• 제목/요약/키워드: Reproductive responses

검색결과 129건 처리시간 0.024초

Male Hynobius leechii (Amphibia: Hynobiidae) Discriminate Female Reproductive States Based on Chemical Cues

  • Park, Dae-Sik;Sung, Ha-Cheol
    • Animal cells and systems
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    • 제10권3호
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    • pp.137-143
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    • 2006
  • A series of no-choice olfactory response tests using water pre-conditioned with females, with intact and surgically removed ventral glands, at various reproductive states were conducted to determine whether male Hynobius leechii discriminates among females in different reproductive states based on chemical cues. Similarly, ventral gland extracts were tested, and ventral glands were examined histologically. Males’ responses to putative odors of females in four (ovulating, ovulated, ovipositing, and oviposited) reproductive states were independently measured by: i) the latency time to initiate male behavioral response, ii) the arrival time at a fixed point of putative odor source, and iii) the staying time close to the odor point source. Male salamanders showed significant olfactory responses to recently ovulated and ovipositing female odors by quickly arriving at odor sources and staying longer at the origin of the source, but the olfactory responses to the earlier staged ovulating females and the later stage of already oviposited females were not different from controls. Olfactory responses of test males to water preconditioned by intact females or females with ventral glands excised were not different. In addition, ventral gland extracts did not induce significant olfactory responses of test males although the lumens of alveoli in ventral glands of oviposited females were smaller than those of ovulated females. These results indicate that male H. leechii recognizes ovulated and ovipositing females based on chemical cues released but not from the ventral glands.

Effects of dietary fiber in gestating sow diets - A review

  • Hyunwoong Jo;Beob Gyun Kim
    • Animal Bioscience
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    • 제36권11호
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    • pp.1619-1631
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    • 2023
  • The objective of this review was to provide an overview of the effects of dietary fiber (DF) on reproductive performance in gestating sows. Dietary fibers have been suggested to modulate microbiota in the intestine and the immune system of gestating sows and to improve gut health. Thus, DF may help alleviate the adverse effects of the stressful production cycle of gestating sows. These benefits may subsequently result in improved reproductive performance of sows. Previous studies have reported changes in microbiota by providing gestating sows with DF, and the responses of microbiota varied depending on the source of DF. The responses by providing DF to gestating sows were inconsistent for antioxidative capacity, hormonal response, and inflammatory response among the studies. The effects of DF on reproductive performance were also inconsistent among the previous studies. Potential reasons contributing to these inconsistent results would include variability in reproductive performance data, insufficient replication, influence of other nutrients contained in the DF diets, characteristics of DF, and experimental periods. The present meta-analysis suggests that increasing the total DF concentration by 10 percentage units (e.g., 12% to 22% as-fed basis) in gestating sow diets compared to the control group improves the litter born alive by 0.49 pigs per litter. However, based on the present review, questions remain regarding the benefits of fibers in gestating sow diets. Further research is warranted to clarify the mode of action of fibers and the association with subsequent reproductive performance in gestating sows.

Responses of Soybean Cultivars to Excessive Soil Moisture Imposed at Different Growth Stages

  • Seong, Rak-Chun;Sohn, Joo-Yong;Shim, Sang-In
    • 한국작물학회지
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    • 제45권5호
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    • pp.282-287
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    • 2000
  • Soybean [Glycine max (L.) Merrill] crops, grown in a rice soybean rotation, can suffer when grown in soil with excessive moisture. The objective of this work were to determine the reduction in growth and yield, responses of vegetative and reproductive growth of soybean to excessive soil moisture achieved by prolonged irrigation. Responses of different cultivars were determined at growth stages from V6 to R8 to clarify the sensitive growth stages or characteristics to excessive soil moisture. Cultivar differences in response to excessive soil moisture condition were conspicuous in seed dry weight and harvest index (HI) but not in the response of seed number or pod number per plant. The timing of irrigation causing the condition of excessive soil moisture influenced the vegetative or reproductive traits. Soybean plants were more affected by irrigation commencing at the pre-flowering than at the post-flowering stage. Post-flowering irrigation did not reduce growth of vegetative organs significantly; in fact the growth of stems and leaves was facilitated by the prolonged irrigation commencing at flowering. Differences between cultivar response to prolonged irrigation were assumed to relate to the reduced amount of assimilates translocated to the reproductive organ.

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Endoplasmic reticulum stress in periimplantation embryos

  • Michalak, Marek;Gye, Myung Chan
    • Clinical and Experimental Reproductive Medicine
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    • 제42권1호
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    • pp.1-7
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    • 2015
  • Stress coping mechanisms are critical to minimize or overcome damage caused by ever changing environmental conditions. They are designed to promote cell survival. The unfolded protein response (UPR) pathway is mobilized in response to the accumulation of unfolded proteins, ultimately in order to regain endoplasmic reticulum (ER) homeostasis. Various elements of coping responses to ER stress including Perk, Ask1, Bip, Chop, Gadd34, Ire1, Atf4, Atf6, and Xbp1 have been identified and were found to be inducible in oocytes and preimplantation embryos, suggesting that, as a normal part of the cellular adaptive mechanism, these coping responses, including the UPR, play a pivotal role in the development of preimplantation embryos. As such, the UPR-associated molecules and pathways may become useful markers for the potential diagnosis of stress conditions for preimplantation embryos. After implantation, ER stress-induced coping responses become physiologically important for a normal decidual response, placentation, and early organogenesis. Attenuation of ER stress coping responses by tauroursodeoxycholate and salubrinal was effective for prevention of cell death of cultured embryos. Further elucidation of new and relevant ER stress coping responses in periimplantation embryos might contribute to a comprehensive understanding of the regulation of normal development of embryonic development and potentiation of embryonic development in vitro.

간호대학생의 성지식, 성태도, 생식건강증진행위에 관한 연구 (A Study on Sexual Knowledge, Sexual Attitude and Reproductive Health Promoting Behaviors in Nursing Students)

  • 구윤정;홍선연
    • 문화기술의 융합
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    • 제10권2호
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    • pp.439-446
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    • 2024
  • 본 연구는 간호대학생의 성지식, 성태도, 생식건강증진행위를 확인하고 이들의 상관관계 확인을 위한 서술적 조사연구이다. 간호대학생 300명을 대상으로 설문하고 229부로 분석하였다. 연구도구는 Jeon(2004)의 성지식, Ho(2009)의 성태도, Jo(2014)의 생식건강증진행위 측정도구를 사용하였다. 자료분석은 일반적 특성은 실수와 백분율, 평균과 표준편차, 성지식, 성태도, 생식건강증진행위는 평균과 표준편차를 이용하였다. 일반적 특성에 따른 성지식, 성태도, 건강증진행위 차이는 independent t-test, one-way ANOVA, 사후검정으로 Scheffe's test를 이용하였다. 상관관계는 Pearson's correlation coefficients로 분석하였다. 여학생의 성지식이 높았으며, 생식건강증진행위 교육은 저학년이 적절한 시기임을 알 수 있다. 또한, 성지식이 높을수록 생식건강증진행위가 높아 생식건강증진행위 향상을 위한 성교육의 필요성이 여전히 요구됨을 시사한다. 이에, 본 연구는 간호대학생의 생식건강을 위한 상담과 교육에 활용할 생식건강증진행위의 교육자료 개발에 기초자료로 활용될 수 있을 것이다.

The use of RKPM meshfree methods to compute responses to projectile impacts and blasts nearby charges

  • Choi, Hyung-Jin;Crawford, John;Wu, Youcai
    • Computers and Concrete
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    • 제7권2호
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    • pp.119-143
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    • 2010
  • This paper presents results from a study concerning the capability afforded by the RKPM (reproducing kernel particle method) meshfree analysis formulation to predict responses of concrete and UHPC components resulting from projectile impacts and blasts from nearby charges. In this paper, the basic features offered by the RKPM method are described, especially as they are implemented in the analysis code KC-FEMFRE, which was developed by Karagozian & Case (K&C).

젖소에 있어서 개량생산 비율에 의한 유전 개량 효과 (Possible Genetic Improvement in Dairy Cattle with Improving Reproductive Rates)

  • 전광주
    • 한국수정란이식학회지
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    • 제10권1호
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    • pp.33-44
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    • 1995
  • Genetic changes from improving female's reproductive rate through in vitro fertilization of large number of oocytes were studied. The breeding scheme employed was multiple ovulation and embryo transfer of juveniles and adults. Both balanced and unbalanced matings were examined for the four closed progeny population sizes, 10$^3$, 10$^4$, 105, 106. In balanced matings, all selected sires and dams were mated to each other(cross-classified mating) while unbalanced matings allowed selected dams and sires mated partially, eg. unbalanced matings allowed averages of .5 and .25 progeny per each mating. Various numbers of selected sires and dams were also examined in both balanced and unbalanced matings. In all mating schemes, selection of males and females was restricted to he one from each fullsib family to reduce the rate of inbreeding. The model calculations were deterministic and accounted for the effects of selection and inbreeding on loss of the genetic variation in succeeding generations. Balanced rectangular mating schemes, where more donors were selected than sires, resulted in larger selection responses than balanced square mating schemes, where equal numbers of sires and donors were selected, and unbalanced rectangular mating. The first round selection responses from the balanced rectangular matings of juvenile MOET, eg. number of progeny per mating equals 2 with 10 sires selected, were 1.192, 1.406, 1.580 and 1.735 times larger than the first round selection responses from the balanced square mating schemes for the given four progeny population sizes, 10$^3$, 10$^4$, 105 and 106, respectively. Similar results were obtained in adult MOET breeding schemes. However, balanced square matings gave greater selection responses than the unbalanced rectangular matings.

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Assessing systemic, developmental, and reproductive toxicity and estrogenicity of Korean red ginseng extract G1899 in juvenile Sprague-Dawley Rats

  • Sangyun Kim;Ji-Seong Jeong;Woojin Kim;Onju Ham;Yixian Quah;Soontag Jung;Dong-Ju Park;Min Jae Kim;Byung-Cheol Han;Eunji Kim;Seung-Jin Lee;Wook-Joon Yu
    • Journal of Ginseng Research
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    • 제48권3호
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    • pp.333-340
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    • 2024
  • Background: Korean red ginseng (KRG) is a product from ginseng roots, which is enriched with ginsenosides and has been utilized for a long time as an adaptogen to alleviate various physiological or disease conditions. While KRG is generally considered safe, conducting a thorough toxicological assessment of the spray-dried powder G1899 during the juvenile period is essential to establish its safety profile. This study aimed to assess the safety of G1899 during the juvenile period using Sprague-Dawley rats. Methods: Two studies were conducted separately: a juvenile toxicity study and a uterotrophic bioassay. To assess the potential toxicity at systemic, postnatal developmental, and reproductive levels, G1899 was orally gavaged once a day in post-weaning juvenile Sprague-Dawley (SD) rats at 0, 1250, 2500, or 5000 mg/kg/day. Estrogenicity was assessed by orally gavaging G1899 in immature female SD rats at 0, 2500, or 5000 mg/kg/day on postnatal days (PND) 19-21, followed by a uterotrophic bioassay. These studies were conducted in accordance with the Good Laboratory Practice (GLP) regulations and regulatory test guidelines. Results: Regarding juvenile toxicity, no abnormalities related to the G1899 treatment were observed in any group during the experiment. Moreover, no uterotrophic responses were observed in the dosed female group. Based on these results, the no observed adverse effect level (NOAEL) of G1899 was determined to be at least 5000 mg/kg/day for general systemic function, developmental/reproductive function, and estrogenic activity. Conclusion: Our results suggest that G1899 is not toxic to juveniles at doses of up to 5000 mg/kg/day.

Comparison of physiological responses soybean [Glycine max (L.) Merill] of different irrigation Periods

  • Kim, Eun Hye;Chung, Ill Min
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.195-195
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    • 2017
  • The water in the crop cultivation shows difference according to the variety of crop, cultivations period and climatic condition. The growth and development, quantity and fruit enlargements are affected by soil water conditions. In previous study, leaf area and photosynthesis are decreased by lower soil moisture. Other research reported that excess moisture condition at vegetative and reproductive growth period in cultivation of soybean caused highest reduction in crop growth rate (CGR) and dry weights of plant parts. In particular, the damage was bigger during vegetative growth stage than reproductive growth period. Soybean (Glycine max (L.) Merill) is useful and popular crop throughout the world. It is very popular crop in Korea, China, Japan and other Asian countries. Soybeans used in various way including soybean sprouts, paste, soymilk, oil and tofu. Two soybean cultivars grown in four different irrigation conditions were determined for physiological responses. In this study, we examined leaf area (LA), leaf dry weight (LDW), specific leaf area (SLA), root dry weight (RDW) and shoot height (SH) in different water conditions. 50mL/9day irrigation periods showed the lowest contents in LA, LDW, RDW, SH. Water deficit caused increase of leaf Water saturation deficits (WSD), Cheongjakong 3 and Taekwangkong showed increase of leaf water saturation deficits (WSD) in drought conditions and leaf water potential and stomatal conductance were decreased. Photochemical efficiency was decreased in 50mL/1day irrigation condition while, there was decrease of growth and development in 50mL/9day with drought.

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