• 제목/요약/키워드: climatology

검색결과 181건 처리시간 0.023초

Effect of Induced Hypothyroidism on the Fertility of Male Goats

  • Reddy, I.J.;Varshney, V.P.;Sanwal, P.C.;Agarwal, N.;Pande, J.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권1호
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    • pp.55-59
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    • 1998
  • To study the effect of induced hypothyroidism on fertility status of male Black Bengal goats, 10 adult healthy mature males were divided into control and treated groups. Hypothyroidism was induced successfully by injecting thiourea subcutaneously initially for 15 days at the rate of 100 mg/kg body weight, followed by 66.7 mg/kg body weight for the subse quent 15 days. This resulted in a decrease (p < 0.01) in plasma tri-iodothyronine, thyroxine and testosterone levels, with increasing duration of thiourea treatment. It also adversely affected semen quality, ejaculate volume, sperm concentration, motility and viability. Live percentage declined to 75% for treated and control remained at 90%. Artificial insemination fo female goats with semen of thiourea-treated goats, resulted in failure of conception. However, females inseminated with semen of male goats of control group showed 100% conception. These observations indicate that, thyroid hormones play a key role in maintaining the normal reproductive processes of male goats.

Assessment of New High-resolution Regional Climatology in the East/Japan Sea

  • Lee, Jae-Ho;Chang, You-Soon
    • 한국지구과학회지
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    • 제42권4호
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    • pp.401-411
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    • 2021
  • This study provides comprehensive assessment results for the most recent high-resolution regional climatology in the East/Japan Sea by comparing with the various existing climatologies. This new high-resolution climatology is generated based on the Optimal Interpolation (OI) method with individual profiles from the World Ocean Database and gridded World Ocean Atlas provided by the National Centers for Environmental Information (NCEI). It was generated from the recent previous study which had a primary focus to solve the abnormal horizontal gradient problem appearing in the other high-resolution climatology version of NCEI. This study showed that this new OI field simulates well the meso-scale features including closed-curve temperature spatial distribution associated with eddy formation. Quantitative spatial variability was compared to the other four different climatologies and significant variability at 160 km was presented through a wavelet spectrum analysis. In addition, the general improvement of the new OI field except for warm bias in the coastal area was confirmed from the comparison with serial observation data provided by the National Fisheries Research and Development Institute's Korean Oceanic Data Center.

ECMWF 계절 기상 전망 기술의 정확성 및 국내 유역단위 적용성 평가 (Assessment of ECMWF's seasonal weather forecasting skill and Its applicability across South Korean catchments)

  • 이용신;강신욱
    • 한국수자원학회논문집
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    • 제56권9호
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    • pp.529-541
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    • 2023
  • 기후변화에 따른 가뭄 등 극한 기상을 예측하기 위해, 최근 전 세계적으로 GCMs 모델에 기반하여 향후 7개월까지를 전망하는 계절 기상 전망(Seasonal Forecasts) 기술이 꾸준히 관심을 받고 있다. 그러나 국내에서의 연구 및 적용사례는 많지 않으며, 특히 유역단위에서 그 활용성에 대해서는 검증이 필요하다. 따라서 본 연구에서는 국내 12개 다목적댐 유역에 대해 2011년부터 2020년까지 계절 기상 전망의 정확성을 과거 45년간의 기상 자료(climatology)와 비교하여 평가하였다. 본 연구에서는 ECMWF에서 제공하는 계절 기상 전망의 인자로 향후 수문전망에 활용성이 높은 강수, 기온 그리고 증발산을 선정하였고, 앙상블 전망의 정확성 평가를 위해 Continuous Ranked Probability Skill Score (CRPSS) 기법을 적용하였다. 또한, 계절 기상 전망에 대해 선형 편의 보정기법(Linear scaling)을 적용하여 그 효과를 평가하였다. 연구결과, 계절 기상 전망이 향후 1개월 간은 climatology와 유사한 정확도를 보이나 전망 리드타임이 증가함에 따라 그 정확도가 크게 낮아지는 특성을 나타냈다. Climatology와 비교하여, 계절적으로는 Dry season보다는 Wet season이 더 나은 결과를 보였으며, 특히 건조했던 2015년과 2017년의 Wet season에서는 장기간에 걸친 전망 정확도가 모두 높게 나타났다.

Effects of Long-term Heat Exposure on Adaptive Mechanism of Blood Acid-base in Buffalo Calves

  • Korde, J.P.;Singh, G.;Varshney, V.P.;Shukla, D.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권5호
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    • pp.742-747
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    • 2007
  • In order to investigate the mechanism of adaptation to long-term heat stress, six female buffalo calves of about 7 to 8 months age, were exposed to the cool-comfort environment (THI 65) for 21 days to obtain normal values of blood acid-base. An adaptive response of acid-base regulation was determined to long term (21 days) exposure of buffalo calves to hot-dry (THI 80) and hot-humid (THI 84) conditions. Higher rectal temperature and respiratory rate was recorded under hot-humid exposure compared to hot-dry. Significant reduction in the rectal temperature and respiratory rate on day 21 of hot-dry exposure indicated early thermal adaptation compared to hot-humid. Decreasing rectal temperature and respiratory rate from day 1 to 21 was associated with concurrent decrease in blood pH and pCO2. Increased plasma chloride concentration with low base excess in blood and in extracellular fluid suggested compensatory response to respiratory alkalosis. Reduced fractional excretion of sodium with increased fractional excretion of potassium and urine flow rate indicated renal adaptive response to heat stress.

북극 다산기지에서의 플럭스 발자취 기후도와 플럭스 자료 품질 (Flux Footprint Climatology and Data Quality at Dasan Station in the Arctic)

  • 이방용;최태진;이희춘;윤영준
    • 지구물리
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    • 제8권4호
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    • pp.201-205
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    • 2005
  • Turbulent fluxes of heat, water vapor, and CO2 have been measured since August, 2003 at Dasan Station (78o 55’ N, 11o50’E) in the Arctic. These data can allow us to better understand the interactions between the Polar ecosystems and the atmosphere together with those at King Sejong Station in the Antarctic. Due to the buildings and measurement platforms around the flux tower, it is required to evaluate how they influence measured flux data. By using one-year turbulence statistics data and footprint model, flux footprint climatology was analyzed together with data availability. The upwind distance of source area ranged from 150 to 300 m, where the buildings and measurement platforms existed. However, flow distortion due to them may be not a major factor to reduce the data availability significantly. Based on, the dominant wind direction of SW and footprint climatology, the location of flux tower is considered suitable for flux measurement.

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Supplementation of retinoic acid alone in MSC culture medium induced germ cell-like cell differentiation

  • Kuldeep Kumar;Kinsuk Das;Ajay Kumar;Purnima Singh;Madhusoodan A. P.;Triveni Dutt;Sadhan Bag
    • 한국동물생명공학회지
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    • 제38권2호
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    • pp.54-61
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    • 2023
  • Background: Germ cells undergo towards male or female pathways to produce spermatozoa or oocyte respectively which is essential for sexual reproduction. Mesenchymal stem cells (MSCs) have the potential of trans-differentiation to the multiple cell lineages. Methods: Herein, rat MSCs were isolated from bone marrow and characterized by their morphological features, expression of MSC surface markers, and in vitro differentiation capability. Results: Thereafter, we induced these cells only by retinoic acid supplementation in MSC medium and, could able to show that bone marrow derived MSCs are capable to trans-differentiate into male germ cell-like cells in vitro. We characterized these cells by morphological changes, the expressions of germ cell specific markers by immunophenotyping and molecular biology tools. Further, we quantified these differentiated cells. Conclusions: This study suggests that only Retinoic acid in culture medium could induce bone marrow MSCs to differentiate germ cell-like cells in vitro. This basic method of germ cell generation might be helpful in the prospective applications of this technology.