Population geography in China since the 1980s： Forging the links between population studies and human geography

This paper reviews the progress of population geography in China since the 1980 s. The review results suggest that contrary to the common perception of its invisibility and marginalized status in the field, tremendous progress has been made in population geography in China since the 1980 s. Population geographers have made significant contribution to the understanding of a wide range of population issues from geographical perspectives, including migration, urbanization, population distribution, the relationships between population, environment and resources, aging, marriage patterns, and migrants＇ crimes, although such contribution often did not appear in the geographical circle. Furthermore, population geographers have played an indispensable role in revitalizing population studies in China and forging its links to human geography, occupying an important position in this multi-disciplinary field. Population geographers＇ contribution to the areas of migration and urbanization research has been particularly significant, reflected in their leading roles in these areas＇ research. The paper demonstrates that as latecomers in the field after more than 20 years of isolation, population geographers in China have gone through a process of catching up and increasing engagement with developments in social sciences and increasing interaction with social scientists since the 1980 s, and have benefited greatly from it; however, there is a tendency for population geography to be increasingly alienated from the main stream human geography, a phenomenon similar to but not exactly the same as Anglo-American geography in the late 1990 s and early 2000 s. The paper argues that population geography is only half way in the course to forge the links between population studies and human geography, and it needs to return to geographical sciences to strike a healthy balance between the field of population studies and that of human geography, and promote its further development in a multi-disciplinary field.

Main visual symptoms associated with refractive errors and spectacle need in a Brazilian population

AIM： To determine the main visual symptoms in a Brazilian population sample, associated to refractive errors（REs） and spectacle need to suggest priorities in preventive programs.METHODS： A cross-sectional study was conducted in nine counties of the southeast region of Brazil, using a systematic sampling of households, between March 2004 and July 2005. The population was defined as individuals aged between 1 and 96 y, inhabitants of 3600 residences to be evaluated and 3012 households were included,corresponding to 8010 subjects considered for participation in the survey, of whom 7654 underwent ophthalmic examinations. The individuals were evaluated according their demographic data, eye complaints and eye examination including the RE and the need to prescribe spectacles according to age. Statistical analysis was performed using SPSS software package and descriptive analysis using 95% confidence intervals（P〈0.05）. RESULTS： The main symptom detected was asthenopia, most frequent in the 2ndand 3rddecades of life, with a significant decline after the 4thdecade.Astigmatism was the RE most associated with asthenopia. Reduced near vision sight was more frequent in those ≥40y with a progressive decline thereafter.Spectacles were most frequently required in subjects of≥40 years of age.CONCLUSION： The main symptom related to the vision was asthenopia and was associated to astigmatism. The greatest need for spectacles prescription occurred after40＇s, mainly to correct near vision. Subjects of ≥40years old were determined to be at high risk of uncorrected REs. These observations can guide intervention programs for the Brazilian population.

A STUDY OF PRECANCEROUS GASTRIC LESIONS IN A HIGH RISK POPULATION

A study of precancerous gastric lesion was conducted in a randomly selected high risk population in Linqu, Shandong Province of China. 849 subjects aged from 30-64 were examined bioptically. There were 8 cases of gastric cancer, the prevalence rate was 0.9%. 169 subjects were diagnosed to be dysplasia, the prevalence rate of dysplasia was increased significantly with age. The regression equation was Y=0.47X-0.25. The prevalence of CAG was found in 36 per cent of the studied subjects and both dysplasia and CAG were more serious in the antrum than the. fundus. The results showed a natural history of precancerous gastric lesions in a high risk population in a high risk area.

The Study of Health Effects of Vinyl Chloride AirPollution on Population

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR),-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control,but noγ-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs

Identification of individuals with non-alcoholic fatty liver disease by the diagnostic criteria for the metabolic syndrome

AIM:To clarify the efficiency of the criterion of metabolic syndrome to detecting non-alcoholic fatty liver disease(NAFLD).METHODS:Authors performed a cross-sectional study involving participants of a medical health checkup program including abdominal ultrasonography.This study involved 11 714 apparently healthy Japanese men and women,18 to 83 years of age.NAFLD was defined by abdominal ultrasonography without an alcohol intake of more than 20 g/d,known liver disease,or current use of medication.The revised criteria of the National Cholesterol Education Program Adult Treatment PanelⅢ were used to characterize the metabolic syndrome.RESULTS:NAFLD was detected in 32.2%(95%CI:31.0%-33.5%)of men(n=1874 of 5811)and in 8.7%(95%CI:8.0%-9.5%)of women(n=514 of 5903).Among obese people,the prevalence of NAFLD was as high as 67.3%(95%CI:64.8%-69.7%)in men and 45.8%(95%CI:41.7%-50.0%)in women.Although NAFLD was thought of as being the liver phenotype of metabolic syndrome,the prevalence of the metabolic syndrome among subjects with NAFLD was low both in men and women.66.8%of men and 70.4%of women with NAFLD were not diagnosed with the metabolic syndrome.48.2%of men with NAFLD and 49.8%of women with NAFLD weren't overweight[body mass index(BMI)≥25 kg/m2].In the same way,68.6%of men with NAFLD and 37.9%of women with NAFLD weren't satisfied with abdominal classification(≥90 cm for men and≥80 cm for women).Next,authors defined it as positive at screening for NAFLD when participants satisfied at least one criterion of metabolic syndrome.The sensitivity of the definition"at least 1 criterion"was as good as 84.8%in men and 86.6%in women.Separating subjects by BMI,the sensitivity was higher in obese men and women than in non-obese men and women(92.3%vs 76.8%in men,96.1%vs 77.0%in women,respectively).CONCLUSION:Authors could determine NAFLD effectively in epidemiological study by modifying the usage of the criteria for metabolic syndrome.

Pancreatic ductal adenocarcinoma screening:New perspectives

Pancreatic ductal adenocarcinoma accounts for more than 90% of all pancreatic cancers and its incidence has increased significantly worldwide.Patients with pancreatic ductal adenocarcinoma have a poor outcome and more than 95% of the people affected die from the disease within 12 mo after diagnosis.Surgery is the first-line treatment in the case of resectable neoplasm,but only 20% of patients are candidates for this approach.One of the reasons there are few candidates for surgery is that,during the early phases of the disease,the symptoms are poor or non-specific.Early diagnosis is of crucial importance to improve patient outcome;therefore,we are looking for a good screening test.The screening test must identify the disease in an early stage in order to be effective;having said this,a need exists to introduce the concept of "early" ductal adenocarcinoma.It has been reported that at least five additional years after the occurrence of the initiating mutation are required for the acquisition of metastatic ability of pancreatic adenocarcinoma and patients die an average of two years thereafter.We have reviewed the most recent literature in order to evaluate the present and future perspectives of screening programs of this deadly disease.

Four decades of studies on population aging in China

The last 4 decades of reform and opening up have not only witnessed the rapid development of China’s social economy,but have also marked the crucial transition of China’s demographic structure from one that is mature to one that is old.As China’s population has aged rapidly in recent years,studies of aging have made worthwhile achievements documenting the process.This article mainly summarizes the development of studies on aging in China during the past 40 years and finds that research into the topic of aging during these years can be divided into three phases.The phases are characterized by particular kinds of research.Phase one,the study of aging trends and causes;phase two,the study of aging characteristics and policy responses;and phase three,the study of top-level design of aging policies and programs,and the development of integrated interdisciplinary research efforts.The five main characteristics of China’s studies on aging during the past 4 decades and five future prospects for studies on aging are discussed at the end of this paper.

Times Series Applied to Study Vitamin D Seasonality in Argentina

In this study, we analyze how vitamin D (VD) serum levels flow with latitude and throughout seasons of the year within a population sample over three years, taking into account that VD is mainly photosynthesized in the skin from sun exposure. Vitamin D levels have been measured in 80,763 patients during 2013, 2014, and 2015. To accomplish the objectives, we first perform some inference tests like two-way Analysis of Variance (ANOVA) followed by post-hoc tests. Secondly, we develop time series techniques including cross correlation calculations. Least than 10% of the sample had healthy VD levels, which should be a fact of public health major concern. The effect of the interaction between the two factors, zones and seasons, was proved by ANOVA. The mean values which are significantly different were determined by post hoc test. Furthermore, we find that mean serum VD levels, measured as 25-hydroxy-VD, follow a seasonal lag pattern of 9 weeks, a delay for minimum and maximum values after the respective equinoxes and daily sunlight duration. Reliable estimates of the population are provided in the present study, since one of the strengths is its huge sample size. We have quantitatively characterized the seasonality of serum vitamin D levels in the Argentine and the seasonal lag pattern has been determined for the study region.

The Role of Recruitment and Retention in Clinical Trials

It is evident that both recruitment and retention play critical roles in clinical trials. Recruitment and retention models are beginning to be analyzed worldwide in an effort to assess how to conduct studies more efficiently, all the while, allowing researchers to provide sound and ethical data to help advance medicine through clinical studies. Sponsors and sites have recognized that clinical trial enrollment must become more diverse and inclusive. In this review, we address the important topics of recruitment and retention in clinical trials. Specifically, the obstacles in regard to recruiting vulnerable populations. Methodologies to improve both the understanding of the study population and community engagement are outlined. In particular, newer strategies such as use of social media and more reliable strategies such as trust and relationship building are described in detail. A strong focus on recruitment is becoming widely recognized as being of such importance that consideration is given to this key component even during initial protocol development. Attention to recruitment and retention in the strategic planning process of clinical trials can mitigate enrollment issues that clinical researchers are experiencing.

Personalities and health in older cat and dog owners: A HUNT-study

The aim of this population study was to identify personality traits among older (>65 years) male and female owners of cats and dogs and to compare their general health status in relation to their personality. Further, the aim was to examine whether current cat and dog ownership could be predicted by the owners’ personality and health. Data were collected from the North-Tr&#248ndelag Health Study (HUNT) in Norway. Included were a total of 1897 cat or dog owners between the ages of 65 years and 101 years. The results showed that there were a higher proportion of introverted male cat owners than extraverted ones. Moreover, a majority of women with cats reported that their health was not good. Furthermore, female cat owners who displayed higher scores on neurotic traits experienced significantly poorer health compared to those female cat owners that experienced good health. The same was true for female cat owners who considered themselves to be introverted. Neither personality nor health could predict pet-ownership, but it was more likely for older individuals (80-101 years) to own a cat than a dog. This study has shown that human personality is associated with cat and dog ownership, but there are other factors connected with pet ownership as well.

Study on three level system population transfer

Stimulated-Raman-adiabatic-passage (STIRAP) process provides an effective technique to transfer electron population from an initial state (e.g. ground state) to excited final state for both atoms and molecules. In this paper, we present the results of the study on electron population transfer in three level system. We have analyzed the effects of various conditions on the transfer process, such as the time delay of the two laser beams, two-photon off-resonance, one-photon off-resonance and the change of relative laser intensity. The numerical result is compared with experiment, and the reasons for the effects are also given.

Variables associated with olfactory disorders in adults: A U.S.population-based analysis

Objective:Olfactory dysfunction is known to have significant social,psychological,and safety implications.Despite increasingly recognized prevalence,potential risk factors for olfactory loss have been arbitrarily documented and knowledge is limited in scale.The aim of this study is to identify potential demographic and exposure variables correlating with olfactory dysfunction.Methods:Cross-sectional analysis of the 2011-2012 and 2013-2014 editions of the National Health Examination and Nutrition Survey was performed.The utilized survey reports from a nationally representative sample of about 5000 persons each year located in counties across the United States.There is an interview and physical examination component which includes demographic,socioeconomic,dietary,and health-related questions as well as medical,dental,physiologic measurements,and laboratory tests.3594 adult respondents from 2011 to 2012 and 3708 respondents from 2013 to 2014 were identified from the above population-based database.The frequency of self-reported disorders as well as performance on odor identification testing was determined in relation to demographic factors,occupational or environmental exposures,and urinary levels of environmental and industrial compounds.Results:In both subjective and objective analysis,smell disorders were significantly more common with increasing age.While the non-Hispanic Black and non-Hispanic Asian populations were less likely to report subjective olfactory loss,they,along with Hispanics,performed more poorly on odor identification than Caucasians.Those with limited education had a decreased prevalence of hyposmia.Women outperformed men on smell testing.Those reporting exposure to vapors were more likely to experience olfactory dysfunction,and urinary levels of manganese,2-Thioxothiazolidine-4-carboxylic acid,and 2-Aminothiazoline-4-carboxylic acid were lower among respondents with subjective smell disturbance.In odor detection,elevated serum levels of lead and urinary levels of 2,4 dichlorophenol were associated with anosmia and hyposmia,respectively.Conclusions:This study provides current,population-based data identifying demographic and exposure elements related to smell disturbances in U.S.adults.Age,race,gender,education,exposure to vapors,urinary levels of manganese,2-Thioxothiazolidine-4-carboxylic acid,2-Aminothiazoline-4-carboxylic acid,2,4 dichlorophenol,and serum lead levels were all implicated in smell disturbance.Care should be taken in interpretation due to lack of consistency between subjective and objective measures of olfaction as well as limitations related to population-based data.Prospective trials are indicated to further elucidate these relationships.

Population inversion study of GaAs/AlGaAs three-quantum-well quantum cascade structures

A population inversion study of GaAs/AlxGa1-xAs three-quantum-well quantum cascade structures is presented. We derive the population inversion condition （PIC） of the active region （AR） and discuss the PICs on different structures by changing structural parameters such as the widths of quantum wells or barriers in the AR. For some instances, the PIC can be simplified and is proportional to the spontaneous emission lifetime between the second and the first excited states, whereas some other instances imply that the PIC is proportional to the state lifetime of the second excited state.

A study of population pharmacokinetics of linezolid in Chinese

Objective To study the population pharmacokinetic(PPK)profiles of linezolid in Chinese healthy volunteers and infected patients.Methods Linezolid 600 mg was administered to 31 Chinese healthy volunteers with a single dose and to 57 infected patients every 12 h for at least5 doses.High performance liquid chromatography was applied to determine the plasma concentration of linezol-

Large Disparity between Prevalence and Treatment Rates for Hepatitis C in Western China

Background and Aims:Recently,the World Health Organization adopted the first-ever global hepatitis strategy with the dream of eliminating viral hepatitis as a public health threat by 2030.However,the epidemiology and treatment rates of hepatitis C virus(HCV)infection in Western China are still unknown.Methods:A total of 111,916 adult individuals(15-96 years)who underwent the HCV-antibody(HCV-Ab)test in the Second Affiliated Hospital of Chongqing Medical University between 2013 and 2015 were included in this study.We retrospectively analyzed the electronic medical records'data for each,and the positivity of HCV-Ab and the treatment of HCV RNA-positive patients were evaluated.Results:During 2013-2015,the crude prevalence of HCVAb was 1.4%(95%CI:1.4-1.5;1,611/111,916)and the adjusted prevalence of HCV-Ab was 1.7%(95%CI:1.6-1.8),which was higher than in the 2006 national study(0.43%).The prevalence was 2-times higher in males than females(2.0%vs.1.1%,p<0.01).Notably,only 46%(434/951)of the HCV RNA-positive patients received standard peginterferon plus ribavirin treatment,with 370(82%)that completed treatment,of whom 272(74%)achieved sustained virologic response(SVR).Particularly,11%(32/292)of HCV RNA-positive patients were HBsAg-positive,and the SVR rate for them was lower than for the HBsAg-negative patients,but no significant difference was observed.Conclusions:HCV infection may have increased since 2006 in Western China.The SVR rate of peg-interferon plus ribavirin treatment was high,but the proportion of untreated HCV patients was large.Thus,more efforts need to be made by the government to create a scientific-based policy for HCV treatment and prevention.