Insights for the Captive Management of South China Tigers Based on a Large-Scale Genetic Survey.

There is an urgent need to find a way to improve the genetic diversity of captive South China tiger (SCT, Panthera tigris amoyensis), the most critically endangered taxon of living tigers, facing inbreeding depression. The genomes showed that 13 hybrid SCTs from Meihuashan were divided into two groups; one group included three individuals who had a closer relationship with pureblood SCTs than another group. The three individuals shared more that 40% of their genome with pureblood SCTs and might be potential individuals for genetic rescuing in SCTs. A large-scale genetic survey based on 319 pureblood SCTs showed that the mean microsatellite inbreeding coefficient of pureblood SCTs decreased significantly from 0.1789 to 0.0600 (p = 0.000009) and the ratio of heterozygous loci increased significantly from 38.5% to 43.2% (p = 0.02) after one individual of the Chongqing line joined the Suzhou line and began to breed in the mid-1980s, which is a reason why the current SCTs keep a moderate level of microsatellite heterozygosity and nucleotide diversity. However, it is important to establish a back-up population based on the three individuals through introducing one pureblood SCT into the back-up population every year. The back-up population should be an important reserve in case the pureblood SCTs are in danger in the future.

Three-Dimensional-Printed Carbon Nanotube/Polylactic Acid Composite for Efficient Electromagnetic Interference Shielding.

High-performance electromagnetic interference (EMI) shielding materials with ultralow density and environment-friendly properties are greatly demanded to address electromagnetic radiation pollution. Herein, carbon nanotube/polylactic acid (CNT/PLA) materials with different CNT contents, which exhibit characteristics of light weight, environmental protection and good chemical stability, are fabricated using 3D printing technology, where CNTs are evenly distributed and bind well with PLA. The performances of 3D-printed CNT/PLA composites are improved compared to pure 3D-printed PLA composites, which include mechanical properties, conductive behaviors and electromagnetic interference (EMI) shielding. The EMI shielding effectiveness (SE) of CNT/PLA composites could be improved when the content of CNTs increase. When it reaches 15 wt%, the EMI SE of 3D-printed CNT/PLA composites could get up to 47.1 dB, which shields 99.998% of electromagnetic energy. Meanwhile, the EMI shielding mechanism of 3D-printed CNT/PLA composites is mainly of absorption loss, and it generally accounts for more than 80% of the total shielding loss. These excellent comprehensive performances endow a 3D-printed CNT/PLA composite with great potential for use in industrial and aerospace areas.

Insights into the roles of fungi and protist in the giant panda gut microbiome and antibiotic resistome.

The mammal gut is a rich reservoir of antibiotic resistance genes (ARGs), and the relationship between bacterial communities and ARGs has been widely studied. Despite ecological significance of microeukaryotes (fungi and protists), our understanding of their roles in the mammal gut microbiome and antibiotic resistome is still limited. Here, we used amplicon sequencing, metagenomic sequencing and high-throughput quantitative PCR to examine microbiomes and antibiotic resistomes of 41 giant panda fecal samples from individuals with different genders, ages, sampling sites and diet. Our results show that diverse protists inhabit in the giant panda gut ecosystem, dominated by consumers. Higher abundance of protistan consumers was detected in the elder compared to sub-adult and adult giant pandas. Diet is the main driving factor of variation in ARGs in the giant panda gut microbiome. Weighted correlation network analysis identified two key microbial modules from multitrophic communities, which all contributed to the variation in ARGs in the giant panda gut. Protists occupied an important position in the two modules which were dominated by fungal taxa. Deterministic processes made a more important contribution to microbial community assembly of the two modules than to bacterial, fungal and protistan communities. This study sheds new light on how key microbial modules contribute to the variation in ARGs, which is crucial in understanding dynamics of antibiotic resistome in the mammal gut, particularly endangered species.

Chromosome-scale genomes provide new insights into subspecies divergence and evolutionary characteristics of the giant panda.

Extant giant pandas are divided into Sichuan and Qinling subspecies. The giant panda has many species-specific characteristics, including comparatively small organs for body size, small genitalia of male individuals, and low reproduction. Here, we report the most contiguous, high-quality chromosome-level genomes of two extant giant panda subspecies to date, with the first genome assembly of the Qinling subspecies. Compared with the previously assembled giant panda genomes based on short reads, our two assembled genomes increased contiguity over 200-fold at the contig level. Additional sequencing of 25 individuals dated the divergence of the Sichuan and Qinling subspecies into two distinct clusters from 10,000 to 12,000 years ago. Comparative genomic analyses identified the loss of regulatory elements in the dachshund family transcription factor 2 (DACH2) gene and specific changes in the synaptotagmin 6 (SYT6) gene, which may be responsible for the reduced fertility of the giant panda. Positive selection analysis between the two subspecies indicated that the reproduction-associated IQ motif containing D (IQCD) gene may at least partly explain the different reproduction rates of the two subspecies. Furthermore, several genes in the Hippo pathway exhibited signs of rapid evolution with giant panda-specific variants and divergent regulatory elements, which may contribute to the reduced inner organ sizes of the giant panda.

Giant panda foraging and movement patterns in response to bamboo shoot growth.

Diet plays a pivotal role in dictating behavioral patterns of herbivorous animals, particularly specialist species. The giant panda (Ailuropoda melanoleuca) is well-known as a bamboo specialist. In the present study, the response of giant pandas to spatiotemporal variation of bamboo shoots was explored using field surveys and GPS collar tracking. Results show the dynamics in panda-bamboo space-time relationships that have not been previously articulated. For instance, we found a higher bamboo stump height of foraged bamboo with increasing elevation, places where pandas foraged later in spring when bamboo shoots become more fibrous and woody. The time required for shoots to reach optimum height for foraging was significantly delayed as elevation increased, a pattern which corresponded with panda elevational migration patterns beginning from the lower elevational end of Fargesia robusta distribution and gradually shifting upward until the end of the shooting season. These results indicate that giant pandas can respond to spatiotemporal variation of bamboo resources, such as available shoots. Anthropogenic interference of low-elevation F. robusta habitat should be mitigated, and conservation attention and increased monitoring should be given to F. robusta areas at the low- and mid-elevation ranges, particularly in the spring shooting season.

Scoring model to predict outcome in critically ill cirrhotic patients with acute respiratory failure: comparison with MELD scoring models and CLIF-SOFA score.

BACKGROUND: Critically ill cirrhotic patients have a high mortality, particularly with concomitant respiratory failure on admission. There are no specific models in use for mortality risk assessment in critically ill cirrhotic patients with acute respiratory failure (CICRF). The aim is to develop a risk prediction model specific to CICRF in order to quantify the severity of illness. METHODS: We analyzed 949 CICRF patients extracted from the MIMIC-III database. The novel model (ARF-CLIF-SOFA) was developed from the CLIF-SOFA score. Cox regression analysis and AUROC were implemented to test the predictive accuracy, compared with existing scores including the CLIF-SOFA score and MELD-related scores. RESULTS: ARF-CLIF-SOFA contains PaO2/FiO2 ratio, lactate, MAP, vasopressor therapy, bilirubin and creatinine (1 point each; score range: 0-6). Based on our patient cohort, the ARF-CLIF-SOFA score had good predictive accuracy for predicting the 30-, 90-day and 1-year mortality (AUROC = 0.767 at 30-day, 0.768 at 90-day, 0.765 at 1-year, respectively). Additionally, the performance of the ARF-CLIF-SOFA is superior to existing scores (all P < 0.001). CONCLUSION: The ARF-CLIF-SOFA score can be considered a CICRF specific score with a better predictive accuracy compared to the existing scores.

The Lushan earthquake and the giant panda: impacts and conservation.

Earthquakes not only result in a great loss of human life and property, but also have profound effects on the Earth's biodiversity. The Lushan earthquake occurred on 20 Apr 2013, with a magnitude of 7.0 and an intensity of 9.0 degrees. A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined. Making use of research on the Wenchuan earthquake (with a magnitude of 8.0), which occurred approximately 5 years ago, we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat. An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death. In addition, an earthquake can damage conservation facilities for pandas, and result in further habitat fragmentation and degradation. However, from a historical point of view, the impacts of human activities on giant pandas and their habitat may, in fact, far outweigh those of natural disasters such as earthquakes. Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas, not those of humans.

Degradation kinetics of jujuboside b by rat intestinal flora in vitro with an RRLC-MS-MS method.

Jujuboside B (JuB) is a main bioactive saponin constituent of Ziziphi Spinosae Semen, which is a traditional herb for the treatment of insomnia and anxiety. However, the detailed metabolic mechanism of JuB is poorly understood. In this study, a novel method of rapid resolution liquid chromatography-triple quadrupole mass spectrometry was developed and validated for the analysis of JuB. With the method, the degradation kinetics of JuB by rat intestinal flora in vitro was investigated. The analysis was performed with an Agilent Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 µm) column and an aqueous mobile phase (containing 0.1% formic acid) modified by methanol. The analyte was measured by multiple reaction-monitoring (MRM) modes with m/z 1043.3 → m/z 749.2. This method was validated with perfect accuracy, precision and limit of quantitation. It showed that jujuboside B (JuB) degradation started slowly as incubation with rat feces. The rate constant was correlated greatly with the concentration of sample solutions. Furthermore, some metabolites were elucidated with their chromatographic behavior and typical fragment ions. The results might help better interpret the metabolic and pharmacological mechanism of JuB.

Composition of fatty oils from semen ziziphi spinosae and its cardiotonic effect on isolated toad hearts.

In this study, the composition of fatty oil from Semen Ziziphi Spinosae and its cardiotonic activity on the heart isolated from a toad were studied. Oil-in-water (O/W) emulsions of fatty oil were prepared by the perfusion method. The fatty oil had a positive inotropic effect on isolated rat hearts at a concentration between 5 × 10(-3) and 2 × 10(-2) mL/10 mL, and the effect was in positive correlation with the concentration of calcium ions. In addition, this effect was inhibited by 2 mg/mL nifedipine, suggesting that the cardiotonic mechanism could be responsible for accelerating the inflow of calcium ions. Gas chromatography-mass spectrometry analysis showed that the main constituents of the fatty oil were 9-octadecenoic acid (43.32%), 9,12-octadecadienoic acid (42.57%), hexadecanoic acid (4.76%), 9-eicosenoic acid (2.95%), stearic acid (2.41%) and arachidic acid (0.81%). This preliminary study revealed that the fatty oil of Semen Ziziphi Spinosae exhibited remarkable cardiotonic activity in the tested models, and it is necessary to further reveal the effective substances of the fatty oil.

Modulation effect of Semen Ziziphi Spinosae extracts on IL-1ß, IL-4, IL-6, IL-10, TNF-α and IFN-γ in mouse serum.

This study aims to explore and evaluate the effects of Semen Ziziphi Spinosae extracts on the serum levels of interleukin (IL)-6, IFN-γ, IL-1ß, TNF-α, IL-10 and IL-4 in mice, and the regulative effect of Semen Ziziphi Spinosae on the cytokine system. Using an ELISA assay, the serum levels of IL-6, IFN-γ, IL-1ß, TNF-α, IL-10 and IL-4 were examined in mice after intraperitoneal injection (i.p.) with Semen Ziziphi Spinosae extracts. The results showed that the levels of IL-6 and IL-1ß were significantly increased compared with the control groups (p<0.01), while the level of tumour necrosis factor-α (TNF-α) was significantly decreased (p<0.01). Semen Ziziphi Spinosae possesses certain modulation effects on cytokines, and the immuno-regulating function and hypnosis effects of Semen Ziziphi Spinosae may be relevant to these modulation effects on cytokines.

Simultaneous determination of jujuboside A, B and betulinic acid in semen Ziziphi spinosae by high performance liquid chromatography-evaporative light scattering detection.

A reverse phase high performance liquid chromatographic (HPLC) method with evaporative light scattering detection (ELSD) was developed for simultaneous determination of jujuboside A, B and betulinic acid in semen Ziziphi spinosae. The analysis was performed by gradient elution, using an aqueous mobile phase (containing 0.1% acetic acid) modified by acetonitrile. The evaporator tube temperature of ELSD was set at 45 degrees C, and with the nebulizing gas flow-rate of 1.8l/min. The method was validated for accuracy, reproducibility, precision and limits of detection and quantification. Quantification of the three active compounds in semen Ziziphi spinosae from different locations was performed by this method, which provides a new tool for quality assessment of semen Ziziphi spinosae.