Cardiorespiratory fitness attenuates the association between fatness and cardiometabolic risk in Chinese children.

Background: Childhood obesity tends to persist into adulthood, predisposing individuals to cardiometabolic risk (CMR). This study aims to investigate the mediating role of cardiorespiratory fitness (CRF) in the associations between multiple fatness indicators and individual CMR markers and clustered CMR-score, and explore sex differences. Methods: We recruited 1,557 children (age: 8 to 10, male/female: 52.7%/47.3%) in September 2022 in Ningbo, China. Physical examinations, overnight fasting blood test, and CRF was evaluated. The CMR-score was calculated by summing age- and sex-specific z scores of four CMR markers, including mean arterial blood pressure, triglycerides, the total cholesterol to high-density lipoprotein cholesterol ratio, and homeostatic model assessment for insulin resistance. Generalized linear mixed models were used to identify the associations, mediation analyses were performed to dissect the function of CRF. Results: Partial correlation analyses revealed positive associations between high fatness indicators (including body mass index [BMI], BMI z score, body fat mass index [BFMI] and waist-to-height ratio [WHtR]) and increased CMR markers, whereas high CRF was associated with decreased CMR markers (all P < 0.05). In the mediation analyses, CRF emerged as a partial mediator, attenuating the relationship between four fatness indicators and CMR-score. Specifically, CRF mediated 6.5%, 7.7%, 5.3%, and 12.5% of the association between BMI, BMI z score, BFMI, WHtR and CMR-score (all P < 0.001). And the mediating effects of CRF between WHtR and four individual CMR markers was particularly robust, ranging from 10.4% to 21.1% (all P < 0.05). What's more, CRF mediates the associations between WHtR and CMR-score more pronounced in girls than boys with a mediation effect size of 17.3% (P < 0.001). Conclusion: In Chinese children, CRF partially mitigates the adverse effects of fatness on CMR, underscoring the significance of enhancing CRF in children.

The genetic status and rescue measure for a geographically isolated population of Amur tigers.

The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population's genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.

Full counting statistics, fluctuation relations, and linear response properties in a one-dimensional Kitaev chain.

We analytically calculate the cumulant generating function of energy and particle transport in an open one-dimensional Kitaev chain at finite temperature by utilizing the Keldysh technique. The joint distribution of particle and energy currents satisfies different fluctuation relations in different regions of the parameter space as a result of U(1) symmetry breaking and energy conservation. Furthermore, we investigate the linear response behavior of the Kitaev chain within the framework of three-terminal systems, deriving the expressions for the Seebeck coefficient and thermal conductance. Notably, we observe a pronounced peak in the thermal conductance near the phase transition point, in agreement with previous predictions. Additionally, we prove that the peak value saturates at half of the thermal conductance quantum for finite-length chains at the zero temperature limit.

Impacts of top predators and humans on the mammal communities of recovering temperate forest regions.

Top predators are important drivers in shaping ecological community structure via top-down effects. However, the ecological consequences and mechanisms of top predator loss under accelerated human impacts have rarely been quantitatively assessed due to the limited availability of long-term community data. With increases in top predator populations in northern China over the past two decades, forests with varying densities of top predators and humans provide an opportunity to study their ecological effects on mammal communities. We hypothesized a priori of conceptual models and tested these using structural equation models (SEMs) with multi-year camera trap data, aiming to reveal the underlying independent ecological effects of top predators (tigers, bears, and leopards) and humans on mammal communities. We used random forest models and correlations among species pairs to validate results. We found that top predator reduction could be related to augmented populations of large ungulates ("large ungulate release") and mesopredators ("mesopredator release"), consistent with observations of mammal communities in other ecosystems. Additionally, top predator reduction could be related to reduced small mammal abundance. Hierarchical SEMs identified three bottom-up pathways from forest quality to human activities, large ungulates, and some small mammals, and five top-down pathways from human activities and top predators to some small mammals, large ungulates, and mesopredators. Furthermore, our results suggest that humans showed predominant top-down effects on multiple functional groups, partially replacing the role of top predators, rather than be mediated by them; effects of humans and top predators appeared largely independent. Effects of humans on top predators were non-significant. This study provides novel insights into the effects of top predators and humans as super-predators on mammal communities in forest ecosystems and presents cues of bottom-up effects that can be translated into actionable management plans for improving forest quality, thereby supporting top predator recovery and work/life activities of local people.

Full counting statistics and fluctuation theorem for the currents in the discrete model of Feynman's ratchet.

We provide a detailed investigation of the fluctuations of the currents in the discrete model of Feynman's ratchet proposed by Jarzynski and Mazonka in 1999. Two macroscopic currents are identified, with the corresponding affinities determined using Schnakenberg's graph analysis. We also investigate full counting statistics of the two currents and show that fluctuation theorem holds for their joint probability distribution. Moreover, fluctuation-dissipation relation, Onsager reciprocal relation and their nonlinear generalizations are numerically shown to be satisfied in this model.

Unambiguously Testing Positivity at Lepton Colliders.

The diphoton channel at lepton colliders, e^{+}e^{-}(µ^{+}µ^{-})→γγ, has a remarkable feature that the leading new physics contribution comes only from dimension-eight operators. This contribution is subject to a set of positivity bounds, derived from the fundamental principles of quantum field theory, such as unitarity, locality, analyticity and Lorentz invariance. These positivity bounds are thus applicable to the most direct observable: the diphoton cross section. This unique feature provides a clear, robust, and unambiguous test of these principles. We estimate the capability of various future lepton colliders in probing the dimension-eight operators and testing the positivity bounds in this channel. We show that positivity bounds can lift certain flat directions among the effective operators and significantly change the perspectives of a global analysis. We also discuss the positivity bounds of the Zγ/ZZ processes which are related to the γγ ones, but are more complicated due to the massive Z boson.

Historical records reveal the distinctive associations of human disturbance and extreme climate change with local extinction of mammals.

Accelerated anthropogenic impacts and climatic changes are widely considered to be responsible for unprecedented species extinction. However, determining their effects on extinction is challenging owing to the lack of long-term data with high spatial and temporal resolution. In this study, using historical occurrence records of 11 medium- to large-sized mammal species or groups of species in China from 905 BC to AD 2006, we quantified the distinctive associations of anthropogenic stressors (represented by cropland coverage and human population density) and climatic stressors (represented by air temperature) with the local extinction of these mammals. We found that both intensified human disturbances and extreme climate change were associated with the increased local extinction of the study mammals. In the cold phase (the premodern period of China), climate cooling was positively associated with increased local extinction, while in the warm phase (the modern period) global warming was associated with increased local extinction. Interactive effects between human disturbance and temperature change with the local extinction of elephants, rhinos, pandas, and water deer were found. Large-sized mammals, such as elephants, rhinos, and pandas, showed earlier and larger population declines than small-sized ones. The local extinction sensitivities of these mammals to the human population density and standardized temperature were estimated during 1700 to 2000. The quantitative evidence for anthropogenic and climatic associations with mammalian extinction provided insights into the driving processes of species extinction, which has important implications for biodiversity conservation under accelerating global changes.

Microreversibility, fluctuations, and nonlinear transport in transistors.

We present a stochastic approach for charge transport in transistors. In this approach, the electron and hole densities are governed by diffusion-reaction stochastic differential equations satisfying local detailed balance and the electric field is determined with the Poisson equation. The approach is consistent with the laws of electricity, thermodynamics, and microreversibility. In this way, the signal amplifying effect of transistors is verified under their working conditions. We also perform the full counting statistics of the two electric currents coupled together in transistors and we show that the fluctuation theorem holds for their joint probability distribution. Similar results are obtained including the displacement currents. In addition, the Onsager reciprocal relations and their generalizations to nonlinear transport properties deduced from the fluctuation theorem are numerically shown to be satisfied.

Stochastic approach and fluctuation theorem for charge transport in diodes.

A stochastic approach for charge transport in diodes is developed in consistency with the laws of electricity, thermodynamics, and microreversibility. In this approach, the electron and hole densities are ruled by diffusion-reaction stochastic partial differential equations and the electric field generated by the charges is determined with the Poisson equation. These equations are discretized in space for the numerical simulations of the mean density profiles, the mean electric potential, and the current-voltage characteristics. Moreover, the full counting statistics of the carrier current and the measured total current including the contribution of the displacement current are investigated. On the basis of local detailed balance, the fluctuation theorem is shown to hold for both currents.

A comparison of food habits and prey preferences of Amur tiger (Panthera tigris altaica) at the southwest Primorskii Krai in Russia and Hunchun in China.

A small, isolated Amur tiger population ranges across the southwest Primorskii Krai region in Russia and Hunchun region in China. Many individuals, with "dual nationality," cross the border frequently. Formulating effective conservation strategies requires a clear understanding of tiger food requirements in both countries. While the diets of tigers ranging in Russia is clearly understood, little is known of the tigers' feeding habits in China.. We used scat analysis combined with data on the abundance of 4 prey species to examine Amur tiger diet and prey preferences in Hunchun. We examined 53 tiger scat samples from 2011 to 2016 and found that tigers preyed on 12 species (11 species in winter), 4 of which were domestic animals with 33.58% biomass contribution; this was the first record of Amur tigers eating lynx in this area. Tigers showed a strong preference for wild boar (Jacobs index: +0.849), which were also the most frequently consumed prey, and a strong avoidance of roe deer (Jacobs index: -0.693). On the Russian side, domestic animals (just dog) were rarely found in tiger scat, and tigers did not show strong avoidance of roe deer, but of sika deer. We also found red deer footprints during winter surveys and that tigers ate red deer on the Chinese side, while there was no record of red deer feeding on the Russian side. Reducing or eliminating human disturbance, such as grazing, is essential to recovering tiger prey and habitat in this area and the Sino-Russian joint ungulate annual survey is indispensable for prey estimates of this small, isolated Amur tiger population.

A comparison of reproductive parameters of female Amur tigers (Panthera tigris altaica) in the wild and captivity.

A healthy population of captive Amur tigers might assist recovery of the wild population in Northeast China if individuals were properly prepared and considered suitable for release in the wild. We analyzed the breeding records of 68 female Amur tigers from 1995 to 2010 in the Hengdaohezi Felid Breeding Center of China and compared the reproductive parameters of this population to wild female Amur tigers. We found that the reproductive parameters of the captive population (the age of first parturition, length of gestation and litter survival rate) were not significantly different from those of wild Amur tigers. Differences in birth date and litter size between wild and captive populations may be caused by management protocols for the captive population or insufficient field data from the wild population. Reproductive parameters of females giving birth after losing a litter were similar to parameters of females that did not lose a litter, except for birth date. These results provide no indication of major problems in using captive females for a breeding program for release of cubs into the wild, but additional information is still needed to assess their suitability.

New hope for the survival of the Amur leopard in China.

Natural range loss limits the population growth of Asian big cats and may determine their survival. Over the past decade, we collected occurrence data of the critically endangered Amur leopard worldwide and developed a distribution model of the leopard's historical range in northeastern China over the past decade. We were interested to explore how much current range area exists, learn what factors limit their spatial distribution, determine the population size and estimate the extent of potential habitat. Our results identify 48,252 km(2) of current range and 21,173.7 km(2) of suitable habitat patches and these patches may support 195.1 individuals. We found that prey presence drives leopard distribution, that leopard density exhibits a negative response to tiger occurrence and that the largest habitat patch connects with 5,200 km(2)of Russian current range. These insights provide a deeper understanding of the means by which endangered predators might be saved and survival prospects for the Amur leopard not only in China, but also through imperative conservation cooperation internationally.

CEP biomarkers as potential tools for monitoring therapeutics.

BACKGROUND: Carboxyethylpyrrole (CEP) adducts are oxidative modifications derived from docosahexaenoate-containing lipids that are elevated in ocular tissues and plasma in age-related macular degeneration (AMD) and in rodents exposed to intense light. The goal of this study was to determine whether light-induced CEP adducts and autoantibodies are modulated by pretreatment with AL-8309A under conditions that prevent photo-oxidative damage of rat retina. AL-8309A is a serotonin 5-HT1A receptor agonist. METHODS: Albino rats were dark adapted prior to blue light exposure. Control rats were maintained in normal cyclic light. Rats were injected subcutaneously 3x with 10 mg/kg AL-8309A (2 days, 1 day and 0 hours) before light exposure for 6 h (3.1 mW/cm(2), λ=450 nm). Animals were sacrificed immediately following light exposure and eyes, retinas and plasma were collected. CEP adducts and autoantibodies were quantified by Western analysis or ELISA. RESULTS: ANOVA supported significant differences in mean amounts of CEP adducts and autoantibodies among the light + vehicle, light + drug and dark control groups from both retina and plasma. Light-induced CEP adducts in retina were reduced ~20% following pretreatment with AL-8309A (n = 62 rats, p = 0.006) and retinal CEP immunoreactivity was less intense by immunohistochemistry. Plasma levels of light-induced CEP adducts were reduced at least 30% (n = 15 rats, p = 0.004) by drug pretreatment. Following drug treatment, average CEP autoantibody titer in light exposed rats (n = 22) was unchanged from dark control levels, and ~20% (p = 0.046) lower than in vehicle-treated rats. CONCLUSIONS: Light-induced CEP adducts in rat retina and plasma were significantly decreased by pretreatment with AL-8309A. These results are consistent with and extend previous studies showing AL-8309A reduces light-induced retinal lesions in rats and support CEP biomarkers as possible tools for monitoring the efficacy of select therapeutics.

Proteomic and genomic biomarkers for age-related macular degeneration.

Toward early detection of susceptibility to age-related macular degeneration (AMD), we quantified plasma carboxyethylpyrrole (CEP) oxidative protein modifications and CEP autoantibodies by ELISA in 916 AMD and 488 control donors. Mean CEP adduct and autoantibody levels were elevated in AMD plasma by ∼60 and ∼30%, respectively, and the odds ratio for both CEP markers elevated was ∼3-fold greater in AMD than in control patients. Genotyping was performed for AMD risk polymorphisms associated with age-related maculopathy susceptibility 2 (ARMS2), high-temperature requirement factor A1 (HTRA1), complement factor H (CFH), and complement C3. The AMD risk predicted for those exhibiting elevated CEP markers and risk genotypes was 2- to 3-fold greater than the risk based on genotype alone. AMD donors carrying the ARMS2 and HTRA1 risk alleles were the most likely to exhibit elevated CEP markers. Receiver operating characteristic curves suggest that CEP markers alone can discriminate between AMD and control plasma donors with ∼76% accuracy and in combination with genomic markers, provide up to ∼80% discrimination accuracy. CEP plasma biomarkers, particularly in combination with genomic markers, offer a potential early warning system for predicting susceptibility to this blinding disease.

Plasma protein pentosidine and carboxymethyllysine, biomarkers for age-related macular degeneration.

Age-related macular degeneration (AMD) causes severe vision loss in the elderly; early identification of AMD risk could help slow or prevent disease progression. Toward the discovery of AMD biomarkers, we quantified plasma protein N(epsilon)-carboxymethyllysine (CML) and pentosidine from 58 AMD and 32 control donors. CML and pentosidine are advanced glycation end products that are abundant in Bruch membrane, the extracellular matrix separating the retinal pigment epithelium from the blood-bearing choriocapillaris. We measured CML and pentosidine by LC-MS/MS and LC-fluorometry, respectively, and found higher mean levels of CML (approximately 54%) and pentosidine (approximately 64%) in AMD (p < 0.0001) relative to normal controls. Plasma protein fructosyl-lysine, a marker of early glycation, was found by amino acid analysis to be in equal amounts in control and non-diabetic AMD donors, supporting an association between AMD and increased levels of CML and pentosidine independent of other diseases like diabetes. Carboxyethylpyrrole (CEP), an oxidative modification from docosahexaenoate-containing lipids and also abundant in AMD Bruch membrane, was elevated approximately 86% in the AMD cohort, but autoantibody titers to CEP, CML, and pentosidine were not significantly increased. Compellingly higher mean levels of CML and pentosidine were present in AMD plasma protein over a broad age range. Receiver operating curves indicate that CML, CEP adducts, and pentosidine alone discriminated between AMD and control subjects with 78, 79, and 88% accuracy, respectively, whereas CML in combination with pentosidine provided approximately 89% accuracy, and CEP plus pentosidine provided approximately 92% accuracy. Pentosidine levels appeared slightly altered in AMD patients with hypertension and cardiovascular disease, indicating further studies are warranted. Overall this study supports the potential utility of plasma protein CML and pentosidine as biomarkers for assessing AMD risk and susceptibility, particularly in combination with CEP adducts and with concurrent analyses of fructosyl-lysine to detect confounding factors.

Assessing susceptibility to age-related macular degeneration with proteomic and genomic biomarkers.

Age-related macular degeneration (AMD) is a progressive disease and major cause of severe visual loss. Toward the discovery of tools for early identification of AMD susceptibility, we evaluated the combined predictive capability of proteomic and genomic AMD biomarkers. We quantified plasma carboxyethylpyrrole (CEP) oxidative protein modifications and CEP autoantibodies by ELISA in 916 AMD and 488 control donors. CEP adducts are uniquely generated from oxidation of docosahexaenoate-containing lipids that are abundant in the retina. Mean CEP adduct and autoantibody levels were found to be elevated in AMD plasma by approximately 60 and approximately 30%, respectively. The odds ratio for both CEP markers elevated was 3-fold greater or more in AMD than in control patients. Genotyping was performed for AMD risk polymorphisms associated with age-related maculopathy susceptibility 2 (ARMS2), high temperature requirement factor A1 (HTRA1), complement factor H, and complement C3, and the risk of AMD was predicted based on genotype alone or in combination with the CEP markers. The AMD risk predicted for those exhibiting elevated CEP markers and risk genotypes was 2-3-fold greater than the risk based on genotype alone. AMD donors carrying the ARMS2 and HTRA1 risk alleles were the most likely to exhibit elevated CEP markers. The results compellingly demonstrate higher mean CEP marker levels in AMD plasma over a broad age range. Receiver operating characteristic curves suggest that CEP markers alone can discriminate between AMD and control plasma donors with approximately 76% accuracy and in combination with genomic markers provide up to approximately 80% discrimination accuracy. Plasma CEP marker levels were altered slightly by several demographic and health factors that warrant further study. We conclude that CEP plasma biomarkers, particularly in combination with genomic markers, offer a potential early warning system for assessing susceptibility to this blinding, multifactorial disease.