• 제목/요약/키워드: population migration

검색결과 372건 처리시간 0.027초

Regenwurmpopulationen in ackerbaulich ge-nutzten Flachen und deren Randbereichen. I.Ostliches Harzvorland

  • christine Hemmann;Leithold, und-Gunter
    • 한국유기농업학회지
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    • 제3권1호
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    • pp.23-42
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    • 1994
  • This paper studied earthworm populations in fields under practical cultivation in the Eastern Harzforeland (Germany). The examined sites differed insignificantly in their climatic and soil conditions. The examination was a comparison between a field and a narrow edge or meadow. A combination of Oktett method and handsortin was used. The five different habitates seven earthworm species were discoverd. The most frequently foundd were A. rosea, A. caliginosa, and A. chlorotica. There were clear differences in species between the habitates of each site. Generally the edge or the meadow contained one (Zoeberitz) or two (Zscherben) more species than the field. The composition of species differed between 1990 and 1992. In the dry Autumn of 1991 there were less species found at both sites. The occurance of earthworm species depends on the weather. Moisture influencing similiarity of abundance and bio-mass were recorded in three out of four habitates. Starting on a high level in Autumn 1990 the abundance as well as biomass decreased until Autumn 1991 and increased the following year. The number from 1990 were never reached again during the examination. One year of normal precipita-tion was not enough to return the population to the beginning level. Great differences in the number of earthworms between the compared habitats suggest that the edges and meadows are a potential immigration source into a field which is poor on earthworms. Structrues of distribution near the edge refer to a migration from a high populated edge into an almost empty field.

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Complete mitochondrial genome of Nyctalus aviator and phylogenetic analysis of the family Vespertilionidae

  • Lee, Seon-Mi;Lee, Mu-Yeong;Kim, Sun-sook;Kim, Hee-Jong;Jeon, Hye Sook;An, Junghwa
    • Journal of Species Research
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    • 제8권3호
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    • pp.313-317
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    • 2019
  • Bats influence overall ecosystem health by regulating species diversity and being a major source of zoonotic viruses. Hence, there is a need to elucidate their migration, population structure, and phylogenetic relationship. The complete mitochondrial genome is widely used for studying the genome-level characteristics and phylogenetic relationship of various animals due to its high mutation rate, simple structure, and maternal inheritance. In this study, we determined the complete mitogenome sequence of the bird-like noctule (Nyctalus aviator) by Illumina next-generation sequencing. The sequences obtained were used to reconstruct a phylogenic tree of Vespertilionidae to elucidate the phylogenetic relationship among its members. The mitogenome of N. aviator is 16,863-bp long with a typical vertebrate gene arrangement, consisting of 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 putative control region. Overall, the nucleotide composition is as follows: 32.3% A, 24.2% C, 14.3% G, and 29.2% T, with a slight AT bias (61.5%). The base composition of the 13 PCGs is as follows: 30.3% A, 13.4% G, 31.0% T, and 25.2% C. The phylogenetic analysis, based on 13 concatenated PCG sequences, infers that N. aviator is closely related to N. noctula with a high bootstrap value (100%).

Landuse and Landcover Change and the Impacts on Soil Carbon Storage on the Bagmati Basin of Nepal

  • Bastola, Shiksha;Lim, Kyuong Jae;Yang, Jae Eui;Shin, Yongchul;Jung, Younghun
    • 한국지반환경공학회 논문집
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    • 제20권12호
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    • pp.33-39
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    • 2019
  • The upsurge of population, internal migration, economic activities and developmental works has brought significant land use and land cover (LULC) change over the period of 1990 and 2010 in the Bagmati basin of Nepal. Along with alteration on various other ecosystem services like water yield, water quality, soil loss etc. carbon sequestration is also altered. This study thus primary deals with evaluation of LULC change and its impact on the soil carbon storage for the period 1990 to 2010. For the evaluation, InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Carbon model is used. Residential and several other infrastructural development activities were prevalent on the study period and as a result in 2010 major soil carbon reserve like forest area is decreased by 7.17% of its original coverage in 1990. This decrement has brought about a subsequent decrement of 1.39 million tons of carbon in the basin. Conversion from barren land, water bodies and built up areas to higher carbon reserve like forest and agriculture land has slightly increased soil carbon storage but still, net reduction is higher. Thus, the spatial output of the model in the form of maps is expected to help in decision making for future land use planning and for restoration policies.

Opportunities and Constraints of Beekeeping Practices in Ethiopia

  • Dekebo, Aman;Bisrat, Daniel;Jung, Chuleui
    • 한국양봉학회지
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    • 제34권2호
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    • pp.169-180
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    • 2019
  • Beekeeping has been practiced for centuries in Ethiopia. Currently, there are three broad classification of honey production systems in Ethiopia; these are traditional (forest and backyard), transitional(intermediate) and modern(frame beehive) systems. Ethiopian honey production is characterized by the widespread use of traditional technology resulting in relatively low honey yield and poor honey quality. Despite the challenges and constraints, Ethiopia has the largest bee population in Africa with over 10 million bee colonies, of which 5 to 7.5million are hived while the remaining exists in the wild. Consequently, these figures, indeed, has put Ethiopia as the leading honey and beeswax producer in Africa. In fact, Ethiopia has even bigger potential than the current honey production due to the availability of plenty apicultural resources such as natural forests with adequate apiculture flora, water resources and a high number of existing bee colonies. However, lack of well-trained man powers, lack of standardization, problems associated with honey bee pests and diseases, high price and limited availability of modern beekeeping equipment's for beekeepers and absconding and migration of bee colonies are some of the major constraints reported for beekeeping in Ethiopia. In this review, an attempt was made to present all beekeeping practices in Ethiopia. The opportunities and major constraints of the sector were also discussed.

Cochlear Implant Failure in the Pediatric Population

  • Ozer, Fulya;Yavuz, Haluk;Yilmaz, Ismail;Ozluoglu, Levent N.
    • Journal of Audiology & Otology
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    • 제25권4호
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    • pp.217-223
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    • 2021
  • Background and Objectives: In cochlear implant (CI) surgery, the results and causes of revision and reimplantation may guide surgeons in establishing surgical protocols for revision surgery with safe audiological outcomes. The aim of this study was to review our experience in terms of etiology, surgical strategy, and hearing outcomes in pediatric patients who underwent CI removal and reimplantation. Subjects and Methods: All patients received implants of the same brand. Pre and postoperative Categories of Auditory Performance score and aided free-field pure tone audiometry thresholds were noted. In vivo integrity tests were performed for each patient and the results of ex vivo tests of each implant were obtained from manufacturer. Results: A total of 149 CIs were placed in 121 patients aged <18 years. The revision rate in children was 6.7% (10/121 children). Six patients had a history of head injury leading to a hard failure. The causes of reimplantation in others were soft failure (n=1), electrode migration (n=1), infection (n=1), and other (n=1). All patients showed better or similar postreimplantation audiological performance compared with pre-reimplantation results. Conclusions: It is very important to provide a safe school and home environment and educate the family for reducing reimplantation due to trauma. Especially for active children, psychiatric consultation should be continued postoperatively.

Cochlear Implant Failure in the Pediatric Population

  • Ozer, Fulya;Yavuz, Haluk;Yilmaz, Ismail;Ozluoglu, Levent N.
    • 대한청각학회지
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    • 제25권4호
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    • pp.217-223
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    • 2021
  • Background and Objectives: In cochlear implant (CI) surgery, the results and causes of revision and reimplantation may guide surgeons in establishing surgical protocols for revision surgery with safe audiological outcomes. The aim of this study was to review our experience in terms of etiology, surgical strategy, and hearing outcomes in pediatric patients who underwent CI removal and reimplantation. Subjects and Methods: All patients received implants of the same brand. Pre and postoperative Categories of Auditory Performance score and aided free-field pure tone audiometry thresholds were noted. In vivo integrity tests were performed for each patient and the results of ex vivo tests of each implant were obtained from manufacturer. Results: A total of 149 CIs were placed in 121 patients aged <18 years. The revision rate in children was 6.7% (10/121 children). Six patients had a history of head injury leading to a hard failure. The causes of reimplantation in others were soft failure (n=1), electrode migration (n=1), infection (n=1), and other (n=1). All patients showed better or similar postreimplantation audiological performance compared with pre-reimplantation results. Conclusions: It is very important to provide a safe school and home environment and educate the family for reducing reimplantation due to trauma. Especially for active children, psychiatric consultation should be continued postoperatively.

Characteristics of Wintering Habitat use by Black-tailed Gulls (Larus crassirostris) on the West Coast of Korea

  • Tehan Kang;Soon Sik Kim;Daehan Cho;Tae Wan Kim;Woon Kee Paek;Si-Wan Lee
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제5권2호
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    • pp.37-42
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    • 2024
  • This study used a GPS tracker to determine characteristics of wintering habitat use by black-tailed gulls on the west coast of Korea. Results of this study showed a southward movement in December and a northward movement in March. The wintering habitat was confirmed to include the southwest coastal island area (Group 1), the inland coastal area (Group 2), and China (Group 3). The wintering home range was the narrowest in October and the widest in December. Home range of Group 1 was increased from November, showing the maximum in December, decreased in February, and then tended to increase again in March. Group 2 showed the widest home range in November and a narrow range of home range from December. Home range of Group 3 showed a mixed pattern of group 1 and group 2. The flight rate was the lowest in January and the highest in March. Day and night flight rates showed significant differences by month. This study identified wintering characteristics of the West Coast population of black-tailed gulls on the West Coast, including their wintering areas, migration periods, and use patterns. These wintering characteristics of black-tailed gull in the west coast area are thought to be affected by environmental factors (such as food resources and fishing activities) and geographical characteristics of the West Coast where many islands are distributed.

한국인 혼인행태 변화분석 (Analysis on Change in Korean Marriage Behaviors)

  • 이삼식
    • 한국인구학
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    • 제16권2호
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    • pp.84-110
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    • 1993
  • This study aims at identifying the recent change in marriage behaviors in Korea. The data used here is the vital statistics compiled from the vital registration system of which registration form is put on one from together with the civil registration form. According to the results of this analysis, since 1970 the number of marriages has steadily increased from about 300, 000 in the former of 1970s to about 400, 000 in the latter of 1980s, appproximately coincided with the change in population size at the marriageable age span. The few exceptions that can be seen in the 1970s seem to result from the impact of social upheavals during 1950s; since the birth cohorts affected by the low fertility during the Korean war and the post-war baby-boom generations chracterized by the high fertility entered the marriage market in the 1970s. However, the marriage rate shows a little increase from around 7 in the former of 1970s to around 9 in the latter of 1980s, indicating that the marriage prevalence has been more or less inconsiderably changed during this period. It is also found that the proportion of remarriage to the total marriages has increased to around 10 per cent in 1989, while decreasing that of first marriage. This fact can be attributable to the higher prevalence of divorces and the collapsing of the Confucianism ethic which contributed to expediting the remarriage of widows. Although this proportion is insignificant compared with that of the of more developed countries, it is not difficult to say that the proportion of remarriages will continue to increase in future. The age first at first marriage(AFM) which directly affects the span exposed to the risks pregnancy has increased to the age about 28 for male and about 25 for female in recent years. However, big difference in AFM between urban and rural areas has narrowed, resultant from the increasing involuntary postponement of marriage of rural young population who have met difficulties in seeking their bride or bridegroom in rural areas characterized by the heavy out-migration of young, particularly female, population. The present study shows the reverse relationship between AFM and educational attainment; i.e, the higher the educational attainment the lower the AFM. The conditions which are taken into considerations were the class and the family in the past time but which are, educational attainment, job and personal characteristics. With regard to the age condition, in recent years the male prefers the female younger than himself on the average by 3 years and vice versa, which is reduced form 4-5 years in beginning of 1970s. The age difference bride and bridegroom tends to decrease with the educational attainment increase. This may be attributable to the fact that the persons with the higher educational attainment prefer the love marriage and hence are more likely to choose their counterparts in the about same age. The education condition is characterized by the bridegroom having the higher educational level than bride. It is also significant to note that the proportion of love marriage has increased, whereas that of traditional arranged marriage has decreased. This is true in the urban areas than the rural areas, indicating that rights as well as responsibilities for marriage have been handed over the young population from their parents. In conclusion, the change in the marriage behaviors in Korea are characterized by increasing tendency for the postponement of first marriage, higher prevalences of divorces and a result remarriages, increase of love marriages, narrowing age difference between bride and bridegroom, etc. which are the main results of rapid industrization, increase in educational and economic activity opportunities and change in the ideals of marriages during the past decades. These phenomena prevailing in Korean society would affect not only the family structure that will become less proliferiated but the population size and structure. The most important is that the changes in marriage behaviors of Koreans and their impact on the society with respect to norms, values, morals, of individual and family in the social aspect, change in population size and structure in the demograpic aspects, and economic development in the economic aspects should be integrated into the plannings towards to the future.

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가족계획과 보건사업의 통합시도 및 평가결과 (Review of Family Planning / Health Integration Efforts and Evaluation Results in Korea)

  • Bang, Sook
    • 한국인구학
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    • 제10권2호
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    • pp.58-81
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    • 1987
  • 본 연구의 목적은 미국에 거주하는 65세 이상의 한국 영주권자 노인들의 주거형태에 영향을 끼치는 요인들을 조사하는 것이다. 이를 위해 1990년 미국 센서스 데이터인 Public Use Microdata(Samples PUMS)의 8% sub-sample을 이용하였다. 주거형태에 영향을 주는 주요변인들로 동화과정(이민 온 연령과 영어구사능력), 경제적 요인 (지난 일년간의 개인수입과 보조적 보장소득 수혜여부), 건강상태(외출활동과 일상생활 활동능력), 그리고 민족 지역공동체 등이 포함되었으며, 나이, 성별, 교육, 결혼상태 등의 변인들을 함께 통제하여 분석하였다. 연구결과 동화과정과 경제적 여유는 재미 한국 영주권자 노인의 단독주거에 긍정적인 역할을 하고 있는 반면, 건강과 한국 지역공동체는 주거형태에 통계적으로 일관된 영향력을 보이지 않았다. 동화과정의 측정변수로서 이민연령의 효과는 배우자 유무에 상관없이 통계적으로 유의미하게 한국 노인들의 단독거주에 긍정적인 것으로 나타난 반면, 영어구사 능력의 경우, 무배우자 노인들 중 영어구사능력이 높을수록 가족과 함께 살고 있었고, 유배우자 노인들에게는 영어를 구사할 수 있는 능력이 가족과 떨어져 사는 데 긍정적인 역할을 하였다. 특히 무배우자 노인들의 경우, 이민연령의 효과 역시 순수한 의미의 동화과정이라기보다는 사회보장 프로그램을 수혜하기 위한 자격조건과 한인지역 네트워트 파악을 위한 적응기간이라는 설명이 더 설득력이 있다. 배우자의 유무와는 무관하게 보조적 보장소득의 혜택을 받고 있는 한국 노인들이 그렇지 않은 노인들보다 두 세배 이상 단독주거를 하고 있었다. 일단 보조적 보장소득을 수혜하고 있는 노인들에게는 메디케이드, 푸드스탬프, 정부지원 월세보조금, 공공요금 할인 등 다양한 사회보장 프로그램을 받을 수 있는 자격이 주어지므로 대부분의 보조적 보장소득 수혜 노인들은 단순히 금전적인 수입의 측면뿐 아니라 그 외의 사회보장 프로그램에 의존하고 있다. 이러한 면에서 보조적 보장소득의 수혜는 한국 영주권자 노인들의 독립적인 삶에 큰 역할을 하고 있다. 이러한 사회복지 프로그램을 영주권자들에게는 전면 금지하는 새로운 사회복지법은 재미 한국 영주권자 노인들뿐 아니라 그들의 가족들에게도 막대한 경제적 부담을 줄 것이다. 본 논문은 영주권자 노인들을 대상으로 분석한 것이지만, 주거형태를 비롯한 일반적인 특성을 비교해 보면 영주권자, 귀화 시민권자, 그리고 미국태생 노인들은 다른 성격의 집단들임을 보여주고 있다. 종래의 소수민족 노인들에 관한 연구들이 이민자 노인들을 영주권자와 귀화 시민권자의 구분없이 하나의 집단으로 간주하고 분석해 왔던 것을 볼 때, 앞으로의 연구는 이론적으로나 방법론적으로 시민권의 유무가 주거형태에 끼치는 영향도 함께 고려해야 할 것이다.

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재미 한국 영주권자 노인들의 주거형태에 관한 연구 (A Study on Living Arrangement of Older Korean Noncitizens in the United States)

  • 이금룡
    • 한국인구학
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    • 제20권2호
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    • pp.99-134
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    • 1997
  • 본 연구의 목적은 미국에 거주하는 65세 이상의 한국 영주권자 노인들의 주거형태에 영향을 끼치는 요인들을 조사하는 것이다. 이를 위해 1990년 미국 센서스 데이터인 Public Use Microdata(Samples PUMS)의 8% sub-sample을 이용하였다. 주거형태에 영향을 주는 주요변인들로 동화과정(이민 온 연령과 영어구사능력), 경제적 요인 (지난 일년간의 개인수입과 보조적 보장소득 수혜여부), 건강상태(외출활동과 일상생활 활동능력), 그리고 민족 지역공동체 등이 포함되었으며, 나이, 성별, 교육, 결혼상태 등의 변인들을 함께 통제하여 분석하였다. 연구결과 동화과정과 경제적 여유는 재미 한국 영주권자 노인의 단독주거에 긍정적인 역할을 하고 있는 반면, 건강과 한국 지역공동체는 주거형태에 통계적으로 일관된 영향력을 보이지 않았다. 동화과정의 측정변수로서 이민연령의 효과는 배우자 유무에 상관없이 통계적으로 유의미하게 한국 노인들의 단독거주에 긍정적인 것으로 나타난 반면, 영어구사 능력의 경우, 무배우자 노인들 중 영어구사능력이 높을수록 가족과 함께 살고 있었고, 유배우자 노인들에게는 영어를 구사할 수 있는 능력이 가족과 떨어져 사는 데 긍정적인 역할을 하였다. 특히 무배우자 노인들의 경우, 이민연령의 효과 역시 순수한 의미의 동화과정이라기보다는 사회보장 프로그램을 수혜하기 위한 자격조건과 한인지역 네트워트 파악을 위한 적응기간이라는 설명이 더 설득력이 있다. 배우자의 유무와는 무관하게 보조적 보장소득의 혜택을 받고 있는 한국 노인들이 그렇지 않은 노인들보다 두 세배 이상 단독주거를 하고 있었다. 일단 보조적 보장소득을 수혜하고 있는 노인들에게는 메디케이드, 푸드스탬프, 정부지원 월세보조금, 공공요금 할인 등 다양한 사회보장 프로그램을 받을 수 있는 자격이 주어지므로 대부분의 보조적 보장소득 수혜 노인들은 단순히 금전적인 수입의 측면뿐 아니라 그 외의 사회보장 프로그램에 의존하고 있다. 이러한 면에서 보조적 보장소득의 수혜는 한국 영주권자 노인들의 독립적인 삶에 큰 역할을 하고 있다. 이러한 사회복지 프로그램을 영주권자들에게는 전면 금지하는 새로운 사회복지법은 재미 한국 영주권자 노인들뿐 아니라 그들의 가족들에게도 막대한 경제적 부담을 줄 것이다. 본 논문은 영주권자 노인들을 대상으로 분석한 것이지만, 주거형태를 비롯한 일반적인 특성을 비교해 보면 영주권자, 귀화 시민권자, 그리고 미국태생 노인들은 다른 성격의 집단들임을 보여주고 있다. 종래의 소수민족 노인들에 관한 연구들이 이민자 노인들을 영주권자와 귀화 시민권자의 구분없이 하나의 집단으로 간주하고 분석해 왔던 것을 볼 때, 앞으로의 연구는 이론적으로나 방법론적으로 시민권의 유무가 주거형태에 끼치는 영향도 함께 고려해야 할 것이다.

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