基于多源遥感数据的景观格局及预测研究

以TM、中巴资源卫星和环境与灾害监测预报小卫星等遥感影像为数据源,利用ENVI 4.7、ARCGIS 9.2、IDRISI 15等软件,研究了西安市辖区的景观特征与空间格局,预测了未来的景观变化,提出了景观格局预测的数据转化和多距离空间分析的精简步骤.结果表明:研究区的景观本底是一个由林地和耕地构成的复合景观基质,建设用地在研究时段内呈现持续增加趋势,且2004-2011年间的增加量高于2000-2004年间的增加量;林地面积略有降低,林地和草地总面积略呈增长趋势,水域和未利用地面积变化较小.研究时段内的景观破碎化程度在降低,林地景观的连通性增强了,耕地的降低了.各景观类型在所设定的最大预期研究尺度下均呈现显著的聚集空间格局;各年和各景观类型之间的聚集、随机和离散的临界阈值差别相对比较大;水域和未利用地的空间聚集强度明显高于耕地、林地、草地和城乡建设用地;耕地和草地空间分布存在一个异质性最大的特征尺度,且均出现了聚集分布、随机分布和离散分布3种分布格局,以2011年最为明显.利用景观指数法和多距离空间聚类分析方法研究景观格局特征的效果要比单一的景观指数法较理想.CA-Markov模型模拟的结果基本能够反映未来的景观格局状况.     

The aging of the 2000 and 2011 Hallmarks of Cancer reviews: A critique

Two review articles published in 2000 and 2011 by Hanahan and Weinberg have dominated the discourse about carcinogenesis among researchers in the recent past. The basic tenets of their arguments favour considering cancer as a cell-based, genetic disease whereby DNA mutations cause uncontrolled cell proliferation. Their explanation of cancer phenotypes is based on the premises adopted by the somatic mutation theory (SMT) and its cell-centered variants. From their perspective, eight broad features have been identified as so-called ‘Hallmarks of Cancer’. Here, we criticize the value of these features based on the numerous intrinsic inconsistencies in the data and in the rationale behind SMT. An alternative interpretation of the same data plus data mostly ignored by Hanahan and Weinberg is proposed, based instead on evolutionarily relevant premises. From such a perspective, cancer is viewed as a tissue-based disease. This alternative, called the tissue organization field theory, incorporates the premise that proliferation and motility are the default state of all cells, and that carcinogenesis is due to alterations on the reciprocal interactions among cells and between cells and their extracellular matrix. In this view, cancer is development gone awry.     

Discrepancies in Outcome Reporting Exist Between Protocols and Published Oral Health Cochrane Systematic Reviews

Objectives

To assess discrepancies in the analyzed outcomes between protocols and published reviews within Cochrane oral health systematic reviews (COHG) on the Cochrane Database of Systematic Reviews (CDSR).

Study Design and Setting

All COHG systematic reviews on the CDSR and the corresponding protocols were retrieved in November 2014 and information on the reported outcomes was recorded. Data was collected at the systematic review level by two reviewers independently.

Results

One hundred and fifty two reviews were included. In relation to primary outcomes, 11.2% were downgraded to secondary outcomes, 9.9% were omitted altogether in the final publication and new primary outcomes were identified in 18.4% of publications. For secondary outcomes, 2% were upgraded to primary, 12.5% were omitted and 30.9% were newly introduced in the publication. Overall, 45.4% of reviews had at least one discrepancy when compared to the protocol; these were reported in 14.5% reviews. The number of review updates appears to be associated with discrepancies between final review and protocol (OR: 3.18, 95% CI: 1.77, 5.74, p<0.001). The risk of reporting significant results was lower for both downgraded outcomes [RR: 0.52, 95% CI: 0.17, 1.58, p = 0.24] and upgraded or newly introduced outcomes [RR: 0.77, 95% CI: 0.36, 1.64, p = 0.50] compared to outcomes with no discrepancies. The risk of reporting significant results was higher for upgraded or newly introduced outcomes compared to downgraded outcomes (RR = 1.19, 95% CI: 0.65, 2.16, p = 0.57). None of the comparisons reached statistical significance.

Conclusion

While no evidence of selective outcome reporting was found in this study, based on the present analysis of SRs published within COHG systematic reviews, discrepancies between outcomes in pre-published protocols and final reviews continue to be common. Solutions such as the use of standardized outcomes to reduce the prevalence of this issue may need to be explored.     

Epidemiological Trends of Dengue Disease in Colombia (2000-2011): A Systematic Review

A systematic literature review was conducted to describe the epidemiology of dengue disease in Colombia. Searches of published literature in epidemiological studies of dengue disease encompassing the terms “dengue”, “epidemiology,” and “Colombia” were conducted. Studies in English or Spanish published between 1 January 2000 and 23 February 2012 were included. The searches identified 225 relevant citations, 30 of which fulfilled the inclusion criteria defined in the review protocol. The epidemiology of dengue disease in Colombia was characterized by a stable “baseline” annual number of dengue fever cases, with major outbreaks in 2001–2003 and 2010. The geographical spread of dengue disease cases showed a steady increase, with most of the country affected by the 2010 outbreak. The majority of dengue disease recorded during the review period was among those <15 years of age. Gaps identified in epidemiological knowledge regarding dengue disease in Colombia may provide several avenues for future research, namely studies of asymptomatic dengue virus infection, primary versus secondary infections, and under-reporting of the disease. Improved understanding of the factors that determine disease expression and enable improvement in disease control and management is also important.     

2000-2006年《中国应用生理学杂志》载文分析

目的:分析<中国应用生理学杂志>2000-2006年的载文特点,了解该刊的编辑质量和期刊论文的学术水平,为进一步办好刊物提供依据.方法:依据<中国期刊网全文期刊数据库>(CNKI)与手工检索,统计2000-2006年出版的<中国应用生理学杂志>所载论文的多项文献定量指标.结果:<中国应用生理学杂志>7年总载文量为968篇,期均篇数为34.6篇,篇均页数为3.1页.在栏目中,研究论文发文数量最多,占总发文量的66.22%.在引文统计中,含引文文章逐年增加,2004-2006年引文率为100%,英文引文条数很高,平均占76.52%.在文章时滞统计中,最长为510 d,最短为60 d,平均为196.5 d.在基金资助文章统计中,受资助级别越来越高,获资助篇数越来越多,最多是2005年,为97篇.在作者职称和学位统计中,作者的级别越来越高.在作者分布统计中,北京作者人数最多,有162人,占16.74%.结论:<中国应用生理学杂志>所载文献质量较高.该刊不仅是我国生理学研究领域最重要的信息源之一,也是我国医学领域的主要核心期刊.     

Time Trend Analysis of the Prevalence and Incidence of Diagnosed Asthma and Traditional Chinese Medicine Use among Adults in Taiwan from 2000 to 2011: A Population-Based Study

Background

The aim of this study was to determine the annual trends of traditional Chinese medicine (TCM) use for prevalent and incident asthmatic adults in Taiwan from 2000 to 2011. The annual prevalence and incidence of asthma in adults among subgroups of sociodemographic factors were also investigated.

Methods

A population-based study was conducted using a random sample with one million beneficiaries of all residents aged ≥18 years enrolled in the National Health Insurance program. Adults diagnosed with asthma were identified from the National Health Insurance Research Database. The annual prevalence and incidence of asthma in the adult population were estimated by using International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes to identify relevant cases from 2000 to 2011.

Results

The number of annual prevalent cases of diagnosed asthma increased from 56,885 in 2000 to 101,535 in 2011. The prevalence increased significantly on annual basis, whereas the incidence rate fluctuated over time. The prevalence of TCM use by adults with asthma decreased significantly (p<0.05), from 38.58% in 2000 to 29.26% in 2011. The number of annual incident cases of diagnosed asthma decreased from 3,896 in 2000 to 2,684 in 2011. TCM use rates in asthma incident adults decreased significantly (p<0.05), from 54.24% in 2000 to 38.19% in 2011.

Conclusion

The prevalence of TCM utilization is high among adults with asthma in Taiwan. However, our study demonstrated a substantial decrease in the annual prevalence of TCM use by prevalent and incident asthmatic adults in Taiwan from 2000 to 2011. In addition, the prevalence of TCM use was higher among incident cases, compared with those with prevalent cases.     

Trends of Modern Contraceptive Use among Young Married Women Based on the 2000, 2005, and 2011 Ethiopian Demographic and Health Surveys: A Multivariate Decomposition Analysis

Introduction

Accessing family planning can reduce a significant proportion of maternal, infant, and childhood deaths. In Ethiopia, use of modern contraceptive methods is low but it is increasing. This study aimed to analyze the trends and determinants of changes in modern contraceptive use over time among young married women in Ethiopia.

Methods

The study used data from the three Demographic Health Surveys conducted in Ethiopia, in 2000, 2005, and 2011. Young married women age 15–24 years with sample sizes of 2,157 in 2000, 1,904 in 2005, and 2,146 in 2011 were included. Logit-based decomposition analysis technique was used for analysis of factors contributing to the recent changes. STATA 12 was employed for data management and analyses. All calculations presented in this paper were weighted for the sampling probabilities and non-response. Complex sampling procedures were also considered during testing of statistical significance.

Results

Among young married women, modern contraceptive prevalence increased from 6% in 2000 to 16% in 2005 and to 36% in 2011. The decomposition analysis indicated that 34% of the overall change in modern contraceptive use was due to difference in women’s characteristics. Changes in the composition of young women’s characteristics according to age, educational status, religion, couple concordance on family size, and fertility preference were the major sources of this increase. Two-thirds of the increase in modern contraceptive use was due to difference in coefficients. Most importantly, the increase was due to change in contraceptive use behavior among the rural population (33%) and among Orthodox Christians (16%) and Protestants (4%).

Conclusions

Modern contraceptive use among young married women has showed a remarkable increase over the last decade in Ethiopia. Programmatic interventions targeting poor, younger (adolescent), illiterate, and Muslim women would help to maintain the increasing trend in modern contraceptive use.     

Drought-induced dynamics of carbon and water use efficiency of global grasslands from 2000 to 2011

Drought is frequently recorded as a result of climate warming and elevated concentration of greenhouse gases, which affect the carbon and water cycles in terrestrial ecosystems, particularly in arid and semi-arid regions. To identify the drought in grassland ecosystems and to determine how such drought affects grassland ecosystems in terms of carbon and water cycles across the globe, this study evaluated the drought conditions of global grassland ecosystems from 2000 to 2011 on the basis of the remotely sensed Drought Severity Index (DSI) data. The temporal dynamics of grassland carbon use efficiency (CUE) and water use efficiency (WUE), as well as their correlations with DSI, were also investigated at the global scale. Results showed that 57.04% of grassland ecosystems experienced a dry trend over this period. In general, most grassland ecosystems in the northern hemisphere (N.H.) were in near normal condition, whereas those in the southern hemisphere (S.H.) experienced a clear drying and wetting trend, with the year 2005 regarded as the turning point. Grassland CUE increased continually despite the varied drought conditions over this period. By contrast, WUE increased in the closed shrublands and woody savannas but decreased in all the other grassland types. The drought conditions affected the carbon and water use mainly by influencing the primary production and evapotranspiration of grass through photosynthesis and transpiration process. The CUE and WUE of savannas was most sensitive to droughts among all the grassland types. The areas of grassland DSI that showed significant correlations with CUE and WUE were 52.92% and 22.11% of the total grassland areas, respectively. Overall, droughts sufficiently explained the dynamics of grassland CUE, especially in the S.H. In comparison with grassland CUE, the grassland WUE was less sensitive to drought conditions at the global scale.     

Association between P16INK4a Promoter Methylation and HNSCC: A Meta-Analysis of 21 Published Studies

Background

The p16^INK4a is an important tumor suppressor gene (TSG) and aberrant methylation of promoter is known to be a major inactivation mechanism of the tumor suppressor and tumor-related genes. Aberrant TSG methylation was considered an important epigenetic silencing mechanism in the progression of head and neck squamous cell carcinoma (HNSCC). However, some studies have reported differences in the methylation frequencies of P^16INK4a promoter between cancer and the corresponding control group. Therefore, we conducted a meta-analysis to better identify the association.

Methods

PubMed, Ovid, ISI Web of Science, and EMBASE were searched to identify eligible studies to evaluate the association of p16^INK4a promoter methylation and HNSCC. Odds ratio (ORs) and 95% confidence intervals (95%CI) were calculated to evaluate the strength of association between p16^INK4a promoter methylation and HNSCC.

Results

A total of twenty-one studies with 1155 cases and 1017 controls were included in the meta-analysis. The frequencies of p16^INK4a promoter methylation in the cancer group were significantly higher than those in the control group (cancer group: median: 46.67%, range = 7.84%-95.12%; control group: median: 18.37%, range = 0–83.33%; respectively). The pooled odds ratio was 3.37 (95%CI = 2.32–4.90) in the cancer group versus the corresponding control group under the random-effects model.

Conclusion

This meta-analysis of 21 published studies identified that aberrant methylation of p16^INK4a promoter was found to be significantly associated with HNSCC.     

Time Trends and Inequalities of Under-Five Mortality in Nepal: A Secondary Data Analysis of Four Demographic and Health Surveys between 1996 and 2011

Background

Inequalities in progress towards achievement of Millennium Development Goal four (MDG-4) reflect unequal access to child health services.

Objective

To examine the time trends, socio-economic and regional inequalities of under-five mortality rate (U5MR) in Nepal.

Methods

We analyzed the data from complete birth histories of four Nepal Demographic and Health Surveys (NDHS) done in the years 1996, 2001, 2006 and 2011. For each livebirth, we computed survival period from birth until either fifth birthday or the survey date. Using direct methods i.e. by constructing life tables, we calculated yearly U5MRs from 1991 to 2010. Projections were made for the years 2011 to 2015. For each NDHS, U5MRs were calculated according to child''s sex, mother’s education, household wealth index, rural/urban residence, development regions and ecological zones. Inequalities were calculated as rate difference, rate ratio, population attributable risk and hazard ratio.

Results

Yearly U5MR (per 1000 live births) had decreased from 157.3 (95% CIs 178.0-138.9) in 1991 to 43.2 (95% CIs 59.1-31.5) in 2010 i.e. 114.1 reduction in absolute risk. Projected U5MR for the year 2015 was 54.33. U5MRs had decreased in absolute terms in all sub groups but relative inequalities had reduced for gender and rural/urban residence only. Wide inequalities existed by wealth and education and increased between 1996 and 2011. For lowest wealth quintile (as compared to highest quintile) hazard ratio (HR) increased from 1.37 (95% CIs 1.27, 1.49) to 2.54 ( 95% CIs 2.25, 2.86) and for mothers having no education (as compared to higher education) HR increased from 2.55 (95% CIs 1.95, 3.33) to 3.75 (95% CIs 3.17, 4.44). Changes in regional inequities were marginal and irregular.

Conclusions

Nepal is most likely to achieve MDG-4 but eductional and wealth inequalities may widen further. National health policies should address to reduce inequalities in U5MR through ‘inclusive policies''.