Sociodemographic determinants associated with breastfeeding in term infants with low birth weight in Latin American countries

BACKGROUND A progressive decrease in exclusive breastfeeding(BF)is observed in Latin America and the Caribbean compared with global results.The possibility of being breastfed and continuing BF for>6 months is lower in low birth weight than in healthy-weight infants.AIM To identify factors associated with BF maintenance and promotion,with particular attention to low-and middle-income countries,by studying geographic,socioeconomic,and individual or neonatal health factors.METHODS A scoping review was conducted in 2018 using the conceptual model of social determinants of health published by the Commission on Equity and Health Inequalities in the United States.The extracted data with common characteristics were synthesized and categorized into two main themes:(1)Sociodemographic factors and proximal determinants involved in the initiation and maintenance of BF in low-birth-weight term infants in Latin America;and(2)individual characteristics related to the self-efficacy capacity for BF maintenance and adherence in low-birth-weight term infants.RESULTS This study identified maternal age,educational level,maternal economic capacity,social stratum,exposure to BF substitutes,access to BF information,and quality of health services as mediators for maintaining BF.CONCLUSION Individual self-efficacy factors that enable BF adherence in at-risk populations should be analyzed for better health outcomes.

中美地理学近百年发展脉络的比较研究——基于《地理学报》和Annals of the Association of American Geographers学术论文的统计分析

基于《地理学报》和Annals of the Association of American Geographers学术论文的统计,对比近百年中美两国地理学的发展脉络,着重从总体特征、重点研究内容及其变化、理论—实践关系三方面对比异同,获得经验和借鉴。美国地理学经过初期发展、高速发展后,目前进入持续发展阶段;中国地理学在曲折中崛起,目前正处在高速发展时期。美国地理学中人文地理学一直居主导地位,中国则从重视自然地理开始逐渐向自然、人文、方法三足鼎立方向迈进;美国地理学家非常重视微观、中观实践,但在国家宏观决策中远没有中国地理学家发挥作用更直接。美国地理学研究水平高于中国,但这种差距正在缩小,研究方向的变化相差3～5年。世界地理研究中心有向亚太地区、向中国转移的可能,中国地理学家要勇于创建具有中国特色的地理学派。

Climatic Factors for Limiting Northward Distribution of Eight Temperate Tree Species in Eastern North America

Eight temperate deciduous tree species, Acer rubrum L., A. saccharinum L., A. saccharum Marsh., Belluta alleghaniensis Britton., Fraxinus nigra Marsh., Quercus rubra L., Titia americana L., and Ulmus americana L. in eastern North America, were selected to explore relationship between the northward distribution of temperate tree species and climatic factors. For each species, more than 30 sites at their north limits of distribution were obtained from their distribution maps, and 11 climatic indices at the north limits were computed. The standardized standard deviation (SD) method, which compares the magnitude of variance of climatic indices, was used to detect which climatic parameter was the most important for explaining northward distribution of these species. We presume that the climatic parameter that has the smallest variance at the north limit would be assigned as the dominant climatic factor for limiting the distribution of this species. The results derived from the standardized SD method indicated that the SD value of warmth index (WI) and/or annual biotemperature (ABT) were the smallest among the 11 climatic indices. Since both WI and ABT represent growing season temperature, it suggested that growing season temperature was the most important climatic factor for explaining the northward distribution of these temperate tree species. The relationships between several climatic indices, WI, coldness index (CI), annual precipitation (AP), annual range of temperature (ART) and humid/arid index were also analyzed. As a result, at the north limits of all these species, both WI and CI decreased with an increase of AP, and CI increased with an increase of ART. Besides growing season temperature, precipitation and climatic continentality also have influence on the northward distribution of the temperate trees in eastern North America.

美国政府数字化转型的路径框架研究——基于NEW AMERICA智库报告的分析

2020年9月16日,美国智库NEW AMERICA发布报告《The Digital Government Mapping Project》.该报告就数字政府的建设问题进行了分析研究,针对后疫情时代政府数字化转型提出了"数字政府堆栈"的概念框架;同时对数字政府建设的成功案例进行了整合,并且为政府和相关的利益者就如何加快政府数字化转型提出了建议.着力报告解析,为中国数字政府的建设工作提供有益的参考和借鉴.

America的词汇理据与文化意蕴

从历时角度看,America这个词自1507年面世至今,已有500多年的历史,当时德国人用它命名哥伦布发现的新大陆,西班牙人为此愤愤不平并竭力抵制。从共时角度看,America一词仰仗"美国"的影响力,显示出特有的活力,其词义不断延伸,用法日趋扩大,能产性逐渐增强,使用频率持续攀升。从文化角度看,在发现新大陆、美洲命名和"哥伦布交流"的叙事中,America是一个关键词和文化象征符号,具有丰富的政治色彩和文化意蕴。

Democracy in America

Democracy is what people in every corner of the world pursue. Americans are of no exception. The United States of American has long enjoyed a reputation of high democracy. Thus, this paper will dig deep to see the development and nature of American Democracy based on the discussion of three significant documents: the Declaration of Independence, the US Constitution and the Gettysburg Address.

The Comparison between "I Hear America Singing " and "春望"

Through the introduction of the American poem "I Hear America Singing" and its writer Walt Whitman, the Chinese poem " 春望 "and its writer:杜甫, and the comparison of these two poems in prosody, language, contents and emotion, writing techniques, political views field, etc, this essay analyses further some poetic phenomenon, and also draws a vivid picture of America in 19 century and China in 8 century.

An Analysis of Dean Moriarty in On the Road——A True Hero in the 1950's America

This paper studies post-war America around the 1950's when On the Road was written and analyzes the protagonist Dean Moriarty as a spokesman of the Beat Generation.He is a typical beat who revolts against the traditional social values and chases after the spiritual complacency.In addition,he opposes wars and advocates the equality between men and women.Thus in a sense Dean is a rebellious hero and stands ahead of his age.

A Comparative Study on Family Education in America and China

Family education is an important complement to school education.This paper focuses on the differences and similarities of family education in America and China to accelerate their learning from each other and improvement.

Hepatocellular carcinoma in Latin America: Diagnosis and treatment challenges

Latin America, a region with a population greater than 600000000 individuals, is well known due to its wide geographic, socio-cultural and economic heterogeneity. Access to health care remains as the main barrier that challenges routine screening, early diagnosis and proper treatment of hepatocellular carcinoma(HCC). Therefore, identification of population at risk, implementation of surveillance programs and access to curative treatments has been poorly obtained in the region. Different retrospective cohort studies from the region have shown flaws in the implementation process of routine surveillance and early HCC diagnosis. Furthermore, adherence to clinical practice guidelines recommendations assessed in two studies from Brazil and Argentina demonstrated that there is also room for improvement in this field, similarly than the one observed in Europe and the United States. In summary, Latin America shares difficulties in HCC decision-making processes similar to those from developed countries. However, a transversal limitation in the region is the poor access to health care with the consequent limitation to standard treatments for overall population. Specifically, universal health care access to the different World Health Organization levels is crucial, including improvement in research, education and continuous medical training in order to expand knowledge and generation of data promoting a continuous improvement in the care of HCC patients.

Role of gene polymorphisms in gastric cancer and its precursor lesions:Current knowledge and perspectives in Latin American countries

Latin America shows one of the highest incidence rates of gastric cancer in the world,with variations in mortality rates among nations or even within countries belonging to this region.Gastric cancer is the result of a multifactorial complex process,for which a multistep model of carcinogenesis is currently accepted.Additionally to the infection with Helicobacter pylori,that plays a major role,environmental factors as well as genetic susceptibility factors are significant players at different stages in the gastric cancer process.The differences in population origin,demographic structure,socio-economic development,and the impact of globalization lifestyles experienced in Latin America in the last decades,all together offer opportunities for studying in this context the influence of genetic polymorphisms in the susceptibility to gastric cancer.The aim of this article is to discuss current trends on gastric cancer in Latin American countries and to review the available published information about studies of association of gene polymorphisms involved in gastric cancer susceptibility from this region of the world.A total of 40 genes or genomic regions and69 genetic variants,58%representing markers involved in inflammatory response,have been used in a number of studies in which predominates a low number of individuals(cases and controls)included.Polymorphisms of IL-1B(-511 C/T,14 studies;-31 T/C,10 studies)and IL-1RN(variable number of tandem repeats,17 studies)are the most represented ones in the reviewed studies.Other genetic variants recently evaluated in large metaanalyses and associated with gastric cancer risk were also analyzed in a few studies[e.g.,prostate stem cell antigen(PSCA),CDH1,Survivin].Further and better analysis centered in gene polymorphisms linked to other covariates,epidemiological studies and the information provided by meta-analyses and genome-wide association studies should help to improve our understanding of gastric cancer etiology in order to develop appropriate health programs in Latin America.

Epidemiology of inflammatory bowel disease in South America: A systematic review

BACKGROUND The worldwide epidemiology of inflammatory bowel disease(IBD)is rapidly changing.Increasing Crohn’s disease(CD)and ulcerative colitis(UC)incidence and prevalence have been recorded in developing regions such as Asia,Africa and Eastern Europe where it was previously thought to be uncommon.Whether this is also the case in South America is not well known.Demonstration that developing regions worldwide have increasing IBD incidence would indicate that environmental change plays a significant role in the development of IBD.AIM To report the incidence,prevalence and disease characteristics of CD and UC within the South American continent.METHODS A systematic review was conducted by searching published studies in major international and regional databases(MEDLINE,EMBASE and Scopus)between January 1990 and December 2018.Outcomes considered were incidence,prevalence,phenotype,environmental and genetic factors,ethnicity and gender.A pair of independent reviewers screened and reviewed all identified articles.RESULTS One hundred and sixty two citations were initially retrieved with 18 studies included in this systematic review.The majority of included studies were from Brazil(n=13,72%).The incidence of UC ranged from 4.3-5.3/100000 personyears whilst the incidence of CD ranged from 0.74-3.5/100000 person-years.Prevalence ranged from 15.0-24.1/100000 inhabitants for UC and from 2.4-14.1/100000 inhabitants for CD.The incidence and prevalence of both UC and CD has increased significantly in Brazil over the past 21 years.Pancolitis was the most common disease distribution in patients with UC whilst colonic involvement was the most common distribution in CD.People residing in urban areas were at higher risk of developing both CD and UC.CONCLUSION The IBD burden in South America is increasing at a rate possibly even greater than other developing regions around the world.There is a paucity of highquality epidemiological studies and further robust and representative data are required to further explore modifiable risk factors and disease phenotypes.

Hepatitis B virus infection in Latin America:A genomic medicine approach

Hepatitis B virus(HBV)infection is the leading cause of severe chronic liver disease.This article provides a critical view of the importance of genomic medicine for the study of HBV infection and its clinical outcomes in Latin America.Three levels of evolutionary adaptation may correlate with the clinical outcomes of HBV infection.Infections in Latin America are predominantly of genotype H in Mexico and genotype F in Central and South America;these strains have historically circulated among the indigenous population.Both genotypes appear to be linked to a benign course of disease among the native and mestizo Mexicans and native South Americans.In contrast,genotypes F,A and D are common in acute and chronic infections among mestizos with Caucasian ancestry.Hepatocellular carcinoma is rare in Mexicans,but it has been associated with genotype F1b among Argentineans.This observation illustrates the significance of ascertaining the genetic and environmental factors involved in the development of HBV-related liver disease in Latin America,which contrast with those reported in other regions of the world.

Evolution of biogeographic disjunction between eastern Asia and North America in Chamaecyparis:Insights from ecological niche models

The disjunct distribution of plants between eastern Asia(EA) and North America(NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long debated. Chamaecyparis is a good model to test previous hypotheses about the formation of this disjunct pattern as it contains six species disjunctly distributed in EA, western North America(WNA)and eastern North America(ENA). In this study, we applied ecological niche models to test the formation of the disjunct pattern of Chamaecyparis. The model calibrated with the EA species was able to predict the distribution of eastern NA species well, but not the western NA species. Furthermore, the eastern Asian species were shown to have higher niche overlap with the eastern North American species. The EA species were also shown to share more similar habitats with ENA species than with WNA species in the genus. Chamaecyparis species in WNA experienced a significant niche shift compared with congeneric species. Chamaecyparis had a low number of suitable regions in Europe and the middle and western NA during the Last Glacial Maximum(LGM) period, and became extinct in the former region whereas it retains residual distribution in the latter. The extirpations in western NA and Europe in response to the late Neogene and Quaternary climatic cooling and the more similar habitats between ENA and EA ultimately shaped the current intercontinental disjunct distribution of Chamaecyparis. Both current hypotheses may be also jointly applied to explain more eastern Asian and eastern North American disjunctions observed today.

Dining Culture Difference between China and America in The Joy Luck Club

The paper focuses on the dining culture difference between china and America according to analyzing the period of the film, The Joy Luck Club, in which Waverly takes her boyfriend Rich to meet his future mother-in-law.

Helicobacter pylori recurrence after eradication in Latin America:Implications for gastric cancer prevention

To estimate Helicobacter pylori (H. pylori) recurrence rate in Latin America, a region with a significant H. pylori prevalence and gastric cancer burden. METHODSPubMed, LILACS, SciELO, Cochrane databases and abstracts from relevant meetings were reviewed. Information collected included: Participants’ characteristics, recruitment strategy, diagnostic modality, treatment arms, follow-up and recurrence rates. Recurrence was calculated using 100-patients-year rates, and data were pooled using a random effects model. The I2 statistic assessed between study heterogeneity. Meta-regression analyses evaluated for effect modifying variables. RESULTSLiterature search yielded 163 articles. Twelve studies involving 4848 patients from 9 countries met inclusion criteria. Four hundred and thirty-two reinfections were recorded in 5487 person-years of follow-up. Pooled analysis showed a recurrence rate of 7.9 cases per 100 person-years (95%CI: 5.3-10.5). Meta-regression revealed that neither the antibiotic schema, a second antibiotic course, nor the diagnostic modality had an impact on the observed risk of recurrence. The recurrence rate in the first year after treatment, predominantly recrudescence, was 11.2 (6.1-16.4) per 100 patient years. Recurrence in subsequent years, was only 6.2 (3.8-8.7). CONCLUSIONH. pylori recurrence rates in Latin America are significant, and with geographic variability, yet are acceptable based upon the current literature for consideration of large scale intervention trials. Further research in Latin America is warranted to evaluate the efficacy, cost-effectiveness, and potential adverse outcomes of proposed eradication programs.

Impact of the Kuroshio Extension Oceanic Front on Autumn and Winter Surface Air Temperatures over North America

Mid-latitude air-sea interaction is an important topic that attracts a considerable amount of research interest. The Kuroshio Extension(KE) is one of the main western boundary currents and plays a critical role in the mid-latitude atmospheric circulation. This paper uses the NCEP/NCAR reanalysis and Hadley sea surface temperature datasets to investigate the influence of oceanic fronts in the KE region on surface air temperature in North America over the period 1949–2014. A significant correlation was found between the KE front intensity and the temperatures over North America in autumn and winter. A strong(weak) KE front anomaly in autumn is associated with an increasing(decreasing) surface temperature over western North America but a decreasing(increasing) surface temperature over eastern North America. In winter, central North America warms(cools) when the KE front is strong(weak). The response of the atmospheric circulation, including wind in the high and low troposphere, troughs, and ridges, to the strengthening(weakening) of the KE front is the main cause of these changes in surface temperature.

Latitudinal trends in genus richness of vascular plants in the Eocene and Oligocene of North America

The latitudinal richness gradient is a frequent topic of study on the modern landscape,but its history in deep time is much less well known.Here,we preliminarily evaluated the paleolatitudinal richness gradient of vascular plants for the Eocene(56-33.9 million years ago) and Oligocene(33.9-23 million years ago) epochs of North America north of IVlexico using 201 fossil floras.We calculated the direction and shape of the gradient using quadratic regression to detect linear and curvilinear trends.We performed regressions for the Eocene and Oligocene as well as for informal time intervals within the Eocene:early,middle,and middle + late.We found that quadratic models better explain the data than linear models for both epochs as well as for the early Eocene.A roughly linear trend in the middle and middle + late intervals may reflect limited sampling of high latitude floras for those times.The curvilinear relationship was weak for the Eocene and the model showed a peak in richness at 45.5°N.The curvilinear relationship was much stronger for the Oligocene and the peak occurred at 48.5°N.In the Eocene,the mid-latitude peak in richness may be explained by mean annual temperature,which was probably higher at some mid-latitudes than at lower ones.For the Oligocene,the peak in richness at midlatitudes may be explained by evolutionary diversification within the temperate zone or by increased aridity at low latitudes.We also assessed the latitudinal richness gradient of genera within modern floras in North America north of Mexico and we found a weak,curvilinear trend with a peak in richness at 31.5°N.Our results suggest that the latitudinal genus richness gradient of vascular plants in North America continued to develop into its modern structure following the Oligocene.

African Cassava Whitefly,Bemisia tabaci,Resistance in African and South American Cassava Genotypes

The whitefly,Bemisia tabaci,is a major pest of cassava,particularly in Africa where it is responsible both for the transmission of plant viruses and,increasingly,for direct damage due to feeding by high populations.To date,there have been no practical solutions to combat this emerging problem,due to the inability of the subsistence farmers that grow cassava to afford expensive inputs such as insecticides.A programme of research was carried out linking institutes in Africa,the UK and South America,to identify possible resistance sources in cassava to the whitefly,Bemisia tabaci.The South American genotype MEcu 72 and several Ugandan cassava landraces including Ofumba Chai,Nabwire 1 and Mercury showed good levels of resistance to B.tabaci.Field and screen-house experiments showed that all of the improved,high-yielding cassava mosaic disease（CMD）resistant cassava genotypes assessed were highly susceptible to B.tabaci and supported high populations of all life stages.These data support the hypothesis that the continuing high populations of cassava B.tabaci in Uganda are due,in part,to the widespread adoption of CMD-resistant cassava varieties during the CMD pandemic.They also show that the whitefly,Aleurotrachelus socialis,resistance present in the South American cassava genotypes could have broader applicability in the Old World.

Distribution,Properties,Land Use and Management of Mollisols in South America

Mollisols are common in South America. They cover about 8.87 × 107ha, 1.3 × 107ha and 4.3 × 106ha in Argentina, Uruguay and Southern Brazil respectively, which is 11.5% of the world total. Most of South American Mollisols were developed on Pleistocene and Holocene sediments and lie within the limits of the temperate zone, though the extreme north is bordering subtropical and the extreme south is within a cold-temperate zone. All suborders of Mollisols occur in Argentina, the most extensive being Udolls followed by Ustolls, whereas only Udolls, Aquolls and Albolls occur in Uruguay. Vertisols in Uruguay have many properties similar to Mollisols, and the occurrence of Vertisols is strongly associated with Mollisols. The Pampean Mollisols are a significant component of the global breadbasket of modem times. The main Argentine crops are wheat, corn, sorghum, barmy, soybeans and sunflower, while Mollisols in Uruguay remain mostly dedicated to cattle and sheep grazing though crop production has been increasing very rapidly in the last decade. Throughout South America, research has shown that Mollisols are experiencing losses of soil organic matter and nutrients, and degradation of physical properties after long cropping periods, resulting in soil scientists calling for increased conservation practices to reduce future losses and a deterioration of soil quality, and thus a more sustainable agriculture in the region.