Association of triglyceride glucose-related parameters with all-cause mortality and cardiovascular disease in NAFLD patients: NHANES 1999-2018.

BACKGROUND: The relationship between the triglyceride-glucose (TyG) index and its derived index, the triglyceride glucose-waist height ratio (TyG-WHtR), with mortality and cardiovascular diseases (CVDs) in patients with non-alcoholic fatty liver disease (NAFLD) remains unclear. METHODS: This study enrolled 6627 adults aged 18 and above diagnosed NAFLD from the National Health and Nutrition Examination Survey (NHANES, 1999-2018). Binary weighted logistic regression analyses, cox proportional hazards model and restricted cubic spline (RCS) were used to analyze the relationship between TyG and TyG-WHtR with all-cause mortality, CVD mortality and CVDs. Mediation analysis explored the mediating role of glycohemoglobin, insulin and hypertension in the above relationships. Meanwhile, the incremental predictive value of the TyG index and TyG-WHtR was further assessed. RESULTS: Except for no significant association between the TyG index and both all-cause mortality and chronic heart failure (CHF), both TyG and TyG-WHtR exhibited significant positive correlations or trends of positive correlation with all-cause mortality, CVD mortality, total-CVD, CHF, coronary heart disease (CHD) and angina pectoris. For all-cause mortality, CVD mortality and CHF, TyG-WHtR was a better predictor than TyG (TyG-WHtR: HR 1.31, 95%CI 1.03-1.66; HR 2.22, 95%CI 1.42-3.47; OR 3.99, 95%CI 1.79-8.93). In contrast, TyG index demonstrated a stronger association with total-CVD, CHD and angina pectoris (TyG index: OR 2.00, 95%CI 1.26-3.18; OR 1.85, 95%CI 1.19-2.91; OR 2.93, 95%CI 1.23-7.00). RCS analysis showed that after adjusting for covariates, most of the aforementioned relationships were linear(P overall < 0.0001, P-nonlinear > 0.05), while the associations of the TyG index and TyG-WHtR with all-cause mortality and CHF were non-linear(P overall < 0.0001, P nonlinear < 0.05). The addition of the TyG index and TyG-WHtR to the basic model for outcomes improved the C-statistics, net reclassification improvement value, and integrated discrimination improvement value. CONCLUSIONS: The predictive value of TyG or TyG-WHtR for all-cause mortality and cardiovascular risk in NAFLD patients was significant. The TyG index and TyG-WHtR might be valid predictors of cardiovascular outcomes of patients with NAFLD.

The serum soluble ASGR1 concentration is elevated in patients with coronary artery disease and is associated with inflammatory markers.

BACKGROUND AND AIMS: Current research has suggested that asialoglycoprotein receptor 1 (ASGR1) is involved in cholesterol metabolism and is also related to systemic inflammation. This study aimed to assess the correlation between the serum soluble ASGR1 (sASGR1) concentration and inflammatory marker levels. Moreover, the second objective of the study was to assess the association between sASGR1 levels and the presence of coronary artery disease (CAD). METHODS: The study subjects included 160 patients who underwent coronary angiography. Ninety patients were diagnosed with CAD, while seventy age- and sex-matched non-CAD patients served as controls. We measured the serum sASGR1 levels using an ELISA kit after collecting clinical baseline characteristics. RESULTS: Patients with CAD had higher serum sASGR1 levels than non-CAD patients did (P < 0.0001). sASGR1 was independently correlated with the risk of CAD after adjusting for confounding variables (OR = 1.522, P = 0.012). The receiver operating characteristic (ROC) curve showed that sASGR1 had a larger area under the curve (AUC) than did the conventional biomarkers apolipoprotein B (APO-B) and low-density lipoprotein cholesterol (LDL-C). In addition, multivariate linear regression models revealed that sASGR1 is independently and positively correlated with high-sensitivity C-reactive protein (CRP) (ß = 0.86, P < 0.001) and WBC (ß = 0.13, P = 0.004) counts even after adjusting for lipid parameters. According to our subgroup analysis, this relationship existed only for CAD patients. CONCLUSION: Our research demonstrated the link between CAD and sASGR1 levels, suggesting that sASGR1 may be an independent risk factor for CAD. In addition, this study provides a reference for revealing the potential role of sASGR1 in the inflammation of atherosclerosis.

Effects of Prophylactic Antibiotics on Intestinal Microflora Diversity in Preterm Infants: A Meta-analysis.

Objective: This meta-analysis aims to investigate the effects of prenatal prophylactic antibiotics on the diversity of intestinal flora in premature infants, with a focus on elucidating the rationale behind this investigation and the potential impact of altered intestinal flora on the health of preterm infants, such as increased susceptibility to infections, impaired nutrient absorption, and compromised immune function. Methods: Relevant literature consistent with the effects of prenatal prophylactic antibiotics on intestinal flora diversity in preterm infants was systematically searched and screened from both domestic and foreign databases, including Wanfang Medical Center, CNKNET, VIpp, and PubMed. Meta-analysis was performed using RevMan 5.2 software. Inclusion criteria for the study were: (1) comparison of prophylactic antibiotic use versus non-use, (2) no restrictions on subjects' characteristics, (3) follow-up loss < 20%, (4) institutional approval, (5) publication within the time frame from January 2017 to December 2022, (6) minimal missing data or suppliable by author contact, and (7) no major errors in sequencing or detection. Outcome measures included intestinal flora composition, phylum flora content, abundance index, and Shannon index, comparing antibiotic-treated and non-treated groups. RevMan 5.2 software was used for statistical analysis. Counting data was expressed as risk ratio (RR), and weighted mean difference (WMD) or standard mean difference (SMD) was selected as analysis statistics. Results: The study encompassed five Chinese literature sources, with one deemed low quality and four high quality. No significant publication bias was observed. Among the included studies, a significant reduction in the intestinal flora abundance index ACE was noted in the treated group compared to the non-treated group (RR: -8.10, 95% CI: -8.81 to -7.40, P < .00001). ACE estimates species richness in a microbial community by considering both abundant and rare species. Higher ACE values indicate greater diversity. Similarly, the Shannon diversity index was lower in the medication group compared to the non-medication group (RR: 0.73, 95% CI: 0.64 to 0.82, P < .00001). Shannon Diversity Index measures species diversity and evenness within a community. Higher values indicate higher diversity, considering both the number of species and their relative abundance. Analysis of Firmicutes content revealed a higher level in the treated group (RR: -6.44, 95% CI: -7.26 to -5.63, P < .00001). Additionally, lower Proteus (RR: 10.96, 95% CI: 9.47 to 12.45, P < .00001) and Klebsiella (RR: 15.96, 95% CI: 15.31 to 16.62, P < .00001) content was observed in the treated group. Conversely, Enterococcus content was higher in the treated group (RR: 2.18, 95% CI: 1.84 to 2.52, P < .00001), along with a higher proportion of Enterococcus (RR: 0.45, 95% CI: 0.27 to 0.76, P = .003). These findings collectively suggest that prophylactic antibiotic use in preterm infants significantly alters the composition of intestinal flora. Conclusion: Our findings suggest that prophylactic antibiotic use in preterm infants leads to a notable reduction in intestinal flora diversity, potentially impacting their health outcomes. Decreased microbial diversity has been linked to gastrointestinal issues, infections, and weakened immune function. These results highlight the importance of cautious antibiotic use in this vulnerable population and the need for further research to better understand and mitigate the potential health implications.

Enhanced Coexistence of Quantum Key Distribution and Classical Communication over Hollow-Core and Multi-Core Fibers.

In this paper, we investigate the impact of classical optical communications in quantum key distribution (QKD) over hollow-core fiber (HCF), multi-core fiber (MCF) and single-core fiber (SCF) and propose wavelength allocation schemes to enhance QKD performance. Firstly, we theoretically analyze noise interference in QKD over HCF, MCF and SCF, such as spontaneous Raman scattering (SpRS) and four-wave mixing (FWM). To mitigate these noise types and optimize QKD performance, we propose a joint noise suppression wavelength allocation (JSWA) scheme. FWM noise suppression wavelength allocation and Raman noise suppression wavelength allocation are also proposed for comparison. The JSWA scheme indicates a significant enhancement in extending the simultaneous transmission distance of classical signals and QKD, reaching approximately 100 km in HCF and 165 km in MCF under a classical power per channel of 10 dBm. Therefore, MCF offers a longer secure transmission distance compared with HCF when classical signals and QKD coexist in the C-band. However, when classical signals are in the C-band and QKD operates in the O-band, the performance of QKD in HCF surpasses that in MCF. This research establishes technical foundations for the design and deployment of QKD optical networks.

Arterial remodeling: the role of mitochondrial metabolism in vascular smooth muscle cells.

Arterial remodeling is a common pathological basis of cardiovascular diseases such as atherosclerosis, vascular restenosis, hypertension, pulmonary hypertension, aortic dissection, and aneurysm. Vascular smooth muscle cells (VSMCs) are not only the main cellular components in the middle layer of the arterial wall but also the main cells involved in arterial remodeling. Dedifferentiated VSMCs lose their contractile properties and are converted to a synthetic, secretory, proliferative, and migratory phenotype, playing key roles in the pathogenesis of arterial remodeling. As mitochondria are the main site of biological oxidation and energy transformation in eukaryotic cells, mitochondrial numbers and function are very important in maintaining the metabolic processes in VSMCs. Mitochondrial dysfunction and oxidative stress are novel triggers of the phenotypic transformation of VSMCs, leading to the onset and development of arterial remodeling. Therefore, pharmacological measures that alleviate mitochondrial dysfunction reverse arterial remodeling by ameliorating VSMCs metabolic dysfunction and phenotypic transformation, providing new options for the treatment of cardiovascular diseases related to arterial remodeling. This review summarizes the relationship between mitochondrial dysfunction and cardiovascular diseases associated with arterial remodeling and then discusses the potential mechanism by which mitochondrial dysfunction participates in pathological arterial remodeling. Furthermore, maintaining or improving mitochondrial function may be a new intervention strategy to prevent the progression of arterial remodeling.

Coexistence of 1 Tbps classical optical communication and quantum key distribution over a 100.96 km few-mode fiber.

The integration of quantum key distribution (QKD) and classical optical communication has attracted widespread attention. In this Letter, we experimentally demonstrate a real-time co-propagation of 1 Tbps for 10 classical channels with one discrete-variable QKD channel in the weakly coupled few-mode fiber (FMF). Based on the selection of optimal device parameters and wavelength assignment of classical channels, as well as the optimization of equipment performance, a secure key rate of as high as 2.7 kbps of coexistence transmission of QKD and classical optical communication can be achieved using a 100.96 km weakly coupled FMF. Therefore, this study is a step toward realizing long-distance quantum-classical coexistence transmission.

Few-mode erbium-doped fiber with trench and weak coupling for mode gain equalization based on layered-doping technology.

A few-mode erbium-doped fiber (FM-EDF) with a step refractive index and trench structure is designed and proposed to realize the modal gain equalization of a few-mode erbium-doped fiber amplifier (FM-EDFA). The layered-doping technology is used to reduce the mode gain difference (DMG). The doping radius and doping concentration are adjusted to obtain the optimum FM-EDF structure. When the designed FM-EDF is applied to the FM-EDFA, the DMG of the whole C-band is less than 0.15 dB and the DMG is less than 0.12 dB at 1550 nm. The minimum refractive index difference (Δ n eff) between modes can be calculated according to the refractive index and radius of the fiber core; i.e., 1.35×10-3, which will greatly reduce the coupling between modes in a practical application. Tolerances in the fiber manufacturing process are also considered for reliable FM-EDFA performance. When the doping radius and concentration of each doping layer fluctuate by ±15% based on the precise value, the maximum DMG increases to 1.8 dB. In general, DMG can maintain a small value, which is beneficial for application in optical communications systems.

Design of few-mode erbium-doped fiber with a low differential modal gain and weak coupling based on layered doping.

A step index few-mode erbium-doped fiber (FM-EDF) for mode gain equalization is designed and proposed in this paper, which uses the layered-doping method to reduce the differential mode gain (DMG). The optimum structure of FM-EDF is obtained by adjusting the doping radius and doping concentration. When this structure is applied to a few-mode erbium-doped fiber amplifier (FM-EDFA), the DMG in the range of 1550-1565 nm is ∼0.28d B, and the DMG of the whole C-band is usually less than 0.5 dB. At the same time, the gain of each mode in 1530-1555 nm is ∼20d B, while the gain decreases gradually in the 1555-1565 nm due to the absorption characteristics of erbium ions. In addition, the minimum refractive index difference (Δ n eff) between modes is 1.29∗10-3 due to the selection of the refractive index and radius of the fiber core, which will greatly reduce the coupling between modes in practical application. Tolerances in the fiber manufacturing process are also considered for reliable FM-EDFA performance. When the doping concentration or the doping radius changes based on the precise value, the DMG will increase to a certain extent. In general, the DMG can maintain a small value, which is beneficial to applications in optical communication systems.

Dietary fruits and vegetables and risk of cardiovascular diseases in elderly Chinese.

BACKGROUND: Evidence regarding the potential effect of fruit and vegetable consumption on cardiovascular diseases (CVD) was limited and inconsistent among Asian people. METHODS: We prospectively examined associations of fruit and vegetable consumption with the risk of CVD among 9740 participants aged 65 years and older (mean baseline age: 88 years) in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) (2008-2018). Dietary data were collected using a validated food frequency questionnaire. RESULTS: During 37 366 person-years of follow-up, a total of 3738 CVD cases were recorded. After adjusting for demographics, dietary, lifestyle and economical social factors, higher intakes of total fruits and vegetables were associated with lower risk of CVD [comparing with extreme quintiles, hazard ratio and 95% confidence interval: 0.84 (0.74, 0.95)]. The inverse association was mainly driven by vegetable consumption [0.86 (0.77, 0.95)]. Furthermore, the inverse association was stronger for the risk of hypertension [0.84 (0.72, 0.98)]. These associations were consistent across age, sex, body mass index, residence, exercise status, smoking, drinking, meat intake, modified hPDI and health status. CONCLUSIONS: This study suggests higher intakes of total fruits and vegetables are associated with a lower risk of CVD among elderly Chinese people, supporting the current recommendations of increasing fruit and vegetable consumption as part of a healthy diet for the prevention of CVD.

Life history responses of the small brown planthopper Laodelphax striatellus to temperature change.

Temperature is a key environmental factor in ectotherms and influences many life history traits. In the present study, the nymphal development time, sex ratio and wing dimorphism of the small brown planthopper Laodelphax striatellus were examined under the conditions of constant temperatures, naturally varying temperatures (or different generations), and different temperatures combined with different photoperiod. The results showed that from 18 to 28 °C, the developmental time of nymphs was gradually shortened with the increase of temperature, whereas the high temperatures of 30 and 32 °C in the third to fifth instar nymphal stages and high summer temperature of 28.8 and 29.7 °C significantly delayed developmental time and resulted in higher mortality of nymphs. In all treatments, the developmental time was longer in females than males. The nymphs took significantly longer time to develop in the short daylength of 12 h than in longer daylengths of 13, 14, 15 and 16. Differences in developmental time were also found between wing morph, with long-winged individuals being significantly longer than the short-winged individuals at lower temperatures and significantly shorter than the short-winged individuals at higher temperatures. In all treatments, the sex ratio was stable, approaching 1:1, without being affected by temperature, generations and photoperiod. Photoperiod and temperature had significantly influence on the wing dimorphism. Long daylength combined with different temperatures resulted in significantly higher proportions of long-winged morph, whereas the low temperatures combined with the short daylengths in autumn and winter resulted in significantly high proportion of short-winged morph. This study broadens our understanding of the life-history traits of this planthopper and provides basic data for analyzing the effects of climate change on the planthopper reproduction.

Hyb4mC: a hybrid DNA2vec-based model for DNA N4-methylcytosine sites prediction.

BACKGROUND: DNA N4-methylcytosine is part of the restrictive modification system, which works by regulating some biological processes, for example, the initiation of DNA replication, mismatch repair and inactivation of transposon. However, using experimental methods to detect 4mC sites is time-consuming and expensive. Besides, considering the huge differences in the number of 4mC samples among different species, it is challenging to achieve a robust multi-species 4mC site prediction performance. Hence, it is of great significance to develop effective computational tools to identify 4mC sites. RESULTS: This work proposes a flexible deep learning-based framework to predict 4mC sites, called Hyb4mC. Hyb4mC adopts the DNA2vec method for sequence embedding, which captures more efficient and comprehensive information compared with the sequence-based feature method. Then, two different subnets are used for further analysis: Hyb_Caps and Hyb_Conv. Hyb_Caps is composed of a capsule neural network and can generalize from fewer samples. Hyb_Conv combines the attention mechanism with a text convolutional neural network for further feature learning. CONCLUSIONS: Extensive benchmark tests have shown that Hyb4mC can significantly enhance the performance of predicting 4mC sites compared with the recently proposed methods.

Effects of Land-Use Type and Flooding on the Soil Microbial Community and Functional Genes in Reservoir Riparian Zones.

Ecological processes (e.g., nutrient cycling) in riparian zones are often affected by land-use type and flooding. The extent to which land-use types and flooding conditions affect soil microorganisms and their ecological functions in riparian zones is not well known. By using high-throughput sequencing and quantitative PCR (q-PCR), we tested the effects of three land-use types (i.e., forest, wetland, and grassland) and two flooding conditions (i.e., landward locations and waterward locations within the land-use types) on soil microbial communities and microbial functional genes in the riparian zones of a reservoir. Land-use type but not flooding significantly affected soil microbial community composition at the phylum level, while both land-use type and flooding significantly affected the orders Nitrosotaleales and Nitrososphaerales. Alpha diversity was higher in the wetland and forest regardless of flooding conditions. Functional gene abundance differed among the three land-use types. Archaeal amoA (AOA) and nirS genes were more abundant in the wetland than in the grassland or forest. Bacterial amoA (AOB), nirK, nirS, and nosZ genes were more abundant in the waterward location than in the landward location but only in the wetland. Soil pH, moisture, and concentrations of soil organic matter and total soil nitrogen were significantly associated with the composition of archaeal and bacterial communities as well as with their gene abundance. This study revealed that soil microorganisms putatively involved in nitrogen cycling in riparian zones were more affected by land-use type than flooding.

Downregulation of SUN2 promotes metastasis of colon cancer by activating BDNF/TrkB signalling by interacting with SIRT1.

Distant metastasis is the major cause of colon cancer (CC) treatment failure. SAD1/UNC84 domain protein-2 (SUN2) is a key component of linker of the nucleoskeleton and cytoskeleton (LINC) complexes that may be relevant for metastasis in several cancers. Here, we first confirmed that SUN2 levels were significantly lower in primary CC tissues and distant metastasis than in normal colon tissues, and high SUN2 expression predicted good overall survival. Overexpression of SUN2 or knockdown of SUN2 inhibited or promoted cell migration and invasion in vitro, respectively. Moreover, silencing of SUN2 promoted metastasis in vivo. Mechanistically, we showed that SUN2 exerts its tumour suppressor functions by decreasing the expression of brain derived neurotrophic factor (BDNF) to inhibit BDNF/tropomyosin-related kinase B (TrkB) signalling. Additionally, SUN2 associated with SIRT1 and increased the acetylation of methyl-CpG binding protein 2 (MeCP2) to increase its occupancy at the BDNF promoter. Taken together, our findings indicate that SUN2 is a key component in CC progression that acts by inhibiting metastasis and that novel SUN2-SIRT1-MeCP2-BDNF signalling may prove to be useful for the development of new strategies for treating patients with CC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Deep Compressive Sensing on ECG Signals with Modified Inception Block and LSTM.

In practical electrocardiogram (ECG) monitoring, there are some challenges in reducing the data burden and energy costs. Therefore, compressed sensing (CS) which can conduct under-sampling and reconstruction at the same time is adopted in the ECG monitoring application. Recently, deep learning used in CS methods improves the reconstruction performance significantly and can removes of some of the constraints in traditional CS. In this paper, we propose a deep compressive-sensing scheme for ECG signals, based on modified-Inception block and long short-term memory (LSTM). The framework is comprised of four modules: preprocessing; compression; initial; and final reconstruction. We adaptively compressed the normalized ECG signals, sequentially using three convolutional layers, and reconstructed the signals with a modified Inception block and LSTM. We conducted our experiments on the MIT-BIH Arrhythmia Database and Non-Invasive Fetal ECG Arrhythmia Database to validate the robustness of our model, adopting Signal-to-Noise Ratio (SNR) and percentage Root-mean-square Difference (PRD) as the evaluation metrics. The PRD of our scheme was the lowest and the SNR was the highest at all of the sensing rates in our experiments on both of the databases, and when the sensing rate was higher than 0.5, the PRD was lower than 2%, showing significant improvement in reconstruction performance compared to the comparative methods. Our method also showed good recovering quality in the noisy data.

HMGB1 impairs endothelium-dependent relaxation in diabetes through TLR4/eNOS pathway.

Endothelium-dependent relaxation (EDR) is an initial key step leading to various vascular complications in patients with diabetes. However, the underlying mechanism of EDR impairment in diabetes is not fully understood. Present study defined the role of high-mobility group protein (HMGB1) in EDR related to diabetes. Serum level of HMGB1 was increased in diabetic patients and in db/db mice. Serum HMGB1 level was also positively correlated with HbA1c and negatively correlated with nitric oxide (NO) in diabetic patients. Results from wire myograph showed that recombinant HMGB1 (rHMGB1) was capable of impairing EDR of aortas from wild-type (WT) mice by an eNOS-dependent mechanism. Consistently, HMGB1 inhibitor glycyrrhizin acid (GA) decreased the serum level of HMGB1 and rescued EDR impairment partly in db/db mice. Furthermore, rHMGB1 mediated EDR impairment was abolished in aortas of TLR4-/- mice. In addition, high-glucose-induced HMGB1 upregulation and secretion in endothelial cells. In conclusion, HMGB1 contributes to the EDR impairment through TLR4/eNOS pathway in the setting of diabetes. GA as the HMGB1 inhibitor could attenuate EDR impairment in an animal model of diabetes.

A real-world study on diagnosis and prognosis of light-chain cardiac amyloidosis in Southern China.

BACKGROUND: Light-chain cardiac amyloidosis (AL-CA) has been highly valued in developed countries, but in developing countries, the recognition and diagnosis of this condition is still limited. There are currently few reports on a large number of Chinese patients with AL-CA. The present study aimed to report real-world clinical characteristics and prognosis of AL-CA in China. METHODS AND RESULTS: Consecutive patients with AL-CA diagnosed at the Second Xiangya Hospital of Central South University between June 2012 and September 2020 were reviewed. A total of 170 patients with AL-CA have been recruited, whose mean ages were 60.81 ± 10.46. 70.59% of the patients were male. They were from eight provinces in southern China, 55.7% were referred patients, and 37.3% had been misdiagnosed previously. 64 (37.6%) patients received chemotherapy. The median survival time for patients with AL-CA was 8.00 months, and survival time for patients who received chemotherapy was 13.00 months, which was significantly longer than that of patients with palliative treatment (13.00 vs 6.00, p = 0.004). CONCLUSIONS: Although clinicians have improved their understanding of AL-CA in recent years, the prognosis of AL-CA is still poor, and the misdiagnosis rate and missed diagnosis rate are still very high in China. It is imperative to improve the recognition and early diagnosis of this condition, which may require multidisciplinary collaboration among cardiologists, hematologists and nephrologists.

A Brief Review of circRNA Biogenesis, Detection, and Function.

Circular RNA (circRNA) is a non-coding molecule produced through alternative splicing of one or more exons of a gene in the presence of an RNA-induced silencing complex (RISC). Its formation depends on complementary intron sequences on both sides of the circularized sequence. CircRNA functions as a sponge for miRNA, playing the role of the transcriptional regulator or potential biomarker. It has an impact on fetal growth and on synaptic facilitation in the brain. In this review, we illustrate biogenesis mechanisms, characteristics, and functions of cirRNAs. We also summarize methods using sequence feature and RNA next-generation sequencing data for circRNA prediction. Finally, we discuss the state of the research on circRNA in diseases, which will bring new contributions to future disease treatments.

Inheritance of key life-history traits in crosses between northern and southern populations of the cabbage beetle Colaphellus bowringi (Coleoptera: Chrysomelidae).

A southern population (S) from Xiushui County (29°1'N, 114°4'E) and a northern population (N) from Shenyang city (41°48'N, 123°23'E) of the cabbage beetle, Colaphellus bowringi vary greatly in their life-history traits, and may serve as an excellent model with which to study the inheritance of life-history traits. In the present study, we performed intraspecific hybridization using the two populations, comparing the key life-history traits (fecundity, development time, body weight, growth rate, and sexual size dimorphism (SDD)) between the two populations (S♀ × S♂ and N♀ × N♂) and their two hybrid populations (S♀ × N♂ and N♀ × S♂ populations) at 19, 22, 25, and 28°C. Our results showed that there were significant differences in life-history traits between the two parental populations, with the S population having a significantly higher fecundity, shorter larval development time, larger body weight, higher growth rate, and greater weight loss during metamorphosis than the N population at almost all temperatures. However, these life-history traits in the two hybrid populations were intermediate between those of their parents. The life-history traits in the S × N and N × S populations more closely resembled those of the maternal S population and N population, respectively, showing maternal effects. Weight loss for both sexes was highest in the S population, followed by the S × N, N × S, and N populations at all temperatures, suggesting that larger pupae lost more weight during metamorphosis. The changes in SSD with temperature were similar between the S and the S × N populations and between the N and the N × S populations, also suggesting a maternal effect. Overall, our results showed no drastic effect of hybridization on C. bowringi, being neither negative (hybrid inferiority) nor positive (heterosis). Rather, the phenotypes of hybrids were intermediate between the phenotypes of their parents.

Preservation of the genetic diversity of a local common carp in the agricultural heritage rice-fish system.

We examined how traditional farmers preserve the genetic diversity of a local common carp (Cyprinus carpio), which is locally referred to as "paddy field carp" (PF-carp), in a "globally important agricultural heritage system" (GIAHS), i.e., the 1,200-y-old rice-fish coculture system in Zhejiang Province, China. Our molecular and morphological analysis showed that the PF-carp has changed into a distinct local population with higher genetic diversity and diverse color types. Within this GIAHS region, PF-carps exist as a continuous metapopulation, although three genetic groups could be identified by microsatellite markers. Thousands of small farmer households interdependently obtained fry and parental carps for their own rice-fish production, resulting in a high gene flow and large numbers of parent carps distributing in a mosaic pattern in the region. Landscape genetic analysis indicated that farmers' connectivity was one of the major factors that shaped this genetic pattern. Population viability analysis further revealed that the numbers of these interconnected small farmer households and their connection intensity affect the carps' inherent genetic diversity. The practice of mixed culturing of carps with diverse color types helped to preserve a wide range of genetic resources in the paddy field. This widespread traditional practice increases fish yield and resource use, which, in return, encourages famers to continue their practice of selecting and conserving diverse color types of PF-carp. Our results suggested that traditional farmers secure the genetic diversity of PF-carp and its viability over generations in this region through interdependently incubating and mixed-culturing practices within the rice-fish system.

Intended and unintended environmental consequences of grassland rental in pastoral China.

Among herders, market-oriented grassland rental has been prevalent in China following the implementation of the Household Contracted Responsibility System, which allocated formerly collectively-owned use rights to individual herders. However, empirical evidence on the effect of grassland rental on herder households' overgrazing behaviour is scant, despite the fact that it is one of the main determinants of the severe grassland degradation in China. This study thus investigates the effects of grassland rental on both household- and plot-level grazing intensity and overgrazing based on a survey of 876 plots and 516 households in the Inner Mongolia, Qinghai, and Gansu provinces in China. An instrumental variable approach is utilised to correct the endogeneity bias of herders' decision to rent in grassland. The household-level empirical results show that each 1000-mu increment of rent-in grassland leads to an intended 42% decrease in the overall grazing intensity and a 61% decrease in the overgrazing index. However, a plot-level analysis pooling both rent-in and self-owned grassland plots reveals the unintended consequence that herders are over-exploiting rent-in grassland plots; as a result, the grazing intensity on rent-in grassland is 2.03 times that on owned grassland. Therefore, grassland rental should be encouraged, but the monitoring system should pay more attention to the overgrazing of rental grassland.