• 제목/요약/키워드: W.T.

검색결과 6,538건 처리시간 0.032초

FREE-FLOATING PLANETS, THE EINSTEIN DESERT, AND 'OUMUAMUA

  • Gould, Andrew;Jung, Youn Kil;Hwang, Kyu-Ha;Dong, Subo;Albrow, Michael D.;Chung, Sun-Ju;Han, Cheongho;Ryu, Yoon-Hyun;Shin, In-Gu;Shvartzvald, Yossi;Yang, Hongjing;Yee, Jennifer C.;Zang, Weicheng;Cha, Sang-Mok;Kim, Dong-Jin;Kim, Seung-Lee;Lee, Chung-Uk;Lee, Dong-Joo;Lee, Yongseok;Park, Byeong-Gon;Pogge, Richard W.
    • 천문학회지
    • /
    • 제55권5호
    • /
    • pp.173-194
    • /
    • 2022
  • We complete the survey for finite-source/point-lens (FSPL) giant-source events in 2016-2019 KMTNet microlensing data. The 30 FSPL events show a clear gap in Einstein radius, 9 𝜇as < 𝜃E < 26 𝜇as, which is consistent with the gap in Einstein timescales near tE ~ 0.5 days found by Mróz et al. (2017) in an independent sample of point-source/point-lens (PSPL) events. We demonstrate that the two surveys are consistent. We estimate that the 4 events below this gap are due to a power-law distribution of free-floating planet candidates (FFPs) dNFFP/d log M = (0.4 ± 0.2) (M/38 M)-p/star, with 0.9 ≲ p ≲ 1.2. There are substantially more FFPs than known bound planets, implying that the bound planet power-law index 𝛾 = 0.6 is likely shaped by the ejection process at least as much as by formation. The mass density per decade of FFPs in the Solar neighborhood is of the same order as that of 'Oumuamua-like objects. In particular, if we assume that 'Oumuamua is part of the same process that ejected the FFPs to very wide or unbound orbits, the power-law index is p = 0.89 ± 0.06. If the Solar System's endowment of Neptune-mass objects in Neptune-like orbits is typical, which is consistent with the results of Poleski et al. (2021), then these could account for a substantial fraction of the FFPs in the Neptune-mass range.

Apparent metabolizable energy, growth performance and carcass traits of Japanese quail fed select modern grain sorghum varieties

  • Moritz, A.H.;Krombeen, S.K.;Presgraves, J.;Blair, M.E.;Buresh, R.E.;Bridges, W.C.;Arguelles-Ramos, M.;Wilmoth, T.A.
    • Animal Bioscience
    • /
    • 제35권12호
    • /
    • pp.1911-1920
    • /
    • 2022
  • Objective: This study was performed to determine the apparent metabolizable energy (AMEn) content of tannin-free red/bronze, white/tan and U.S. No. 2 varieties of grain sorghum for feeding Japanese quail and validate their nutrient profile by evaluating effects on performance and carcass traits with full-substitution of corn. Methods: Experiment 1 determined the AMEn content of red/bronze, white/tan, and U.S. No. 2 grain sorghum varieties fed to mixed-sex Japanese quail (Coturnix japonica) (n = 314) at 3 and 6-weeks of age. Analyses were based on a 2×4 factorial treatment design with age and grain types defining the treatments, and a randomized complete block experiment design with cage and trials defining the block. AMEn values were validated by evaluating the performance and carcass traits of Japanese quail (n = 644) from 1 to 40 days of age in Experiment 2 with birds were fed 1 of 4 complete diets. Statistical analyses were conducted on performance data and select individual carcass trait measurements. Results: Determined AMEn values at 3-weeks of age were 3,524±122.03 (red/bronze), 3,252±122.03 (white/tan), and 3,039±123.44 (U.S. No. 2) kcal/kg. At 6-weeks of age, determined AMEn were 3,373±297.35 (red/bronze), 3,279±297.35 (white/tan), and 2,966±298.64 (U.S. No. 2) kcal/kg. Carcass traits showed live body weight (p = 0.0409) and hot carcass weight (p = 0.0234) were greatest in U.S. No. 2; however, carcass yield (p<0.0001) was lowest. No significant differences were observed among treatments for feed intake, feed conversion ratio, breast weight and breast yield (p>0.05). Conclusion: These studies demonstrated that tannin-free grain sorghum varieties may be a potential alternative to corn in quail diets while maintaining growth performance and carcass parameters.

Relationships of Cocaine and Amphetamine Regulated Transcript with Serotonin in the Brain

  • Park, S. H.;B. S. Kwon;J. R. Chun;J. W. Jahng;Lee, H. T.;K. S. Chung
    • 한국동물번식학회:학술대회논문집
    • /
    • 한국동물번식학회 2001년도 춘계학술발표대회
    • /
    • pp.51-51
    • /
    • 2001
  • Cocaine and amphetamine-regulated transcript (CART) is a satiety factor that is regulated by leptin. It was reported that the mice intracerebroventricularly injected with CART showed behavioral changes resembled with the typical behavioral alterations found in the mice carrying disorders in the brain serotonergic (5-HT) system. Hence, this study was conducted to find out the relationships between CART and 5-HT. We first examined the mRNA levels of CART after the injections of para-chlorophenylalanine (pCPA, 300 mg/kg i.p., single injection or daily for three consecutive days) in the rat brains by in situ hybridization using the mouse CART cDNA probe cloned in our laboratory. Systemic administrations of pCPA, a potent inhibitor of tryptophan hydroxylase, the rate limiting enzyme of 5-HT biosynthesis, acutely depletes the brain 5-HT transporter (5-HTT) in the dorsal raphe nucleus (DRN), which reuptakes terminal 5-HT. Results indicated that the mRNA level of CART significantly decreased in the arcuate nucleus, paraventricular nucleus, and lateral hypothalamic nucleus by three days of daily injection with pCPA with no noticeable change detected 24 hrs after the single injection. The message levels of 5-HTT in DRN decreased in both single and three days of injections. Secondly, to investigate whether CART affect to 5-HT, mouse genomic CART gene, which is consist of 3 exons and 2 introns and mouse neurofilament light (NF-L) chain promoter were cloned. Then, we constructed neuron specific expression vector, which was transfected into HeLa cell using lipid-mediated transfection system. Expression of GFP and CART linked to NF-L-chain promoter in the transfected HeLa cell were detected by using fluorescent microscope and RT-PCR. These results confirmed normal expression of DNA constructs in vitro. Then, to increase brain specific expression of CART in vivo transgenic mice carrying CART gene controlled the deleted NF-L-chain promoter were generated by the DNA microinjection into pronuclei of fertilized embryos. Transgenic mice were detected by Southern blot. Further study is necessary to examine CART expression and 5-HTT in these transgenic mice. Therefore, these results suggest that there maybe a positive molecular correlation between CART and 5-HT in responding to the stimuli.

  • PDF

수도에 대한 완효성비료 METAP의 비효시험(1972) (Studies on the Controlled Release Fertilizer METAP Application on Paddy Rice (1972))

  • 이은웅;안수봉;이문희;이주열;송남현;권순목;김칠용;최병초;정현식;조병옥;이일주;박창서;고춘산;박건호;정성채;정환수;이희덕;박성태;이한생;최승락
    • 한국작물학회지
    • /
    • 제13권
    • /
    • pp.107-118
    • /
    • 1973
  • 완효성 비료로서 METAP이 수도의 생육 수량 및 그 구성요소에 미치는 영향을 검토하고 그 효과를 단비와 비교하고자 농촌진흥청산하 3개작물시험장과 7개 농촌진흥원에서 동일한 설계하에서 일련의 시험을 실시하였다. METAP의 효과는 토양의 물리, 화학적 성질, 시용시기, 기상조건, 품종 및 재배법에 따라서도 다른 것 같으며 각 시험장에서 얻은 결과를 요약하면 다음과 같다. 1. 사질토에서 METAP의 시용은 수수를 증가시켜 수량이 증가하였으며 분시가 전량기비시용보다 효과가 좋았다. 그러나 해성토, 배수불량한 토양 및 비옥한 토양에서는 단비시용과 차이가 없었다. 2. 등숙에 요하는 온도가 높고, 조식에서 다수성인 품종(통일)을 비식하고 출수전후에 일조가 부족하고 온도가 낮으면 METAP시용이 등숙률 향상이나 1,000 입중을 증가시키지 못한다.

  • PDF

화성지역 '캠벨얼리' 포도원의 수체영양과 과실품질의 평가 (Evaluation of Nutrient Condition and Fruit Quality of 'Campbell Early' Grapevines in Hwaseong Area)

  • 이영철;문병우
    • 현장농수산연구지
    • /
    • 제5권1호
    • /
    • pp.28-35
    • /
    • 2003
  • 화성지역 '캠벨얼리' 포도 포도원의 엽병의 무기성분, 수체생육 및 과실품질을 조사하였다. 토양의 물리·화학성은 Y포도원은 적정기준 농도보다 pH는 높고 유기물 함량은 낮으며 인산은 2.8배, 칼륨은 3.6배 높았으나 칼슘, 마그네슘, 양이 온치환용량은 큰 차이가 없었다. H포도원은 pH와 유기물함량은 낮고 인산, 칼륨, 칼슘 및 마그네슘 함량은 적당하였다. C포도원은 유기물함량은 낮은 편이며 인산은 3.5배 높았으나, pH, 칼륨, 칼슘, 마그네슘 및 양이온치환용량은 적당한 편이었다. 그러나 심토는 배수 잘 안 되는 토양이었다. 엽병의 질소, 칼슘 및 마그네슘 함량은 적당하였으나 인산은 Y 및 C포도원에서 기준치보다 8~6배, 칼리는 Y포도원에서 1.8배 높았다. 포도원간 과실 경도, 착색정도 및 과분발생정도는 큰 차이는 없었으나, 가용성고형물, 주당수량 및 상품과율은 Y와 H포도원에 비하여 C포도원가 현저히 떨어졌다. 생리장해 및 병 발생은 Y포도원에서 동녹 발생이 H포도원은 착색불량과가 C포도원은 수정불량과, 열과 및 탄저병 발생이 많았다.

참깨 품종개량에 관한 연구 제2보 지역차이 및 기상환경에 따른 참깨 지방산변화 (Breeding of Sesame (Sesamum indicum L.) for Oil Quality Improvement II. FattyAcid Composition of Sesame Seeds under Different Climatic Conditions and Locations)

  • 이정일;이승택;오성근;강철환
    • 한국작물학회지
    • /
    • 제26권1호
    • /
    • pp.90-95
    • /
    • 1981
  • 참깨 재배지역 차이에 따른 품종문제를 추적하여 본 결과 다음과 같은 결론을 얻였다. 1. 참깨 재배지역에 따른 품질은 남부지역에서 생산된 것보다 중북부지역에서 생산된 것이 리놀산함량이 많았다. 2. 러놀산함량은 등열기간 중 적산온도와 r =-0.595**의 부상관관계를 일사량과는 r=0.613**의 정상관을 보여서 등열기간의 적산온도가 낮고 일사양이 많으며 강우량도 많은 조건에서 리놀산함량 높았다. 3. 오레인산함량에서는 리놀산의 경우와 달리 남부지방에서 생산된 참깨가 중북부산 참깨보다 오레인산함량이 더 높았다. 4. 오레인산함량은 등숙기간 중 적정평균 온도와 r=0.644**의 정상관관계를 일사량과는 r=-0.456**의 부상관 관계를 보였다. 5. 참깨 지방산중 오레인산과 리놀산함량은 이두 지방산함량이 대부분 차지하고 있음으로 서로 상대적인 함량관계를 가지고 있는 경향이다. 6. 참깨의 유질은 주산지인 남부보다 중북부산 참깨의 품질이 더 우수하다.

  • PDF

Improvement of lower hybrid current drive systems for high-power and long-pulse operation on EAST

  • M. Wang;L. Liu;L.M. Zhao;M.H. Li ;W.D. Ma;H.C. Hu ;Z.G. Wu;J.Q. Feng ;Y. Yang ;L. Zhu ;M. Chen ;T.A. Zhou;H. Jia;J. Zhang ;L. Cao ;L. Zhang ;R.R. Liang;B.J. Ding ;X.J. Zhang ;J.F. Shan;F.K. Liu ;A. Ekedahl ;M. Goniche ;J. Hillairet;L. Delpech
    • Nuclear Engineering and Technology
    • /
    • 제54권11호
    • /
    • pp.4102-4110
    • /
    • 2022
  • Aiming at high-power and long-pulse operation up to 1000 s, some improvements have been made for both 2.45 GHz and 4.6 GHz lower hybrid (LH) systems during the recent 5 years. At first, the guard limiters of the LH antennas with graphite tiles were upgraded to tungsten, the most promising material for plasma facing components in nuclear fusion devices. These new guard limiters can operate at a peak power density of 12.9 MW/m2. Strong hot spots were usually observed on the old graphite limiters when 4.6 GHz system operated with power >2.0 MW [B. N. Wan et al., Nucl. Fusion 57 (2017) 102019], leading to a reduction of the maximum power capability. With the new limiters, 4.6 GHz LH system, the main current drive (CD) and electron heating tool for EAST, can be operated with power >2.5 MW routinely. Long-pulse operation up to 100 s with 4.6 GHz LH power of 2.4 MW was achieved in 2021 and the maximal temperature on the guard limiters measured by an infrared (IR) camera was about 540 ℃, much below the permissible value of tungsten material (~1200 ℃). A discharge with a duration of 1056 s was achieved and the 4.6 GHz LH energy injected into the plasma was up to 1.05 GJ. Secondly, the fully-active-multijunction (FAM) launcher of 2.45 GHz system was upgraded to a passive-active-multijunction (PAM), for which the density of optimum coupling was relatively low (below the cut-off value). Good coupling with reflection coefficient ~3% has been achieved with plasma-antenna distance up to 11 cm for the new PAM. Finally, in order to eliminate the effect of ion cyclotron range of frequencies (ICRF) wave on 4.6 GHz LH wave coupling, the location of the ICRF launcher was changed to a port that is located 157.5° toroidally from the 4.6 GHz LH system and is not magnetically connected.

Alternative Immunossays

  • Barnard, G.J.R.;Kim, J.B.;Collins, W.P.
    • 한국가축번식학회지
    • /
    • 제9권2호
    • /
    • pp.133-139
    • /
    • 1985
  • An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

  • PDF

요드분위기에서 지르칼로이 피복재의 저변형율속도 의존성(I) (The Slow Strain Rate Dependence of Zircaloy-4 Cladding Tube in Iodine Atmosphere (I))

  • 최용;강영환;류우석;임창생
    • Nuclear Engineering and Technology
    • /
    • 제17권3호
    • /
    • pp.211-215
    • /
    • 1985
  • 온도 및 연신율 변촤가 Zircaloy-4의 요드 응력부식 거동에 미치는 영향을 30$0^{\circ}C$에서 일정 하중법과 300, 350, 40$0^{\circ}C$에서 일정 연신율법으로 ($10^{-5}$sec~$10^{-6}$ sec) 3.34mg $I_2$/㎤의 요드분위기에서 연구하였다. 요드 응력부식균열에 대한 저항성은 온도가 상승하거나 변형속도가 감소하면 감소했고 파손 시간과 응력과의 관계는1/tf∝exp (0.3$\sigma$/$\sigma$uTs-31.5)로 표시할 수 있었다. 30$0^{\circ}C$에서 요드 응력 부식 균열에 대한 저항성을 불활성 분위기에서의 파손에너지에 대한 요드분위기에서의 파손 에너지의 비율로 표시할 때 변형속도가 7.6$\times$$10^{-6}$ sec 부근에서 저항성이 가장 낮았고 온도가 35$0^{\circ}C$, 40$0^{\circ}C$ 로 증가함에 따라 보다 높은 변형속도에서 최저 저항성을 나타내는 경향을 보였다. 요드 응력부식 균열의 파단면에서 준-벽계 파면(quasi-cleavage fracture)을 관찰했다. 전술한 결과에 의하면 Zircaloy-4의 요드 응력부식균열의 기구에 있어서 보호 피막파손단계 (film rupture step)가 중요한 과정으로 추정된다.

  • PDF

형질전환 생쥐에서 Antisense 비만유전자의 발현 (Expression of Antisense Mouse Obese Gene in Transgenic Mice)

  • 권범섭;홍권호;장정원;이훈택;정길생
    • 한국가축번식학회지
    • /
    • 제24권4호
    • /
    • pp.419-428
    • /
    • 2000
  • 랩틴은 지방세포의 비만유전자에서 분비되는 포식인자로써 음식섭취, 에너지대사, 체중, 번식생리 및 신경호르몬 분비를 조절하는 역할을 한다. 본 연구는 antisense 비만유전자를 발현하는 형질전환 생쥐를 생산하기 위하여 실시하였다. 먼저 랩틴을 분비하는 지방세포에서 RNA 를 추출한 후 역전사 PCR을 실시하여 303 bp의 anti I과 635 bp의 anti II cDNA 들을 합성하였다. 이러한 cDNA 들을 지방세포 특이적 발현 프로모터인 aP2 프로모터와 SV40 poly(A) 사이에 역방향으로 결합하여 미세주입용 유전자를 구축하였다. 생쥐의 수정란전핵에 antisense 비만유전자를 미세 주입하여 14 마리의 형질전환 생쥐를 생산하였으며, anti I 을 지닌 4 마리의 형질전환 생쥐와 anti II를 지닌 5마리의 형질전환 생쥐계통을 확립하였다. 그리고 형질전환 생쥐의 지방세포를 추출하여 RT -PCR을 실시한 결과 antisense 비만유전자 mRNA발현을 확인하였다. 따라서, 본 연구에서 생산된 형질전환생쥐는 생체 랩틴저하에 의해 비만을 일으키는 질환모텔동물로써의 사용가능성을 나타내었다.

  • PDF