• Title/Summary/Keyword: reproductive fitness

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The Effect of Fluctuations in Photoperiod and Ambient Temperature on the Timing of Flowering: Time to Move on Natural Environmental Conditions

  • Song, Young Hun
    • Molecules and Cells
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    • v.39 no.10
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    • pp.715-721
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    • 2016
  • Plants have become physiologically adapted to a seasonally shifting environment by evolving many sensory mechanisms. Seasonal flowering is a good example of adaptation to local environmental demands and is crucial for maximizing reproductive fitness. Photoperiod and temperature are major environmental stimuli that control flowering through expression of a floral inducer, FLOWERING LOCUS T (FT) protein. Recent discoveries made using the model plant Arabidopsis thaliana have shown that the functions of photoreceptors are essential for the timing of FT gene induction, via modulation of the transcriptional activator CONSTANS (CO) at transcriptional and post-translational levels in response to seasonal variations. The activation of FT transcription by the fine-tuned CO protein enables plants to switch from vegetative growth to flowering under inductive environmental conditions. The present review briefly summarizes our current understanding of the molecular mechanisms by which the information of environmental stimuli is sensed and transduced to trigger FT induction in leaves.

The Evolutionary Medicine of Birth Decision: Psycho-Socio-Ecological Explanations (출산 의사 결정의 진화의학: 정신-사회-생태적 설명)

  • Jihyun, Ryou;Jain, Gu;Hanson, Park
    • Korean Journal of Psychosomatic Medicine
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    • v.30 no.2
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    • pp.99-111
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    • 2022
  • Akey factor in evolution is reproduction, which is also a major concern in medicine. Evolutionists have proposed many theories and hypotheses to explain the low fertility rates of modern industrial societies, which are contrary to maximization of biological fitness. Given that childbirth is the most significant factor affecting reproductive fitness, it is likely that a variety of psychological modules related to childbirth behavior and intention evolved over time. Several evolutionary psychological modules have been proposed in relation to reproduction, including sexual desire, status-seeking, a need for nurturing, and the desire for children. Previously adaptive psychological modules may now be expressed maladaptively due to the discrepancy between the Environment of Evolutionary Adaptedness (EEA) and the environment of modern industrial society. Several evolutionary ecological factors influence childbirth intention in modern society, including individual personality factors, childhood life history experiences, and socioecological factors throughout reproductive life. By focusing on mental, social, and ecological factors, this review examines several hypothetical models relating to evolutionary psychological factors and childbirth decisions in modern industrial society, as well as a possible explanation for the low birth rate.

A culture study of women's sports of babyboom generation in Korea: through oral history interview (한국 베이비붐 세대 여성의 운동문화 연구: 구술생애사인터뷰를 중심으로)

  • Kim, Young-Sun
    • 한국체육학회지인문사회과학편
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    • v.54 no.4
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    • pp.439-452
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    • 2015
  • The purpose of this study was to criticize the sport culture of babyboom generation women in Korea society. In the traditional society with Confucianism dominating, women were told to walk in small strides with modesty, keep footsteps narrower than the size of foot and never run frivolously. But in the modern society, many middle aged women-babyboom generation who was born in 1955-1963 and the first generation was served high level education engaged to enjoy various physical activities. For this study, there is a important method to analysis through three oral history interviews. It can be seen the cultural context in the result of sport as a play, restricted P·E class, forced motive-a good motherhood, survival fitness and ready for later life. These results will can be founded as a reality of dynamic relations and provided implications about founding the important of women voice and creating important data for people who want to be engaged in sports as a physical activities.

Life Cycle of Dermacentor everestianus Hirst, 1926 (Acari: Ixodidae) under Laboratory Conditions

  • Jin, Shang;Wang, Tianhong;Li, Tuo;Liu, Ming;Jia, Qingying;Yang, Xiaolong;Wang, Hui;Yu, Zhijun;Liu, Jingze
    • Parasites, Hosts and Diseases
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    • v.55 no.2
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    • pp.193-196
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    • 2017
  • This study investigated the development characteristics of Dermacentor everestianus under laboratory conditions. The time taken for D. everestianus to complete the whole life cycle was 110.2 days on average, and the average developmental durations of larvae and nymphs were 17.1 days and 29.5 days, respectively. The summation of the prefeeding, feeding, and preoviposition periods of females was 17.8 days, and the oviposition and egg incubation lasted for 18.1 days and 27.7 days, respectively. A highly positive correlation was observed between the weight of engorged female and the number of egg mass laid (r=0.947). The reproductive efficiency index and the reproductive fitness index were 7.1 and 6.1, respectively.

Development of Genetic Algorithm based 3D-PTV and its Application to the Measurement of the Wake of a Circular Cylinder (GA기반 3D-PTV 개발과 원주 후류계측)

  • Doh, D.H.;Cho, G.R.;Cho, Y.B.;Moon, J.S.;Pyun, Y.B.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.548-554
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    • 2001
  • A GA(Genetic Algorithm) based 3D-PTV technique has been developed. The measurement system consists of three CCD cameras, Ar-ion laser, an image grabber and a host computer. The fundamental of the developed technique was based on that one-to-one correspondence is found between two tracer particles selected at two different image frames taking advantage of combinatorial optimization of the genetic algorithm. The fitness function controlling reproductive success in the genetic algorithm was expressed by a kind of continuum theory on the sparsely distributed particles in space. In order to verify the capability of the constructed measurement system, a performance test was made using the LES data set of an impinging jet. The developed 3D-PTV system was applied to the measurement of flow characteristics of the wake of a circular cylinder.

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Reproduction Strategies of Clonal Plants of Potentilla conferta in Uzbekistan and Mongol

  • Huh, Man-Kyu;Lee, Byeong-Ryong
    • Journal of Environmental Science International
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    • v.21 no.11
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    • pp.1297-1305
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    • 2012
  • Clonal plants combine sexual and clonal reproduction, which contribute differently to plant fitness. Reproductive analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Potentilla conferta Bunge, a herbaceous rhizomatic clonal distributed in hot sand dunes. We investigated the reproduction system of P. conferta at two populations in Mongol and three natural populations in Uzbekistan. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Some morphological characteristics between Mongolia and Uzbekistan populations showed a slight heterogeneity of variance. Especially, the length of internodes (LFI and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two countries (P<0.05). P. conferta of Uzbekistan has most ramets at short distance intervals 30~100 cm. In light conditions, P. conferta of Uzbekistan was significantly less resilience than P. conferta of Mogol. In drought conditions, although there was not shown significant difference, P. conferta in Uzbekistan was less resilience than that in Mogol. The core analysis indicates that P. conferta in Uzbekistan is the more resistant than that of Mongol and seems to do by sexual reproduction strategy during several strong environmental disadvantages such as drought events.

Changes in the Aggressiveness and Fecundity of Hot Pepper Anthracnose Pathogen (Colletotricum acutatum) under Elevated CO2 and Temperature over 100 Infection Cycles

  • Koo, Tae-Hoon;Hong, Sung-Jun;Yun, Sung-Chul
    • The Plant Pathology Journal
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    • v.32 no.3
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    • pp.260-265
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    • 2016
  • We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.

Effects of Panax ginseng, zearalenol, and estradiol on sperm function

  • Gray, Sandra L.;Lackey, Brett R.;Boone, William R.
    • Journal of Ginseng Research
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    • v.40 no.3
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    • pp.251-259
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    • 2016
  • Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

Impact of Ambrosia trifida L. (invasive plant) on the Plant Diversity and Performance of Polygonatum stenophyllum Maxim. (near threatened) and Management Suggestion for the Habitat Conservation. (침입외래식물 단풍잎돼지풀(Ambrosia trifida L.)이 식물종다양성과 준위협종 층층둥굴레(Polygonatum stenophyllum Maxim.)의 활력도에 미치는 영향 및 서식지 보전을 위한 관리방안)

  • Kim, EuiJoo;Kim, MiHee;Lee, SooIn;Hong, Yong Sik;Lee, EungPill;Park, JaeHoon;Lee, SeungYeon;Cho, KyuTae;You, YoungHan
    • Journal of Wetlands Research
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    • v.20 no.3
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    • pp.249-255
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    • 2018
  • This study was carried out to investigate the on the fitness of Polygonatum stenophyllum Maxim. along the coverage of Ambrosia trifida L. We were measured the number of species, death rate of P. stenophyllum, vegetative and reproductive growth of P. stenophyllum and analyzed from June 2015 to October 2016. The coverage gradient of A. trifida was divided none removed control (Control, C), 40 ~ 60% removed treatment (Treatment 1, T1) and 100% removed treatment (Treatment 2, T2) of A. trifida. As a result, When the more than 40% of removal coverage of A. trifida, the number of plant speciecs, the number of P. stenophyllum and vegetative and reproductive growth of P. stenophyllum were higher than none removed the A. trifida during the two years. Therefore, We suggest that the removal of more than 40% coverage of A. trifida from the habitats is effective in preserving the plant species diversity and conserving the populations of P. stenophyllum in this study area.

Analysis of Effects of Multiple Environmental Factors on Early Life-history for Growth and Stress Accumulation Using a Dynamic-state-dependent Model (동적상태의존모델을 이용하여 복합적 환경영향이 어류의 초기 생활사에 미치는 영향 분석)

  • Lee, Who-Seung
    • Journal of Environmental Impact Assessment
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    • v.28 no.1
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    • pp.49-62
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    • 2019
  • Environmental changes can affect life-history traits, such as growth rate and reproduction, and organisms adapt on a given environmental condition to maximize ecological fitness. This study shows the effects of water temperature and dissolved oxygen level on early growth and accumulated damage in fish using a dynamic-state-dependent model. I have hypothesized that the level of foraging activity is related to growth and stress and so the optimal level can maximize reproductive success - ultimately, fitness. The critical temperature and dissolved oxygen (DO) is also defined as inducing the maximum growth rate at the level. So, the model predicts the highest growth rate at oxygen saturation and lower growth rate at lower or higher level of DO in water. Lower DO (i.e., hypoxia) causes slower growth rate through higher amount of accumulated stress whereas higher DO (i.e., hyperoxia) induces faster growth rate, but smaller body size. In addition, I show that there is lower impact when considering simple or independent environmental factors on environmental assessment. My findings suggest that multiple environmental factors as physiological ecology approach should be considered to improve impact assessment in environmental changes and a further study is needed to develop advanced assessment tools considering multiple environmental factors.