• 제목/요약/키워드: pooled sample

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열탈착/GC/FID를 이용한 B, T, X 분석의 정확도 및 정밀도 평가 (A Study on Evaluation of Accuracy and Precision on B, T, X Analysis Using Thermal Desorption/Gas Chromatograph/Flams Ionization Detector)

  • 박정근;유기호
    • 한국대기환경학회지
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    • 제16권3호
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    • pp.265-275
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    • 2000
  • By using thermal desorption/gas chromatograph/flame ionization detector(TD/GC/FID), this study was carried out to evalute an accuracy and a precision on Benzene(B), Toluene(T), o-Xylene(X) analysis in an industrial hygiene laboratory. Limits of detection of TD/GC/FID on B, T, X were showed 13.75ng/sample or less. For the accuracy of the method by concentration levels, overall bias was showed 7.7% as an absolute value, and the pooled coefficient of variation showed 3.51%. For the precision on repeatability of peak area and retention time between within-run and between-run of analytical system, it is showed the results of within-run gave better than those of between-run. Also the accuracy by sorbents(Tenax TA and Chromosorb 106)was evaluated, and the precision on reproducibility between MDHS72 and this study was compared. It is showed it is possible for TD/GC/FID to evaluate accurately B, T, X concentration levels of less than 1ppm at indoor or outdoor of workplaces in Korea.

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Genetic association study of a single nucleotide polymorphism of kallikrein-related peptidase 2 with male infertility

  • Lee, Sun-Hee;Lee, Su-Man
    • Clinical and Experimental Reproductive Medicine
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    • 제38권1호
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    • pp.6-9
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    • 2011
  • Objective: To investigate a kallikrein-related peptidase 2 (KLK2) single nucleotide polymorphism (SNP) in relation to male infertility because of its role in semen processing. We investigated the genetic association of the KLK2+255G>A genotype with male infertility. Methods: We genotyped the SNP site located in intron 1 (+255G>A, rs2664155) of KLK2 from 218 men with male infertility (cases) and 220 fertile males (controls). Pyrosequencing analysis was performed for the genotyping. Results: The SNP of the KLK2 gene had a statistically significant association with male infertility (p<0.05). The odds ratio for the minor allele (+255A) in the pooled sample was 0.47 (95% confidence intervals, 0.26-0.85) for rs2664155. Conclusion: The relationship of KLK2 SNP to male infertility is statistically significant, especially within the non-azoospermia group. Further study is needed to understand the mechanisms associated with male infertility.

Two tests using more assumptions but lower power

  • Sang Kyu Lee;Hyoung-Moon Kim
    • Communications for Statistical Applications and Methods
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    • 제30권1호
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    • pp.109-117
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    • 2023
  • Intuitively, a test with more assumptions has greater power than a test with fewer assumptions. This kind of examples are abundant in the nonparametric tests vs corresponding parametric ones. In general, the nonparametric tests are less efficient in terms of asymptotic relative efficiency (ARE) compared to corresponding parametric tests (Daniel, 1990). However, this is not always true. To test equal means under independent normal samples, the usual test involves using the t-distribution with the pooled estimator of the common variance. Adding the assumption of equal sample size, we may derive another test. In this case, two tests using more assumptions were performed for univariate (multivariate) cases. For these examples, it was found that the power function of a test with more assumptions is less than or equal to that of a test with fewer assumptions. This finding can be used as an expository example in master's mathematical statistics courses.

Performance of Drip Irrigation System in Banana Cultuivation - Data Envelopment Analysis Approach

  • Kumar, K. Nirmal Ravi;Kumar, M. Suresh
    • Agribusiness and Information Management
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    • 제8권1호
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    • pp.17-26
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    • 2016
  • India is largest producer of banana in the world producing 29.72 million tonnes from an area of 0.803 million ha with a productivity of 35.7 MT ha-1 and accounted for 15.48 and 27.01 per cent of the world's area and production respectively (www.nhb.gov.in). In India, Tamil Nadu leads other states both in terms of area and production followed by Maharashtra, Gujarat and Andhra Pradesh. In Rayalaseema region of Andhra Pradesh, Kurnool district had special reputation in the cultivation of banana in an area of 5765 hectares with an annual production of 2.01 lakh tonnes in the year 2012-13 and hence, it was purposively chosen for the study. On $23^{rd}$ November 2003, the Government of Andhra Pradesh has commenced a comprehensive project called 'Andhra Pradesh Micro Irrigation Project (APMIP)', first of its kind in the world so as to promote water use efficiency. APMIP is offering 100 per cent of subsidy in case of SC, ST and 90 per cent in case of other categories of farmers up to 5.0 acres of land. In case of acreage between 5-10 acres, 70 per cent subsidy and acreage above 10, 50 per cent of subsidy is given to the farmer beneficiaries. The sampling frame consists of Kurnool district, two mandals, four villages and 180 sample farmers comprising of 60 farmers each from Marginal (<1ha), Small (1-2ha) and Other (>2ha) categories. A well structured pre-tested schedule was employed to collect the requisite information pertaining to the performance of drip irrigation among the sample farmers and Data Envelopment Analysis (DEA) model was employed to analyze the performance of drip irrigation in banana farms. The performance of drip irrigation was assessed based on the parameters like: Land Development Works (LDW), Fertigation costs (FC), Volume of water supplied (VWS), Annual maintenance costs of drip irrigation (AMC), Economic Status of the farmer (ES), Crop Productivity (CP) etc. The first four parameters are considered as inputs and last two as outputs for DEA modelling purposes. The findings revealed that, the number of farms operating at CRS are more in number in other farms (46.66%) followed by marginal (45%) and small farms (28.33%). Similarly, regarding the number of farmers operating at VRS, the other farms are again more in number with 61.66 per cent followed by marginal (53.33%) and small farms (35%). With reference to scale efficiency, marginal farms dominate the scenario with 57 per cent followed by others (55%) and small farms (50%). At pooled level, 26.11 per cent of the farms are being operated at CRS with an average technical efficiency score of 0.6138 i.e., 47 out of 180 farms. Nearly 40 per cent of the farmers at pooled level are being operated at VRS with an average technical efficiency score of 0.7241. As regards to scale efficiency, nearly 52 per cent of the farmers (94 out of 180 farmers) at pooled level, either performed at the optimum scale or were close to the optimum scale (farms having scale efficiency values equal to or more than 0.90). Majority of the farms (39.44%) are operating at IRS and only 29 per cent of the farmers are operating at DRS. This signifies that, more resources should be provided to these farms operating at IRS and the same should be decreased towards the farms operating at DRS. Nearly 32 per cent of the farms are operating at CRS indicating efficient utilization of resources. Log linear regression model was used to analyze the major determinants of input use efficiency in banana farms. The input variables considered under DEA model were again considered as influential factors for the CRS obtained for the three categories of farmers. Volume of water supplied ($X_1$) and fertigation cost ($X_2$) are the major determinants of banana farms across all the farmer categories and even at pooled level. In view of their positive influence on the CRS, it is essential to strengthen modern irrigation infrastructure like drip irrigation and offer more fertilizer subsidies to the farmer to enhance the crop production on cost-effective basis in Kurnool district of Andhra Pradesh, India. This study further suggests that, the present era of Information Technology will help the irrigation management in the context of generating new techniques, extension, adoption and information. It will also guide the farmers in irrigation scheduling and quantifying the irrigation water requirements in accordance with the water availability in a particular season. So, it is high time for the Government of India to pay adequate attention towards the applications of 'Information and Communication Technology (ICT) and its applications in irrigation water management' for facilitating the deployment of Decision Supports Systems (DSSs) at various levels of planning and management of water resources in the country.

Association Between Gestational Diabetes Mellitus and Subsequent Risk of Cancer: a Systematic Review of Epidemiological Studies

  • Tong, Gui-Xian;Cheng, Jing;Chai, Jing;Geng, Qing-Qing;Chen, Peng-Lai;Shen, Xin-Rong;Liang, Han;Wang, De-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권10호
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    • pp.4265-4269
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    • 2014
  • Purpose: This study aimed at summarizing epidemiological evidence of the association between gestational diabetes mellitus (GDM) and subsequent risk of cancer. Materials and Methods: We searched Medline, Embase, Cancer Lit and CINAHL for epidemiological studies published by February 1, 2014 examining the risk of cancer in patients with history of GDM using highly inclusive algorithms. Information about first author, year of publication, country of study, study design, cancer sites, sample sizes, attained age of subjects and methods used for determining GDM status were extracted by two researchers and Stata version 11.0 was used to perform the meta-analysis and estimate the pooled effects. Results: A total of 9 articles documented 5 cohort and 4 case-control studies containing 10,630 cancer cases and 14,608 women with a history of GDM were included in this review. Taken together, the pooled odds ratio (OR) between GDM and breast cancer risk was 1.01 (0.87-1.17); yet the same pooled ORs of case-control and cohort studies were 0.87 (0.71-1.06) and 1.25 (1.00-1.56) respectively. There are indications that GDM is strongly associated with higher risk of pancreatic cancer (HR=8.68) and hematologic malignancies (HR=4.53), but no relationships were detected between GDM and other types of cancer. Conclusions: Although GDM increases the risk of certain types of cancer, these results should be interpreted with caution becuase of some methodological flaws. The issue merits added investigation and coordinated efforts between researchers, antenatal clinics and cancer treatment and registration agencies to help attain better understanding.

국가부채 및 재정수지와 국채이자율의 장기적 관계: 현대화폐이론 검증을 중심으로 (The Long-Run Relation of Public Debt and Fiscal Balance to Government Bond Rates: An Empirical Study on the Validity of Modern Monetary Theory)

  • 박강우
    • 분석과 대안
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    • 제7권3호
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    • pp.181-230
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    • 2023
  • 본 연구에서는 현대화폐이론(Modern Monetary Theory)의 실증적 타당성을 평가하기 위해 OECD 국가의 연간 패널자료(2000~2022년)를 이용하여 패널 공적분 분석을 수행하였다. 구체적으로 OECD 가입국을 대상으로 주권화폐(sovereign currency) 보유 여부에 따라 국가그룹을 나눈 후, 각 그룹별로 국가부채 또는 재정적자 비율과 국채이자율 간의 장기균형 관계, 즉 공적분 관계를 검정 및 추정하였다. 실증분석 결과를 정리하면 다음과 같다. 통합 평균-그룹(pooled mean-group) 추정법을 통한 패널 공적분 추정 결과, 유로존 또는 고정환율제 그룹과 같은 비주권화폐국에서는 국가부채 및 재정적자 비율이 국채이자율과 장기적으로 유의한 양(+)의 상관관계를 가지는 반면, 비유로존 또는 변동환율제 그룹과 같은 주권화폐국의 경우에는 음(-)의 상관관계를 가지거나 유의한 관계가 나타나지 않았다. 특히 비주권화폐국에서 국가부채 비율은 장기뿐만 아니라 단기적으로도 실질 국채이자율과 유의한 양(+)의 상관관계를 가지는 것으로 나타났다. 이러한 결과는 국가부채 또는 재정적자 비율과 국채이자율 간의 관계에 대한 현대화폐이론의 예측과 부합하는 것이며, 따라서 동 이론의 실증적 타당성을 지지하는 하나의 근거가 될 수 있다.

구강액을 이용한 양돈장의 Porcine circovirus-2 감염에 대한 모니터링 (Application of Oral Fluid Sample to Monitor Porcine circovirus-2 Infection in Pig Farms)

  • 김원일
    • 한국임상수의학회지
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    • 제27권6호
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    • pp.704-712
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    • 2010
  • Porcine circovirus-2 (PCV2) 는 돼지에서 여러 형태의 질병과 증후군의 발생과 관련이 되어있어 현재는 PCV-associated diseases (PCVAD)로 총괄적으로 분류된다. PCVAD에 의한 높은 경제적 손실 때문에 많은 양돈장들이 PCV2의 감염을 확인하기 위하여 혈청을 검사하고 있다. 하지만, 기존의 혈액채취법은 비용이 높고 많은 인력이 소요되므로 큰 규모의 병원체 검사에는 어려움이 있었다. 이에 본 연구에서는 혈액채취법을 이용한 돈군의 PCV2 검사법에 대한 대체방법으로 돈방 단위의 구강액채취법의 유용성을 실제 농장에서 평가하였다. 세 곳의 다른 양돈 농장들에서 각각 6개의 25두 규모의 돈방들을 선정하여 생후 3, 5, 8, 12, 16주에 돈방 마다 하나의 구강액과 5개의 혈청을 채취하였다. 모든 시료들은 real-time PCR을 이용하여 PCV2 DNA를 검사하였고 IgG 또는 IgA 간접형광항체 검사법및 세 가지의 ELISA 검사법 (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA)을 이용하여 PCV2에 대한 항체를 검사하였다. 구강액에서 PCV2 DNA는 8주까지는 간헐적으로 검출이 되다가 16주에는 모든 돈방에서 검출이 되었으며, 모체유래 PCV2 특이 IgG는 3주부터 검출이 되었고 모든 농장에서 5-8주까지 지속이 되었다. 16주에는 한 농장 (Site 1)의 모든 돈방에서 감염에 의한 IgG와 IgA가 검출되었다. 혈청에서의 PCV2 DNA와 PCV2 항체의 검출은 구강액에서의 검출과 높은 상관관계를 보였다. 따라서 구강액은 돈군의 PCV2 감염을 모니터링 하기 위해 혈청대신 사용할 수 있는 저비용, 고효율의 시료가 될 수 있을 것으로 사료된다.

Estrogen activity of Silkworm (Bombyx mori) Pupa water extract and its fractions

  • Ryu, Jae-Sung;Jo, Gyeong-Jong;Jin, Jung-Woo;Yang, Hyo-Jung;Park, Yong-Il;Na, Ye-Seul;Nam, Kyung-Su;Keum, Kyung-Soo;Choo, Young-Kug
    • Advances in Traditional Medicine
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    • 제8권3호
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    • pp.228-235
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    • 2008
  • This study was conducted to evaluate the estrogen activity of silkworm (Bombyx mori) pupa extracts and their fractions. Powdered samples of freeze-dried silkworm pupa were extracted at room temperature (RT), $40^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$ in water (D.W), chloroform, ethyl acetate, and methanol for 6h and then filtered (0.45 um). The extracts were then freeze-dried. The estrogenic activity of these extracts was then investigated by competition binding assays using estrogen receptor ${\alpha}\;(ER{\alpha})$ and $ER{\beta}$, and by evaluating their effects on the proliferation of the human breast cancer cell line, MCF-7. Among the extracts evaluated, water extracts prepared at RT showed the highest binding affinity to $ER{\alpha}$ ($IC_{50}$, 1.76 ug/ml) and $ER{\beta}$ ($IC_{50}$, 0.07 ug/ml). In addition, MCF-7 cells that were treated with 62.5 ug/ml of the RT extract showed the greatest increase in proliferation (2-fold; 1291.79%) when compared to control cells (659.82%). Next, the water extract that was prepared at RT (sample 1) was dissolved in D.W. and further fractionated using a Dowex 50W - 8X ($H^+$) column. The flow-through and wash were then pooled together and freeze-dried (sample 2). The bound materials were then eluted with 20 mM NaCl, after which they were applied to a Dowex 1X2 - 200 ($Cl^-$) column and washed with D.W. to remove the sodium ions. The eluants were then freeze-dried (sample 3). Of these fractions, sample 2 showed the highest binding affinity to ER{\alpha} ($IC_{50}$, 1.44 ug/ml) and $ER{\beta}$ ($IC_{50}$, 1.18 ug/ml). In addition, MCF-7 cells that were treated with sample 2 (15.6 ug/ml) showed the largest increase in growth (1159.39%) when compared to control cells (525.26%). Taken together, these results suggest that the fraction of the RT water extract of silkworm pupa referred to as sample 2 may be useful as a phytoestrogen.

우리나라 성인 여성의 Na 섭취량 측정방법의 모색 (Measurement of Na intake in Korean Adult Females)

  • 김영선
    • Journal of Nutrition and Health
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    • 제20권5호
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    • pp.341-349
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    • 1987
  • Dietary intakes of na include both the amount present in food materials (nondiscretionary Na intake) and the amount added during cooking and eating to increase salty taste and flavor (discretionary Na intake). In the present study, total Na intake was measured by duplicate food sample collected from each subject for 1 day, nondiscretionary Na intake was calculated by dietary intake record, optimum gustation of salt was measured of from pooled 3-day urine collection in healthy female college students, to measure Na intake more accurately and to find suitable method to estimate total Na intake. Mean values of total, discretionary and mondiscretionary Na intakes were 169.6 mEq, 46.2mEq, and 123.4mEq. respectively. Mean 24-hour urinary Na excretion was 137.9mEq., which was about 84.5% of total intake. Subjects with optimum gustation of salt equal to or higher than 0.5% had significantly higher total Na intake and urinary Na excretion compared to subjects with optimum gustation of salt lower than 5%. Total Na intake of subjects were significantly correlated with optimum gustation of salt, non-discretionary and discretionary Na intakes, and urinary Na excretion. Multiple regression analysis showed that the best estimate of total Na intake is obtained when both optimum gustation of salt and non-discredinary Na intake were used as independent variables (r=.7071). Among the equations using one independent variable, regression, equation with urinary Na excretion provides the best approximation (r=.6627) of total Na intake.

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The Determinants of Distribution of Credit: Evidence from Vietnam

  • TRAN, Anh Thi;NGUYEN, Tue Dang;PHAM, Giang Hoang
    • 유통과학연구
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    • 제18권6호
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    • pp.47-55
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    • 2020
  • Purpose: The issue of access to credit for private enterprises has been given an increased amount of attention given their crucial role in fueling economic growth. Vietnamese small and medium-sized businesses, however, face many obstacles in accessing financing for profitable investment opportunities, with up to 70% unable to access or obtain bank loans. This paper aims to address the factors affecting the credit accessibility of Vietnamese enterprises, and provide further insights of this issue under the new context of Basel II. Research design, data and methodology: We adopt a pooled sections approach to construct a sample of 155 firm observations before and after the implementation of Basel II accord in Vietnam and employing binary logistic regression and interaction terms for data analysis. Results: We find that firm characteristics (export participation, female ownership) and proxies for bank-borrower relationship (deposit, overdraft facility) have significant and positive effects on firm's access to credit. Notably, the sign of interaction coefficient shows that the implementation of Basel II tends to benefit small-sized firms in terms of credit accessibility. Conclusions: The finding further emphasizes the important role of relationship lending in Vietnam's credit market, which is even more critical for small firms when Basel II is universally applied as the new banking standards in the coming years.