• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.115-123
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• 2003

Oviposition and egg laying is an important physiological and behavioural event in the life cycle of the silkworm, Bombyx mori (L). Oviposition and egg laying is dependent on a number of intrinsic and extrinsic factors viz., neural, hormonal, environmental, physical, behavioral etc for the perpetuation of population. Although, the virgin female moths have fully developed embryos but active egg laying begins under the influence of mating which provides essential copulation stimulus for oviposition. After mating drastic biochemical changes occurred that incites egg laying under the influence of optimum environmental conditions. Weight of pupae as well as larval density has significant role on oviposition and egg laying behaviour in the silkworm wherein high pupal weight and inadequate rearing space affects not only the biology, morphology and physiology but also the oviposition and egg laying. Surface topography, plane of inclination, mating length, age of male moth, temperature and photoperiod etc has significant effect on reproductive physiology of silkworm. An attempt has been made in this review article to elucidate briefly the works carried out on mating behaviour, direct and indirect copulation stimulus, vitellogenesis, influence of environmental factors besides effect of weight of pupae and or pharate adult and larval density on oviposition and egg laying behavior in the silkworm, B. mori and its significance in silkworm seed production.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.440-447
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• 2009

Domestic ruminant animals are reared in diverse production systems, ranging from extensive systems under semi-arid and tropical conditions with poor feed resources to intensive systems in temperate and cold areas with high quality feed. Nitrogen (N) recycling between the body and gut of ruminants plays a key role in the adaptation to such diverse nutritional conditions. Ammonia and microbial protein produced in the gut and urea synthesized in the liver are major players in N-recycling transactions. In this review, we focus on the physiological factors affecting urea production and recycling. Sheep and buffalo probably have higher abilities to reabsorb urea from the kidney compared with cattle. This affects the degree of urea-N recycling between the body and gut at both low and high N intakes. The synthesis and gut entry of urea also differs between cattle bred for either dairy or beef production. Lactating dairy cows show a higher gut entry of urea compared with growing cattle. The synthesis and recycling of urea dramatically increases after weaning, so that the functional development of the rumen exerts an essential role in N transactions. Furthermore, high ambient temperature increases urea production but reduces urea gut entry. An increase in total urea flux, caused by the return to the ornithine cycle from the gut entry, is considered to serve as a labile N pool in the whole body to permit metabolic plasticity under a variety of physiological, environmental and nutritional conditions.

• BMB Reports
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• 제47권2호
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• pp.51-59
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• 2014

Cellular senescence is a physiological process of irreversible cell-cycle arrest that contributes to various physiological and pathological processes of aging. Whereas replicative senescence is associated with telomere attrition after repeated cell division, stress-induced premature senescence occurs in response to aberrant oncogenic signaling, oxidative stress, and DNA damage which is independent of telomere dysfunction. Recent evidence indicates that cellular senescence provides a barrier to tumorigenesis and is a determinant of the outcome of cancer treatment. However, the senescence-associated secretory phenotype, which contributes to multiple facets of senescent cancer cells, may influence both cancer-inhibitory and cancer-promoting mechanisms of neighboring cells. Conventional treatments, such as chemo- and radiotherapies, preferentially induce premature senescence instead of apoptosis in the appropriate cellular context. In addition, treatment-induced premature senescence could compensate for resistance to apoptosis via alternative signaling pathways. Therefore, we believe that an intensive effort to understand cancer cell senescence could facilitate the development of novel therapeutic strategies for improving the efficacy of anticancer therapies. This review summarizes the current understanding of molecular mechanisms, functions, and clinical applications of cellular senescence for anticancer therapy.

• 수면정신생리
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• 제15권1호
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• pp.5-11
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• 2008

Sleep is an essential process maintaining the life cycle of the human. In parallel with physiological, cognitive, subjective, and behavioral changes that take place during the sleep, there are remarkable changes in the electroencephalogram (EEG) that reflect the underlying electro-physiological activity of the brain. However, analyzing EEG and relating the results to clinical observations is often very hard due to the complexity and a huge data amount. In this article, I introduce several linear and non-linear tools, developed to analyze a huge time series data in many scientific researches, and apply them to EEG to characterize various sleep states. In particular, the spectral analysis, detrended fluctuation analysis (DFA), and synchrony analysis are administered to EEG recorded during nocturnal polysomnography (NPSG) processes and daytime multiple sleep latency tests (MSLT). I report that 1) sleep stages could be differentiated by the spectral analysis and the DFA ; 2) the gradual transition from Wake to Sleep during the sleep onset could be illustrated by the spectral analysis and the DFA ; 3) electrophysiological properties of narcolepsy could be characterized by the DFA ; 4) hypnic jerks (sleep starts) could be quantified by the synchrony analysis.

• 대한인간공학회지
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• 제4권2호
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• pp.17-24
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• 1985

To compare heart rate, $O_2$ uptake, $Vo_2$ ($O_2$ consumption), blood pressure (systolic, diastolic), reaction time, stability, flicker fusion value during 4 load levels with Rs (self-paced respiration) and Rp (paced respiration), 4 subjects participated in this experiment 1 hour/day, 6 days/week for 9 weeks. The cycle of Rp is 6 sec. (inspiration: 3 sec. & expiration: 3 sec.) Implications of the results are discussed in terms of the change in the physiological responses and human performance by the respiratory pattern. The results are as follows, 1. The changing magnitude of heart rate with Rp was larger than with Rs and the variance during load level 4 was significant. 2. The $Vo_2$ with Rp was smaller than with Rs and maximal $O_2$ uptake given load levels with Rp occurred and for two subjects, it significantly moved from low load level to high load level. 3. The changing magnitude of blood pressure was not consistent but the systolic pressure with Rp was smaller at rest than with Rs. 4. The score of reaction time test and stability test with Rp was better than with Rs.

• 한국발생생물학회지:발생과생식
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• 제14권3호
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• pp.185-197
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• 2010

The reproduction of animals is a means to maintain their species. The golden hamsters are seasonal breeders, and their reproduction is regulated by the photoperiod. The shifts of the sexual functions imply the changes of the protein expression, and those are reflected by the proteome. Thus the present study was to examine via two dimensional polyacrylamide gel electrophoresis (2d PAGE), the physiological changes and the alterations of protein expressions in hypothalamus upon the reproductive situation related to the pineal gland. Among the pineal intact animals, the reproductive functions were sustained in animals housed in long photoperiod (LP) but regressed in animals housed in short photoperiod. And those pinealectomized animals showed high sexual activities regardless of photoperiod. Ultimately they were branched into dichotomy, sexually active and inactive animals. Apart from the changes of physiological parameters upon the reproductive conditions, there were obvious differences in proteins extracted from the hypothalamus. The hypothalamus of LP animals presented high levels of enzymes which are involved in the production of energy, glycolysis and Krebs cycle. The increased energy might be related to the GnRH synthesis in hypothalamus and indirectly to the constant cell divisions in spermatogenesis. Taken together, the impacts of the photoperiodic information controlling reproduction could be observed through 2d PAGE. Therefore, the present results suggest the potential of biomarkers collectively to diagnose the fertility and the infertility by way of proteomics in organs with regard to the reproductive system, further could be applied to diagnose various diseases.

• Animal Bioscience
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• 제35권11호
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• pp.1800-1807
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• 2022

Objective: This study aimed to determine the effect of different cooling sessions (CSs) as a water conservation strategy on physiological, and production responses and welfare in Holstein Friesian cows during subtropical summer in Pakistan. Methods: Twenty-one cows were subjected to three CS in a completely randomized design. The treatments were: i) eleven hours continuous cooling with sprinklers - control (CNT), ii) four CS, and iii) two CS. The CNT represented the practices of the commercial dairy farms in the area, while the other CSs were used as water reduction strategies. Each CS lasted for 1 h with a 12 min cycle (3 min water on and 9 min off) with a sprinkler flow rate of 1.25 L/min. Results: The average temperature humidity index of the shed and the outside open area were 81.9 and 82.5, respectively. The results showed that both physiological responses were highest in the 2CS group followed by the CNT and the 4CS (p = 0.001). The CNT and 4CS groups had similar milk yield (p = 0.040). The 4CS group had more lying and eating times than the CNT and 2CS groups (p = 0.000). The cortisol level in the 2CS group was 2.0 and 2.2 ㎍/dL more than the CNT and the 4CS groups, respectively (p = 0.000). Conclusion: In conclusion, the 4CS was more efficient in cooling the cows and had better welfare, as it yielded similar milk yield, and better physiological responses than the CNT despite using 90% less water.

• 한국수산과학회지
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• 제27권4호
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• pp.380-389
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• 1994

담수산 징거미새우, Macrobrachium nipponense의 유생을 부화후부터 후기유생단계까지의 전 유생기간동안 수온 $25^{\circ}C$, 염분 $7\%0$의 일정한 조건하에서 사육하고 섭이율, 호흡율, 배설율 및 성장율을 측정하였다. 성장은 건중, 탄소, 질소, 수소 및 단백질, 지질의 함량변화로서 측정하였는데 단백질보다는 지질이 더 높은 비율로 축적되었다. 그리고 모든 생리적, 생화학적 특성은 각 유생단계간에 그리고 개체의 탈피주기에 따라서 상당한 변화를 나타내었다. 평균섭이율은 탈피간기에 가장 높았으며 bell-shaped 양상을 나타내었다. 호흡율은 부화후부터 후기유생 단계까지 계속 증가한 반면, 배설율은 탈피간기에서 증가하여 bell-shaped 양상을 나타내었다. 이러한 생리적, 생화학적 자료로서 시간의 경과에 따른 발생변화의 양상과 생물에너지학적 효율을 분석하기 위하여 섭이율, 성장율, 호흡율 및 배설율등을 회귀방정식으로 나타내었다. 탈피주기동안 탄소는 초기에 증가하는 경향을 나타내었으며, 암모니아 질소는 탈피전기까지 꾸준히 증가하는 경향을 나타내었다. 단백질은 탈피전기의 중기에 다소 높은 축적을 보이면서 탈피전기의 말기까지 일정량을 유지하면서 체물질을 구성하는 우점성분으로 일정하게 유지되었다.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.298-304
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• 1998

Retinoids are applied to not only cancer prevention but also cancer chemotherapy by stimulating differentiation of cells. We studied differentiation inducing effect of all-trans retinoic acid (ATRA) by studying proportion of high dense fractions of stem-like cells and the size of S phase fraction in cell cycle. From mammary organoids obtained from 7- to 8-week old F344 female rat mammary gland, we cultured rat mammary epithelial cells (RMEC) and treated physiological doses of $10^{-6}$, $10^{-7}$, and $10^{-8}$ M ATRA from the first day and then cultured for 4, 7, and 14 days. After that, immunostaining was performed using peanut agglutinin (PNA) and anti-Thy-1.1 monoclonal antibody (Thy-1.1) that can be used as markers of differentiation. We separated four different cell subpopulations by flow cytometry: cells negative to both reagents (B-), PNA-positive cells (PNA+), Thy-1.1-positive cells (Thy-1.1+), and cells positive to both reagents (B+). We observed continuous decreases of high dense fractions of stem-like cells (PNA+ subpopulations) for 14 days and as much decreases as high doses of ATRA, which were thought to be proportional to doses of ATRA. We labeled RMEC with bromodeoxyuridine and investigated cell cycle fractions that went through S phase. We observed a tendency of decrease of S phase fraction with time in culture, which, is thought to be related to continuous decreases of PNA+ subpopulations and inhibitory role of ATRA on cell cycle. These results suggest that physiological doses of ATRA could stimulate differentiation of RMEC and convert stem-like RMEC to differentiated cells in SFM for a relatively long period of 14 days.

• 동의생리병리학회지
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• 제27권2호
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• pp.202-211
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• 2013

The purpose of this study is to investigate the apoptotic effect of Phellodendri Cortex water extract (PCWE) on pancreatic cancer cells and to find out the regulating mechanisms. Human-derived pancreatic cancer cell line, MIA PaCa-2 cells were treated by PCWE with various concentrations and the cytotoxicity was determined by MTT assay. The activation of Annexin V, DNA fragmentation, cell cycle arrest and caspase activation were observed to investigate the role of PCWE in pancreatic cancer cells. Also, to find out the regulating mechanisms, we examined the ROS production. The treatment of PCWE induced the cell death in both concentration and time dependent manner. The treatment of PCWE also increased the expression of Annexin V, DNA fragmentation, cell cycle arrest, and cleavage of caspase, which means cell-death PCWE induced was apoptosis but not necrosis. The ROS production was increased by PCWE treatment and the blockade of ROS inhibited the PCWE-induced cell death. These results could suggest that PCWE induced apoptosis via ROS release in pancreatic cancer cell.