transcription start sites and 15 major transcription termination sites were defined, implying 18 viral promoters and 15 polyadenylation signals. The temporal cascade of viral gene transcription was observed in FAdV-4-infected cells, with six promoters possessing considerable activity in the early phase. Unexpectedly, four promoters, instead of one major late promoter, were engaged in the transcription of the viral genus-common genes on the forward strand. The clarification of the FAdV-4 transcriptome laid a solid foundation for the study of viral gene function, virulence and virus evolution, and it would help construct FAdV-4 as a gene transfer vehicle. The strategy of de novo ORF prediction could be used to parse the transcriptome of other novel adenoviruses.

Postmenopausal osteoporosis (PMOP) is a common primary osteoporosis. With the aging of the population, it is becoming a major disease that endangers health and quality of life. The purpose of this study was to explore the effect of gut microbiota on PMOP by observing the changes in the levels of estradiol, bone density, and gut microbiota diversity in rats after 3 months of OVX surgery. 60 female SD rats were randomly divided into four groups: baseline group (6 rats), sham-operated group (18 rats), model group (18 rats), and estrogen-treated group (18 rats). The ovariectomy model of postmenopausal osteoporosis was established by performing bilateral ovariectomy. After surgery, 6 rats from each group were randomly selected for sacrifice every 30 days and subsequent assessment. At the end of 90 days, all rats were sacrificed for evaluation of body weight, bone mineral density (BMD), tissue mineral density (TMD), trabecular bone parameters, femoral bone morphology, hormone levels, and gut microbiota diversity. The analysis revealed that OVX led to a decrease in BMD, TMD, and serum estradiol levels in rats, and increased TNF-α levels. The bone micro-architecture and tissue morphology were also changed, with trabecular fractures, thinning, and decreased numbers. Meanwhile, there was also a shift in the diversity of gut microbiota. The administration of estrogen could potentially ameliorate these alterations. Overall, OVX leads to a persistent decline in estrogen levels in rats. This results in gradual bone loss, which is related to gut microbiota imbalance.

The detailed anatomy of Termination I (TI) is well depicted, but whether changes across Termination II (TII) resemble TI remains controversial. Here we present high-resolution Asian monsoon records covering TII using Shima Cave stalagmites from China. Correlating marine and ice-core records to our U/Th-dated records via millennial-scale variabilities, we find an initial CO 2 rise from 139 ± 1 ka BP concordant with boreal summer insolation increase, which was followed by a major rise phase of CO 2 between 135.7 ± 1 and 129 ± 1 ka BP. The major rise phases of CO 2 were comparable during TI and TII, but the initial CO 2 rise before TII was distinct from CO 2 behavior before TI, likely forced by the Earth’s internal variabilities, in particular an ice-sheet collapse event and a 50% reduction in southern hemisphere dust flux. Here, we show that ~4000–5000-year-long gradual changes in CO 2 , along with insolation rise, preconditioned glacial terminations, supporting the “tipping point” theory. U/Th-dated Asian monsoon records from Shima Cave, covering 142–122 ka BP, constrain the timing of a CO 2 rise at ~139 ka BP caused by millennial-scale variabilities, which, along with increasing orbital solar radiation, prepare for the end of ice age.

Ozone in the atmosphere strongly absorbs deep ultraviolet light with wavelengths between 200 and 280 nm. Therefore, this characteristic is advantageous and promising for unperturbed, non-disturbed information transmission in fields such as secure communications when deep ultraviolet light is employed. However, existing optical communication systems utilizing deep ultraviolet light are characterized by substantial size, which presents significant challenges in terms of local transferability. This paper employs an array of 275 nm deep ultraviolet light-emitting diodes (LEDs) connected in series, paired with photomultiplier tubes (PMTs) as transmitters and receivers. The system is encapsulated with a visual tracking module and mounted on drones and vehicles, achieving mobile duplex real-time communication under sunlight. The communication distance reaches 30 m with a packet loss rate of 1.36%. This work enables rapid and flexible deployment of deep ultraviolet optical communication systems, offering broad application prospects.