[Characteristics and Influencing Factors of Greenhouse Fluxes from Urban Lawn].

As an important component of urban green spaces, greenhouse gas uptake or emissions from urban lawns cannot be ignored. However, studies of greenhouse gas fluxes from subtropical urban lawns are relatively sparse. The static chamber-gas chromatography method was applied to monitor the ground-air exchange fluxes of various greenhouse gases(CO2, CH4, N2O, and CO) in typical urban lawns of Hangzhou City. Our results showed that the average fluxes had significant seasonal cycles but ambiguous diurnal variations. The grassland and the soil(naked soil without vegetation coverage) acted as sources of atmospheric N2O, with the average fluxes of (0.66±0.17) and (0.58±0.20) µg·(m2·min)-1 for N2O, respectively; however, they were also sinks of CH4 and CO, with the average fluxes of (-0.21±0.078) and (-0.26±0.10) µg·(m2·min)-1 for CH4 and (-6.36±1.28) and (-6.55±1.69) µg·(m2·min)-1 for CO, respectively. The average CO2emission fluxes of urban grassland and soil were(5.28±0.75) and (4.83±0.91) mg·(m2·min)-1, respectively. The correlation analysis indicated that the CO2 and N2O fluxes of grassland and soil were negatively correlated with precipitation, whereas the CH4 and CO fluxes were positively correlated with it. There was no significant correlation between grassland CH4 fluxes and soil temperature, and N2O fluxes had a significant negative correlation with soil temperature; the other greenhouse gas fluxes showed a significant positive correlation with soil temperature. In addition, the seasonal variation in CO2 (R2=0.371 and 0.314) and N2O(R2=0.371 and 0.284) fluxes from both grassland and soil was affected by precipitation, whereas CO fluxes (R2=0.290 and 0.234) were mainly driven by soil temperature compared with the other greenhouse gases.

STTA: enhanced text classification via selective test-time augmentation.

Test-time augmentation (TTA) is a well-established technique that involves aggregating transformed examples of test inputs during the inference stage. The goal is to enhance model performance and reduce the uncertainty of predictions. Despite its advantages of not requiring additional training or hyperparameter tuning, and being applicable to any existing model, TTA is still in its early stages in the field of NLP. This is partly due to the difficulty of discerning the contribution of different transformed samples, which can negatively impact predictions. In order to address these issues, we propose Selective Test-Time Augmentation, called STTA, which aims to select the most beneficial transformed samples for aggregation by identifying reliable samples. Furthermore, we analyze and empirically verify why TTA is sensitive to some text data augmentation methods and reveal why some data augmentation methods lead to erroneous predictions. Through extensive experiments, we demonstrate that STTA is a simple and effective method that can produce promising results in various text classification tasks.

[Monitoring of atmospheric CH4, CO, CO2, N2O and SF6 using three-channel gas chromatography].

China is approaching a critical period of carbon peak and carbon neutrality. To assess the impact of carbon peak and carbon neutrality measures, an accurate understanding of the variations of the spatial and temporal distribution of greenhouse gases is crucial. Gas chromatography, a classical approach for greenhouse gas observation, can be employed for the high-precision analysis of partial greenhouse gases. In this research, a new greenhouse gas analytical system capable of measuring five gases (CH4, CO, CO2, N2O and SF6) on a single instrument was developed based on the traditional gas chromatography approach. The following are the chromatographic operation conditions. The carrier gases were high purity N2(99.999%) and argon-methane (5% methane in argon, 99.9999%), and a stainless steel switching valve triggered the injection. Compressed CH4, CO, CO2, N2O and SF6 mixed standard gases were stored in a 0.029 m3 aluminum alloy steel cylinder for this experiment. After numerous rounds of calibration by Greenhouse Gas Laboratory of Atmospheric Sounding Center of China Meteorological Administration, the gas scale met the primary standard of World Meteorological Organization (WMO). The main performance of the system, including the measurement precision, accuracy and linear response, was tested. The results showed that the detection performance of the system met the quality standards of WMO/Global Atmospheric Watch (GAW). Precision test results indicated that the relative standard deviations (RSDs) of the mole fractions of CH4, CO, CO2, N2O and SF6 were 0.08%, 1.90%, 0.05%, 0.08%, and 0.66%, respectively. For the linear and accuracy test, the C1-C5 tested standard gases were employed and the deviations of five gases (CH4, CO, CO2, N2O and SF6) between the calculated mole fractions of the regression equation and calibrated mole fractions were 0.15×10-9, 0.20×10-9, 0.37×10-6, 0.35×10-9 and 0.02×10-12, respectively. For CH4, CO, CO2, N2O and SF6, the linear regression coefficients (R2) between the peak areas or heights and calibrated mole fractions were 0.9999. The linear regression residual and accuracy could roughly meet the expanded target of WMO/GAW quality control. The atmospheric greenhouse gases in the Hangzhou urban area were continuously measured from May 2021 to July 2021 using the developed system. The results revealed that atmospheric CH4, CO, CO2 and N2O have visible diurnal variation characteristics that were primarily affected by anthropogenic emissions. The target standard gases were measured every 2 h to monitor the stability of the system operation, and the gas mole fractions of the system response were routinely computed and compared with the assigned calibrated values. The results demonstrated that the system had good stability during the observation period and could meet the requirements of high-precision monitoring. The comprehensive test and trial operation results showed that the developed system had good precision, accuracy, linearity and stability.

The Improvement of Semen Quality by Dietary Fiber Intake Is Positively Related With Gut Microbiota and SCFA in a Boar Model.

Although fiber-rich diets have been positively associated with sperm quality, there have not been any studies that have examined the effects of dietary fiber and its metabolites on sperm quality in young or pre-pubescent animals. In this study, we aimed to explore the effect of dietary fiber supplementation on semen quality and the underlying mechanisms in a boar model. Sixty purebred Yorkshire weaning boars were randomly divided into the four groups (T1-T4). Groups T1, T2, and T3 boars were fed diets with different levels of fiber until reaching 160 days of age and were then fed the same diet, while group T4 boars were fed a basal diet supplemented with butyrate and probiotics. Compared with T1 boars, sperm motility and effective sperm number were significantly higher among T3 boars. Meanwhile, at 240 days of age, the acetic acid and total short-chain fatty acid (SCFA) contents in the sera of T3 and T4 boars were significantly higher than those in T1 boars. The abundance of microbiota in T2 and T3 boars was significantly higher than that in T1 boars (P < 0.01). Moreover, dietary fiber supplementation increased "beneficial gut microbes" such as UCG-005, Rumenococcus, Rikenellaceae_RC9_gut_group and Lactobacillus and decreased the relative abundance of "harmful microbes" such as Clostridium_sensu_stricto_1, Romboutsia and Turicibacter. Collectively, the findings of this study indicate that dietary fiber supplementation improves gut microbiota and promotes SCFA production, thereby enhancing spermatogenesis and semen quality. Moreover, the effects of dietary fiber are superior to those of derived metabolites.

Methane emission via sediment and water interface in the Bohai Sea, China.

Sediment is recognized as the largest reservoir and source of methane (CH4) in the ocean, especially in the shallow coastal areas. To date, few data of CH4 concentration in sediment have been reported in the China shelf seas. In this study, we measured CH4 concentration in sediment and overlying seawater columns, and conducted an incubation experiment in the Bohai Sea in May 2017. CH4 concentration was found to be ranged from 3.075 to 1.795 µmol/L in sediment, which was 2 to 3 orders of magnitude higher than that in overlying seawater columns. The surface sediment was an important source of CH4, while bottom seawater acted as its sink. Furthermore, the net emission rate via sediment water interface (SWI) was calculated as 2.45 µmol/(m2∙day) based on the incubation experiment at station 73, and the earthquake may enhance CH4 release from sediment to seawater column in the eastern Bohai Sea.

Recent Advances in Oligonucleotide Therapeutics in Oncology.

Cancer is one of the leading causes of death worldwide. Conventional therapies, including surgery, radiation, and chemotherapy have achieved increased survival rates for many types of cancer over the past decades. However, cancer recurrence and/or metastasis to distant organs remain major challenges, resulting in a large, unmet clinical need. Oligonucleotide therapeutics, which include antisense oligonucleotides, small interfering RNAs, and aptamers, show promising clinical outcomes for disease indications such as Duchenne muscular dystrophy, familial amyloid neuropathies, and macular degeneration. While no approved oligonucleotide drug currently exists for any type of cancer, results obtained in preclinical studies and clinical trials are encouraging. Here, we provide an overview of recent developments in the field of oligonucleotide therapeutics in oncology, review current clinical trials, and discuss associated challenges.

Heteroplasmy in the mitochondrial genomes of human lice and ticks revealed by high throughput sequencing.

The typical mitochondrial (mt) genomes of bilateral animals consist of 37 genes on a single circular chromosome. The mt genomes of the human body louse, Pediculus humanus, and the human head louse, Pediculus capitis, however, are extensively fragmented and contain 20 minichromosomes, with one to three genes on each minichromosome. Heteroplasmy, i.e. nucleotide polymorphisms in the mt genome within individuals, has been shown to be significantly higher in the mt cox1 gene of human lice than in humans and other animals that have the typical mt genomes. To understand whether the extent of heteroplasmy in human lice is associated with mt genome fragmentation, we sequenced the entire coding regions of all of the mt minichromosomes of six human body lice and six human head lice from Ethiopia, China and France with an Illumina HiSeq platform. For comparison, we also sequenced the entire coding regions of the mt genomes of seven species of ticks, which have the typical mitochondrial genome organization of bilateral animals. We found that the level of heteroplasmy varies significantly both among the human lice and among the ticks. The human lice from Ethiopia have significantly higher level of heteroplasmy than those from China and France (Pt<0.05). The tick, Amblyomma cajennense, has significantly higher level of heteroplasmy than other ticks (Pt<0.05). Our results indicate that heteroplasmy level can be substantially variable within a species and among closely related species, and does not appear to be determined by single factors such as genome fragmentation.