Biomass Production and Carbon Stocks in Poplar-Crop Agroforestry Chronosequence in Subtropical Central China.

Agroforest systems have been widely recognized as an integrated approach to sustainable land use for addressing the climate change problem because of their greater potential to sequester atmospheric CO2 with multiple economic and ecological benefits. However, the nature and extent of the effects of an age-sequence of agroforestry systems on carbon (C) storage remain largely unknown. To reveal the influence of different aged poplar-crop systems on C stocks, we investigated the variation in biomass and C storage under four aged poplar-crop agroforest systems (3-, 9-, 13-, and 17-year-old) in the Henan province of China. The results showed that stand biomass increased with forest age, ranging from 26.9 to 121.6 t/ha in the corresponding four aged poplar-crop systems. The poplar tree biomass accounted for >80% of the total stand biomass in these poplar-crop agroforestry systems, except in the 3-year-old agroforestry system. The average stand productivity peaked in a 9-year-old poplar-crop system (11.8 t/ha/yr), the next was in 13- and 17-year-old agroforestry systems, and the minimum was found in 3-year-old poplar-crop stands (4.8 t/ha/yr). The total C stocks increased, with aging poplar-crop systems ranging from 99.7 to 189.2 t/ha in the studied agroforestry systems. The proportion of C stocks accounted for about 6, 25, and 69% of the total C stocks in the crop, poplar tree, and soil components in all studied agroforestry ecosystems, respectively. Our results suggested that the poplar-crop system, especially in productive and mature stages, is quite an effective agroforestry model to increase the study site's biomass production and C stocks. This study highlighted the importance of agroforestry systems in C storage. It recommended the poplar-crop agroforest ecosystems as a viable option for sustainable production and C mitigation in the central region of China.

Land Use Changes Influence the Soil Enzymatic Activity and Nutrient Status in the Polluted Taojia River Basin in Sub-Tropical China.

Different land use practices may improve soil quality or lead to soil deterioration. Recently, environmental problems, such as heavy pollution and soil erosion, have led to serious land degradation in the Taojia River basin. In this study, we explored the soil fertility characteristics (mechanical composition; pH; soil organic matter (SOM); soil total nitrogen (TN); and the activity of four enzymes, i.e., urease, hydrogen peroxide, alkaline phosphatase, and sucrose enzymes) under different types of land use in the Taojia River basin. Soil samples were taken from 0-10 cm, 10-20 cm, and 20-40 cm depths from four different land use types that were widely used in the Taojia river basin, including cultivated land, vegetable fields, woodlands, and wastelands. The results showed that the soil enzyme activity and the constituents of the soil were closely related and significantly affected each other (p < 0.05). Woodland soil exhibited the highest content of SOM in all soil depths. Soil total nitrogen mainly depended on the accumulation of biomass and the decomposition intensity of organic matter, so the changes in TN followed the trends of the changes in SOM. Woodland soil showed an improved mechanical composition. We were also able to observe an increased clay content in woodland soil. Woodland soil also exhibited the reversal of soil desertification and an increase in nutrient/water retention capacity. Therefore, an increase in woodland areas would be an appropriate goal in terms of land use in order to improve the eco-environmental quality of the Taojia River basin.

Premature mortality risk in people with convulsive epilepsy: long follow-up of a cohort in rural China.

PURPOSE: Detailed data on the mortality of epilepsy are still lacking from resource-poor settings. We conducted a long-term follow-up survey in a cohort of people with convulsive epilepsy in rural areas of China. In this longitudinal prospective study we investigated the causes of death and premature mortality risk among people with epilepsy. METHODS: We attempted to trace all 2,455 people who had previously participated in a pragmatic assessment of epilepsy management at the primary health level. Putative causes of death were recorded for those who died, according to the International Classification of Diseases. We estimated proportional mortality ratios (PMRs) for each cause, and standardized mortality ratios (SMRs) for each age-group and cause. Survival analysis was used to detect risk factors associated with increased mortality. KEY FINDINGS: During 6.1 years of follow-up there were 206 reported deaths among the 1,986 people with epilepsy who were located. The highest PMRs were for cerebrovascular disease (15%), drowning (14%), self-inflicted injury (13%), and status epilepticus (6%), with probable sudden unexpected death in epilepsy (SUDEP) in 1%. The risk of premature death was 2.9 times greater in people with epilepsy than in the general population. A much higher risk (SMRs 28-37) was found in young people. Duration of epilepsy and living in a waterside area were independent predictors for drowning. SIGNIFICANCE: Drowning and status epilepticus were important, possibly preventable, causes of death. Predictors of increasing mortality suggest interventions with efficient treatment and education to prevent premature mortality among people with epilepsy in resource-poor settings.

Long-term outcome of phenobarbital treatment for epilepsy in rural China: a prospective cohort study.

PURPOSE: To evaluate the long-term outcome of phenobarbital treatment for convulsive epilepsy in rural China, and to explore factors associated with overall seizure outcomes. METHODS: We carried out follow-up assessments of people who took part in an epilepsy community management program conducted in rural counties of six provinces in China. People with convulsive epilepsy who were previously untreated (or on irregular treatment) were commenced on regular treatment with phenobarbital. Information was collected using a standardized questionnaire by face-to-face interviews of the individuals (and their families where necessary). Information collected included treatment status, medication change, seizure frequency, and mortality. KEY FINDINGS: Among the 2,455 people who participated in the original program, outcomes were successfully ascertained during the follow-up assessment in 1986. Among them, 206 had died. Information on treatment response was obtained in 1,780 (56% male; mean age 33.9 years, range 3-84; mean duration of follow-up 6.4 years). Among them, 939 (53%) were still taking phenobarbital. The most common reasons for stopping phenobarbital were seizure freedom or substantial seizure reduction, socioeconomic reasons, and personal preference. Four hundred fifty-three individuals (25%) became seizure-free for at least 1 year while taking phenobarbital, 88% of whom did so at daily doses of 120 mg or below. Four hundred six (23%) reported adverse events, which led to withdrawal of phenobarbital in <1%. The most common adverse effects were malaise/somnolence (7.4%), dizziness (3%), and lethargy (2.6%). At the follow-up assessment, 688 (39%) individuals had been seizure free for at least the previous year. People with persistent seizures had significantly longer duration of epilepsy and higher number of seizures in the 12 months before treatment. People who were taking AED treatment irregularly at recruitment were less likely to become seizure-free. SIGNIFICANCE: We observed long-term benefits of regular treatment with phenobarbital for convulsive epilepsy in rural China. One hundred years after the discovery of its antiepileptic effect, phenobarbital is still playing an important role in the management of epilepsy.

Changes in knowledge, attitude, and practice of people with epilepsy and their families after an intervention in rural China.

To evaluate the effectiveness of a combined intervention on knowledge, attitude, and practice (KAP) of people with epilepsy and their families in rural areas of China, random samples of people with epilepsy and their family members from the intervention populations completed questionnaires prior to the intervention (2002, N=975) and 2 years later (N=950). There was no significant difference in important demographic variables between the two samples. KAP levels of patients and their family members improved over the study period. Worry about seizures, discrimination, and medical costs are the principal factors in patients' psychological burden. Psychological burden and inability to concentrate at work are the main influences of the disease on family members. Reduction of the psychological burden of patients and their family members is a significant aspect of treatment to which more attention should be paid in similar future interventions.

Global campaign against epilepsy: assessment of a demonstration project in rural China.

OBJECTIVE: The Global Campaign Against Epilepsy demonstration project in rural China aimed: to reduce the treatment gap and morbidity of people with epilepsy by using community-level interventions; to train and educate health professionals; to dispel stigma; to identify potential for prevention and to develop models of integration of epilepsy control into the local health systems. We report the overall results of the demonstration project, focusing on the prevalence and the change in the treatment gap of epilepsy after an intervention. METHODS: Door-to-door epidemiological surveys were carried out before, and 6 months after the end of, an intervention project for epilepsy in rural settings in five provinces of China. The intervention consisted of a treatment programme available to patients without prior appropriate treatment and a public health educational programme about epilepsy. The sampled population in the second survey was 51 644 people. FINDINGS: In the second survey, epilepsy was confirmed in 320 people, yielding a lifetime prevalence of 6.2/1000 and a prevalence of active epilepsy of 4.5/1000. The lifetime prevalence and prevalence of active epilepsy in the first survey were 7.0/1000 and 4.6/1000, respectively. The treatment gap of active epilepsy in the second survey was 49.8%, 12.8 percentage points lower than that of the first survey (62.6%). CONCLUSION: The results of this study suggest that the intervention measures used were possibly effective and evidently feasible in rural China, contributing to a decrease in the treatment gap of epilepsy.

Premature mortality in people with epilepsy in rural China: a prospective study.

BACKGROUND: In China, few studies have described annual mortality associated with epilepsy in a general population and these have provided a range of 3.0-7.9 deaths per 100,000 people. We calculated the case fatality rate (CFR), proportional mortality rate (PMR), and standardised mortality ratio (SMR) to assess mortality in people with epilepsy in rural China. METHODS: The target population was people with epilepsy who participated in an assessment of epilepsy management at primary health level in rural China. Neurologists confirmed the diagnosis using strict criteria in all participants who were then treated with phenobarbital. Demographic data and putative cause of death were recorded for each person whose death was reported. PMRs for each cause of death and SMRs were estimated on the basis of the 2004 Chinese population. FINDINGS: Case fatality rate was 1.4% (35 deaths) among 2455 people with epilepsy. The age-adjusted PMRs for injury, stroke, neoplasm, myocardial infarction, and pneumonia were 30%, 30%, 15%, 6%, and 5%, respectively. The SMR was 3.9 (95% CI 3.8-3.9). Patients aged 15-29 years had higher mortality ratios than did those in other age-groups, with SMRs exceeding 23. INTERPRETATION: Risk for premature death is three to four times higher in people with epilepsy than in the general Chinese population. Furthermore, the risk in young people with epilepsy in China is much higher than previously reported. Injury, stroke, myocardial infarction, and pneumonia are among the leading putative causes of death in patients with epilepsy in rural China.

[Evaluation of the efficacy of phenobarbital in treatment of epilepsy in rural areas: study of 2455 patients in rural China].

OBJECTIVE: To evaluate the efficacy of phenobarbital in treatment of patients with convulsive forms of epilepsy in rural areas and to develop a suitable relevant model for rural China. METHODS: A demonstration protocol was conducted in the rural areas of 8 counties from 6 provinces and municipality in China, Heilongjiang, Ningxia, Henan, Jiangsu, Shanxi, and Shanghai from December 2001 to June 2004. Epidemiological investigation of the prevalence and treatment gap of epilepsy was carried out. Patients with convulsive forms of epilepsy thus screened underwent treatment of phenobarbital. Physicians of township hospitals received short-term training to be in charge of the treatment and regular follow-up of the patients. RESULTS: A total of 2455 patients with generalized tonic-clonic seizures in these 6 rural areas were screened and entered the treatment group. 347 patients (26.2%) had been seizure-free during the period of these 2 years, 415 patients (31.3%) had their seizure frequencies decreased by > 75% as compared with those during the period of 6 months before treatment, and the conditions of 26.1% of the patients did not change or even became worse. About 26.1% of the patients had mild side effects, 3.7% had moderate side effects, and only 0.3% had severe side effects when the dosage of phenobarbital in the first 3 months was increased. 597 patients (24.3%) withdrew from the treatment group because of various reasons. CONCLUSION: This protocol was suitable to the rural areas of China. The trained physicians are capable of fulfilling the task to treat the patients with epilepsy. Phenobarbital is an effective drug for most patients with convulsive seizures and has no severe side effect.

[Analysis of 994(G--> T) mutation in the plasma platelet-activating factor acetylhydrolase gene in the patients with cerebral infarction].

OBJECTIVE: To investigate the relationship between plasma platelet-activating factor acetylhydrolase (PAF-AH) gene 994(G--> T) mutation in exon 9 and the patients with cerebral infarction in Chinese Hans. METHODS: The authors conducted a case-control study including 108 patients in three groups (atherosclerotic cerebral infarction group, lacunar infarction group and cerebral embolism group) and 215 normal subjects as controls. Genomic DNA was analyzed for the mutant allele by a specific polymerase chain reaction. RESULTS: The frequency of the mutant genotype in the 102 patients with cerebral infarction was 35.19%(32.41% heterozygotes and 2.78% homozygotes), and was 38.10%(34.92% heterozygotes and 3.18% homozygotes) in the atherosclerotic cerebral infarction group, being all significantly higher than the control group's 20.46% (18.60% heterozygotes and 1.86% homozygotes)(P< 0.01); however, the frequencies of the mutant genotype in the lacunar infarction group and cerebral embolism group were 32.35% (29.41% heterozygotes and 2.94% homozygotes) and 27.27% (27.27% heterozygotes and 0 homozygotes) respectively, being not statistically different from those of the controls (P> 0.05). CONCLUSION: These findings show that the 994(G--> T) mutation of plasma PAF-AH gene may be an independent risk for atherosclerotic cerebral infarction, but not for lacunar infarction.

Age-related increase of plasma platelet-activating factor concentrations in Chinese.

BACKGROUND: Platelet-activating factor (PAF) is a potent bioactive phospholipid, which may be one of the determinants of atherogenesis. The purpose of this study was to investigate the relationship between the concentrations of plasma platelet-activating factor and age in a common Chinese population. METHODS: Two-hundred seventy-nine Han nation subjects (male: n=162; female: n=117) who had visited two hospitals for overall health survey, as an annual medical check-up or for other reasons by clinical examinations were recruited and divided into six age groups (21-30, 31-40, 41-50, 51-60, 61-70, 71-80 years). PAF was extracted from their plasma and purified by thin-layer chromatography (TLC). The PAF concentrations were detected by radioimmunoassay. RESULTS: The PAF concentrations (pg/ml) in plasma showed significantly age-related increase (r=0.3348, P<0.01, n=279). In the 21-30-year group, the PAF concentration was 338+/-96 pg/ml. Except for the 31-40-year group, the PAF concentrations in other four groups were all higher than that of the 21-30-year group (P<0.05, P<0.01, P<0.001 and P<0.001, respectively). CONCLUSIONS: Considering PAF is one of the key factors relevant to progression of atherogenesis, and the high concentrations of plasma PAF may therefore serve as a marker for the risk of atherosclerosis. Adjustment of the concentrations of plasma PAF correlated with aging may be helpful to reducing the prevalence rate of multi-senile arteriosclerosis occlusive diseases.

[Epidemiological survey on epilepsy among rural populations in five provinces in China].

OBJECTIVE: To investigate the prevalence of epilepsy and its treatment gap in rural areas of China. METHODS: A door-to-door epidemiological survey on epilepsy was conducted among 55616 rural residents in 5 counties, each in a province (Heilongjiang, Ningxia, Shanxi, Henan, and Jiangsu) selected by random cluster sampling. All people diagnosed or suspected as epileptic during the screening phase were rechecked by neurologists. RESULTS: A definite diagnosis of epilepsy was made among 387 people with a prevalence rate 7.0 per thousand (age-adjusted rate 6.8 per thousand). The prevalence of active epilepsy was 4.6 per thousand, and the incidence of epilepsy was 28.8/100 000. Of the people with epilepsy, 40.6% had not been treated, 35.4% were treated irregularly. The treatment gap of active epilepsy was 62.6%. CONCLUSION: The prevalence of epilepsy in the rural areas in China was much higher than it was reported previously. About two thirds of the patients with epilepsy has not received regular treatment. A rational intervention strategy should be developed as soon as possible.