• Title/Summary/Keyword: history of natural number

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Current status, challenges and prospects for dairy goat production in the Americas

  • Lu, Christopher D.;Miller, Beth A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.8_spc
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    • pp.1244-1255
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    • 2019
  • Dairy goat production continues to be a socially, economically and culturally important part of the livestock industry in North, Central and South America and the Caribbean islands. Goat milk, cheese and other dairy products offer consumers food products with nutritional, health and environmental benefits. In North America, Mexico produces the greatest volume of goat milk, but most is for family or local consumption that is typical of a mixed farming system adopted by subsistence farmers in dry areas. The United States is not yet a large global goat milk producer, but the sector has expanded rapidly, with dairy goat numbers doubling between 1997 and 2012. The number of dairy goats has also increased dramatically in Canada. Commercial farms are increasingly important, driven by rising demand for good quality and locally sourced goat cheese. In South America, Brazil has the most developed dairy goat industry that includes government assistance to small-scale producers and low-income households. As of 2017, FAO identified Haiti, Peru, Jamaica, and Bolivia as having important goat milk production in the Western Hemisphere. For subsistence goat producers in the Americas on marginal land without prior history of chemical usage, organic dairy goat production can be a viable alternative for income generation, with sufficient transportation, sanitation and marketing initiatives. Production efficiency, greenhouse gas emission, waste disposal, and animal welfare are important challenges for dairy goat producers in the Americas.

Introduction of Western Biology into Korea, with Special Reference to Animal Systematics (서양 근대 생물학의 국내도입에 관한 연구-동물분류학을 중심으로-)

  • 이병훈;김진태
    • Animal Systematics, Evolution and Diversity
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    • v.10 no.1
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    • pp.85-95
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    • 1994
  • When biology as science was fast developing in the West, Korea remained isolated and stayed with traditional biology. This was only followed by western collectors who brought the specimens with them to their home country, their publications including almost 3,000 species (duplication allowed) during 1843-1924. The Journal of Chosen Natural History Society(1924-1944) published 318 papers by 91 authors wherein animal systematics papers predominated with 224 (70.4%) and basic taxonomy of description , list and faunal studies enumerated 201 among others . Even though the number of Korea authors was limited to only seven as compared to 83 Japanese majority two Koreans ranked third and ifth in number of publication. Those Koreans trained by Japanese scholars as their assistants, however, put the corner stone with several Koreans from Japan, upon which direct introuction of western biology to Korea was made possible after World War II.

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Minocycline-Induced Autoimmune Hepatitis: A Rare But Important Cause of Drug-Induced Autoimmune Hepatitis

  • Harmon, Elizabeth G.;McConnie, Randolph;Kesavan, Anil
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.21 no.4
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    • pp.347-350
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    • 2018
  • Drug-induced autoimmune hepatitis (DIAIH) is an increasingly recognized form of drug-induced liver injury that leads to a condition similar to idiopathic autoimmune hepatitis. A number of drugs have been associated with DIAIH, minocycline is one of the most well characterized. Minocycline is a semisynthetic tetracycline antibiotic used in the treatment of acne vulgaris. Minocycline-induced autoimmune hepatitis presents with serologic and histologic features similar to idiopathic autoimmune hepatitis. However, the natural history and outcomes of these two conditions differ significantly. The majority of patients with minocycline-induced autoimmune hepatitis experience complete resolution of symptoms after withdrawal of the medication. Some patients may require a short course of steroids and rarely use of an immunomodulator to achieve resolution of disease. Recurrence of symptoms is rare and typically only occurs with reintroduction of minocycline. It is important for primary care providers to consider minocycline-induced autoimmune hepatitis when liver injury develops during minocycline therapy.

Developmental Characteristics of Eggs and Yolk Sac Larvae of Korean Striped Bitterling, Acheilognathus yamatsutae (Cyprinidae), Spawning in Mussels

  • Song, Ho-Bok;Son, Yeong-Mok
    • The Korean Journal of Ecology
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    • v.28 no.4
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    • pp.193-198
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    • 2005
  • This study investigated the characteristics of the eggs and yolk sac larvae of Korean striped bitterling, Acheilognathus yamatsutae, spawned and grown In mussels. The number of eggs in the ovary was small ($358{\pm}108$ SD). The eggs were oval and large, and the formation of the perivitelline space was narrow. The eggs were hatched at only 41 hours after fertilization but the hatched larvae were underdeveloped. The development of yolk projection and minute tubercles on the skin surface was notable, along with the vividly moving tail in the hatched larvae. The yolk projection and minute tubercles were disappeared upon enhancement of the motor ability of the larvae was enhanced. The formation of eyes and body pigments of the larvae was relatively delayed in comparison with that of other cyprinid larvae. After completely consuming the yolks the larvae escaped from the mussel for free swimming and exogenous feeding.

Guidelines of Designing LRB for a Seismically Excited Cable-Stayed Bridge (지진 하중을 받는 사장교를 위한 납고무 받침의 설계 기준 제안)

  • 이성진;박규식;김운학;이인원
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.326-333
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    • 2003
  • Most long-span bridges such as a cable-stayed bridges have a number of long-period modes due to the flexibility, thus the design concept extending the natural period of structures using base isolation system may be difficult to use directly to these structures. But, the effectiveness of LRB for cable-stayed bridges is indicated in several papers. In this study, the guidelines of designing LRB for a seismically excited cable-stayed bridge using benchmark cable-stayed bridge are presented. The design properties of LRB are chosen that the design index(DI) is minimized or little changed for variation of properties. And the seismic performance of designed LRB is also investigated. The consequences show that the perforamnce of designed LRB is better than that of simply designed LRB for several history earthquakes. Moreover, the design properties of LRB are researched to several diffrent dominant frequency of earthquake. The results present that the plastic and elastic stiffness of LRB are affected by the dominant frequency of earthquake.

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The life history of lymnaea viridis, the intermediate host of fasciola hepatica, in the field (간질(肝蛭)의 중간숙주(中間宿主)인 애기물달팽이의 생태(生態))

  • Wee, Sung-ha;Park, Seung-joo;Lee, Chung-gil
    • Korean Journal of Veterinary Research
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    • v.31 no.4
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    • pp.515-518
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    • 1991
  • A field study of Lymnaea viridis, the intermediate host of Fasciola hepatica, was carried out in the eastern Chonnam area. The snail was distributed all over the place. Their major habitats were rice paddies (60.8%), followed by brooks (23.2%), irrigation canals (8.6%), and drains (5.6%). Other minor habitats included natural ponds (1.5%), lakes (0.4%), and rivers (0.1%). L. viridis was living in wet clay soil, occasionally entering water. The snails discharged egg masses when the temperature was $15{\sim}20^{\circ}C$, and the number of the snails was the highest late in October. At $9^{\circ}C$ the snails were not found on the mud: they were present deep in water or at the base of rice stubbles. These hibernation sites were discussed with the epidemiology of fascioliasis.

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Phylotranscriptomics of the Subfamily Apioideae (Apiaceae) (전사체 데이터에 의한 산형아과 (Apioideae)의 계통과 적응진화)

  • Eun Mi Lee;SeonJoo Park
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2023.04a
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    • pp.11-11
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    • 2023
  • Due to the abundance of information in Nuclear DNA, it has a magnificent phylogenetic resolution. Moreover, because they show biparental inheritance, it has proven to be superior to organelle DNA, which has a limited number of genes and only shows maternal lineage. In particular, the transcriptome, which includes much nuclear DNA but is relatively inexpensive to analyze, can provide valuable insights into evolution through selection analysis and enable gene function research. This study's dataset includes 45 transcriptomes (16 generated for this study). It aims to explore the evolutionary history of Apioideae by comparing the results of the phylogenetic analysis with gene tree discordance and chloroplast phylogeny. The results confirmed the taxonomic positions of Peucedanum terebinthaceum, Ligusticum tachiroei, and Cymopterus melanotilingia and proposed a genus change for Glehnia littoralis. High gene tree discordances were identified in recently diverged clades, suggesting frequent hybridization and introgression. In the most recently diverged tribe of Selineae, the highest number of PSGs (positively selected genes) has been confirmed, which is inferred to be due to the geological and climatic diversity of their originated habitat, Central Asia. These genes include those related to responses to growth and drought, oxidative, and salt stress. In particular, the CYP97A gene confirmed as PSGs in Bupleurum latissimum is inferred to be a result of adaptation to the light-limited environment of Ulleungdo Island, as it is associated with the efficiency of photosynthesis.

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Mayamaea vietnamica sp. nov.: a new, terrestrial diatom (Bacillariophyceae) species from Vietnam

  • Kezlya, Elena;Glushchenko, Anton;Kociolek, John Patrick;Maltsev, Yevhen;Martynenko, Nikita;Genkal, Sergei;Kulikovskiy, Maxim
    • ALGAE
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    • v.35 no.4
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    • pp.325-335
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    • 2020
  • A new diatom species, Mayamaea vietnamica sp. nov., is described from Cát Tiên National Park in Vietnam. This species was discovered and described from soil samples. Algae from soil ecosystems in Vietnam are almost unknown. The new species is described on the basis of an integrated approach with molecular and morphological data, and comparison with similar species. In terms of molecular data, 18S rDNA (including V4 domain), and partial rbcL plastid genes show M. vietnamica sp. nov. is most closely related to M. terrestris N. Abarca and R. Jahn, and together they form a monophyletic group relative to other members of the genus. M. vietnamica sp. nov. differs from other species in the genus by the number of striae and areolae in 10 ㎛, number of areolae per stria, as well as shape and presence or absence of axial and central areas.

What Is the Significance of a Large Number of Ruptured Aneurysms Smaller than 7 mm in Diameter?

  • Joo, Sang-Wook;Lee, Sun-Il;Noh, Seung-Jin;Jeong, Young-Gyun;Kim, Moo-Seong;Jeong, Yong-Tae
    • Journal of Korean Neurosurgical Society
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    • v.45 no.2
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    • pp.85-89
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    • 2009
  • Objective : The International Study of Unruptured Intracranial Aneurysms (ISUIA) reported that the 5-year cumulative rupture rate of small unruptured aneurysms less than 7 mm in diameter is very low depending on the aneurysm's location. However, we have seen a large number of ruptured aneurysms less than 7 mm in clinical practice. The purpose of this study was to review our experience and to measure the size and location at which aneurysms ruptured in our patient population. Methods : We reviewed the characteristics of aneurysms, such as size and location, from the original angiograms of patients who were admitted to our hospital between January 2004 and December 2007. All aneurysms were treated surgically or through endovascular procedures. Results : Interventional or surgical treatment was given to a total of 889 patients, including 568 females and 321 males. At the time of our study, 627 cases were ruptured aneurysms and 262 cases were unruptured aneurysms. Of the ruptured cases, the mean diameter of the aneurysm was 6.28 mm. We found that 71.8% of ruptured aneurysms were smaller than 7 mm in diameter, and 87.9%, were smaller than 10 mm. Based on location, the data show that anterior communicating artery aneurysms most often presented with rupture sizes less than 7 mm (76.8%) and 10 mm (92.1%) in diameter. Most ruptured aneurysms were less than 7 mm in size, although recent studies have noted that small aneurysms are less likely to rupture. Conclusion : Although the natural history of unruptured intracranial aneurysms remains controversial, the aneurysm size and location play a signigicant role in determining the risk of rupture. Larger sample sizes and a long term study are needed to reveal the natural history and the rupture risk of unruptured intracranial aneurysms because the size of most ruptured aneurysms was less than 7 mm in diameter in our series.

An experimental study of a circular cylinder's two-degree-of-freedom motion induced by vortex

  • Kim, Shin-Woong;Lee, Seung-Jae;Park, Cheol-Young;Kang, Donghoon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.4
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    • pp.330-343
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    • 2016
  • This paper presents results of an experimental investigation of vortex-induced vibration (VIV) of a flexibly mounted and rigid cylinder with two-degrees-of-freedom with respect to varying ratio of in-line natural frequency to cross-flow natural frequency, $f^*$, at a fixed low mass ratio. Combined in-line and cross-flow motion was observed in a sub-critical Reynolds number range. Three-dimensional displacement meter and tension meter were used to measure dynamic responses of the model. To validate the results and the experiment system, x and y response amplitudes and ratio of oscillation frequency to cross-flow natural frequency were compared with other experimental results. It has been found that the higher harmonics, such as third and more vibration components, can occur on a certain part of steel catenary riser under a condition of dual resonance mode. In the present work, however, due to the limitation of a size of circulating water channel, the whole test of a whole configuration of the riser at an adequate scale for VIV phenomenon was not able to be conducted. Instead, we have modeled a rigid cylinder and assumed that the cylinder is a part of steel catenary riser where the higher harmonic motions could occur. Through the experiment, we have found that even though the cylinder was assumed to be rigid, the occurrence of the higher harmonic motions was observed in a small reduced velocity ($V_r$) range, where the influence of the in-line response is relatively large. The transition of the vortex shedding mode from one to another was examined by using time history of x and y directional displacement over all experimental cases. We also observed the influence of in-line restoring force power spectral density with $f^*$.