• Title/Summary/Keyword: Central mechanism

Search Result 799, Processing Time 0.032 seconds

Topographic Variability during Typhoon Events in Udo Rhodoliths Beach, Jeju Island, South Korea (제주 우도 홍조단괴해빈의 태풍 시기 지형변화)

  • Yoon, Woo-Seok;Yoon, Seok-Hoon;Moon, Jae-Hong;Hong, Ji-Seok
    • Ocean and Polar Research
    • /
    • v.43 no.4
    • /
    • pp.307-320
    • /
    • 2021
  • Udo Rhodolith Beach is a small-scale, mixed sand-and-gravel beach embayed on the N-S trending rocky coast of Udo, Jeju Island, South Korea. This study analyzes the short-term topographic changes of the beach during the extreme storm conditions of four typhoons from 2016 to 2020: Chaba (2016), Soulik (2018), Lingling (2019), and Maysak (2020). The analysis uses the topographic data of terrestrial LiDAR scanning and drone photogrammetry, aided by weather and oceanographic datasets of wind, wave, current and tide. The analysis suggests two contrasting features of alongshore topographic change depending on the typhoon pathway, although the intensity and duration of the storm conditions differed in each case. During the Soulik and Lingling events, which moved northward following the western sea of the Jeju Island, the northern part of the beach accreted while the southern part eroded. In contrast, the Chaba and Maysak events passed over the eastern sea of Jeju Island. The central part of the beach was then significantly eroded while sediments accumulated mainly at the northern and southern ends of the beach. Based on the wave and current measurements in the nearshore zone and computer simulations of the wave field, it was inferred that the observed topographic change of the beach after the storm events is related to the directions of the wind-driven current and wave propagation in the nearshore zone. The dominant direction of water movement was southeastward and northeastward when the typhoon pathway lay to the east or west of Jeju Island, respectively. As these enhanced waves and currents approached obliquely to the N-S trending coastline, the beach sediments were reworked and transported southward or northward mainly by longshore currents, which likely acts as a major control mechanism regarding alongshore topographic change with respect to Udo Rhodolith Beach. In contrast to the topographic change, the subaerial volume of the beach overall increased after all storms except for Maysak. The volume increase was attributed to the enhanced transport of onshore sediment under the combined effect of storm-induced long periodic waves and a strong residual component of the near-bottom current. In the Maysak event, the raised sea level during the spring tide probably enhanced the backshore erosion by storm waves, eventually causing sediment loss to the inland area.

A Comparative Study of Block Chain : Bitcoin·Namecoin·MediBloc (블록체인 비교연구: 비트코인·네임코인·메디블록)

  • Kim, Ji Yeon
    • Journal of Science and Technology Studies
    • /
    • v.18 no.3
    • /
    • pp.217-255
    • /
    • 2018
  • Bitcoin, which appeared in 2008, was merely a conceptual virtual currency, but it now enjoys the status as actual money. Bitcoin is an electronic money system that can be traded directly without a central trust institution. Thanks to the popularization of Bitcoin, blockchain technology has become a widespread concern. That technology is expanding not only the currency mechanism, but also a variety of other services. The possibility of a blockchain in relation to actual currency is ongoing. This paper investigates the technological characteristics and social construction of the blockchain by comparing the cases of Bitcoin, Namecoin, and MediBloc among blockchain applications. Namecoin emerged in 2013 is an attempt to replace the centralized Internet Domain Name System(DNS). There has been controversy over that current system for a long time, but replacing the already established system is not easy. Nevertheless, Namecoin has potential as an alternative. Meanwhile, MediBloc is an application that involves distributed management of medical data in South Korea. MediBloc claims that the key producers of medical data are patients themselves. This is to challenge to the question who is a knowledge producer of medical data. Through these three cases, it has discussed that blockchain technology does supports to form more democratic decision-making or simply provide a technical solution as automation. As a citizen, we can intervene in the realization of blockchains by presenting social agenda. This will be a method of the social construction of technology.

Fibromyalgia from the Psychiatric Perspective (정신과적 관점에서의 섬유근통)

  • Lee, Yunna;Lee, Sang-Shin;Kim, Hyunseuk;Kim, Hochan
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.28 no.2
    • /
    • pp.99-107
    • /
    • 2020
  • Fibromyalgia is a disorder characterized by the core symptom of chronic widespread pain, along with fatigue, sleep disturbances, mood changes, and cognitive difficulties. The etiology of fibromyalgia involves a combination of biological factors, such as genetic vulnerability, alterations in pain processing and stress response system ; psychological factors, such as anxiety, depression, anger, and perceived stress ; environmental factors, such as infections, febrile diseases, and trauma. Central sensitization, which is amplified in the process of sensory stimulation, has been emphasized as a key etiological factor, as supported by enhanced wind-up, delayed aftersensation, decreased nociceptive flexion reflex threshold and functional imaging studies. Several guidelines recommend that a multimodal approach be used to treat fibromyalgia, including both pharmacological and non-pharmacological treatments, tailored to each individual, and that clinicians should provide an intellectual framework through sufficient education and emphasis on the importance of self-management. The prevalence of mood disorders, anxiety disorders, and other psychiatric problems is 7-9 times higher in patients with fibromyalgia than in the general population ; moreover, the association between fibromyalgia and certain psychopathologies or sleep problems has also been suggested. Since psychiatric problems, with shared vulnerabilities and risk factors, interact with fibromyalgia bidirectionally and also affect the disease course, an integrated management approach is needed to determine the risk of comorbidities.

An Analysis of Indonesia Forest Moratorium: With particular reference to Forest Governance (인도네시아 산림 모라토리엄 분석: 산림 거버넌스를 중심으로)

  • JANG, SangKyung;BAE, Jae Soo
    • The Southeast Asian review
    • /
    • v.23 no.3
    • /
    • pp.49-92
    • /
    • 2013
  • In May 2010, Indonesia and Norway signed a Letter of Intent on "Cooperation on Reducing Greenhouse Gas Emissions from Deforestation and Forest Degradation(REDD)." In the LoI, Norway agreed to offer Indonesia a sum of USD 1 billion with a view to encourage Indonesia to significantly contribute to the successful implementation of REDD+. On 20 May 2011, correspondingly, Indonesia announced the 2011 'Forest Moratorium' (the Presidential Instruction No. 10/2011) which was valid for the following consecutive two years. By means of the 2011 'Forest Moratorium', Indonesia aimed at significant reductions in greenhouse gas emissions from deforestation, forest degradation and peatland conversion. In so doing, it also sought to improve forest governance. Meanwhile, concerned stakeholders also raised various questions about the effectiveness of the 'Forest Moratorium'. As an extension of the 2011 'Forest Moratorium', Indonesia announced the 2013 'Forest Moratorium'(the Presidential Instruction No. 6/2013) for another two-year period on 13 May 2013. Indonesia's 'Forest Moratorium' is concerned with stakeholders at various levels, who may play a role of significant 'agent' in the process of implementing the 'Forest Moratorium'. This mechanism of the 'Forest Moratorium' should be understood in the light of forest governance. Employing stakeholder approach, therefore, this article attempts to analyze Indonesia's 'Forest Moratorium' in the light of forest governance. In this regard, it analyzes the detailed contents of the 'Forest Moratorium', the process of making the 'Forest Moratorium', current development of the Indicative Moratorium Map for suspension of new concessions on forest land, and contesting views of various stakeholders. At the same time, it also talks about how 'weak' forest governance had influence upon Indonesia's 'Forest Moratorium'. In so doing, this article consequently attempts to evaluate Indonesia's 'Forest Moratorium' and also put it into perspective in terms of improving forest governance. The 2013 'Forest Moratorium' fundamentally represents a radical policy that is designed to suspend new concessions on forest conversion for another two-year period and its detailed contents attempt to reflect on various stakeholders from related industries and environmental NGOs. However, there are challenging factors in the process of implementing the 'Forest Moratorium', that is, 'weak' forest governance and also a discrepancy between forest planning maps designated by central and regional governments. The announcement of the 2013 'Forest Moratorium', as an extension of the 2011 'Forest Moratorium', may functionally strengthen and improve Indonesia's forest governance. However, at the same time, there is a practical limit due to the fact that it is merely a Presidential Instruction that lacks legal binding.

Opioids and Antidepressants for Pain Control in Musculoskeletal Disease (근골격계 질환에서 통증 조절을 위한 마약성 진통제 및 항우울제)

  • Park, Se-Jin;Kim, Woo Sub;Jang, Taedong
    • Journal of the Korean Orthopaedic Association
    • /
    • v.55 no.1
    • /
    • pp.1-8
    • /
    • 2020
  • The progression of aging and the increase in musculoskeletal diseases have led to an increase in invasive treatment methods, including various surgical methods, but conservative treatment should be attempted before surgical treatment in musculoskeletal diseases. Medication for pain control, such as acetaminophen, non-steroidal anti-inflammatory drugs, steroid, opioids, antidepressants, etc., is one of the most popular methods for pain control. If the pain receptors on peripheral organ are stimulated, pain is transmitted to the brain by the ascending pathway, and the brain then secretes endogenous opioids, such as endorphin, by the descending pathway for pain control. Opioids are substances that act on the opioid receptors, and there are three receptors for opioids. The affinity for each receptor varies according to the tissue and the patient's systemic status. Antidepressants work on the synapses in the central nervous system and its main mechanism is regulation of the ascending pathway. This is mainly effective in chronic pain and neuropathic pain, which is similar in effectiveness to opioids. This review focuses on the effectiveness, method of use, and side effects of opioids and antidepressants.

Investigating the Role of Microglia in Maternal Immune Activation in Rodent Models (모체 면역 활성화 유도 설치류 모델에서 미세아교세포의 역할 조사)

  • Hyunju Kim
    • Journal of Life Science
    • /
    • v.33 no.5
    • /
    • pp.429-435
    • /
    • 2023
  • Epidemiological studies suggest that maternal infection, maternal stress, and environmental risk factors during pregnancy increase the risk of brain development abnormalities associated with cognitive impairment in the offspring and increase susceptibility to schizophrenia and autism spectrum disorder. Several animal models have demonstrated that maternal immune activation (MIA) is sufficient to induce abnormal brain development and behavioral defects in the fetus. When polyinosine:polycytodylic acid (poly I:C) or lipopolysaccharide (LPS), which is commonly used in maternal immune activation animal models, was introduced into a pregnant dam, an increase in pro-inflammatory cytokines and microglial activity was observed in the offspring's brain. Microglia are brain-resident immune cells that play a mediating role in the central nervous system, and they are responsible for various functions, such as phagocytosis, synapse formation and branching, and angiogenesis. Several studies have reported that microglia are activated in MIA offspring and influence offspring behavior through interactions with various cytokines. In addition, it has been reported that they play an important role in brain circuits through interactions with neurons and astrocytes. However, there is controversy concerning whether microglia are essential to brain development or lead to behavioral defects, and the exact mechanism remains unknown. Therefore, for the potential diagnosis and treatment of brain developmental disorders, a functional study of microglia should be conducted using MIA animal models.

A New Phase of China's Development Against the Background of "Trade War" with the US: View from Russia (Вступление Китая в новую фазу развития на фоне "торговой войны" с США: взгляд из России)

  • Lukonin, Sergey;Ignatev, Sergei
    • Analyses & Alternatives
    • /
    • v.2 no.2
    • /
    • pp.111-141
    • /
    • 2018
  • By the middle of 2018 there are signs of China's entry into a new period of development, characterized by a change in the old model: "market reforms-inner-party democratization - moderate foreign policy" to another: "market reforms - Xi Jinping personality cult - offensive foreign policy." This model contains the risks of arising of the contradiction between economic freedom and political-ideological rigidity which can lead to destabilization of the political life. However, in the current positive economic dynamics, these risks may come out, rather, in the medium and long term. Today, the political situation in China remains stable - despite growing dissatisfaction in scientific expert and educational circles due to increased control over the intellectual sphere by the authorities. The need for a new redistribution of power between central and provincial authorities could potentially disrupt political stability in the medium term, but, at the moment, is not a critical negative factor. The economic situation is positive-stable. Forecasts indicate a possible increase in China's GDP in 2018 at 6.5%. At the same time, there are negative expectations in connection with the Sino-US and potentially Sino-European "trade war". In the Chinese foreign policy, as a response to Western pressure, China increasingly uses the Russian direction of its diplomacy in the expanded version of Russia + SCO. The nuance here is seen in China's adjusted approach to the SCO: first of all, not as a mechanism for cooperation with Russia, but as an organization that allows using Russia's potential for pressure on the US in the Sino-US strategic rivalry. In the second half of 2018, the Chinese economy will continue to develop steadily, albeit with unresolved traditional problems (debts of provinces and state-owned enterprises, ineffective state sector, risks on the financial and real estate market). In politics, discontent with the cult of Xi will accumulate, but without real threats to its power. Weakening in economic opposition between China and the United States is possible due to Beijing's search for compromises on tariffs, intellectual property, trade deficit. To find such trade-offs, Xi will use the so-called. "Personal diplomacy" of direct contacts with Trump.

  • PDF

Effects of particle size and loading rate on the tensile failure of asphalt specimens based on a direct tensile test and particle flow code simulation

  • Q. Wang;D.C. Wang;J.W. Fu;Vahab Sarfarazi;Hadi Haeri;C.L. Guo;L.J. Sun;Mohammad Fatehi Marji
    • Structural Engineering and Mechanics
    • /
    • v.86 no.5
    • /
    • pp.607-619
    • /
    • 2023
  • This study, it was tried to evaluate the asphalt behavior under tensile loading conditions through indirect Brazilian and direct tensile tests, experimentally and numerically. This paper is important from two points of view. The first one, a new test method was developed for the determination of the direct tensile strength of asphalt and its difference was obtained from the indirect test method. The second one, the effects of particle size and loading rate have been cleared on the tensile fracture mechanism. The experimental direct tensile strength of the asphalt specimens was measured in the laboratory using the compression-to-tensile load converting (CTLC) device. Some special types of asphalt specimens were prepared in the form of slabs with a central hole. The CTLC device is then equipped with this specimen and placed in the universal testing machine. Then, the direct tensile strength of asphalt specimens with different sizes of ingredients can be measured at different loading rates in the laboratory. The particle flow code (PFC) was used to numerically simulate the direct tensile strength test of asphalt samples. This numerical modeling technique is based on the versatile discrete element method (DEM). Three different particle diameters were chosen and were tested under three different loading rates. The results show that when the loading rate was 0.016 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis till coalescence to the model boundary. When the loading rate was 0.032 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis. The branching occurs in these cracks. This shows that the crack propagation is under quasi-static conditions. When the loading rate was 0.064 mm/sec, mixed tensile and shear cracks were initiated below the loading walls and branching occurred in these cracks. This shows that the crack propagation is under dynamic conditions. The loading rate increases and the tensile strength increases. Because all defects mobilized under a low loading rate and this led to decreasing the tensile strength. The experimental results for the direct tensile strengths of asphalt specimens of different ingredients were in good accordance with their corresponding results approximated by DEM software.

Gender, A Neglected Variable: An Analysis of a Gender Gap in Voter Turnout (여성, 간과된 변수: 투표율에서의 성차(Gender Gap) 분석)

  • Koo, Bon Sang
    • Korean Journal of Legislative Studies
    • /
    • v.27 no.1
    • /
    • pp.5-40
    • /
    • 2021
  • This study attempts to analyze gender gaps in voter turnout for three different types of elections held since 2017 at the aggregate level using the Central Election Management Commission's turnout data, paying attention to the importance of women's voting. The findings are as follows. First, modern gender gaps in voter turnout at the aggregate level are confirmed in most regions regardless of election types. Second, the gender gap in turnout varies with age. The gender difference is verified in the "widowhood effect," where turnout decreases in the oldest-old. In the new voter group, modern gender gaps appear in most regions. The reversed gender difference in turnout in the late 20s, which reflects the Korean society's characteristics, is confirmed in all elections. Third, it is unclear whether the reverse gender gap in turnout becomes more pronounced in urbanized districts. As urbanization progressed, modern gender differences in voter turnout across age groups are observed at the population-based size level. Paradoxically, the modern gender gap tends to be weak and turns into the traditional gender gap in younger age groups (in the late thirties) in Gangnam-gu and Seocho-gu, the most modernized districts in Seoul. These results show that the modern gender gap in turnout is now a common phenomenon and continues to be strengthened by newly recruited voters in Korea. Thus we should pay more attention to female voters' political behavior and a new approach beyond the developmental theory to understand the causal mechanism to generate the modern gender gap in voter turnout.

Characterization of a Gamma Radiation-Induced Salt-Tolerant Silage Maize Mutant (방사선 유도 내염성 증진 사료용 옥수수 돌연변이체 특성 분석)

  • Cho, Chuloh;Kim, Kyung Hwa;Choi, Man-Soo;Chun, Jaebuhm;Seo, Mi-Suk;Jeong, Namhee;Jin, Mina;Son, Beom-Young;Kim, Dool-Yi
    • Korean Journal of Breeding Science
    • /
    • v.51 no.4
    • /
    • pp.318-325
    • /
    • 2019
  • Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The objective of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M2 mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.