• Title/Summary/Keyword: termination rate

Search Result 175, Processing Time 0.034 seconds

Mutations of Constitutive Activation and Mutations That Impair Signal Transduction Modulate the Agonist-stimulated Internalization of the Lutropin/choriogonadotropin Receptor

  • Park, J.J.;Kim, M.S.;Lee, Y.Y.;H.Y. Kang;Y.M. Chang;Yoon, J.T.;K.S. Min
    • Proceedings of the Korean Society of Developmental Biology Conference
    • /
    • 2003.10a
    • /
    • pp.83-83
    • /
    • 2003
  • The lutropin/choriogonadotropin receptor (LHR) is a member of the rhodopsin-like subfamily of G protein coupled receptor (GPCRs), that has been shown to mediate the internalization of its two naturally occurring agonist, lutropin and choriogonadotropin (CG). The clustered agonist-receptor complex is internalized by a dynamin-dependent pathway and traverses the endosomal compartment without agonist dissociation Dissociation of the agonist-receptor complex occurs in the lysosomes, where both the agonist and receptor are degrade. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty (FMPP). A FMPP is a form of sexual precocious puberty in boys in which testosterone levels are elevated independent of changes in luteinizing hormone-releasing hormone and serum luteinizing hormone levels, We have now analyzed two naturally occurring, constitutively active mutants of the human LHR. These mutations were introduced into the rat LHR (rLHR) and are designated L435R and D556Y. Cells expressing rLHR-D556Y bind human choriogonadotropin (hCG) with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. Cells expressing rLHR-L435R also bind hCG with normal affinity, exhibit a 47-fold increase in basal cAMP, and do not respond to hCG with a further increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17- fold, respectively We conclude that the state of activation of the rLHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing rLHR-L435R is due to the fast rate of internalization of the bound hCG. The finding that membranes expressing rLHR-L435R respond to hCG with an increase in adenylyl cyclase activity supports this suggestion. Autonomous Leydig cell activity in FMPP is caused by a constitutively activating LH/CGR.

  • PDF

Grain Yield and Physiological Responses of Water Stress at Reproductive Stage in Barley (보리 생식생장기의 수분부족이 수량 및 몇 가지 생리적 반응에 미치는 영향)

  • Choi, Won-Yul;Kwon, Yong-Woong;Park, Jong-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.42 no.3
    • /
    • pp.263-269
    • /
    • 1997
  • To cope with increasing importance of water stress in food crop production, some physiological characteristics, their cultivar-differences and grain yield of winter barley cultivars in response to water stress during reproductive stages were studied employing three covered-barley cultivars, Milyang 12, Durubori, and Olbori, one naked-barley cultivar, Baegdong, and one two-row malting-barley cultivar, Hyangmaeg. The barley grown in pot-soil was conditioned for 10 days under water stress, varying the time of water stress : 20 days before heading, 10 days before heading and the time of heading. The decrease in growth due to water stress varied greatly with the cultivars and time of water stress. The greatest injury occurred when water stress was imposed for 10 days from 10 days before heading : the culm length of water-stressed plants have shown reduced by 85∼98% of the non-stressed; the number of spikes per plant by 52∼83%; the number of grains per spike by 71∼86%; 1,000-grain weight by 80∼84%; yield per pot by 60∼94%. The number of spikes per plant as one of yield components was most sensitively affected. As a whole, the drought resistance of cultivars was high in the order of Olbori> Milyang 12 and Durubori> Hyangmaeg>Baegdong. On rewatering the plants after termination of the water stress treatment the recovery rate of free proline content and relative turgidity of flag leaf were higher in 3 covered-barley cultivars, and lower in cultivars Baegdong and Hyangmaeg.

  • PDF

Growth and Physiological Response of Three Evergreen Shrubs to De-icing Salt(CaCl2) at Different Concentrations in Winter - Focusing on Euonymus japonica, Rhodoendron indicum, and Buxus koreana - (겨울철 염화칼슘(CaCl2) 처리에 따른 가로변 3가지 상록 관목류의 생육 및 생리반응 - 사철나무, 영산홍, 회양목을 중심으로 -)

  • Ju, Jin-Hee;Park, Ji-Yeon;Xu, Hui;Lee, Eun-Yeob;Hyun, Kyoung-Hak;Jung, Jong-Suk;Choi, Eun-Young;Yoon, Yong-Han
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.44 no.2
    • /
    • pp.122-129
    • /
    • 2016
  • It is important to know the sensitivity of shrubs to de-icing salt in order to set guidelines for ecological tolerance of evergreen shrubs along roads. Therefore, the aim of this study was to investigate the influence of de-icing salt, calcium chloride($CaCl_2$), on the growth and physiological characteristics of three evergreen shrubs, Euonymus japonica, Rhododendron indicum, and Buxus koreana. Plants were exposed to calcium chloride at different concentrations(weight percentage, 0% as control, 1.0%, 3.0%, and 5.0%) through amended soil maintained from the start of the experiment in October of 2014 until termination in March of 2015. The survival rate, plant height, leaf length, leaf width, leaf shape index, number of leaves, fresh weight, dry weight, dry matter, root/top ratio, chlorophyll contents, fluorescence, photosynthesis, stomatal conduct, and transpiration rate were recorded. Elevated calcium chloride concentrations decreased plant height, leaf length, leaf width, leaf shape index, fresh weight, dry weight, dry matter, and R/T ratio of the three shrubs. Root growth responded more sensitively than the top growth to salinity. However Euonymus japonica was more tolerant to salt stress than Rhododendron indicum and Buxus koreana. Their growths were totally inhibited by $CaCl_2$ above 3.0% and 1.0% concentrations, respectively. Chlorophyll content, fluorescence, photosynthesis, stomatal conduct, and transpiration rate of both Rhododendron indicum and Buxus koreana were reduced sharply, while Euonymus japonica exhibited mild reductions compared to plants grown in control when increasing calcium chloride was used. Especially, the transpiration rates of Rhododendron indicum, and the photosynthesis and stomatal conduct of Buxus koreana were suppressed as the concentrations of calcium chloride increased. Therefore, Euonymus japonica should be considered as an ecologically tolerant species with proven tolerance to de-icing salt.

Estimation of Reliability of Real-time Control Parameters for Animal Wastewater Treatment Process and Establishment of an Index for Supplemental Carbon Source Addition (가축분뇨처리공정의 자동제어 인자 신뢰성 평가 및 적정 외부탄소원 공급량 지표 확립)

  • Pak, JaeIn;Ra, Jae In-
    • Journal of Animal Science and Technology
    • /
    • v.50 no.4
    • /
    • pp.561-572
    • /
    • 2008
  • Responses of real-time control parameters, such as ORP, DO and pH, to the conditions of biological animal wastewater treatment process were examined to evaluate the stability of real-time control using each parameter. Also an optimum index for supplemental carbon source addition based on NOx-N level was determined under a consideration of denitrification rate by endogenous respiration of microorganism and residual organic matter in liquor. Experiment was performed with lab-scale sequencing batch reactor(SBR) and working volume of the process was 45L. The distinctive nitrogen break point(NBP) on ORP-and DO-time profiles, which mean the termination of nitrification, started disappearing with the maintenance of low NH4-N loading rate. Also the NBP on ORP-and DO-time profiles was no longer observed when high NOx-N was loaded into the reactor, and the sensitivity of ORP became dull with the increase of NOx-N level. However, the distinctive NBP was constantly occurred on pH(mV)-time profile, maintaining unique profile patterns. This stable occurrence of NBP on pH(mV)-time profile was lasted even at very high NOx-N:NH4-N ratio(over 80:1) in reactor, and the specific point could be easily detected by tracking moving slope change(MSC) of the curve. Revelation of NBP on pH(mV)-time profile and recognition of the realtime control point using MSC were stable at a condition of over 300mg/L NOx-N level in reactor. The occurrence of distinctive NBP was persistent on pH(mV)-time profile even at a level of 10,000mg/L STOC(soluble total organic carbon) and the recognition of NBP was feasible by tracing MSC, but that point on ORP and DO-time profiles began to disappear with the increase of STOC level in reactor. The denitrfication rate by endogenous respiration and residual organic matter was about 0.4mg/L.hr., and it was found that 0.83 would be accepted as an index for supplemental carbon source addition when 0.1 of safety factor was applied.

A Study on Calculation Method of Compensation for Indirect Damage of Fishery by Undertaking Public Project (공익사업시행(公益事業施行)으로 인한 어업(漁業)의 간접피해(間接被害) 보상액(補償額) 산출방법(算出方法)에 관(關)한 연구(硏究))

  • Kim Ki-Dae;Kim Byung-Ho
    • The Journal of Fisheries Business Administration
    • /
    • v.37 no.1 s.70
    • /
    • pp.25-44
    • /
    • 2006
  • Under the provision of Article 63 of the Enforcement Regulation of the Act on Acquisition and Compensation of Land and Others for Public Project that is recently enacted and implemented (hereinafter referred to as the 'Lend Compensation Act') the compensation is required to make 'When the Actual Damage Amount' is confirmed for the damage in fishery affairs that is outside of the public project area. The compensation for fishery business on the indirect damage area has been excluded from the advance compensation subject to conflict with the existing laws on fishery business compensation with the controversy in method, procedure, time and others to confirm the actual damage amount, and it lacks the standard of calculation for detailed compensation on partial damages outside of business implementation area, which caused the ceaseless conflicts and straggles between the project implementation party and the victimized fishermen regarding the calculation method of damages, standard, compensation period and others. In particular, from the numerous problems in damage compensation in fishery on the indirect damage area, the most recent problem emerged is the issue on application method of damage period in calculating the damage compensation amount that the struggle has been deepened with the differences between the project implementation party and the victimized fishermen without the stipulation on the compensation, that caused the difficulties in carrying out the public project and other serious social problems. In this study, the reasonable application method for the damage period and the calculation plan of the damage amount for calculating the damages on fishery industry outside of the public project implementation zone that is not fully specified under the Land Compensation Act, and the indirect damage area is not influenced for the notification of project recognition, and the compensation to undertake with the damage in the fishery industry in project implementation area to have the nature of damage compensation, the right to engage in fishery industry has the perpetual nature of rights, the fishery damage compensation system of Japan also recognizes the perpetual right on fishery industry to calculate the compensation amount, and the compensation for damage amount has been exercised for the period of actual damage occurrence period regardless of remaining effective period for most of fishery permit and license for fishery compensation outside of the project implementation area following the recent various public projects as well as the development process of theory on fishery loss compensation that the calculation of damage amount on the fishery industry outside of the project implementation zone would be prudent to compensate by calculating the applicable damages during the period of actual damages, and by doing so, the 'just compensation' guaranteed under the Constitution may be materialized. Therefore, the calculation of the damages from the implementation of the public project shall consider the actual period of damages and the degree of damage from the public project to calculate by the income capitalization method, however, considering the equitable consideration with the compensation following the cancellation, it shall not exceed the compensation following the termination of the applicable fishery businesses. Furthermore, the calculation method of partial damage amount on the fishery business following the project implementation shall apply, depending on the period of damage occurrence, by (1) the case of calculating the future damage amount at the present time, and (2) calculating the damage from the past to the present time as well as the damage to be incurred later, by selecting the calculation method for damages following the damage occurrence type.

  • PDF

Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionicgonadotropin Receptor

  • Min, K. S.
    • Proceedings of the KSAR Conference
    • /
    • 2000.10a
    • /
    • pp.10-12
    • /
    • 2000
  • Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

  • PDF

Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionic Gonadotropin Receptor

  • Min, K.S.
    • Korean Journal of Animal Reproduction
    • /
    • v.24 no.4
    • /
    • pp.357-364
    • /
    • 2000
  • Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

  • PDF

Effect of One- or Two-Week Triple Therapy with Omeprazole, Amoxicillin, and Clarithromycin on Eradication of Helicobacter pylori Infection in Children (소아에서 Omeprazole, Amoxicillin, Clarithromycin 삼제 병합 요법의 치료기간별 Helicobacter pylori 제균율)

  • Choi, In-Kyoung;Lee, Seung-Yun;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • v.5 no.1
    • /
    • pp.19-25
    • /
    • 2002
  • Purpose: The triple therapy with proton pump inhibitor (PPI) has been recognized as the treatment of choice in Helicobacter pylori (H. pylori) infection in adults. However, the effect of triple therapy with omeprazole, amoxicillin and clarithromycin (OAC) on eradication of H. pylori infection in children has not been established yet. This study was performed to evaluate the efficacy of OAC triple therapy and to compare the effect of one-week with two-week therapy on H. pylori eradication. Methods: From July 1998 to July 2000, 34 children with upper gastrointestinal symptoms, who underwent upper gastrointestinal endoscopy with biopsy at entry and 4 or more weeks after therapy, were enrolled in this study. H. pylori infection was assessed by CLO test and histologic examination (Hematoxylin-Eosin stain or Alcian yellow stain) with biopsy specimens. The regimen consisted of omeprazole (0.7 mg/kg/day), amoxicillin (50 mg/kg/day), and clarithromycin (25 mg/kg/day) for 1 week (n=21) or 2 weeks (n=13). Eradication of H. pylori was determined after the termination of treatment by the CLO test and histologic examination. Results: One-week treatment group consisted of 21 children (11 male, 10 female) with a mean age of $9.5{\pm}3.0$ years. Two-week group consisted of 13 children (4 male, 9 female) with a mean age of $9.9{\pm}4.0$ years. The endoscopic diagnoses included nodular gastritis in 19 cases, superficial gastritis in 7 cases, gastric ulcer in 4 cases, purpuric duodenitis in 2 cases, and normal in 2 cases. H. pylori was eradicated in 28 of total 34 children (82.4%). In 1-week group, H. pylori was eradicated in 17 of 21 children (81%). In 2-week group, H. pylori was eradicated in 11 of 13 children (84.6%). In remaining 6 cases in whom H. pylori had not been eradicated with OAC regimen, H. pylori infection persisted despite of the treatment with additional drugs such as colloidal bismuth subcitrate ($Denol^{(R)}$) and metronidazole. Conclusion: In this study, eradication rate of H. pylori with OAC regimen was 82.4%, and the triple therapy would be highly effective as primary treatment. However, there was no significant difference in the eradication rate between the 1-week and 2-week treatment group (P=0.785).

  • PDF

THE LUMINOSITY-LINEWIDTH RELATION AS A PROBE OF THE EVOLUTION OF FIELD GALAXIES

  • GUHATHAKURTA PURAGRA;ING KRISTINE;RIX HANS-WALTER;COLLESS MATTHEW;WILLIAMS TED
    • Journal of The Korean Astronomical Society
    • /
    • v.29 no.spc1
    • /
    • pp.63-64
    • /
    • 1996
  • The nature of distant faint blue field galaxies remains a mystery, despite the fact that much attention has been devoted to this subject in the last decade. Galaxy counts, particularly those in the optical and near ultraviolet bandpasses, have been demonstrated to be well in excess of those expected in the 'no-evolution' scenario. This has usually been taken to imply that galaxies were brighter in the past, presumably due to a higher rate of star formation. More recently, redshift surveys of galaxies as faint as B$\~$24 have shown that the mean redshift of faint blue galaxies is lower than that predicted by standard evolutionary models (de-signed to fit the galaxy counts). The galaxy number count data and redshift data suggest that evolutionary effects are most prominent at the faint end of the galaxy luminosity function. While these data constrain the form of evolution of the overall luminosity function, they do not constrain evolution in individual galaxies. We are carrying out a series of observations as part of a long-term program aimed at a better understanding of the nature and amount of luminosity evolution in individual galaxies. Our study uses the luminosity-linewidth relation (Tully-Fisher relation) for disk galaxies as a tool to study luminosity evolution. Several studies of a related nature are being carried out by other groups. A specific experiment to test a 'no-evolution' hypothesis is presented here. We have used the AUTOFIB multifibre spectro-graph on the 4-metre Anglo-Australian Telescope (AAT) and the Rutgers Fabry-Perot imager on the Cerro Tolalo lnteramerican Observatory (CTIO) 4-metre tele-scope to measure the internal kinematics of a representative sample of faint blue field galaxies in the red-shift range z = 0.15-0.4. The emission line profiles of [OII] and [OIII] in a typical sample galaxy are significantly broader than the instrumental resolution (100-120 km $s^{-l}$), and it is possible to make a reliable de-termination of the linewidth. Detailed and realistic simulations based on the properties of nearby, low-luminosity spirals are used to convert the measured linewidth into an estimate of the characteristic rotation speed, making statistical corrections for the effects of inclination, non-uniform distribution of ionized gas, rotation curve shape, finite fibre aperture, etc.. The (corrected) mean characteristic rotation speed for our distant galaxy sample is compared to the mean rotation speed of local galaxies of comparable blue luminosity and colour. The typical galaxy in our distant sample has a B-band luminosity of about 0.25 L$\ast$ and a colour that corresponds to the Sb-Sd/Im range of Hub-ble types. Details of the AUTOFIB fibre spectroscopic study are described by Rix et al. (1996). Follow-up deep near infrared imaging with the 10-metre Keck tele-scope+ NIRC combination and high angular resolution imaging with the Hubble Space Telescope's WFPC2 are being used to determine the structural and orientation parameters of galaxies on an individual basis. This information is being combined with the spatially resolved CTIO Fabry-Perot data to study the internal kinematics of distant galaxies (Ing et al. 1996). The two main questions addressed by these (preliminary studies) are: 1. Do galaxies of a given luminosity and colour have the same characteristic rotation speed in the distant and local Universe? The distant galaxies in our AUTOFIB sample have a mean characteristic rotation speed of $\~$70 km $s^{-l}$ after correction for measurement bias (Fig. 1); this is inconsistent with the characteristic rotation speed of local galaxies of comparable photometric proper-ties (105 km $s^{-l}$) at the > $99\%$ significance level (Fig. 2). A straightforward explanation for this discrepancy is that faint blue galaxies were about 1-1.5 mag brighter (in the B band) at z $\~$ 0.25 than their present-day counterparts. 2. What is the nature of the internal kinematics of faint field galaxies? The linewidths of these faint galaxies appear to be dominated by the global disk rotation. The larger galaxies in our sample are about 2"-.5" in diameter so one can get direct insight into the nature of their internal velocity field from the $\~$ I" seeing CTIO Fabry-Perot data. A montage of Fabry-Perot data is shown in Fig. 3. The linewidths are too large (by. $5\sigma$) to be caused by turbulence in giant HII regions.

  • PDF

Usefulness of DTI-based three dimensional corticospinal tractography in children with hemiplegic cerebral palsy (편마비를 가진 뇌성마비 환아에서 확산 텐서강조영상을 이용한 3차원 피질척수로 영상의 유용성)

  • Yeo, Ji Hyun;Son, Su Min;Lee, Eun Sil;Moon, Han Ku
    • Clinical and Experimental Pediatrics
    • /
    • v.52 no.1
    • /
    • pp.99-104
    • /
    • 2009
  • Purpose : Magnetic resonance diffusion tensor imaging-based three-dimensional fiber tractography (DTI-FT) is a new method which demonstrates the orientation and integrity of white matter fibers in vivo. However, clinical application on children with cerebral palsy is still under investigation. We present various abnormal patterns of DTI-FT findings and accordance rate with clinical findings in children with hemiplegic cerebral palsy, to recognize the use fulness of DTI-FT. Methods : The thirteen children with hemiplegic cerebral palsy evaluated at Yeungnam University hospital from March, 2003 to August, 2007 were enrolled in this study and underwent magnetic resonance DTI-FT of the corticospinal tracts. Two regions of interest (ROI) were applied and the termination criteria were fractional anisotropy ${\geq}0.3$, angle ${\leq}70^{\circ}$. Results : The patterns and distribution of abnormal DTI-based corticospinal tractographic findings were interruption(10 cases, 76.9%), reduction of fiber volume (8 cases, 61.5%), agenesis of corticospinal tract (3 cases, 23.1%), transcallosal fiber (2 cases, 15.4%) and, aberrant corticospinal tracts (4 cases, 30.8%). Abnormal DTI-based corticospinal tractographic findings were in accordance with the clinical findings of cerebral palsy in 84.6% of the enrolled patients. Conclusion : Our results suggest that DTI-FT would be a use ful modality in the assessment of the corticospinal tract abnormalities in children with hemiplegic cerebral palsy.