• 제목/요약/키워드: Many-body interaction

검색결과 89건 처리시간 0.031초

탐구형 초등과학수업 '호흡' 차시에서 교사의 경력에 따른 교수행동 및 시각적 주의 분석 (Analysis of Teaching Behavior and Visual Attention according to Teacher's Career in Elementary Science Inquire-based Class on Respiration)

  • 김장환;신원섭;신동훈
    • 한국초등과학교육학회지:초등과학교육
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    • 제37권2호
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    • pp.206-218
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    • 2018
  • The purpose of this study is to analyze the teaching behaviors and visual attention according to teacher's career in Elementary Science Inquire-based Class. Participants were four elementary school teachers in Seoul. They were all in grade 5 and taught science. According to the experience of elementary science education, two novice teachers and two expert teachers were identified. Participants taught Respiration in the 'Structure and Function of our Body' in the elementary science fifth grade. The mobile eye tracker used in this study is SMI's ETG 2w, which is a binocular tracking system. In addition, a video camera was installed behind the classroom to record the entire class. We recorded all the contents of the recorded video and analyzed the results. In this study, the actual practice time, participant's visual attention, and decentralized attention ability were analyzed by class phase. The results of the study are as follows. First, there was a difference between planned class time and actual practice time. The novice teachers were having difficulty in reconstructing the contents of education, and the expert teachers were reconstructing the curriculum and interacting with the students with high understanding and application of the curriculum. There were many differences between the novice teachers and the expert teachers in the tour guidance to confirm student activities. Second, if we look at the visual attention on the area related to teaching and learning by class phase, the novice teacher concentrates all the steps in a specific area, expert teachers showed an equal visual attention to meaningful areas of teaching and learning activities. Third, there was a statistically significant difference in activities 1-1, 1-2, 2-1, and 2-2 when the participants' decentralized attention ability. Expert teachers frequently checked students' understanding and interests. There was a lot of interaction with students. It is also shown through the decentralized attention ability that the novice teachers concentrate on a specific area, and the expert teachers have a high degree of decentralized attention ability and visual attention evenly.

저소음 청소기 개발 (Low Noise Vacuum Cleaner Design)

  • 주재만;이준화;홍승기;오장근;송화규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.939-942
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    • 2007
  • Vacuum cleaner is a close life product that can remove various dusts from our surroundings. However well vacuum cleaner clean our environments, many people are looking away from it, due to its loud noise. Its noise causes a big trouble in the usual life, for example, catch calls, TV watching and discussing etc. To reduce these inconveniences, noise reduction methods and systematic design of low noise vacuum cleaner are studied in this paper. At first, sound quality investigation is performed to get the noise level and quality that make people TV watching and catch calls available. Based on the European and domestic customer SQ survey result, sound power, peak noise level and target sound spectrum guideline are studied and introduced. As a second, precise product sound spectrums are designed into each part based on the sound quality result. Fan-motor, brush, mainbody, cyclone spectrums are decided to get the final target sound based on the contribution level. Fan-motor is the major noise source of vacuum cleaner. Specially, its peak sound, RPM peak and BPF Peak, cause the people nervous. To reduce these peak sounds, high rotating impeller and diffuser are focused due to its interaction. A lot of experimental and numerical tests, operation points are investigated and optimization of flow path area between diffusers is performed. As a bagless device, cyclones are one of the major noise sources of vacuum cleaner. To reduce its noise, previous research is used and adopted well. Brush is the most difficult part to reduce noise. Its noise sources are all comes from aero-acoustic phenomena. Numerical analysis helps the understanding of flow structure and pattern, and a lot of experimental test are performed to reduce the noise. Gaps between the carpet and brush are optimized and flow paths are re-designed to lower the noise. Reduction is performed with keeping the cleaning efficiency and handling power together and much reduction of noise is acquired. With all above parts, main-body design is studied. To do a systematic design, configuration design developments technique is introduced from airplane design and evolved with each component design. As a first configuration, fan-motor installation position is investigated and 10 configuration ideas are developed and tested. As a second step, reduced size and compressed configuration candidates are tested and evaluated by a lot of major factor. Noise, power, mass production availability, size, flow path are evaluated together. If noise reduction configuration results in other performance degrade, the noise reduction configuration is ineffective. As a third configuration, cyclones are introduced and the size is reduced one more time and fourth, fifth, sixth, seventh configuration are evolved with size and design image with noise and other performance indexes. Finally we can get a overall much noise level reduction configuration. All above investigations are adopted into vacuum cleaner design and final customer satisfaction tests in Europe are performed. 1st grade sound quality and lowest noise level of bagless vacuum cleaner are achieved.

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저온환경 적응에 있어서의 갑상선 Hormone의 변동 (Changes of Thyroid Hormone Levels in Plasma of Rats during Cold Exposure)

  • 이향우;김원준;홍사석;김호석;홍사오
    • 대한약리학회지
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    • 제17권2호
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    • pp.37-45
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    • 1981
  • The importance of thyroid hormones for the survival of rats in the cold is along-established fact. Hypothyroid animals are unable to survive in a cold environment. It was also reported that acute exposure of rats, guinea pigs and rabbits to cold produced an increased secretion of TSH and thereby thyroid hormone secretion within 10 to 30 min, but this increase of thyroid activity disappeared quite rapidly during warming. However, in human study no significant difference was found in the concentration of $T_4$, TSH and cortisol between summer and winter. But plasma $T_3$ concentration was increased significantly in winter in 56 adult men. On the other hand, it has been also known that catecholamines are important in the maintenance of body temperature of rat exposured to cold. Abundant evidences suggest that the sympathetic nervous system is involved in the activation of nonshivering thermogenesis and that thyroid hormone metabolism and secretion are influenced by catecholamines and consequently by the activity of the sympatheticadrenal system. Many of the metabolic effects of catecholamines are associated with an increase in the level of cAMP mediated through activation of adenylate cyclase which converts ATP to cAMP. Other studies have shown that thyroid hormones affect the amount of adenylate cyclase present in the adipose tissue. On the other hand. it was also reported that a particulate cAMP phosphodiesterase activity in fat cells was modulated by the action of thyroid hormones. The objective of the present study was to determine the interaction between thyroid activity and cyclic nucleotides during acute exposure to cold. Albino rats weighing around 200 g were used as the experimental animal. The room temperature group was kept at $25^{\circ}C$ and the cold-exposured group was kept at $4^{\circ}C$ for 1 week or 2 weeks. Each group was subdivided into three subgroups; control, KI, and MTU group. At the end of experiment the animals were etherized and blood was taken from abdominal aorta for $T_4,\;T_3$ and cyclic nucleotides. The determinations of $T_3,\;T_4$ and cyclic nucleotides were carried out with a radioimmunoassay(RIA) method. The results were summerized as followings. 1) A significant increase of thyroid weight was observed in rats exposured to cold for 2 weeks. Furthermore, in rats administered MTU while to exposure to cold the thyroid weight was also increased significantly. 2) After 2 weeks $T_3$ concentration in the plasma of cold-exposured rats was significantly increased in KI group and MTU group as well as in control group. On the contrary, after 2 weeks of cold exposure $T_4$ level was decreased in control group. 3) In the case of cyclic nucleotides, plasma cAMP was increased in the control group after 1 or 2 weeks of cold exposure. However, cAMP level in plasma was rather significantly decreased in KI group and MTU group as well as in control group.

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어깨, 팔꿈치, 손목의 자세에 따른 최대악력과 근육활동에 관한 연구 (Effects of Combinational Posture of Shoulder, Elbow and Wrist on Grip Strength and Muscle Activity)

  • 김태형;정승래;강성식;장성록
    • 한국안전학회지
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    • 제31권4호
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    • pp.111-119
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    • 2016
  • This study aimed to analyze postures that were frequently conducted in manufacturing industry. To find grip strength and muscle activities of each posture, Maximum Voluntary Contraction (MVC) and ElectroMyoGraphy (EMG) were measured. Based on the results of this study, the most appropriate posture could be suggested and used as a basic information for preventing musculoskeletal disorders. Most work-related musculoskeletal disorders have been occurred in the fields of manufacturing industry. According to previous studies, it was reported that the rate of musculoskeletal diseases of upper extremity was higher than that of other body parts. Accordingly, there were many studies about discomfort and grip strength of upper extremity. However, these studies dealt with single selection of wrist, elbow and shoulder. So, it was insufficient for comprehensive studies about upper extremity. And in order to improve the work posture, the physiological changes being generated by the combination of wrist, elbow and shoulder postures should be observed and analyzed. In order to conduct this study, thirty university students who had no records of MSDs involved were recruited. Independent variables were postures of wrist(pronation, neutral, supination), postures of elbow(flexion $45^{\circ}$, $90^{\circ}$) and postures of shoulder(flexion $0^{\circ}$, $90^{\circ}$). And dependent variables were MVC values and EMG values. Jamar dynamometer and TeleMyo 2400T G2 was used to measure MVC and EMG. MVC and EMG for 12 postures were measured for three second and for three times. Experiment was performed randomly. A 10 minutes rest period was provided after each t. To measure muscle load, the EMG signals of eight muscles (Biceps, Medial triceps, Lateral triceps, Brachioradialis, Extensor carpi ulnaris, Extensor carpi radialis, Flexor carpi ulnaris and Flexor carpi radialis) were evaluated. MVC values and EMG values were analyzed using Minitab ver. 14. The results showed that MVC value was the highest at shoulder $0^{\circ}$, elbow $45^{\circ}$ and wrist supination. In case of wrist postures, MVC of supination is the highest. In case of elbow and shoulder postures, MVC of flexion $45^{\circ}$ and $0^{\circ}$ was the highest. It was found that there were interaction between wrist and elbow posture under shoulder flexion and between shoulder and wrist under elbow flexion $45^{\circ}$. In case of the angle of shoulder $0^{\circ}$, elbow $45^{\circ}$ and wrist supination, the EMG values of four muscles(Medial Triceps, Extensor carpi ulnaris, Extensor carpi radialis, Flexor carpi ulnaris) were the highest. Based on this study, it is worth to note that the combination postures of upper extremity have a large impact on the MVC and EMG. The optimal condition upper extremity was shoulder flexion $0^{\circ}$, elbow flexion $45^{\circ}$ and wrist supination for preventing work-related musculoskeletal disease.

노쇠한 사이보그: <공각기동대 Stand Alone Complex>로 본 노화와 과학기술 (The Senile Cyborg: Science, Technology, and Aging in Ghost in the Shell: Stand Alone Complex)

  • 박형욱
    • 과학기술학연구
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    • 제13권1호
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    • pp.41-76
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    • 2013
  • 사이보그와 노화는 현대 과학기술의 두 가지 중요한 화두라 할 수 있다. 이 논문은 일본의 애니메이션 감독 카미야마 켄지(神山健治)의 SF 작품인 <공각기동대 Stand Alone Complex>를 통해 이 두 가지 화두가 만나는 지점을 분석해 본다. 실로 연령은 젠더와 인종, 계급과 더불어 현대 사회와 정치를 구성하는 매우 중요한 범주이나 과 학기술학자들은 이에 대해 깊게 연구하지 않았다. 특히 다너 해러웨이(Donna Haraway)의 "사이보그 선언문(Cyborg Manifesto)"(1991) 이후 현대 과학기술에 의해 변화하는 젠더의 전망에 대해서는 많은 과학기술학적 연구가 있었으나 연령이 과학기술과 맺는 관련과 그 영향에 대해서는 깊은 연구가 이루어지지 못했다. 만약 해러웨이가 주장한 것처럼 사이보그가 여성에게 지워진 생물학적 담론을 넘어설 수 있는 방법을 보여준다면, 그것은 노인들에게도 자신들의 변화하는 몸의 한계와 연령주의적 담론을 넘어설 수 있는 가능성을 열어줄 수 있을까? 마이크 페더스톤(Mike Featherstone)은 과학기술이 늙어가는 몸과 결합하여 생겨난 사이보그적 상태가 만든 새로운 전망을 긍정적으로 분석하고 있다. 그러나 이 글은 <공각기동대>를 통해 노년기의 사이보그화와 관련된 더 복잡한 문제들을 분석한다. 나는 과학기술과 노인의 만남을 통해 태어난 노쇠한 사이보그가 전통적 가족주의와 민족주의를 넘어설 수 있게 하나 연령주의를 극복하지는 못하며, 세계화된 자본주의와 네트워크 속의 통제된 신체를 통한 새로운 개인주의적 삶의 형태를 창조해 내고 있음을 보일 것이다.

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자가간호증진을 위한 건강계약이 고혈압자의 건강행위 이행에 미치는 영향 (A Study of the Effects of Health Contracting on Compliance with Health Behaviors in Clients with Hypertension)

  • 이향련
    • 대한간호학회지
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    • 제17권3호
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    • pp.204-217
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    • 1987
  • It is generally accepted that the delivery of health care is undergoing many changes specially those related to acute, contagious disease care and to the increase of chronic illnesses which can not be cured but are controlable. The health care practitioner can not be soley responsible for the control of their clients' care. Because the clients will play a vital role in controlling their illnesses, long term participation by both the health care provider and the client is necessary. Since most individuals with hypertension do not experience signs or symptoms, the disease is difficult to detect and even when diagnosed, clients do not comply well with their hypertension regimens. The noncompliant client is at increased risk for compliants involving the heart, brain, kidney and other organs. In an effort to explore methods of increasing patient participation in and adherence to treatment programs for hypertension, the researcher used health contracting to promote self care. The research questions are; 1) Will the health contracting increase compliance in health behavior and reduce the blood pressure\ulcorner 2) If clients comply with their regimens will this reduce their blood pressure\ulcorner The research design utilized in this study was a quasi-experimental design. A purposive sample, was abtained from two churches in the 1. area, consisting of 64 clients with hypertension. The data was collected from the middle of January to the 1st of September 1985. Randomization was only of the two church groups into experimental and control groups. Compliance with health behavior related to the hypertensive regimen, blood pressure and body weight were measured, compared and analyzed. In the experimental group measurements were made 6 times; one month before the education program after education program when health contracting was done and 4 more times once a month for 4 months. In the control group measurements were made 3 times; one month before the education program after the education program, and once 4 months later. There was no health contracting. The data were analyzed by t-test, Pearson correlation and ANOVA according to purpose of the study. The result of this study may be summarized as follows: The result related to the hypothesis on the effect of health contracting are as follows: H$_1$; “The hypothesis that the experimental group, with a health contractual agreement will demonstrate increased compliance levels for health behavior than the control group” was supported(t=-5.29, df=62, p=.000). H$_2$; “The hypothesis that the experimental group, with a health contractual agreement, will demonstrate a greater reduction in blood pressure than the control group” was supported (for systolic blood pressure t=2.72, df=62, p=.009, for diastolic blood pressure t=1.95, df=62, p=.050). H$_3$; The hypothesis that the greater the compliance of the client with health behavior the lower the client's blood pressure will be was partially supported (for systolic pressure r=-.2981, p=.008, for diastolic pressure r=-.1720, p=.087). From the examination of the results of this study it can be concluded that the interaction between the nurse and the client, contracting to define goals and reinforcing compliant behavior, leads to improved compliance with health care behaviors and thus to an increase in the effectiveness of nursing care. Further consideration need to be given to the inclusion of the concept of health contracting in primary nursing and to further research in this area.

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숲 체험 프로그램이 뇌파와 맥파에 미치는 영향 (The Effect of Forest Experience Program on Brain Waves & Pulse Waves)

  • 김진국;최경호
    • 한국엔터테인먼트산업학회논문지
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    • 제13권4호
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    • pp.185-194
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    • 2019
  • 본 연구는 단기간 숲 체험자들의 뇌파와 맥파의 변화를 측정하여 정신적인 효능을 확인하는 데 목적이 있다. 이를 위해 경기도 청평에 위치한 자연휴양림에 방문한 484명의 체험자를 대상으로 숲 체험 전·후 뇌파와 맥파를 측정하여 다음과 같은 결과를 도출하였다. 첫째, 숲 체험자들은 집중도, 두뇌활동정도 및 두뇌스트레스에 효과가 있는 것으로 나타났다. 둘째, 숲 체험자들은 심장건강도 및 자율신경건강도 모두 긍정적인 효과가 있는 것으로 확인되었다. 즉, 산림에서 방출되는 여러 가지 물질들이 우리 신체에 호흡기를 통해 들어오게 되면 먼저 심장활동에 긍정적인 영향을 주고, 이는 곧 정서적인 측면인 두뇌에도 작용하여 다양한 호전을 기대할 수 있게 하는 것으로 보인다. 그러므로 숲 체험에 대한 과학적인 근거에 기인한 효능을 바탕으로 많은 사람들이 참여할 수 있는 여건을 만들어 건강한 삶을 위한 하나의 지침으로 숲 체험이 널리 활용되기를 기대한다. 아울러 호흡과 심박 그리고 두뇌의 상호작용에 대한 기전 역시 이를 통해 가능할 것으로 보여 향후 숲 체험에 대한 다양한 실험 연구가 중요하다 하겠다.

재조합 대장균에서 다양한 융합 파트너를 이용한 인간 상피세포성장인자의 발현 연구 (Study on the soluble exoression of recombinant human eoidermal growth factor using various fusion oartners in Escherichia coli)

  • 김병립;백정은;김천석;이혁원;안정오;이홍원;정준기;이은교;김인호
    • KSBB Journal
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    • 제23권3호
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    • pp.205-212
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    • 2008
  • 본 연구의 목적은 위치특이적 펩타이드 및 단백질을 사용하여 재조합 대장균에서 활성형 인간 상피세포성장인자(hEGF)를 고효율로 발현할 수 있는 방법을 찾아내는 데 있다. 재조합 대장균내 cytoplasm 및 periplasm 영역에서 hEGF의 발현을 위해 각각 세개의 응합 펩타이드 및 단백질을 선정하여 상호 비교하였다. 재조합 대장균에서 hEGF의 발현유도시 대부분 불용성 단백질로 생산되는 현상을 극복하기 위해 cytoplasm영역에서는 ATS, thioredoxin, 리파제를 융합파트너로 사용하였으며 periplasm 영역에서는 foldase인 DsbA와 DsbC, 용융성 고발현 단백질인 maltose binding protein을 선택하여 사용하였다. Periplasm영역에서 발현유도를 시키는 융합단백질의 경우 cytoplasm영역에서의 발현양도 용융성 형태로 고발현 되는 것을 알 수 있었으며 전체적으로 약 2배가량의 용융성 형태로 발현되었다. hECF의 발현율을 가장 높일 수 있는 융합단백 질은 maltose binding protein이었으나 발현된 융합단백질의 24%가 불용성 단백질로 형성되어 활성형 형태로 얻는 데 한계가 있었으며, 활성형 형태로 hEGF의 발현을 위해서는 DsbA를 응합단백질로 사용한 경우에 18.1 mg/L로 가장 높은 발현농도를 보였다. Cytoplasm 영역에서 발현유도를 한 경우에는 ATS와 thioredoxin을 응합파트너로 hEGF를 발현한 경우 용융성 형태로 높은 발현율을 보였다. 특히 ATS와 같은 펩타이드를 N-말단에 융합시킨 경우 불용성을 방지하는 효과를 보여 이황화결합의 불완전성이나 소수성으로 인해 불용성 단백질로 발현되는 기존의 단백질을 활성형 형태로 발현하는데 될 수 있음을 확인할 수 있었다.

조직.기관의 분화와 유전자 발현의 조절, 최근의 진보 (Recent Advancement in the Differentiation of Tissues and Organs and Regulation of Gene Expression)

  • Harn, Chang-Yawl
    • 식물조직배양학회지
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    • 제24권1호
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    • pp.1-35
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    • 1997
  • Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.

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