The impact of environmental regulation and economic expectations on crop-livestock integration among hog farmers: a field study from China.

Decoupling of crop-livestock systems increases the risks of pollution, waste of nutrient resources, and biodiversity loss. Crop-livestock integration (CLI) is an effective solution to these problems, and motivating farmers to adopt CLI is the key. Many countries have implemented environmental regulations (ER) aiming to influence farmers' CLI adoption decisions. Based on a field study of 316 hog farmers from Shaanxi Province of China, this paper applies the triple-hurdle model to empirically examine the impacts of economic expectations (EE) and ER on CLI adoption decisions. It also verifies the income effect of CLI. The results are as follows: 90.5% of farmers are willing to adopt CLI, but the adoption rate is only 40.8% and the average integration degree is only 0.236; CLI not been widely popularized. EE and ER promote farmers' CLI adoption significantly, while the impact of interaction between EE and ER on CLI adoption differs. IER weakens the positive impact of EE on farmers' CLI integration degree, which has a "crowding out effect." GER negatively moderates the impact of EE on farmers' adoption willingness of CLI. CER strengthens the positive effect of EE on farmers' adoption behavior and CLI integration degree. CLI increases the farmers' income. These results contribute to our understanding of the mechanisms of CLI adoption decisions and sustainable policy optimization for green agricultural development.

Leaf hydraulics coordinated with leaf economics and leaf size in mangrove species along a salinity gradient.

Independence among leaf economics, leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments. However, it remains unclear whether the independence of the leaf traits revealed across species still holds within species, especially under stressed conditions. Here, a suite of traits in these dimensions were measured in leaves and roots of a typical mangrove species, Ceriops tagal, which grows in habitats with a similar sunny and hot environment but different soil salinity in southern China. Compared with C. tagal under low soil salinity, C. tagal under high soil salinity had lower photosynthetic capacity, as indicated directly by a lower leaf nitrogen concentration and higher water use efficiency, and indirectly by a higher investment in defense function and thinner palisade tissue; had lower water transport capacity, as evidenced by thinner leaf minor veins and thinner root vessels; and also had much smaller single leaf area. Leaf economics, hydraulics and leaf size of the mangrove species appear to be coordinated as one trait dimension, which likely stemmed from co-variation of soil water and nutrient availability along the salinity gradient. The intraspecific leaf trait relationship under a stressful environment is insightful for our understanding of plant adaption to the multifarious environments.

Regional disparities and influencing factors of high quality medical resources distribution in China.

BACKGROUND: With the gradual increase of residents' income and the continuous improvement of medical security system, people's demand for pursuing higher quality and better medical and health services has been released. However, so far little research has been published on China's high quality medical resources (HQMR). This study aims to understand the spatiotemporal variation trend of HQMR from 2006 to 2020, analyze regional disparity of HQMR in 2020, and further explore the main factors influencing the distribution of HQMR in China. METHODS: The study selected Class III level A hospitals (the highest level medical institutions in China) to represent HQMR. Descriptive statistical methods were used to address the changes in the distribution of HQMR from 2006 to 2020. Lorentz curve, Gini coefficient (G), Theil index (T) and High-quality health resource density index (HHRDI) were used to calculate the degree of inequity. The geographical detector method was used to reveal the key factors influencing the distribution of HQMR. RESULTS: The total amount of HQMR in China had increased year by year, from 647 Class III level A hospitals in 2006 to 1580 in 2020. In 2020, G for HQMR by population was 0.166, while by geographic area was 0.614. T was consistent with the results for G, and intra-regional contribution rates were higher than inter-regional contribution rates. HHRDI showed that Beijing, Shanghai, and Tianjin had the highest allocated amounts of HQMR. The results of the geographical detector showed that total health costs, government health expenditure, size of resident populations, GDP, number of medical colleges had a significant impact on the spatial distribution of HQMR and the q values were 0.813, 0.781, 0.719, 0.661, 0.492 respectively. There was an interaction between the influencing factors. CONCLUSIONS: China's total HQMR is growing rapidly but is relatively inadequate. The distribution of HQMR by population is better than by geography, and the distribution by geography is less equitable. Population size and geographical area both need to be taken into account when formulating policies, rather than simply increasing the number of HQMR.

Territory aggression and energy budget in food-restricted striped hamsters.

Food resource availability is one of the most important factors affecting interindividual competition in a variety of animal species. However, the energy budget and territory aggression strategy of small mammals during periods of food restriction remain uncertain. In this study, metabolic rate, body temperature, territory aggression behavior, and fat deposit were measured in male striped hamster (Cricetulus barabensis) restricted by 20% of ad libitum food intake with or without supplementary methimazole. Serum thyroid hormone (tri-iodothyronine, T3 and thyroxine, T4), and cytochrome c oxidase (COX) activity in liver, brown adipose tissue, and skeletal muscle, were also measured. Attack latency, total attack times and duration, and the interval duration between attacks of resident hamsters were not significantly changed during food restriction, which was not significantly affected by supplementary methimazole. Metabolic rate and body temperature was significantly increased in food-restricted hamsters following introduction of an intruder, which was not completely blocked by supplementary methimazole. Serum T3 and T4 levels and BAT COX activity were not significantly changed following aggression, and were significantly decreased by supplementary methimazole. These findings suggest that striped hamsters increase energy expenditure for territory aggression during food restriction, and consequently lead to excessive energy depletion. Territory aggression behavior may decrease the capacity to cope with food shortage, which may be independent of thyroid hormone.

Sustainable Strategies for the Agricultural Development of Shaanxi Province Based on the Risk Assessment of Heavy Metal Pollution.

Heavy metal elements in farmland soil can be absorbed by crops and endanger food security. To assess the risk of heavy metal elements in farmland soil to crops in Shaanxi Province, we collected 693 soil samples and analyzed the concentrations of nine heavy metals (As, Hg, Pb, Cd, Cr, Mn, Cu, Zn, and Ni). According to the National Standard (GB 15619-2018) of the People's Republic of China, the proportions of soil sample points in which the concentration of heavy metals was higher than the risk screening value were 2.02% (Cd), 0.29% (Cr), 0.29% (Zn), 2.31% (Cu), 1.15% (Ni), and 0.14% (Pb). The proportions of areas in which the concentration of heavy metal was higher than the background value were as follows, from largest to smallest: Zn (53.20%) > Mn (49.86%) > Cd (29.51%) > Hg (26.77%) > As (26.58%) > Ni (14.95%) > Cu (13.90%) > Pb (6.49%) > Cr (1.40%). The assessment of the risk of heavy metal exposure (geo-accumulation index (Igeo), pollution load index (PLI), and potential ecological risk index (RI)) determined that Hg was the most concerning heavy metal in the farmland soil of Shaanxi Province. Moreover, 11.56% of these areas had Hg contamination, and they were mainly distributed in the western Guanzhong region. The farmland soil in the Guanzhong region was the most contaminated, followed by the southern Shaanxi region and then the northern Shaanxi region. The main sources of heavy metal contamination causing large-scale farmland soil pollution are agricultural production activities, transportation, and air pollution caused by coal combustion in Shaanxi Province. Therefore, sustainable strategies for the prevention and control of heavy metal pollution and agricultural development must be applied in different regions. Heavy metal pollution should be managed, and relevant policies should be created and enforced, such as the standardization of the use of qualified pesticides and fertilizers, improved treatment of livestock and poultry manure, development of the clean energy industry structure, and promotion of renewable energy vehicles. In terms of the high-quality development of agriculture, developing modern and local agriculture in different regions should be based on local geographical, climatic, and economic conditions.

Cost-Effectiveness Analysis of Pan-Genotypic Sofosbuvir-Based Regimens for Treatment of Chronic Hepatitis C Genotype 1 Infection in China.

Background: Hepatitis C virus (HCV) genotype 1 is the most prevalent HCV infection in China. Sofosbuvir-based direct antiviral agent (DAA) regimens are the current mainstays of treatment. Sofosbuvir/velpatasvir (SOF/VEL) and sofosbuvir/ledipasvir (SOF/LDV) regimens became reimbursable in China in 2020. Thus, this study aimed to identify the optimal SOF-based regimen and to inform efficient use of healthcare resources by optimizing DAA use in treating HCV genotype 1. Methods and Models: A modeling-based cost-utility analysis was conducted from the payer's perspective targeting adult Chinese patients with chronic HCV genotype 1 infection. Direct medical costs and health utilities were inputted into a Markov model to simulate lifetime experiences of chronically infected HCV patients after receiving SOF/LDV, SOF/VEL or the traditional strategy of pegylated interferon (pegIFN) + ribavirin (RBV). Discounted lifetime cost and quality adjusted life years (QALYs) were computed and compared to generate the incremental cost utility ratio (ICUR). An ICUR below the threshold of 31,500 $/QALY suggests cost-effectiveness. Deterministic and probabilistic sensitivity analyses were performed to examine the robustness of model findings. Results: Both SOF/LDV and SOF/VEL regimens were dominant to the pegIFN + RBV regimen by creating more QALYs and incurring less cost. SOF/LDV produced 0.542 more QALYs but cost $10,390 less than pegIFN + RBV. Relative to SOF/LDV, SOF/VEL had an ICUR of 168,239 $/QALY which did not meet the cost-effectiveness standard. Therefore SOF/LDV was the optimal strategy. These findings were robust to linear and random variations of model parameters. However, reducing the SOF/VEL price by 40% would make this regimen the most cost-effective option. Conclusions: SOF/LDV was found to be the most cost-effective treatment, and SOF/VEL was also economically dominant to pegIFN + RBV. These findings indicated that replacing pegIFN + RBV with DAA regimens could be a promising strategy.

Determination of vancomycin exposure target and individualised dosing recommendations for neonates: model-informed precision dosing.

INTRODUCTION: Few studies incorporating population pharmacokinetic/pharmacodynamic (Pop-PK/PD) modelling have been conducted to quantify the exposure target of vancomycin in neonates. A retrospective observational cohort study was undertaken in neonates to determine this target and dosing recommendations (chictr.org.cn, ChiCTR1900027919). METHODS: A Pop-PK model was developed to estimate PK parameters. Causalities between acute kidney injury (AKI) occurrence and vancomycin use were verified using Naranjo criteria. Thresholds of vancomycin exposure in predicting AKI or efficacy were identified via classification and regression tree analysis. Associations between exposure thresholds and clinical outcomes, including AKI and efficacy, were analysed by logistic regression. Dosing recommendations were designed using Monte Carlo simulations based on the optimised exposure target. RESULTS: Pop-PK modelling included 182 neonates with 411 observations. On covariate analysis, neonatal physiological maturation, renal function and concomitant use of vasoactive agents (VAS) significantly affected vancomycin PK. Seven cases of vancomycin-induced AKI were detected. Area under the concentration-time curve from 0-24 hours (AUC0-24) ≥ 485 mg•h/L was an independent risk factor for AKI after adjusting for VAS co-administration. The clinical efficacy of vancomycin was analysed in 42 patients with blood culture-proven staphylococcal sepsis. AUC0-24 to minimum inhibitory concentration (AUC0-24/MIC) ≥ 234 was the only significant predictor of clinical effectiveness. Monte Carlo simulations indicated that regimens in Neonatal Formulary 7 and Red Book (2018) were unsuitable for all neonates. CONCLUSION: An AUC0-24 of 240-480 (assuming MIC = 1 mg/L) is a recommended exposure target of vancomycin in neonates. Model-informed dosing regimens are valuable in clinical practice.

Hospitalization costs among immobile patients with hemorrhagic or ischemic stroke in China: a multicenter cross-sectional study.

BACKGROUND: In this study, we aimed to analyze the hospitalization costs for immobile patients with hemorrhagic stroke (IHS) or ischemic stroke (IIS) in China and to determine the factors associated with hospitalization costs. METHODS: We evaluated patients with IHS and IIS hospitalized between November 2015 and July 2016 in six provinces or municipality cities of China. Linear regression analysis was used to examine the association with hospitalization costs and predictors. RESULTS: In total, 1573 patients with IHS and 3143 with IIS were enrolled and analyzed. For IHS and IIS, the average length of stay (LoS) was 17.40 ± 12.3 and 14.47 ± 11.55 days. The duration of immobility was 12.11 ± 9.98 and 7.36 ± 9.77 days, respectively. Median hospitalization costs were RMB 47000.68 (interquartile range 19,827.37, 91,877.09) for IHS and RMB 16578.44 (IQR 7020.13, 36,357.65) for IIS. In both IHS and IIS groups, medicine fees accounted for more than one-third of hospitalization costs. Materials fees and medical service fees accounted for the second and third largest proportions of hospital charges in both groups. Linear regression analysis showed that LoS, hospital level, and previous surgery were key determinants of hospitalization costs in all immobile patients with stroke. Subgroup analysis indicated that hospital level was highly correlated with hospitalization costs for IHS whereas pneumonia and deep vein thrombosis were key factors associated with hospitalization costs for IIS. CONCLUSIONS: We found that hospitalization costs were notably higher in IHS than IIS, and medicine fees accounted for the largest proportion of hospitalization costs in both patient groups, perhaps because most patients ended up with complications such as pneumonia thereby requiring more medications. LoS and hospital level may greatly affect hospitalization costs. Increasing the reimbursement ratio of medical insurance for patients with IHS is recommended. Decreasing medicine fees and LoS, preventing complications, and improving treatment capability may help to reduce the economic burden of stroke in China.

The energy budget and fat accumulation in striped hamsters (Cricetulus barabensis) during post-lactation.

Adaptive adjustments of energy intake and body fat play an important role in allowing animals' to meet the energy demands of thermoregulation during cold conditions and reproduction. Body fat is usually metabolized during lactation, which is one of the most energetically demanding activities of female mammals, however the effect of this on the energy budget and body fat regulation after lactation remains unclear. We compared the energy intake and body fat of female striped hamsters (Cricetulus barabensis) fed either a high-fat or low-fat diet for 21 days after the end of lactation (post-lactation, PL) to those of virgin controls. Serum leptin levels and the expression of hypothalamic orexigenic and anorexigenic neuropeptide genes were also measured and compared. Although lactating females consumed significantly more food, they had significantly lower body fat than virgin controls. The energy intake and body fat levels of the PL females were, however, significantly higher than those of virgin females. This was particularly true for the PL females that were fed high-fat diet. These females had significantly higher serum leptin concentrations, but lower hypothalamic leptin receptor gene expression, than virgin females. Neither orexigenic nor anorexigenic neuropeptide levels in the hypothalamus differed significantly between the PL and virgin females. This suggests that a negative energy balance during lactation drives fat accumulation after lactation. Furthermore, leptin resistance may occur after the end of lactation, causing females to consume more food, and accumulate more fat, than virgin females.

Socioeconomic inequality in the global burden of refraction disorders: results from the Global Burden of Diseases Study 2017.

PURPOSE: To explore socioeconomic inequality in global burden of refraction disorders using disability-adjusted life years (DALYs). METHODS: World Bank categorical and national DALY numbers, crude rates and age-standardized rates caused by refraction disorders between 1990 and 2017 were obtained. Gini coefficient and concentration index were computed to assess trends in global health inequality in refraction disorders burden. RESULTS: Lower middle-income countries had the highest burden of refraction disorders and greatest decline in age-standardized DALY rates of 15.9% (171.0 in 1990; 143.8 in 2017), followed by upper middle-income countries, with a 9.7% decline (103.7 in 1990; 93.7 in 2017). High-income countries had the lowest age-standardized DALY rates (70.4 in 1990; 65.7 in 2017), while low-income countries had the lowest DALY numbers. Between-country inequality decreased, with Gini coefficient declining from 0.203 in 1990 to 0.184 in 2017. Socioeconomic-associated inequality also decreased, with concentration index changing from -0.060 in 1990 to -0.041 in 2017. Small peaks of DALY numbers and crude rates occurred in the age group of 5-9 years in countries with different income levels. An earlier occurrence of high peaks of DALY estimates in older adults had been observed in countries with lower income. CONCLUSION: Middle-income countries are more burdened with refraction disorders but have achieved great progress in the last few decades. The global health improvement in refraction disorders has been accompanied by narrowing inequality. Older adults in lower income countries tend to suffer from refraction disorders at an earlier age, compared with older adults in higher income countries.

Socio-economic disparity in global burden of near vision loss: an analysis for 2017 with time trends since 1990.

PURPOSE: To investigate the socio-economic disparity in global burden of near vision loss by disability-adjusted life-years (DALYs). METHODS: The DALY numbers of country income groups by World Bank classification and the national age-standardized DALY rates caused by near vision loss were obtained from Global Burden of Disease Study 2017. Human development index (HDI) was collected from the Human Development Report. The association between age-standardized DALY rates and HDI was analysed. Additionally, the concentration index (CI) and the relative index of inequality (RII) were employed to assess the trends of socio-economic disparity in the global burden of near vision loss from 1990 to 2017. RESULTS: The global burden of near vision loss increased from 5.3 million DALYs in 1990 to 9.8 million DALYs in 2017, corresponding to an increase of 82.4%. The highest rate of increase for 1990-2017 occurred in low-income country group (97.7%). Age-standardized DALY rates were inversely correlated with HDI (Standardized ß = -0.679, P < 0.001). Lower HDI countries displayed higher age-standardized DALY rates caused by near vision loss. From 1990 to 2017, CI declined from -0.233 to -0.209, and RII increased from 0.149 to 0.247. CONCLUSION: The total global burden of near vision loss increased greatly in the past few decades, with low-income countries showing the highest growth. The age-standardized burden was higher in countries with lower socio-economic status. Although a declining trend of socio-economic inequalities was observed, the persistence of disparities still highlights the need to provide more eye care services for developing countries.

Assessing the Risk for Development of Deep Vein Thrombosis among Chinese Patients using the 2010 Caprini Risk Assessment Model: A Prospective Multicenter Study.

AIM: We sought to validate the 2010 Caprini risk assessment model (RAM) in risk stratification for deep vein thrombosis (DVT) prophylaxis among Chinese bedridden patients. METHODS: We performed a prospective study in 25 hospitals in China over 9 months. Patients were risk-stratified using the 2010 Caprini RAM. RESULTS: We included a total 24,524 patients. Fresh DVT was found in 221 patients, with overall incidence of DVT 0.9%. We found a correlation of DVT incidence with Caprini score according to risk stratification (χ2 =196.308, P＜0.001). Patients in the low-risk and moderate-risk groups had DVT incidence ＜0.5%. More than half of patients with DVT were in the highest risk group. Compared with the low-risk group, risk was 2.10-fold greater in the moderate-risk group, 3.34-fold greater in the high-risk group, and 16.12-fold greater in the highest-risk group with Caprini scores ≥ 9. The area under the receiver operating characteristic curve was 0.74 (95% confidence interval, 0.71-0.78; P＜0.01) for all patients. A Caprini score of ≥ 5 points was considered the criterion of a reliably increased risk of DVT in surgical patients with standard thromboprophylaxis. Predicting DVT using a cumulative risk score ≥ 4 is recommended for nonsurgical patients. CONCLUSIONS: Our study suggested that the 2010 Caprini RAM can be effectively used to stratify hospitalized Chinese patients into DVT risk categories, based on individual risk factors. Classification of the highest risk levels using a cumulative risk score ≥ 4 and ≥ 5 provides significantly greater clinical information in nonsurgical and surgical patients, respectively.

Environmental taxation and regional inequality in China.

In order to combat environmental pollution, China enacted the Environmental Protection Tax Law in early 2018. Yet the impacts of the environmental tax on individual regions with different socioeconomic statuses, which are crucial for social justice and public acceptance, remain unclear. Based on a Multi-Regional Input-Output (MRIO) table and a nationally regulated tax payment calculation method, this study analyzes the distributional impacts of an environmental tax based upon province's consumption from both inter-provincial and rural-urban aspects. The national tax revenue based on the current levy mechanism is estimated to be only one seventh of the economic loss from premature mortality caused by ambient particulate matter (PM2.5). The taxation may slightly alleviate urban-rural inequality but may not be helpful with reducing inter-provincial inequality. We further analyze two alternative levy mechanisms. If each province imposes taxes to products it consumes (rather than produces, as in the current mechanism), with the tax rate linearly dependent on its per capita consumption expenditure, this would moderately increase the national tax revenue and significantly reduce inter-provincial inequality. To better compensate for the economic costs of air pollution and reduce regional inequality, it would be beneficial to increase the tax rate nationwide and implement a levy mechanism based on provincially differentiated levels of consumption and economic status.

Efficient Grain Boundary Suture by Low-Cost Tetra-ammonium Zinc Phthalocyanine for Stable Perovskite Solar Cells with Expanded Photoresponse.

Defects within the grain boundaries (GBs) of halide perovskite films make fabrication of efficient and stable perovskite solar cells (PSCs) highly challenging. Here, a low-cost tetra-ammonium zinc phthalocyanine (ZnPc) was used to post-treat the MAPbI3 (MA = CH3NH3) film. Two-dimensional (ZnPc)0.5MA n-1Pb nI3 n+1 was successfully constructed within the GBs of MAPbI3 film achieving a GBs suture for passivating the defects in GBs. Time-resolved photoluminescence showed that the modification increased the decay time from 44 to 57 ns indicating the passivation of GBs reduces trap-assisted recombination. The PSCs with modified perovskite exhibited increased photovoltage, and the best efficiency was improved up to 20.3%. More importantly, the long-term stability of the responding PSCs against humidity and heating was further improved unprecedentedly. Moreover, the modified MAPbI3 films revealed a self-repairing capability under mild heating. This work provided a novel insight into ongoing fabrication of efficient and stable PSCs by the efficient GBs suture with low-cost phthalocyanine.

The effect of aggression I: The increases of metabolic cost and mobilization of fat reserves in male striped hamsters.

Aggression can benefit individuals by enhancing their dominance and thereby their ability to acquire and retain resources that increase survival or fitness. Engaging in aggressive behavior costs energy and how animals manage their energy budget to accommodate aggression remains unclear. We conducted three experiments to examine changes in physiological, behavioral and hormonal markers indicative of energy budget in male striped hamsters subject to resident-intruder aggression tests. Body temperature, metabolic rate and serum corticosterone levels significantly increased in resident hamsters immediately after the introduction of intruders. Energy intake did not change, but the metabolic rate of residents increased by 16.1% after 42-days of repeated encounters with intruders. Residents had significantly decreased body fat content and serum thyroxine (T4) levels, and a considerably elevated tri-iodothyronine (T3)/T4 ratio compared to a control group that had no intruders. Attack latency considerably shortened, and the number of attack bouts and total duration of attacks, significantly increased in residents on day 42 compared to day 1 of experiments. These findings may suggest that the conversion of T4 to T3 is involved in defensive aggression behavior. The mobilization of fat reserves resulting in lean body mass is probably common response to the increased metabolic cost of aggression in small mammals. Aggressive behavior, which is important for the successful acquisition and defense of resources, may be of significance for adaptation and evolution of metabolic rate.

Age or health status: which influences medical insurance enrollment greater?

BACKGROUND: The New Cooperative Medical Scheme (NCMS) for peasantries implemented in 2003 and the Urban Resident Basic Medical Insurance (URBMI) for the urban unemployed implemented in 2007 have many similarities. They both apply the financing mode of individual premiums plus government's subsidies, and the voluntary enrollment. The Chinese government plans to integrate these two systems and build a unified basic medical insurance system for the unemployed in order to achieve the medical equity and increase the general health level. Thus, to analyze the main influencing factors of the enrollment of the urban unemployed and rural residents is very important for improving the system and securing the stability of the system during the transition. METHODS: The study uses data from the China Health and Nutrition Survey (CHNS) and adopts logistic regression models to test which factors influence the enrollment of the URBMI and the NCMS under the background of rather high enrollment rate of Chinese basic medical insurances and strong fiscal support of the Chinese government, especially whether health status or age influences enrollment of these two insurances greater. RESULTS: There is indeed some adverse selection in the URBMI and the NCMS. Whether the individual has chronic diseases have significant influence on enrollments of both the urban unemployed and rural residents, while whether the individual got ill in last four weeks just influences enrollments of the urban unemployed. Age influences enrollment greater than health status. The older the insured are, the larger the enrollment rates are. CONCLUSION: Because of the active support for basic medical insurances of the Chinese government, the enrollment performance of the urban unemployed and rural residents has already changed. When implementing the new policy, the government should pay attention to the willingness to enroll in and the change of enrollment performance of the insured. Therefore, under the policy of voluntary enrollment, every coordinated province and city should enlarge the proportion of young people to insuring group, optimizing the age structure, and the financing proportion of governments and individuals should be measured properly. With the increasing of governments' subsidies, the proportion of individual's premiums should also be increased.

A quantitative assessment of source contributions to fine particulate matter (PM2.5)-bound polycyclic aromatic hydrocarbons (PAHs) and their nitrated and hydroxylated derivatives in Hong Kong.

Atmospheric polycyclic aromatic hydrocarbons (PAHs) and their derivatives are of great concern due to their adverse health effects. However, source identification and apportionment of these compounds, particularly their nitrated and hydroxylated derivatives (i.e., NPAHs and OHPAHs), in fine particulate matter (PM2.5) in Hong Kong are still lacking. In this study, we conducted a 1-year observation at an urban site in Hong Kong. PM2.5-bound PAHs and their derivatives were measured, with median concentrations of 4590, 44.4 and 31.6 pg m-3 for ∑21PAHs, ∑13NPAHs, and ∑12OHPAHs, respectively. Higher levels were observed on regional pollution days than on long regional transport (LRT) or local emission days. Based on positive matrix factorization analysis, four sources were determined: marine vessels, vehicle emissions, biomass burning, and a mixed source of coal combustion and NPAHs secondary formation. Coal combustion and biomass burning were the major sources of PAHs, contributing over 85% of PAHs on regional and LRT days. Biomass burning was the predominant source of OHPAHs throughout the year, while NPAHs mainly originated from secondary formation and fuel combustion. For benzo[a]pyrene (BaP)-based PM2.5 toxicity, the mixed source of coal combustion and NPAHs secondary formation was the major contributor, followed by biomass burning and vehicle emissions.

Effect of food restriction on energy budget in warm-acclimated striped hamsters.

The capacity of small mammals to sustain periods of food shortage largely depends on the adaptive regulation of energy budget in response to the decrease in food supply. In addition to food availability, ambient temperature (Ta) is an important factor affecting the rates of both energy intake and expenditure. To examine the effect of Ta on energy strategy and the capacity to sustain food shortage, striped hamsters were exposed to a warm condition (30°C) and were then restricted to 70% of ad libitum food intake. Body mass, energy intake and expenditure and physiological markers indicative of thermogenesis were measured. Warm exposure had no effect on body mass and digestibility, but decreased energy intake, basal metabolic rate and maximum nonshivering thermogenesis. The mitochondria protein content, cytochrome c oxidase activity and uncoupling protein 1 level of brown adipose tissue were significantly lower in hamsters at 30°C than at 21°C. Food restriction induced a significant decrease in body mass, but the decreased body mass was attenuated at 30°C relative to 21°C. This suggests that striped hamsters could not compensate for the limited food supply by decreasing daily energy expenditure at 21°C, whereas they could at 30°C. The significant reductions in the rates of metabolism and thermogenesis in warm-acclimated hamsters increase the capacity to cope with food shortage. Although, it remains uncertain whether this response represents some generalized evolutionary adaptation, the Ta-dependent adjustment in the capacity to survive food restriction may reflect that warm acclimation plays an important role in adaptive regulation of both physiology and behavior in response to the variations of food availability.

Race is a key variable in assigning lipoprotein(a) cutoff values for coronary heart disease risk assessment: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: We aimed to examine associations of lipoprotein(a) (Lp(a)) concentrations with coronary heart disease (CHD) and determine whether current Lp(a) clinical laboratory cut points identify risk of disease incidence in 4 races/ethnicities of the Multi-Ethnic Study of Atherosclerosis (MESA). APPROACH AND RESULTS: A subcohort of 1323 black, 1677 white, 548 Chinese American, and 1044 Hispanic MESA participants were followed up during a mean 8.5-year period in which 235 incident CHD events were recorded. Lp(a) mass concentrations were measured using a turbidimetric immunoassay. Cox regression analysis determined associations of Lp(a) with CHD risk with adjustments for lipid and nonlipid variables. Lp(a) concentrations were continuously associated with risk of CHD incidence in black (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.09-2.04] and white participants (HR, 1.22; 95% CI, 1.02-1.45). Examining Lp(a) risk by the 50 mg/dL cut point revealed higher risks of incident CHD in all races except Chinese Americans: blacks (HR, 1.69; 95% CI, 1.03-2.76), whites (HR, 1.82; 95% CI, 1.15-2.88); Hispanics (HR, 2.37; 95% CI, 1.17-4.78). The lower Lp(a) cut point of 30 mg/dL identified higher risk of CHD in black participants alone (HR, 1.87; 95% CI, 1.08-3.21). CONCLUSIONS: Our findings suggest that the 30 mg/dL cutoff for Lp(a) is not appropriate in white and Hispanic individuals, and the higher 50 mg/dL cutoff should be considered. In contrast, the 30 mg/dL cutoff remains suitable in black individuals. Further research is necessary to develop the most clinically useful Lp(a) cutoff values in individual races/ethnicities.

Seasonal changes of body mass and energy budget in striped hamsters: the role of leptin.

Proper adjustments of physiology and behavior are required for small mammals to cope with seasonal climate change. The aim of this study was to examine the role of leptin in the regulation of body mass and energy budget in striped hamsters. We first investigated seasonal changes in body mass, energy budget, and serum leptin levels in hamsters acclimated to outdoor natural daylight and ambient temperature. Then we assessed the effect of leptin administration on energy budget, serum lipoprotein lipase (LPL) and hepatic lipase (HL) activities, and gene expression of uncoupling protein 1 (UCP1) in brown adipose tissue and of hypothalamic neuropeptides associated with the regulation of energy balance in hamsters maintained at 21° and 5°C. Hamsters showed constant body mass throughout the four seasons but significantly increased food intake and thermogenesis in winter, compared to summer. Minimum body fat was observed in winter, and minimum serum leptin was found in autumn. Hamsters housed at 5°C showed higher energy intake, upregulated gene expression of UCP1 and hormone-sensitive lipase, and lower fat content and LPL and HL activity than the animals maintained at 21°C. Leptin administration had no effect on energy intake but increased maximal thermogenic capacity, as indicated by upregulated UCP1 gene expression at both 21° and 5°C. Body fat and activity of LPL and HL were decreased in hamsters treated with leptin. The results suggest that leptin plays an important role in the seasonal regulation of thermogenic capacity and body composition in striped hamsters. Leptin may be involved in increasing maximal thermogenesis in the cold rather than acting as a starvation signal to increase energy intake.