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1

Satellite cell mitotic activity in posthatch turkey skeletal muscle growth.  

PubMed

The relationship between satellite cell mitotic activity and skeletal myofiber growth was examined in Pectoralis thoracicus and Biceps femoris muscles of Large White tom turkeys (Nicholas strain) at 3, 6, 9, 18, and 26 wk of age. Mitotically active satellite cells were labeled with 5-bromo-2'-deoxyuridine (BrdU). Labeled satellite cells were identified on enzymatically isolated myofiber segments using mouse anti-BrdU followed by fluorescein-5-isothiocyanate (FITC) conjugated goat anti-mouse IgG secondary antibodies. Myofiber nuclei (satellite cell nuclei + myonuclei) were counterstained with propidium iodide (PI). Myofiber segment diameter, myofiber segment length, and number of FITC- and PI-labeled nuclei were determined for each segment. At each age interval there was an increase in myofiber diameter, suggesting that the myofibers were growing during the entire experimental period. There was an age-related (P < .001) decrease in satellite cell mitotic activity and an age-related increase (P < .001) in the cytoplasmic volume to nucleus ratio (CNR) from 3 to 26 wk of age. An early phase of myofiber growth, between 3 and 6 wk of age, was characterized by a high level of satellite cell mitotic activity and increased CNR. Between 6 and 9 wk of age, satellite cell mitotic activity decreased, but the CNR showed no change (P > .05). During a late phase of myofiber growth, beyond 9 wk of age, satellite cell mitotic activity continued to decrease and myofiber growth occurred by an increased CNR. This study demonstrated that both Pectoralis thoracicus and Biceps femoris undergo a significant late phase of growth without appreciable production of myonuclei by satellite cell proliferation. PMID:8202434

Mozdziak, P E; Schultz, E; Cassens, R G

1994-04-01

2

Psychiatric problems within the satellite-extended families of Turkey.  

PubMed

The many Turkish villagers who now migrate to large Turkish cities or enter the European labor force try to create models of the extended families they leave behind. Their satellite families necessarily drift away from tradition, however, in the direction of greater independence. This process often triggers psychiatric symptom formation. PMID:984261

Ozbek, A; Volkan, V D

1976-10-01

3

The effect of in vivo and in vitro irradiation (25 Gy) on the subsequent in vitro growth of satellite cells.  

PubMed

The effect of in vivo and in vitro irradiation on subsequent satellite cell growth, in vitro, was investigated to ascertain the ability of a 25 Gy dose to inhibit satellite cell proliferation. Satellite cells were isolated from the left (irradiated) and right (non-irradiated) Pectoralis thoracicus of two-week-old tom turkeys 16 h (n=3) and seven weeks (n=2) after the left Pectoralis thoracicus had been irradiated (25 Gy). Satellite cells isolated from the irradiated and non-irradiated muscles exhibited similar (P>0.10) in vitro proliferation indicating that a population of satellite cells survived an in vivo dose of 25 Gy. In additional experiments, satellite cell cultures derived from tom turkey Pectoralis thoracicus were irradiated (25 Gy) in vitro. The number of satellite cells did not (P>0.05) increase in irradiated cultures for 134 h following irradiation, while satellite cells in non-irradiated cultures proliferated (P<0.05) over this time. At later time periods, satellite cell number increased (P<0.05) in irradiated cultures indicating that a population of satellite cells survived irradiation. The results of these in vitro experiments suggest that a 25 Gy dose of irradiation does not abolish satellite cell divisions in the turkey Pectoralis thoracicus. PMID:8593649

Mozdziak, P E; Schultz, E; Cassens, R G

1996-02-01

4

The effect of in vivo and in vitro irradiation (25 Gy) on the subsequent in vitro growth of satellite cells  

NASA Technical Reports Server (NTRS)

The effect of in vivo and in vitro irradiation on subsequent satellite cell growth, in vitro, was investigated to ascertain the ability of a 25 Gy dose to inhibit satellite cell proliferation. Satellite cells were isolated from the left (irradiated) and right (non-irradiated) Pectoralis thoracicus of two-week-old tom turkeys 16 h (n=3) and seven weeks (n=2) after the left Pectoralis thoracicus had been irradiated (25 Gy). Satellite cells isolated from the irradiated and non-irradiated muscles exhibited similar (P>0.10) in vitro proliferation indicating that a population of satellite cells survived an in vivo dose of 25 Gy. In additional experiments, satellite cell cultures derived from tom turkey Pectoralis thoracicus were irradiated (25 Gy) in vitro. The number of satellite cells did not (P>0.05) increase in irradiated cultures for 134 h following irradiation, while satellite cells in non-irradiated cultures proliferated (P<0.05) over this time. At later time periods, satellite cell number increased (P<0.05) in irradiated cultures indicating that a population of satellite cells survived irradiation. The results of these in vitro experiments suggest that a 25 Gy dose of irradiation does not abolish satellite cell divisions in the turkey Pectoralis thoracicus.

Mozdziak, P. E.; Schultz, E.; Cassens, R. G.

1996-01-01

5

Turkey.  

PubMed

Focus in this discussion of Turkey is on the following: geography; the people; history; government and political conditions; the economy; defense; and relations between the US and Turkey. In 1986, Turkey's population was estimated to be 51.8 million with an annual growth rate of 2.5%. The infant mortality rate is 12.3/1000 with a life expectancy of 62.7 years. Turkey is located partly in Europe and partly in Asia. Since 1950, urban areas have experienced tremendous growth, and squatter dwellings are evident around the cities' edges. About half of Turkey's population live in urban areas. Turkish culture is made up of both the modern and traditional, Ottoman and folkloric, elements. The Republic of Turkey was founded by Mustafa Kemal, subsequently named Ataturk, in 1982 after the collapse of the 600-year-old Ottoman empire. The new republic focused on modernizing and Westernizing the empire's Turkish core -- Anatolia and a small part of Thrace. The 1982 constitution preserves a democratic, secular, parliamentary form of government with a strengthened presidence. It provides for an independent judiciary along with the safeguarding of internationally recognized human rights. The legislative functions are carried out by the unicameral, 450-member GNA. The economy is developing structurally, yet the agricultural sector remains significant and produces cotton, tobacco, grains, fruits, and vegetables. Over half of the labor force are farmers, contributing over 1/5 of the gross domestic product. A significant portion of industry also is involved in processing agricultural products. The period from the mid-1960s to the mid-1970s was the longest sustained period of economic growth and development in modern Turkish history, with annual growth rates of nearly 7%. Oil price increases after 1973 and the concomitant European recession slowed Turkish growth and also revealed major structural deficiencies. The economic crisis worsened in 1979 as oil prices doubled again. The Demirel government adopted a strong economic reform program in January 1980. As a result of various government economic policies, economic activity increased. The US and Turkey signed a Defense and Economic Cooperation Agreement in March 1980 that provided a new framework for US military activities in Turkey and committed the US to a "best effort" in providing defense support to the Turkish Armed Forces. PMID:12177973

1988-03-01

6

Quantitation of satellite cell proliferation in vivo using image analysis.  

PubMed

A nonisotopic, double fluorescence technique was developed to study myogenic satellite cell proliferation in posthatch turkey skeletal muscle. Labeled satellite cell nuclei were identified on enzymatically isolated myofiber segments using a mouse monoclonal antibody (anti-BrdU) followed by fluorescein-5-isothiocyanate (FITC) conjugated goat anti-mouse IgG secondary antibody. Myofiber nuclei (myonuclei+satellite cell nuclei) were counterstained with propidium iodide (PI). The myofiber segment length, myofiber segment diameter, and the number of PI and FITC labeled nuclei contained in each segment was determined using a Nikon fluorescence microscope, a SIT video camera and Image-1 software. Data collected by three different operators of the image analysis system revealed 5.0 +/- 1.4 satellite cell nuclei per 1000 myofiber nuclei and 5284 +/- 462 microns3 of cytoplasm surrounding each myofiber nucleus in the pectoralis thoracicus of 9-week-old tom turkeys. BrdU immunohistochemistry coupled with the new approach of PI staining of whole myofiber mounts is an effective combination to allow the use of an efficient semi-automated image analysis protocol. PMID:7819418

Mozdziak, P E; Fassel, T; Gregory, R; Schultz, E; Greaser, M L; Cassens, R G

1994-09-01

7

Old high resolution satellite images for landscape archaeology: case studies from Turkey and Iraq  

NASA Astrophysics Data System (ADS)

The paper concerns the contribution for Landscape Archaeology from satellite images of 1960s and 1970s, very useful when old aerial photographs are scarce. Particularly, the study concerns the panchromatic photos taken by USA reconnaissance satellites from 1963 to 1972, declassified for civil use in 1995 and 2002, that in the last years are very used in the archaeological research; in fact, a lot of these images have an high geometric resolution, about between 2.74 and 1.83 m (Corona KH-4A and KH-4B), and some have a ground resolution about between 1.20 and 0.60 m (Gambit KH-7). These satellite images allow to examine very in detail ancient urban areas and territories that later are changed or partially destroyed; so, it is possible to detect and examine ancient structures, palaeo-environmental elements and archaeological traces of buried features now not visible. The paper presents some exemplificative cases study in Turkey and Iraq, in which the analysis of these images has made a fundamental contribution to the archaeological researches: particularly, for the reconstruction of the urban layout of the ancient city of Hierapolis of Phrygia and for the surveys in its territory, and for the study of the ancient topography of some archaeological sites of Iraq. In this second case, the research is gained in the context of the Iraq Virtual Museum Project; the comparison with recent high resolution satellite images (Ikonos-2, QuickBird-2, WorldView-1) also provide a fundamental tool for monitoring archaeological areas and for an evaluation of the situation after the first and the second Gulf War.

Scardozzi, Giuseppe

2008-10-01

8

Heterogeneity in the muscle satellite cell population  

PubMed Central

Satellite cells, the adult stem cells responsible for skeletal muscle regeneration, are defined by their location between the basal lamina and the fiber sarcolemma. Increasing evidence suggests that satellite cells represent a heterogeneous population of cells with distinct embryological origin and multiple levels of biochemical and functional diversity. This review focuses on the rich diversity of the satellite cell population based on studies across species. Ultimately, a more complete characterization of the heterogeneity of satellite cells will be essential to understand the functional significance in terms of muscle growth, homeostasis, tissue repair, and aging.

Biressi, Stefano; Rando, Thomas A.

2010-01-01

9

Determination of horizontal and vertical distribution of Calabrian pine stands in Turkey using SRTM satellite data and GIS.  

PubMed

Forest areas in Turkey are generally spread on rugged terrain and different elevations. Site factors such as location, elevation from sea level, aspect and slope are effective on an ecosystem's climate, soil characteristics, and hence vegetation. Description of such characteristics will allow for the description of forest ecosystems living on these sites and comparison of such ecosystems to each other. Factors such as elevation, aspect and slope can easily be generated from Digital Elevation Models. In this study, using a digital elevation model obtained from SRTM (Shuttle Radar Topography Mission) satellite data and 1/25,000 scale Forest Information System database, horizontal and vertical distribution of Calabrian pine (Pinus brutia Ten.), which is spatially the most extensively spread needled tree species in Turkey, (to elevation classes) is determined and the generated results (map, table etc.) are presented. PMID:24558804

Yener, Hakan

2013-09-01

10

Satellite Cells Say NO to Radiation  

PubMed Central

Skeletal muscles are commonly exposed to radiation for diagnostic procedures and the treatment of cancers and heterotopic bone formation. Few studies have considered the impact of clinical doses of radiation on the ability of satellite cells (myogenic stem cells) to proliferate, differentiate and contribute to recovering/maintaining muscle mass. The primary objective of this study was to determine whether the proliferation of irradiated satellite cells could be rescued by manipulating NO levels via pharmacological approaches and mechanical stretch (which is known to increase NO levels). We used both SNP (NO donor) and PTIO (NO scavenger) to manipulate NO levels in satellite cells. We observed that SNP was highly effective in rescuing the proliferation of irradiated satellite cells, especially at doses less than 5 Gy. The potential importance of NO was further illustrated by the effects of PTIO, which completely inhibited the rescue effect of SNP. Mechanical cyclic stretch was found to produce significant increases in NO levels of irradiated satellite cells, and this was associated with a robust increase in satellite cell proliferation. The effects of both radiation and NO on two key myogenic regulatory factors (MyoD and myogenin) were also explored. Irradiation of satellite cells produced a significant increase in both MyoD and myogenin, effects that were mitigated by manipulating NO levels via SNP. Given the central role of myogenic regulatory factors in the proliferation and differentiation of satellite cells, the findings of the current study underscore the need to more fully understand the relationship between radiation, NO and the functionality of satellite cells.

Cho-Lim, Jennie J.; Caiozzo, Vincent J.; Tseng, Bertrand P.; Giedzinski, Erich; Baker, Mike J.; Limoli, Charles L.

2014-01-01

11

Using Cell Phones From Satellites  

NASA Technical Reports Server (NTRS)

During the past several years, an interest has grown in using commercial telecommunications techniques to supply Telemetry and Command (T&C) services. Recently, the National Aeronautics and Space Administration (NASA) Space Operations Management Office (SOMO) has outlined plans to utilize satellite-based telecommunications services to support space operations in space missions over the next several decades. NASA currently obtains the bulk of its telecommunications services for earth-orbiting satellites via the existing government-owned and controlled Space Network (SN) system. This system consists of the constellation of Tracking and Data Relay Satellites (TDRS) in Geostationary Earth Orbit (GEO) and the associated ground terminals and communications intrastructure. This system is valuable and effective for scientific satellites costing over one million dollars. However, for smaller satellites, this system becomes problematic due to the cost of transponders and support infrastructure. The nominal transponders for using the TDRS cannot be obtained for a cost in dollars, and size, weight, or power that the 3 Corner Satellite project can afford. For these types of nanosatellite missions, alternatives that fit the mission cost and satellite profiles are needed. In particular, low-cost access using existing commercial infrastructure would be useful to mission planners. In particular, the ability to obtain low data rate T&C services would be especially valuable. The nanosatellites generally have low T&C requirements and therefore would benefit from using commercial services that could operate in the 2400 bps - 9600 bps range, especially if contact times longer than the 5 - 10 minute ground station passes could be found.

Horan, Stephen

2000-01-01

12

Analysis of urban growth using multi-temporal satellite data in Istanbul, Turkey  

Microsoft Academic Search

Uncontrolled population growth, especially in developing countries, causes serious problems, such as scarcity of food, informal settlements, environmental pollution, destruction of ecological structure, unemployment, etc. This phenomenon will require advanced methodologies, such as space technologies, to enable city planners, economists, environmentalists, ecologists and resource managers to solve these problems. In Turkey, as a result of the undesired population growth, new

D. Maktav; F. S. Erbek

2005-01-01

13

Investigation the Reasons and Results of the Coastal Erosion of Karasu Region (Turkey) Using Multi-temporal Satellite Sensor Data  

NASA Astrophysics Data System (ADS)

Sakarya River is the second largest Anatolian river discharging into the Black Sea just nearby the Karasu district with a drainage area of 56,504 km2 and a length of 824 km. This area is one of the most sensitive parts of the Black Sea Coast of Turkey is located within the boundaries of the Sakarya Province and has coastal line of 50 kilometers formed with the sediments carried by the Sakarya River. This coastal zone of the Karasu District located at the north-western part of Turkey along the Black Sea Coast is a significant example of heavy coastal erosion and it has been selected as the study area. Besides the impact of the climate change on all over the coastal areas, they are also exposed to significant erosion due to both natural and human-induced activities. In 1996, approximately 1 km east of the Sakarya River mouth nearby the Karasu district, a fishing shelter construction was started. In the following stages, the project was turned out to a harbor extending its breakwater to 1.5 km, and the construction was completed in 2008. During the construction of the harbor, the coastal line progressively moved into inland through the houses on the coastal area. Indeed, the coastal erosion increased gradually in time, and at last the houses in forefront of the coastal line were destructed by the storm that occurred on January 2010. The objective of this study is to determine the level of the coastal erosion occurred in the area between the years 1987 and 2010 using LANDSAT 5 TM satellite sensor data of the year 1987, 2001, 2006, 2009 and 2010 together with GNSS measurement as main data. Coastal lines were extracted from satellite sensor imageries for the different years under inspection and the variations were investigated. Fourth band of the satellite images received in 1987, 2001 and 2010 were combined using layer stack option and a new RGB image was constituted to present the differences occurred within these years. By means of this new image, the differences within the periods were analyzed on the selected 12 cross sections. In some sections the coastal erosion level between 1987 and 2010 was calculated as more than 300 meters. After the analyses of the obtained results and coastal line morphology together with the other parameters obtained from the satellite imageries, the recently constructed harbor was evaluated as the main cause of coastal erosion. This study aims to find a scientific response to this debate and to investigate the temporal speed of coastal erosion by revealing a risk perspective.

Seker, D. Z.; Kutoglu, S. S.; Gormus, S.; Tanik, A.; Musaoglu, N.; Sertel, E.

2011-12-01

14

Metrical use of declassified satellite imagery for an area of archaeological interest in Turkey  

Microsoft Academic Search

The adoption of satellite imagery in archaeology is well recognized today, and is rapidly increasing with the greater availability of high resolution sensors, in the past limited solely to military applications. The metrical use of declassified satellite images from the intelligence CORONA project, the first US operational space photo reconnaissance project operating in the period 1960–1972, has been verified within

Gabriele Bitelli; Valentina Alena Girelli

2009-01-01

15

Solar cells for solar power satellites  

NASA Technical Reports Server (NTRS)

The concept of a solar-cell array for a solar power satellite is developed to permit evaluation of its economic feasibility for generating power for delivery to public utilities on earth. Gallium arsenide solar cells were considered but it could not be assured that the world gallium resources could support constructions of two solar power satellites per year. Therefore, for preliminary design an array blanket made from 5 by 10 cm silicon solar cells, 50 microns thick, and electrostatically bonded between borosilicate glass sheets was adopted. In annealing experiments, a radiated 50 microns thick cell was restored to its initial performance in a 500 C. Solar-cell efficiency effects significantly the solar power satellite mass, which varies from 90,000 metric tons for 20 percent cells to 120,000 metric tons for 12 percent cells. The anticipated cost of delivered power, based on 1977 dollars, varies from 4 cents per kWh with 18 percent cells, to 5 cents per kWh for 12 percent efficient cells.

Oman, H.

1978-01-01

16

Skeletal Muscle Satellite Cells Cultured in Simulated Microgravity.  

National Technical Information Service (NTIS)

Satellite cells are postnatal myoblasts responsible for providing additional nuclei to growing or regenerating muscle cells. Satellite cells retain the capacity to proliferate and differentiate in vitro and therefore provide a useful model to study postna...

G. Molnar C. R. Hartzell N. A. Schroedl S. R. Gonda

1993-01-01

17

Isolation and cell culture propagation of rotaviruses from turkeys and chickens  

Microsoft Academic Search

Summary Rotaviruses were detected by electron microscopy in the faeces of turkey poults and broiler chickens with diarrhoea. Apparently symptomless infection was also observed in broilers. The avian rotaviruses could not be isolated in cell cultures by conventional techniques, but were adapted to serial growth in chick cell cultures following trypsin treatment of the virus and the cells. Immunofluorescence studies

M. S. McNulty; G. M. Allan; D. Todd; J. B. McFerran

1979-01-01

18

The contribution of historical aerial and satellite photos to archaeological and geo-archaeological research: case studies in Italy and Turkey  

Microsoft Academic Search

The paper evidences the importance of old aerial and satellite photos of ancient topography studies, with examples concerning archaeological and geo-archaeological research conducted in Italy and Turkey, during a cooperation between the Ancient Topography, Archaeology and Remote Sensing Laboratory (AnTAReS Lab) of the Institute for Archaeological and Monumental Heritage of the Italian National Research Council (IBAM-CNR) and the Ancient Topography

G. Scardozzi

2010-01-01

19

Satellite Cells and the Muscle Stem Cell Niche  

PubMed Central

Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration.

Yin, Hang; Price, Feodor

2013-01-01

20

Susceptibility of Mammalian (Hamster) Cell Culture to Infection with Herpesvirus of Turkeys  

PubMed Central

Herpesvirus of turkeys (HVT) infected and replicated in hamster kidney cells as evidenced by cytopathic effects, intranuclear inclusions, and by the presence of herpesvirus particles as seen by electron microscopy. Additional evidence for the presence of HVT in cell cultures was determined by the serum neutralization, complement fixation, and the fluorescent-antibody tests. Images

Bedigian, H. G.; Sevoian, Martin

1972-01-01

21

Water quality determination of Küçükçekmece Lake, Turkey by using multispectral satellite data.  

PubMed

This study focuses on the analysis of the Landsat-5 TM + SPOT-Pan (1992), IRS-1C/D LISS + Pan (2000), and Landsat-5 TM (2006) satellite images that reflect the drastic land use/land cover changes in the Küçükçekmece Lake region, Istanbul. Landsat-5 TM satellite data dated 2006 was used for mapping water quality. A multiple regression analysis was carried out between the unitless planetary reflectance values derived from the satellite image and in situ water quality parameters chlorophyll a, total phosphorus, total nitrogen, turbidity, and biological and chemical oxygen demand measured at a number of stations homogenously distributed over the lake surface. The results of this study provided valuable information to local administrators on the water quality of Küçükçekmece Lake, which is a large water resource of the Istanbul Metropolitan Area. Results also show that such a methodology structured by use of reflectance values provided from satellite imagery, in situ water quality measurements, and basin land use/land cover characteristics obtained from images can serve as a powerful and rapid monitoring tool for the drinking water basins that suffer from rapid urbanization and pollution, all around the world. PMID:19882091

Alparslan, Erhan; Coskun, Gonca; Alganci, Ugur

2009-01-01

22

Rosiglitazone modifies the adipogenic potential of human muscle satellite cells  

Microsoft Academic Search

Aims\\/hypothesis  Satellite cells are responsible for postnatal skeletal muscle regeneration. It has been demonstrated that mouse satellite cells behave as multipotent stem cells. We studied the differentiation capacities of human satellite cells and evaluated the effect of the insulin sensitiser rosiglitazone, a well known peroxisome proliferative activated receptor gamma (PPARG) agonist, on their adipogenic conversion.Subjects, materials and methods  We obtained human satellite

P. De Coppi; G. Milan; A. Scarda; L. Boldrin; C. Centobene; M. Pozzobon; C. Pagano; P. Gamba; R. Vettor

2006-01-01

23

Extrinsic regulation of domestic animal-derived satellite cells  

Microsoft Academic Search

Satellite cells are the postnatal myogenic cells, as they provide myonuclei to support skeletal muscle hypertrophy and are principal cells responsible for myofiber repair and regeneration. Even though research with satellite cells from meat animals is new, considerable data exist to suggest that these cells are regulated through both intrinsic and extrinsic mechanisms. This review covers the present status of

M. V. Dodson; D. C. McFarland; A. L. Grant; M. E. Doumit; S. G. Velleman

1996-01-01

24

Donor satellite cell engraftment is significantly augmented when the host niche is preserved and endogenous satellite cells are incapacitated.  

PubMed

Stem cell transplantation is already in clinical practice for certain genetic diseases and is a promising therapy for dystrophic muscle. We used the mdx mouse model of Duchenne muscular dystrophy to investigate the effect of the host satellite cell niche on the contribution of donor muscle stem cells (satellite cells) to muscle regeneration. We found that incapacitation of the host satellite cells and preservation of the muscle niche promote donor satellite cell contribution to muscle regeneration and functional reconstitution of the satellite cell compartment. But, if the host niche is not promptly refilled, or is filled by competent host satellite cells, it becomes nonfunctional and donor engraftment is negligible. Application of this regimen to aged host muscles also promotes efficient regeneration from aged donor satellite cells. In contrast, if the niche is destroyed, yet host satellite cells remain proliferation-competent, donor-derived engraftment is trivial. Thus preservation of the satellite cell niche, concomitant with functional impairment of the majority of satellite cells within dystrophic human muscles, may improve the efficiency of stem cell therapy. PMID:22730231

Boldrin, Luisa; Neal, Alice; Zammit, Peter S; Muntoni, Francesco; Morgan, Jennifer E

2012-09-01

25

The potential for archiving and reconstituting valuable strains of turkey (Meleagris gallopavo) using primordial germ cells.  

PubMed

Diseases such as avian in?uenza can destroy turkey ?ocks, potentially resulting in the loss of valuable or rare genetic material. Consequently, there is an urgent need to develop a means to archive such germplasm. Germline chimeras produced by intravascular transfer of primordial germ cells (PGC) have been reported in other avian species but not turkeys. This study examined the feasibility of both establishing an archive of frozen PGC, and producing germline chimeras by injecting the thawed PGC into host embryos. To meet these aims, the following experiments were performed: (1) PGC identification within turkey embryos; (2) development of an efficient method for isolation of turkey PGC; (3) demonstration that PGC can be cryopreserved, recovered, and retain viability; (4) reinjection into embryos and detection of injected PGC. Primordial germ cells were identified using periodic acid-Schiff reagent and the immunological marker OLP-1. Bloodstream PGC were isolated using Ficoll density gradient centrifugation with PGC recovery peaking at stages 13, 14, and 15 with 32 ± 4.9, 33 ± 6.4, and 26 ± 5.4 PGC recovered, respectively. Primordial germ cells were frozen using Dulbecco's modified Eagle medium, 20% fetal calf serum, and 10% dimethylsulfoxide and demonstrated 90 ± 1.7% viability after 3 mo frozen in liquid nitrogen. Freshly isolated and frozen thawed DiI- and Q-Tracker-labeled PGC repopulated stage 30 gonads after vascular transfer into ex ovo cultured embryos. The DiI-labeled cells repopulated gonads less frequently, with 36 ± 13.2% of gonads containing the DiI-labeled PGC, and 7 ± 3.8% of reinjected PGC reaching the gonads of positive embryos. The Q-tracker-labeled cells were detected more frequently in embryos, with 67 ± 21.1% having positive signals, and 44 ± 4.9% of reinjected Q-tracker-labeled PGC colonized the gonads of positive embryos. This study demonstrated the feasibility of using turkey PGC to archive turkey germplasm from different strains because frozen PGC reintroduced into host embryos can colonize the host gonads, suggesting the possibility of producing turkey germline chimeras. PMID:24706956

Wade, Alexander J; French, Nick A; Ireland, Grenham W

2014-04-01

26

Advanced solar cells for satellite power systems  

NASA Astrophysics Data System (ADS)

The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

Flood, Dennis J.; Weinberg, Irving

1994-11-01

27

Advanced solar cells for satellite power systems  

NASA Technical Reports Server (NTRS)

The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

Flood, Dennis J.; Weinberg, Irving

1994-01-01

28

Initiation of satellite cell replication in bupivacaine-induced myonecrosis  

Microsoft Academic Search

To determine how and when the satellite cells are stimulated to replicate in muscle regeneration, the rat soleus muscle was examined chronologically after bupivacaine-induced myonecrosis. Bromodeoxyuridine and desmin-positive mononuclear cells, indicating the start of satellite cell replication, were seen 25 h after bupivacaine treatment when macrophages had already invaded the sarcoplasm of necrotic fiber. These findings suggest that muscle regeneration

Y. Saito; I. Nonaka

1994-01-01

29

3D Timelapse Analysis of Muscle Satellite Cell Motility  

PubMed Central

Skeletal muscle repair and regeneration requires the activity of satellite cells, a population of myogenic stem cells scattered throughout the tissue and activated to proliferate and differentiate in response to myotrauma or disease. While it seems likely that satellite cells would need to navigate local muscle tissue to reach damaged areas, relatively little data on such motility exist, and most studies have been with immortalized cell lines. We find that primary satellite cells are significantly more motile than myoblast cell lines, and that adhesion to laminin promotes primary cell motility more than fourfold over other substrates. Using timelapse videomicroscopy to assess satellite cell motility on single living myofibers, we have identified a requirement for the laminin-binding integrin ?7?1 in satellite cell motility, as well as a role for hepatocyte growth factor in promoting directional persistence. The extensive migratory behavior of satellite cells resident on muscle fibers suggests caution when determining, based on fixed specimens, whether adjacent cells are daughters from the same mother cell. We also observed more persistent long-term contact between individual satellite cells than has been previously supposed, potential cell-cell attractive and repulsive interactions, and migration between host myofibers. Based on such activity, we assayed for expression of “pathfinding” cues, and found that satellite cells express multiple guidance ligands and receptors. Together, these data suggest that satellite cell migration in vivo may be more extensive than currently thought, and could be regulated by combinations of signals, including adhesive haptotaxis, soluble factors, and guidance cues. Stem Cells 2009;27:2527–2538

Siegel, Ashley L; Atchison, Kevin; Fisher, Kevin E; Davis, George E; Cornelison, DDW

2009-01-01

30

Myogenic Potential of Canine Craniofacial Satellite Cells  

PubMed Central

The skeletal fibers have different embryological origin; the extraocular and jaw-closer muscles develop from prechordal mesoderm while the limb and trunk muscles from somites. These different origins characterize also the adult muscle stem cells, known as satellite cells (SCs) and responsible for the fiber growth and regeneration. The physiological properties of presomitic SCs and their epigenetics are poorly studied despite their peculiar characteristics to preserve muscle integrity during chronic muscle degeneration. Here, we isolated SCs from canine somitic [somite-derived muscle (SDM): vastus lateralis, rectus abdominis, gluteus superficialis, biceps femoris, psoas] and presomitic [pre-somite-derived muscle (PSDM): lateral rectus, temporalis, and retractor bulbi] muscles as myogenic progenitor cells from young and old animals. In addition, SDM and PSDM-SCs were obtained also from golden retrievers affected by muscular dystrophy (GRMD). We characterized the lifespan, the myogenic potential and functions, and oxidative stress of both somitic and presomitic SCs with the aim to reveal differences with aging and between healthy and dystrophic animals. The different proliferation rate was consistent with higher telomerase activity in PSDM-SCs compared to SDM-SCs, although restricted at early passages. SDM-SCs express early (Pax7, MyoD) and late (myosin heavy chain, myogenin) myogenic markers differently from PSDM-SCs resulting in a more efficient and faster cell differentiation. Taken together, our results showed that PSDM-SCs elicit a stronger stem cell phenotype compared to SDM ones. Finally, myomiR expression profile reveals a unique epigenetic signature in GRMD SCs and miR-206, highly expressed in dystrophic SCs, seems to play a critical role in muscle degeneration. Thus, miR-206 could represent a potential target for novel therapeutic approaches.

La Rovere, Rita Maria Laura; Quattrocelli, Mattia; Pietrangelo, Tiziana; Di Filippo, Ester Sara; Maccatrozzo, Lisa; Cassano, Marco; Mascarello, Francesco; Barthelemy, Ines; Blot, Stephane; Sampaolesi, Maurilio; Fulle, Stefania

2014-01-01

31

Purification of human muscle satellite cells by flow cytometry.  

PubMed

To purify satellite cells directly from human muscle biopsies, we have developed a method based on size separation of dissociated cells by flow cytometry. Immediately after tryptic dissociation of human muscle biopsies and elimination of erythrocytes, microscopic observation and flow cytometry analysis of cell suspensions revealed two populations of cells differing in size and nucleocytoplasmic ratio. Clonal cultures of these two cell types with a manual procedure demonstrated that only the small cells were myogenic satellite cells. Flow cytometry-sorting and analysis of the small cell population showed that (1) all sorted cells contained desmin immediately after dissociation and plating; (2) more than 98% of the cells expressed the 5.1.H11 epitope after 2 weeks of proliferation in culture; and (3) 90% of the sorted cells were able to form myotubes when cultivated at low density or in clonal cultures. Thus, human muscle satellite cells can be directly purified from human muscle samples using flow cytometry. PMID:8515758

Baroffio, A; Aubry, J P; Kaelin, A; Krause, R M; Hamann, M; Bader, C R

1993-05-01

32

Use of advanced solar cells for commercial communication satellites  

NASA Technical Reports Server (NTRS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

33

Use of advanced solar cells for commercial communication satellites  

NASA Astrophysics Data System (ADS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Bailey, Sheila G.; Landis, Geoffrey A.

1995-03-01

34

Use of advanced solar cells for commerical communication satellites  

NASA Astrophysics Data System (ADS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar- and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because of the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from Low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Landis, Geoffrey A.; Bailey, Sheila G.

1995-01-01

35

M-cadherin-mediated intercellular interactions activate satellite cell division.  

PubMed

Adult muscle stem cells and their committed myogenic precursors, commonly referred to as the satellite cell population, are involved in both muscle growth after birth and regeneration after damage. It has been previously proposed that, under these circumstances, satellite cells first become activated, divide and differentiate, and only later fuse to the existing myofiber through M-cadherin-mediated intercellular interactions. Our data show that satellite cells fuse with the myofiber concomitantly to cell division, and only when the nuclei of the daughter cells are inside the myofiber, do they complete the process of differentiation. Here we demonstrate that M-cadherin plays an important role in cell-to-cell recognition and fusion, and is crucial for cell division activation. Treatment of satellite cells with M-cadherin in vitro stimulates cell division, whereas addition of anti-M-cadherin antibodies reduces the cell division rate. Our results suggest an alternative model for the contribution of satellite cells to muscle development, which might be useful in understanding muscle regeneration, as well as muscle-related dystrophies. PMID:24046443

Marti, Merce; Montserrat, Núria; Pardo, Cristina; Mulero, Lola; Miquel-Serra, Laia; Rodrigues, Alexandre Miguel Cavaco; Andrés Vaquero, José; Kuebler, Bernd; Morera, Cristina; Barrero, María José; Izpisua Belmonte, Juan Carlos

2013-11-15

36

The muscle satellite cell at 50: the formative years  

PubMed Central

In February 1961, Alexander Mauro described a cell 'wedged' between the plasma membrane of the muscle fibre and the surrounding basement membrane. He postulated that it could be a dormant myoblast, poised to repair muscle when needed. In the same month, Bernard Katz also reported a cell in a similar location on muscle spindles, suggesting that it was associated with development and growth of intrafusal muscle fibres. Both Mauro and Katz used the term 'satellite cell' in relation to their discoveries. Today, the muscle satellite cell is widely accepted as the resident stem cell of skeletal muscle, supplying myoblasts for growth, homeostasis and repair. Since 2011 marks both the 50th anniversary of the discovery of the satellite cell, and the launch of Skeletal Muscle, it seems an opportune moment to summarise the seminal events in the history of research into muscle regeneration. We start with the 19th-century pioneers who showed that muscle had a regenerative capacity, through to the descriptions from the mid-20th century of the underlying cellular mechanisms. The journey of the satellite cell from electron microscope curio, to its gradual acceptance as a bona fide myoblast precursor, is then charted: work that provided the foundations for our understanding of the role of the satellite cell. Finally, the rapid progress in the age of molecular biology is briefly discussed, and some ongoing debates on satellite cell function highlighted.

2011-01-01

37

Evaluation of solar cell materials for a Solar Power Satellite  

NASA Technical Reports Server (NTRS)

Alternative solar cell materials being considered for the solar power satellite are described and price, production, and availability projections through the year 2000 are presented. The chief materials considered are silicon and gallium arsenide.

Glaser, P. E.; Almgren, D. W.; Csigi, K. I.

1980-01-01

38

Preliminary results for a semi-automated quantification of site effects using geomorphometry and ASTER satellite data for Mozambique, Pakistan and Turkey  

NASA Astrophysics Data System (ADS)

Estimation of the degree of local seismic wave amplification (site effects) requires precise information about the local site conditions. In many regions of the world, local geologic information is either sparse or is not readily available. Because of this, seismic hazard maps for countries such as Mozambique, Pakistan and Turkey are developed without consideration of site factors and, therefore, do not provide a complete assessment of future hazards. Where local geologic information is available, details on the traditional maps often lack the precision (better than 1:10,000 scale) or the level of information required for modern seismic microzonation requirements. We use high-resolution (1:50,000) satellite imagery and newly developed image analysis methods to begin addressing this problem. Our imagery, consisting of optical data and digital elevation models (DEMs), is recorded from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor system. We apply a semi-automated, object-oriented, multi-resolution feature segmentation method to identify and extract local terrain features. Then we classify the terrain types into mountain, piedmont and basin units using geomorphometry (topographic slope) as our parameter. Next, on the basis of the site classification schemes from the Wills and Silva (1998) study and the Wills et al (2000) and Wills and Clahan (2006) maps of California, we assign the local terrain units with V s 30 (the average seismic shear-wave velocity through the upper 30m of the subsurface) ranges for selected regions in Mozambique, Pakistan and Turkey. We find that the applicability of our site class assignments in each region is a good first-approximation for quantifying local site conditions and that additional work, such as the verification of the terrain’s compositional rigidity, is needed.

Yong, Alan; Hough, Susan E.; Abrams, Michael J.; Wills, Christopher J.

2008-11-01

39

Solar cell reverse bias testing to meet new cell technology and satellite applications demands  

Microsoft Academic Search

This paper examines the capabilities of specific silicon solar cell types to withstand reverse-bias stresses resulting from or intensified by changes in cell technology, and to withstand the more severe shadowing conditions inherent in current satellite designs. Sample groups of cells were tested using voltages suggested by recent satellite mission requirements. The sample groups of cells had the following characteristics:

R. D. Williams; G. S. Goodelle; N. Mardesich

1984-01-01

40

The contribution of high resolution satellite images to the production of base-maps and cartographies for archaeological research in Turkey and Iraq  

NASA Astrophysics Data System (ADS)

The paper concerns the contribution of high resolution satellite images to the production of base-maps and cartographies for archaeological research, using both during field work and in GIS dedicated to Cultural Heritage. Particularly, some experiences conducted during researches on Turkish and Iraqi archaeological sites are presented, where the use of satellite images was necessary because of both large scale cartographies and aero-photogrammetrical photos are not available. In the case of archaeological surveys in Hierapolis of Phrygia (south-western Turkey) they provided a fundamental tool for the research on the ground and for the analysis and management of data in the archaeological GIS of the territory. Ikonos-2 and QuickBird-2 images were ortho-rectified with the use of GCPs (taken with a differential GPS) and with DEMs and DSMs processed thanks different remote sensing data, radar (SRTM) and optical (Ikonos-2 and ASTER stereo-pairs), for the creation of space-maps and the extraction of cartographical elements: these (hydrology, modern topography, field boundaries, archaeological remains and traces, etc.) were used with the aims of the creation of new maps for archaeological purpose (the orography was extracted from DEMs) and the update of the existing ones. In the case of some ancient sites studied for the contextualization of the objects showed in the Virtual Museum of Iraq, high resolution images of the same satellites (and of WorldView-1) were ortho-rectified without GPCs and used for the creation or the update of the archaeological maps (generally very old), on which plans of excavated structures, recent discoveries, and archaeological traces and paleo-environmental elements were geo-referenced.

Scardozzi, Giuseppe

2009-09-01

41

Solar power satellites - Heat engine or solar cells  

NASA Technical Reports Server (NTRS)

A solar power satellite is the energy-converting element of a system that can deliver some 10 GW of power to utilities on the earth's surface. We evaluated heat engines and solar cells for converting sunshine to electric power at the satellite. A potassium Rankine cycle was the best of the heat engines, and 50 microns thick single-crystal silicon cells were the best of the photovoltaic converters. Neither solar cells nor heat engines had a clear advantage when all factors were considered. The potassium-turbine power plant, however, was more difficult to assemble and required a more expensive orbital assembly base. We therefore based our cost analyses on solar-cell energy conversion, concluding that satellite-generated power could be delivered to utilities for around 4 to 5 cents a kWh.

Oman, H.; Gregory, D. L.

1978-01-01

42

Solar cell coverglasses for satellites in the intermediate Earth orbit  

Microsoft Academic Search

Satellites in an Earth orbit where high levels of radiation are experienced require greater protection for their solar cell arrays than is normal. This may be provided by the use of thicker coverglasses to minimise solar cell degradation. This paper describes the development by Pilkingtons of a new glass CMO, which has a high transmission in the visible spectrum, is

C. Kitchen; K. Mullaney; M. Price; A. Dollery; K. Fyles; H. Eaves; R. Crabb; P. Bula

1997-01-01

43

Monitoring the changing position of coastlines using aerial and satellite image data: an example from the eastern coast of Trabzon, Turkey.  

PubMed

Coastline mapping and coastline change detection are critical issues for safe navigation, coastal resource management, coastal environmental protection, and sustainable coastal development and planning. Changes in the shape of coastline may fundamentally affect the environment of the coastal zone. This may be caused by natural processes and/or human activities. Over the past 30 years, the coastal sites in Turkey have been under an intensive restraint associated with a population press due to the internal and external touristic demand. In addition, urbanization on the filled up areas, settlements, and the highways constructed to overcome the traffic problems and the other applications in the coastal region clearly confirm an intensive restraint. Aerial photos with medium spatial resolution and high resolution satellite imagery are ideal data sources for mapping coastal land use and monitoring their changes for a large area. This study introduces an efficient method to monitor coastline and coastal land use changes using time series aerial photos (1973 and 2002) and satellite imagery (2005) covering the same geographical area. Results show the effectiveness of the use of digital photogrammetry and remote sensing data on monitoring large area of coastal land use status. This study also showed that over 161 ha areas were filled up in the research area and along the coastal land 12.2 ha of coastal erosion is determined for the period of 1973 to 2005. Consequently, monitoring of coastal land use is thus necessary for coastal area planning in order to protecting the coastal areas from climate changes and other coastal processes. PMID:18560986

Sesli, Faik Ahmet; Karsli, Fevzi; Colkesen, Ismail; Akyol, Nihat

2009-06-01

44

Infrared power cells for satellite power conversion  

NASA Technical Reports Server (NTRS)

An analytical investigation is performed to assess the feasibility of long-wavelength power converters for the direct conversion of IR radiation onto electrical power. Because theses devices need to operate between 5 and 30 um the only material system possible for this application is the HgCdTe system which is currently being developed for IR detectors. Thus solar cell and IR detector theories and technologies are combined. The following subject areas are covered: electronic and optical properties of HgCdTe alloys; optimum device geometry; junction theory; model calculation for homojunction power cell efficiency; and calculation for HgCdTe power cell and power beaming.

Summers, Christopher J.

1991-01-01

45

Satellite cell numbers in senile rat levator ani muscle  

Microsoft Academic Search

Ageing in skeletal muscle results in motor frailty and a reduced capacity for self repair after injury. The contractile characteristics of muscle are determined principally by the myosin heavy chain (MHC) composition of its myofibers. During the restorative process, satellite cells play a central role. The present study compares the levator ani muscle of very old (32 months) and young

Joseph O Nnodim

2000-01-01

46

Epigenetic regulation of satellite cell activation during muscle regeneration  

PubMed Central

Satellite cells are a population of adult muscle stem cells that play a key role in mediating muscle regeneration. Activation of these quiescent stem cells in response to muscle injury involves modulating expression of multiple developmentally regulated genes, including mediators of the muscle-specific transcription program: Pax7, Myf5, MyoD and myogenin. Here we present evidence suggesting an essential role for the antagonistic Polycomb group and Trithorax group proteins in the epigenetic marking of muscle-specific genes to ensure proper temporal and spatial expression during muscle regeneration. The importance of Polycomb group and Trithorax group proteins in establishing chromatin structure at muscle-specific genes suggests that therapeutic modulation of their activity in satellite cells could represent a viable approach for repairing damaged muscle in muscular dystrophy.

2011-01-01

47

Adult Bone Marrow-Derived Stem Cells in Muscle Connective Tissue and Satellite Cell Niches  

PubMed Central

Skeletal muscle includes satellite cells, which reside beneath the muscle fiber basal lamina and mainly represent committed myogenic precursor cells, and multipotent stem cells of unknown origin that are present in muscle connective tissue, express the stem cell markers Sca-1 and CD34, and can differentiate into different cell types. We tracked bone marrow (BM)-derived stem cells in both muscle connective tissue and satellite cell niches of irradiated mice transplanted with green fluorescent protein (GFP)-expressing BM cells. An increasing number of GFP+ mononucleated cells, located both inside and outside of the muscle fiber basal lamina, were observed 1, 3, and 6 months after transplantation. Sublaminal cells expressed unambiguous satellite cell markers (M-cadherin, Pax7, NCAM) and fused into scattered GFP+ muscle fibers. In muscle connective tissue there were GFP+ cells located close to blood vessels that expressed the ScaI or CD34 stem-cell antigens. The rate of settlement of extra- and intralaminal compartments by BM-derived cells was compatible with the view that extralaminal cells constitute a reservoir of satellite cells. We conclude that both muscle satellite cells and stem cell marker-expressing cells located in muscle connective tissue can derive from BM in adulthood.

Dreyfus, Patrick A.; Chretien, Fabrice; Chazaud, Benedicte; Kirova, Youlia; Caramelle, Philippe; Garcia, Luis; Butler-Browne, Gillian; Gherardi, Romain K.

2004-01-01

48

Substrate elasticity affects bovine satellite cell activation kinetics in vitro.  

PubMed

Satellite cells support efficient postnatal skeletal muscle hypertrophy through fusion into the adjacent muscle fiber. Nuclear contribution allows for maintenance of the fiber myonuclear domain and proficient transcription of myogenic genes. Niche growth factors affect satellite cell biology; however, the interplay between fiber elasticity and microenvironment proteins remains largely unknown. The objective of the experiment was to examine the effects of hepatocyte growth factor (HGF) and surface elasticity on bovine satellite cell (BSC) activation kinetics in vitro. Young's elastic modulus was calculated for the semimembranosus (SM) and LM muscles of young bulls (5 d; n = 8) and adult cows (27 mo; n = 4) cattle. Results indicate that LM elasticity decreased (P < 0.05) with age; no difference in Young's modulus for the SM was noted. Bovine satellite cells were seeded atop polyacrylamide bioscaffolds with surface elasticities that mimic young bull and adult cow LM or traditional cultureware. Cells were maintained in low-serum media supplemented with 5 ng/mL HGF or vehicle only for 24 or 48 h. Activation was evaluated by proliferating cell nuclear antigen (PCNA) immunocytochemistry. Results indicate that BSC maintained on rigid surfaces were activated at 24 h and refractive to HGF supplementation. By contrast, fewer (P < 0.05) BSC had exited quiescence after 24 h of culture on surfaces reflective of either young bull (8.1 ± 1.7 kPa) or adult cow (14.6 ± 1.6 kPa) LM. Supplementation with HGF promoted activation of BSC cultured on bioscaffolds as measured by an increase (P < 0.05) in PCNA immunopositive cells. Culture on pliant surfaces affected neither activation kinetics nor numbers of Paired box 7 (Pax7) immunopositive muscle stem cells (P > 0.05). However, with increasing surface elasticity, an increase (P < 0.05) in the numbers of muscle progenitors was observed. These results confirm that biophysical and biochemical signals regulate BSC activation. PMID:23463548

Lapin, M R; Gonzalez, J M; Johnson, S E

2013-05-01

49

Tissue-specific stem cells: Lessons from the skeletal muscle satellite cell  

PubMed Central

In 1961, the satellite cell was first identified when electron microscopic examination of skeletal muscle demonstrated a cell wedged between the plasma membrane of the muscle fiber and the basement membrane. In recent years it has been conclusively demonstrated that the satellite cell is the primary cellular source for muscle regeneration and is equipped with the potential to self renew, thus functioning as a bone fide skeletal muscle stem cell (MuSC). As we move past the 50th anniversary of the satellite cell, we take this opportunity to discuss the current state of the art and dissect the unknowns in the MuSC field.

Brack, Andrew S.; Rando, Thomas A.

2012-01-01

50

Real time of earthquakes prone areas by RST analysis of satellite TIR radiances: results of continuous monitoring over Italy and Turkey regions.  

NASA Astrophysics Data System (ADS)

Meteorological satellites offering global coverage, continuity of observations and long term time series (starting even 30 years ago) offer a unique possibility not only to learn from the past but also to guarantee continuous monitoring whereas other observation technologies are lacking because too expensive or (like in the case of earthquake precursor studies) or considered useless by decision-makers. Space-time fluctuations of Earth's emitted Thermal Infrared (TIR) radiation have been observed from satellite months to weeks before earthquakes occurrence. The general RST approach has been proposed (since 2001) in order to discriminate normal (i.e. related to the change of natural factor and/or observation conditions) TIR signal fluctuations from anomalous signal transient possibly associated to earthquake occurrence. Since then several earthquakes occurred in Europe, Africa and America have been studied by analyzing decades of satellite observations always using a validation/confutation approach in order to verify the presence/absence of anomalous space-time TIR transients in presence/absence of significant seismic activity. In the framework of PRE-EARTHQUAKES EU-FP7 Project (www.pre-earthquakes.org) , starting from October 2010 (still continuing) RST approach has been applied to MSG/SEVIRI data to generate TIR anomaly maps over Italian peninsula, continuously for all the midnight slots. Since September 2011 the same monitoring activity (still continuing) started for Turkey region. For the first time a similar analysis has been performed in real-time, systematically analyzing TIR anomaly maps in order to identify day by day possible significant (e.g. persistent in the space-time domain) thermal anomalies. During 2011 only in very few cases (1 in Italy in July and 2 in the Turkish region in September and November) the day by day analysis enhanced significant anomalies that in two cases were communicated to the other PRE-EARTHQUAKES partners asking for their attention. In this paper results of such analysis will be presented which seem to confirm results independently achieved (unfortunately without their knowledge) by other authors applying a similar approach to EOS/MODIS data over California region.

Tramutoli, V.; Filizzola, C.; Genzano, N.; Lisi, M.; Paciello, R.; Pergola, N.

2012-04-01

51

Observations on ploidy of cells and on reproductive performance in parthenogenetic turkeys.  

PubMed

Using flow cytometry, the ploidy levels of parthenogenetic turkeys were quantified from blastodisc stage to adulthood. Eggs were collected from noninseminated hens of the Beltsville Small White flock, known for their high degree of parthenogenesis, and the blastodermal cells from developing embryos were compared with those of embryos produced by hens inseminated with semen from males of the same flock. Erythrocytes of parthenogens from Day 10 of incubation to 27 mo of age were also used for ploidy determination. Sperm and erythrocyte preparations from normal males of the above flock served as haploid and diploid standards, respectively. In parthenogenetically developing blastoderms, 40.3 +/- 14.5% of the cells were haploid and 48.9 +/- 11.9% diploid; blastoderms from fertilized eggs had no haploid cells. The haploid cell content of parthenogens declined from the blastodermal stage to adult life, with 1.9 +/- 2.3% at 10 to 20 d of embryonic development, 1.5 +/- 1.4% at 21 to 29 d of development, 1.4 +/- 2.6% at 4 wk posthatch, and 1.3 +/- 1.9% in adulthood, although changes between the 1st mo after hatch and adult stage were not significant. It is possible, therefore, that parthenogenetic embryos with a low proportion of haploid cells could be the ones that survive to Day 10 of development and beyond, whereas those with a higher proportion of haploid cells fail to develop. The semen volume of male parthenogens was significantly lower than that of normal males, although the concentration of spermatozoa and their fertilizing capacity did not vary significantly between groups, suggesting that the germ cells of these parthenogens are capable of normal meiosis and sperm maturation leading to a normal fertility. PMID:9776050

Cassar, G; John, T M; Etches, R J

1998-10-01

52

Sphingosine-1-phosphate receptor 3 influences cell cycle progression in muscle satellite cells.  

PubMed

Skeletal muscle retains a resident stem cell population called satellite cells, which are mitotically quiescent in mature muscle, but can be activated to produce myoblast progeny for muscle homeostasis, hypertrophy and repair. We have previously shown that satellite cell activation is partially controlled by the bioactive phospholipid, sphingosine-1-phosphate, and that S1P biosynthesis is required for muscle regeneration. Here we investigate the role of sphingosine-1-phosphate receptor 3 (S1PR3) in regulating murine satellite cell function. S1PR3 levels were high in quiescent myogenic cells before falling during entry into cell cycle. Retrovirally-mediated constitutive expression of S1PR3 led to suppressed cell cycle progression in satellite cells, but did not overtly affect the myogenic program. Conversely, satellite cells isolated from S1PR3-null mice exhibited enhanced proliferation ex-vivo. In vivo, acute cardiotoxin-induced muscle regeneration was enhanced in S1PR3-null mice, with bigger muscle fibres compared to control mice. Importantly, genetically deleting S1PR3 in the mdx mouse model of Duchenne muscular dystrophy produced a less severe muscle dystrophic phenotype, than when signalling though S1PR3 was operational. In conclusion, signalling though S1PR3 suppresses cell cycle progression to regulate function in muscle satellite cells. PMID:23911934

Fortier, Mathieu; Figeac, Nicolas; White, Robert B; Knopp, Paul; Zammit, Peter S

2013-10-15

53

Sphingosine-1-phosphate receptor 3 influences cell cycle progression in muscle satellite cells  

PubMed Central

Skeletal muscle retains a resident stem cell population called satellite cells, which are mitotically quiescent in mature muscle, but can be activated to produce myoblast progeny for muscle homeostasis, hypertrophy and repair. We have previously shown that satellite cell activation is partially controlled by the bioactive phospholipid, sphingosine-1-phosphate, and that S1P biosynthesis is required for muscle regeneration. Here we investigate the role of sphingosine-1-phosphate receptor 3 (S1PR3) in regulating murine satellite cell function. S1PR3 levels were high in quiescent myogenic cells before falling during entry into cell cycle. Retrovirally-mediated constitutive expression of S1PR3 led to suppressed cell cycle progression in satellite cells, but did not overtly affect the myogenic program. Conversely, satellite cells isolated from S1PR3-null mice exhibited enhanced proliferation ex-vivo. In vivo, acute cardiotoxin-induced muscle regeneration was enhanced in S1PR3-null mice, with bigger muscle fibres compared to control mice. Importantly, genetically deleting S1PR3 in the mdx mouse model of Duchenne muscular dystrophy produced a less severe muscle dystrophic phenotype, than when signalling though S1PR3 was operational. In conclusion, signalling though S1PR3 suppresses cell cycle progression to regulate function in muscle satellite cells.

Fortier, Mathieu; Figeac, Nicolas; White, Robert B.; Knopp, Paul; Zammit, Peter S.

2013-01-01

54

The Radiosensitivity of Satellite Cells: Cell Cycle Regulation, Apoptosis and Oxidative Stress  

PubMed Central

Skeletal muscles are the organ of movement, and their growth, regeneration and maintenance are dependent in large part on a population of myogenic stem cells known as satellite cells. Skeletal muscles and these resident myogenic stem cells (i.e., satellite cells) are commonly exposed to significant doses of radiation during diagnostic procedures and/or during the radiotherapeutic management of cancer. The main objective of this study was to examine the effects of clinically relevant doses of ? radiation on satellite cell survival and proliferation, cell cycle regulation, apoptosis, DNA double-strand break repair, oxidative stress and NO production. Overall, our findings demonstrate that doses of ? radiation ?5 Gy reduced satellite cell numbers by at least 70% due in part to elevated apoptosis and the inhibition of cell cycle progression. Radiation was also found to cause a significant and persistent increase in the level of reactive oxygen and nitrogen species. Interestingly, and within this backdrop of elevated oxidative stress, similar doses were found to produce substantial reductions in the levels of nitric oxide (NO). Proliferation of satellite cells has been shown to depend in part on the production of NO, and our findings give rise to the possibility that radiation-induced reductions in NO levels may provide a mechanism for the inhibition of satellite cell proliferation in vitro and possibly the regrowth of skeletal muscle exposed during clinical irradiation procedures.

Caiozzo, Vincent J.; Giedzinski, Erich; Baker, Mike; Suarez, Tatiana; Izadi, Atefeh; Lan, Mary; Cho-Lim, Jennie; Tseng, Bertrand P.; Limoli, Charles L.

2014-01-01

55

Turkey Versus Guinea Pig Red Blood Cells: Hemagglutination Differences Alter Hemagglutination Inhibition Responses Against Influenza A/H1N1.  

PubMed

Abstract For influenza hemagglutination inhibition (HAI) assays, species selection of red blood cells (RBCs) is critical to determine antibody titers to influenza viruses reliably. We compared pandemic influenza virus A/H1N1 (pdH1N1) HAI titers using turkey or guinea pig RBCs. Turkey RBCs appear to be the more appropriate species choice for influenza A/pH1N1 HAI assays. PMID:24787023

Ovsyannikova, Inna G; White, Sarah J; Albrecht, Randy A; García-Sastre, Adolfo; Poland, Gregory A

2014-05-01

56

Notch signaling deficiency underlies age-dependent depletion of satellite cells in muscular dystrophy.  

PubMed

Duchenne muscular dystrophy (DMD) is a devastating disease characterized by muscle wasting, loss of mobility and death in early adulthood. Satellite cells are muscle-resident stem cells responsible for the repair and regeneration of damaged muscles. One pathological feature of DMD is the progressive depletion of satellite cells, leading to the failure of muscle repair. Here, we attempted to explore the molecular mechanisms underlying satellite cell ablation in the dystrophin mutant mdx mouse, a well-established model for DMD. Initial muscle degeneration activates satellite cells, resulting in increased satellite cell number in young mdx mice. This is followed by rapid loss of satellite cells with age due to the reduced self-renewal ability of mdx satellite cells. In addition, satellite cell composition is altered even in young mdx mice, with significant reductions in the abundance of non-committed (Pax7(+) and Myf5(-)) satellite cells. Using a Notch-reporter mouse, we found that the mdx satellite cells have reduced activation of Notch signaling, which has been shown to be necessary to maintain satellite cell quiescence and self-renewal. Concomitantly, the expression of Notch1, Notch3, Jag1, Hey1 and HeyL are reduced in the mdx primary myoblast. Finally, we established a mouse model to constitutively activate Notch signaling in satellite cells, and show that Notch activation is sufficient to rescue the self-renewal deficiencies of mdx satellite cells. These results demonstrate that Notch signaling is essential for maintaining the satellite cell pool and that its deficiency leads to depletion of satellite cells in DMD. PMID:24906372

Jiang, Chunhui; Wen, Yefei; Kuroda, Kazuki; Hannon, Kevin; Rudnicki, Michael A; Kuang, Shihuan

2014-08-01

57

Pax7 Is Required for the Specification of Myogenic Satellite Cells  

Microsoft Academic Search

The paired box transcription factor Pax7 was isolated by representational difference analysis as a gene specifically expressed in cultured satellite cell-derived myoblasts. In situ hybridization revealed that Pax7 was also expressed in satellite cells residing in adult muscle. Cell culture and electron microscopic analysis revealed a complete absence of satellite cells in Pax7?\\/? skeletal muscle. Surprisingly, fluorescence-activated cell sorting analysis

Patrick Seale; Luc A. Sabourin; Adele Girgis-Gabardo; Ahmed Mansouri; Peter Gruss; Michael A. Rudnicki

2000-01-01

58

Isolation and trypsin-enhanced propagation of turkey enteric (bluecomb) coronaviruses in a continuous human rectal adenocarcinoma cell line.  

PubMed

Turkey enteric coronavirus (TCV) from intestinal contents of diarrheal poults was isolated and serially propagated in HRT-18 cells, an established cell line derived from a human rectal adenocarcinoma. In these cells, TCV induced cytopathic changes, including polykaryocytosis, which depended on trypsin in the medium and incubation at 41 C. Viral antigens could be demonstrated in the cytoplasm by immunofluorescence, and extracellular virus was detected by an ELISA and negative electron microscopy. The cell-free virus had characteristics of TCV: shape, surface projections, buoyant density of 1.18 to 1.20 g/ml in sucrose, and hemagglutination of rat RBC. The one-step growth curve was complete by postinoculation hours 14 to 16, and maximal titers reached 9 to 9.5 log10 TCID50/ml during 5 passages, after which the titer remained stable. Electron microscopic examination of infected cell monolayers revealed budding of typical coronavirus particles through intracytoplasmic membranes and accumulation of complete virus in cytoplasmic vesicles. Late in the infection, aggregated progeny vial particles were detected near the outer surface of infected cells. One-day-old turkey poults inoculated orally with tissue culture-adapted TCV isolates developed mild to severe diarrhea. PMID:2551201

Dea, S; Garzon, S; Tijssen, P

1989-08-01

59

The satellite cell in male and female, developing and adult mouse muscle: distinct stem cells for growth and regeneration.  

PubMed

Satellite cells are myogenic cells found between the basal lamina and the sarcolemma of the muscle fibre. Satellite cells are the source of new myofibres; as such, satellite cell transplantation holds promise as a treatment for muscular dystrophies. We have investigated age and sex differences between mouse satellite cells in vitro and assessed the importance of these factors as mediators of donor cell engraftment in an in vivo model of satellite cell transplantation. We found that satellite cell numbers are increased in growing compared to adult and in male compared to female adult mice. We saw no difference in the expression of the myogenic regulatory factors between male and female mice, but distinct profiles were observed according to developmental stage. We show that, in contrast to adult mice, the majority of satellite cells from two week old mice are proliferating to facilitate myofibre growth; however a small proportion of these cells are quiescent and not contributing to this growth programme. Despite observed changes in satellite cell populations, there is no difference in engraftment efficiency either between satellite cells derived from adult or pre-weaned donor mice, male or female donor cells, or between male and female host muscle environments. We suggest there exist two distinct satellite cell populations: one for muscle growth and maintenance and one for muscle regeneration. PMID:22662253

Neal, Alice; Boldrin, Luisa; Morgan, Jennifer Elizabeth

2012-01-01

60

Regenerative fuel cell study for satellites in GEO orbit  

NASA Technical Reports Server (NTRS)

Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. The first, the integrated design, utilized a configuration in which the fuel cell and electrolysis cells are alternately stacked inside a pressure vessel. Product water is transferred by diffusion during electrolysis and waste heat is conducted through the pressure wall, thus using completely passive means for transfer and control. The second alkaline system, the dedicated design, uses a separate fuel cell and electrolysis stack so that each unit can be optimized in size and weight based on its orbital operating period. The third design was a dual function stack configuration, in which each cell can operate in both fuel cell and electrolysis mode, thus eliminating the need for two separate stacks and associated equipment. Results indicate that using near term technology energy densities between 46 and 52 W-hr/lb can be achieved at efficiencies of 55 percent. System densities of 115 W-hr/lb are contemplated.

Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

1987-01-01

61

Coordination of Satellite Cell Activation and Self-Renewal by Par-Complex-Dependent Asymmetric Activation of p38?/? MAPK  

PubMed Central

SUMMARY In response to muscle injury, satellite cells activate the p38?/? MAPK pathway to exit quiescence, then proliferate, repair skeletal muscle, and self-renew, replenishing the quiescent satellite cell pool. Although satellite cells are capable of asymmetric division, the mechanisms regulating satellite cell self-renewal are not understood. We found that satellite cells, once activated, enter the cell cycle and a subset undergoes asymmetric division, renewing the satellite cell pool. Asymmetric localization of the Par complex activates p38?/? MAPK in only one daughter cell, inducing MyoD, which permits cell cycle entry and generates a proliferating myoblast. The absence of p38?/? MAPK signaling in the other daughter cell prevents MyoD induction, renewing the quiescent satellite cell. Thus, satellite cells employ a mechanism to generate distinct daughter cells, coupling the Par complex and p38?/? MAPK signaling to link the response to muscle injury with satellite cell self-renewal.

Troy, Andrew; Cadwallader, Adam B.; Fedorov, Yuri; Tyner, Kristina; Tanaka, Kathleen Kelly; Olwin, Bradley B.

2014-01-01

62

Skeletal Muscle Satellite Cells Are Committed to Myogenesis and Do Not Spontaneously Adopt Nonmyogenic Fates  

PubMed Central

The developmental potential of skeletal muscle stem cells (satellite cells) remains controversial. The authors investigated satellite cell developmental potential in single fiber and clonal cultures derived from MyoDiCre/+;R26REYFP/+ muscle, in which essentially all satellite cells are permanently labeled. Approximately 60% of the clones derived from cells that co-purified with muscle fibers spontaneously underwent adipogenic differentiation. These adipocytes stained with Oil-Red-O and expressed the terminal differentiation markers, adipsin and fatty acid binding protein 4, but did not express EYFP and were therefore not of satellite cell origin. Satellite cells mutant for either MyoD or Myf-5 also maintained myogenic programming in culture and did not adopt an adipogenic fate. Incorporation of additional wash steps prior to muscle fiber plating virtually eliminated the non-myogenic cells but did not reduce the number of adherent Pax7+ satellite cells. More than half of the adipocytes observed in cultures from Tie2-Cre mice were recombined, further demonstrating a non-satellite cell origin. Under adipogenesis-inducing conditions, satellite cells accumulated cytoplasmic lipid but maintained myogenic protein expression and did not fully execute the adipogenic differentiation program, distinguishing them from adipocytes observed in muscle fiber cultures. The authors conclude that skeletal muscle satellite cells are committed to myogenesis and do not spontaneously adopt an adipogenic fate.

Starkey, Jessica D.; Yamamoto, Masakazu; Yamamoto, Shoko; Goldhamer, David J.

2011-01-01

63

Genetic Background Affects Properties of Satellite Cells and mdx Phenotypes  

PubMed Central

Duchenne muscular dystrophy (DMD) is the most common lethal genetic disorder of children. The mdx (C57BL/10 background, C57BL/10-mdx) mouse is a widely used model of DMD, but the histopathological hallmarks of DMD, such as the smaller number of myofibers, accumulation of fat and fibrosis, and insufficient regeneration of myofibers, are not observed in adult C57BL/10-mdx except for in the diaphragm. In this study, we showed that DBA/2 mice exhibited decreased muscle weight, as well as lower myofiber numbers after repeated degeneration–regeneration cycles. Furthermore, the self-renewal efficiency of satellite cells of DBA/2 is lower than that of C57BL/6. Therefore, we produced a DBA/2-mdx strain by crossing DBA/2 and C57BL/10-mdx. The hind limb muscles of DBA/2-mdx mice exhibited lower muscle weight, fewer myofibers, and increased fat and fibrosis, in comparison with C57BL/10-mdx. Moreover, remarkable muscle weakness was observed in DBA/2-mdx. These results indicate that the DBA/2-mdx mouse is a more suitable model for DMD studies, and the efficient satellite cell self-renewal ability of C57BL/10-mdx might explain the difference in pathologies between humans and mice.

Fukada, So-ichiro; Morikawa, Daisuke; Yamamoto, Yukiko; Yoshida, Tokuyuki; Sumie, Noriaki; Yamaguchi, Masahiko; Ito, Takahito; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi; Tsujikawa, Kazutake; Yamamoto, Hiroshi

2010-01-01

64

Heterogeneity in the progeny of single human muscle satellite cells.  

PubMed

We examined whether freshly isolated (native) human muscle satellite cells (HMSC), as well as their proliferating clonal progenies, were heterogeneous. We studied the expression of the cytoskeletal proteins, desmin (DSM), alpha-sarcomeric and alpha-smooth muscle actins (alpha-SR actin, alpha-SM actin), three markers that may be expressed prior to the fusion process. We found that native HMSC constituted a homogeneous population of cells expressing desmin and giving rise to similar clones in vitro. The clonal progeny of HMSC was heterogeneous, including several subpopulations of myoblasts with different cytoskeletal phenotypes, commitment states and fusion abilities. A major subpopulation that expressed both alpha-sarcomeric actin and desmin during the proliferative stage corresponded to a "predifferentiated" population of myoblasts, committed to fusion. Another subpopulation, expressing exclusively desmin, and phenotypically similar to native HMSC, failed to fuse under fusion-promoting conditions and could represent a new generation of HMSC born in culture. PMID:8575648

Baroffio, A; Bochaton-Piallat, M L; Gabbiani, G; Bader, C R

1995-11-01

65

Skeletal Muscle Satellite Cells Appear during Late Chicken Embryogenesis  

PubMed Central

The emergence of avian satellite cells during development has been studied using markers that distinguish adult from fetal cells. Previous studies by us have shown that myogenic cultures from fetal (Embryonic Day 10) and adult (12–16 weeks) chicken pectoralis muscle (PM) each regulate expression of the embryonic isoform of fast myosin heavy chain (MHC) differently. In fetal cultures, embryonic MHC is coexpressed with a ventricular MHC in both myocytes (differentiated myoblasts) and myotubes. In contrast, myocytes and newly formed myotubes in adult cultures express ventricular but not embryonic MHC. In the current study, the appearance of myocytes and myotubes which express ventricular but not embryonic MHC was used to determine when adult myoblasts first emerge during avian development. By examining patterns of MHC expression in mass and clonal cultures prepared from embryonic and posthatch chicken skeletal muscle using double-label immunofluorescence with isoform-specific monoclonal antibodies, we show that a significant number of myocytes and myotubes which stain for ventricular but not embryonic MHC are first seen in cultures derived from PM during fetal development (Embryonic Day 18) and comprise the majority, if not all, of the myoblasts present at hatching and beyond. These results suggest that adult type myoblasts become dominant in late embryogenesis. We also show that satellite cell cultures derived from adult slow muscle give results similar to those of cultures derived from adult fast muscle. Cultures derived from Embryonic Day 10 hindlimb form myocytes and myotubes that coexpress ventricular and embryonic MHCs in a manner similar to cells of the Embryonic Day 10 PM. Thus, adult and fetal expression patterns of ventricular and embryonic MHCs are correlated with developmental age but not muscle fiber type.

Hartley, Rebecca S.; Bandman, Everett

2014-01-01

66

Hematopoietic Cell Transplantation Directly into Dystrophic Muscle Fails to Reconstitute Satellite Cells and Myofibers  

PubMed Central

We sought to determine whether wild-type hematopoietic cell transplantation directly into muscle could restore dystrophin expression in a relevant pre-clinical canine model of Duchenne muscular dystrophy (DMD). In recipients rendered tolerant to their dog leukocyte antigen (DLA)-matched unaffected littermates, through hematopoietic stem cell transplantation (HCT), intramuscular injection of donor marrow cells produced no evidence of dystrophin expression, and clonal analysis of satellite cells failed to reveal donor contribution.

Kuhr, Christian S.; Lupu, Marilena; Storb, Rainer

2007-01-01

67

Differences between cystic fibrosis and normal cells in the degree of satellite association  

Microsoft Academic Search

The degree of satellite association was found to be significantly higher in phytohemagglutinin (PHA)-stimulated lymphocytes from cystic fibrosis (CF) patients than from those of control individuals. PHA-stimulated lymphocytes from obligatory heterozygotes for the CF mutant allele showed an intermediate degree of satellite association. The degree of satellite association was estimated by the frequency of cells exhibiting associations, by the number

Yehoshua Ravia; Lydia Avivi; Boleslaw Goldman

1985-01-01

68

Muscle satellite cells are multipotential stem cells that exhibit myogenic, osteogenic, and adipogenic differentiation  

Microsoft Academic Search

Muscle satellite cells are believed to represent a committed stem cell population that is responsible for the postnatal growth and regeneration of skeletal muscle. However, the observation that cultured myoblasts differentiate into osteocytes or adipocytes following treatment with bone morphogenetic proteins (BMPs) or adipogenic inducers, respectively, suggests some degree of plasticity within the mesenchymal lineage. To further investigate this phenomenon,

Atsushi Asakura; Michael A. Rudnicki; Motohiro Komaki

2001-01-01

69

Istanbul, Turkey  

NASA Technical Reports Server (NTRS)

This June 16, 2000 image of Istanbul, Turkey show a full 60 by 60 km ASTER scene in the visible and infrared channels. Vegetation appears red, and urban areas blue-green. Bustling Istanbul, with its magnificent historical heritage, has spanned the divide between Europe and Asia for more than 2,500 years. Originally called Byzantium, the city was founded in the 7th century BC on the Golden Horn, an arm of the narrow Bosporus (also spelled Bosphorus) Strait, which connects the Sea of Marmara to the south, with the Black Sea to the north. Constantine I made it his capital of the Eastern Roman Empire in AD 330. As Constantinople, the strategically located city arose as the preeminent cultural, religious, and political center of the Western world. It reached the height of its wealth and glory in the early 5th century. After centuries of decline, the city entered another period of tremendous growth and prosperity when, as Istanbul, it became the capital of the Turkish Ottoman Empire in 1457. Although Turkey moved its capital to Ankara in 1923, Istanbul remains the nation's largest city with a population of over 8 million, its commercial center, and a major port. Two bridges spanning the Bosporus, and ships in the busy channel can be seen on the enlargement. On the image, the water areas have been replaced with a thermal image: colder waters are displayed in dark blue, warmer areas in light blue. Note the dark lines showing boat wakes, and the cold water entering the Sea of Marmara from deeper waters of the Bosporus.

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance.

2000-01-01

70

Multi-cell satellite for the communications of year 2000  

NASA Astrophysics Data System (ADS)

The multi-cell communication satellite concept allows an efficient use of the geostationary orbit and a large reduction of the bit transmission cost, as a Bell-type (phased array), multiple mobile narrow beams arrangement with SS-TDMA. It has a flat hexagonal flying-saucer shape, being erected in a low altitude orbit, through an automatic assembly process of a large number of quasi-identical hexagonal cells. Each cell has independent power supply, thrusters, RF modules etc…. Total assembly requires 10 ARIANE V or 4 SHUTTLE launches. An automatic tooling assembly using simple iterative manoeuvers is used to obtain the final shape, from initial cylindrical packages. Transfer into geostationary orbit is provided by low-thrust bi-propellant units attached to the cells, and released after burn-out. Assembly and transfer duration is about 6 months. Total traffic to 1000-2000 towns being 100 Gbits/s, the expected reduction of bit-transmission cost relative to year 1981 is 75-100 fold.

Golden, E.; Dilly, J.

71

FGF2 activates TRPC and Ca(2+) signaling leading to satellite cell activation.  

PubMed

Satellite cells, as stem cells of adult skeletal muscle, are tightly associated with the differentiated muscle fibers and remain quiescent in the absence of muscle damage. In response to an injury, the quiescent satellite cell is activated by soluble factors, including FGFs released from injured myofibers. Using immunostaining, we here first show that TRPC1 channels are highly expressed in satellite cells attached to muscle fibers. Since CD34, a traditional stem cell marker, was recently found to be expressed in skeletal muscle satellite cells we labeled living satellite cells in their physiological niche associated with host FDB fibers using anti-CD34-FITC antibody. We then monitored intra-cellular calcium in anti-CD34-FITC labeled satellite cells attached to muscle fibers using the calcium sensitive dye X rhod-1 which has little fluorescence cross talk with FITC. FGF2 increased intracellular calcium in satellite cells, which was antagonized by the TRPC channel blocker SKF 96365. Immunostaining showed that NFATc3 is highly expressed in satellite cells, but not in host FDB fibers. Elevation of intracellular calcium by FGF2 is accompanied by nuclear translocation of NFATc3 and NFATc2 and by an increase in the number of MyoD positive cells per muscle fiber, both of which were attenuated by TRPC blocker SKF 96365. Our results suggest a novel pathway of satellite cell activation where FGF2 enhances calcium influx through a TRPC channel, and the increased cytosolic calcium leads to both NFATc3 and NFATc2 nuclear translocation and enhanced number of MyoD positive satellite cells per muscle fiber. PMID:24575047

Liu, Yewei; Schneider, Martin F

2014-01-01

72

Solar cell reverse bias testing to meet new cell technology and satellite applications demands  

SciTech Connect

This paper examines the capabilities of specific silicon solar cell types to withstand reverse bias stresses resulting from or intensified by changes in cell technology and to withstand more severe shadowing conditions inherent in current satellite designs. Sample groups of cells were tested using voltages suggested by recent satellite mission requirements. The sample groups of cells had the following characteristics: shallow junctions (less than or equal to0.2 ..mu..m), back surface fields and reflectors, laser-scribed edges, and welded interconnects. Test results show high variability and leakiness among the reverse bias characteristics. Cell failures caused by reverse bias stresses under simulated mission conditions may become a significant consideration at -40 volts or less.

Williams, R.D.; Goodelle, G.S.; Mardesich, N.

1984-05-01

73

Solar cell reverse bias testing to meet new cell technology and satellite applications demands  

NASA Astrophysics Data System (ADS)

This paper examines the capabilities of specific silicon solar cell types to withstand reverse-bias stresses resulting from or intensified by changes in cell technology, and to withstand the more severe shadowing conditions inherent in current satellite designs. Sample groups of cells were tested using voltages suggested by recent satellite mission requirements. The sample groups of cells had the following characteristics: shallow junctions (less than 200 nm), back surface fields and reflectors, laser-scribed edges, and welded interconnects. Test results show high variability and leakiness among the reverse-bias characteristics. Cell failures caused by reverse-bias stresses under simulated mission conditions may become a significant consideration at -40 volts or less.

Williams, R. D.; Goodelle, G. S.; Mardesich, N.

74

The Ets domain transcription factor Erm distinguishes rat satellite glia from Schwann cells and is regulated in satellite cells by neuregulin signaling.  

PubMed

Distinct glial cell types of the vertebrate peripheral nervous system (PNS) are derived from the neural crest. Here we show that the expression of the Ets domain transcription factor Erm distinguishes satellite glia from Schwann cells beginning early in rat PNS development. In developing dorsal root ganglia (DRG), Erm is present both in presumptive satellite glia and in neurons. In contrast, Erm is not detectable at any developmental stage in Schwann cells in peripheral nerves. In addition, Erm is downregulated in DRG-derived glia adopting Schwann cell traits in culture. Thus, Erm is the first described transcription factor expressed in satellite glia but not in Schwann cells. In culture, the Neuregulin1 (NRG1) isoform GGF2 maintains Erm expression in presumptive satellite cells and reinduces Erm expression in DRG-derived glia but not in Schwann cells from sciatic nerve. These data demonstrate that there are intrinsic differences between these glial subtypes in their response to NRG1 signaling. In neural crest cultures, Erm-positive progenitor cells give rise to two distinct glial subtypes: Erm-positive, Oct-6-negative satellite glia in response to GGF2, and Erm-negative, Oct-6-positive Schwann cells in the presence of serum and the adenylate cyclase activator forskolin. Thus, Erm-positive neural crest-derived progenitor cells and presumptive satellite glia are able to acquire Schwann cell features. Given the in vivo expression of Erm in peripheral ganglia, we suggest that ganglionic Erm-positive cells may be precursors of Schwann cells. PMID:10677254

Hagedorn, L; Paratore, C; Brugnoli, G; Baert, J L; Mercader, N; Suter, U; Sommer, L

2000-03-01

75

SV40 Large T Antigen Interferes with Adult Myosin Heavy Chain Expression, but Not with Differentiation of Human Satellite Cells  

Microsoft Academic Search

The growth of muscle fibers during late development as well as in regeneration following muscle injury is the result of the proliferation and differentiation of satellite cells. However, all human cells, including satellite cells, show a limit in their proliferation. In order to define a cellular system with enhanced proliferative capacity, human satellite cells were transfected with a construct containing

V. Mouly; F. Edom; S. Decary; P. Vicart; J. P. Barbet; G. S. Butler-Browne

1996-01-01

76

Slow-dividing satellite cells retain long-term self-renewal ability in adult muscle.  

PubMed

Satellite cells are muscle stem cells that have important roles in postnatal muscle growth and adult muscle regeneration. Although fast- and slow-dividing populations in activated satellite cells have been observed, the functional differences between them remain unclear. Here we elucidated the relationship between proliferation behaviour and satellite cell function. To assess the frequency of cell division, satellite cells isolated from mouse EDL muscle were labelled with the fluorescent dye PKH26, stimulated to proliferate and then sorted by FACS. The vast majority of activated satellite cells were PKH26(low) fast-dividing cells, whereas PKH26(high) slow-dividing cells were observed as a minority population. The fast-dividing cells generated a higher number of differentiated and self-renewed cells compared with the slow-dividing cells. However, cells derived from the slow-dividing population formed secondary myogenic colonies when passaged, whereas those from the fast-dividing population rapidly underwent myogenic differentiation without producing self-renewing cells after a few rounds of cell division. Furthermore, slow-dividing cells transplanted into injured muscle extensively contributed to muscle regeneration in vivo. Id1, a HLH protein, was expressed by all activated satellite cells, but the expression level varied within the slow-dividing cell population. We show that the slow-dividing cells retaining long-term self-renewal ability are restricted to an undifferentiated population that express high levels of Id1 protein (PKH26(high)Id1(high) population). Finally, genome-wide gene expression analysis described the molecular characteristics of the PKH26(high)Id1(high) population. Taken together, our results indicate that undifferentiated slow-dividing satellite cells retain stemness for generating progeny capable of long-term self-renewal, and so might be essential for muscle homeostasis throughout life. PMID:22349695

Ono, Yusuke; Masuda, Satoru; Nam, Hyung-Song; Benezra, Robert; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi

2012-03-01

77

Ultrastructural localization of concanavalin A-binding sites in satellite cells of human skeletal muscle  

Microsoft Academic Search

Electron-microscopic cytochemical studies on satellite cells of normal human skeletal muscle were carried out using the concanavalin Aperoxidase (Con A-HRP) coupling method. Con A-binding sites, which probably correspond to glycoproteins, were found to be associated with the cell surface, smooth surfaced vesicles, nuclear envelope and endoplasmic reticulum of the satellite cells and were also identified at the cell surface of

Yoshihiro Wakayama; Eduardo Bonilla; Donald L. Schotland

1980-01-01

78

Collagen VI regulates satellite cell self-renewal and muscle regeneration  

PubMed Central

Adult muscle stem cells, or satellite cells play essential roles in homeostasis and regeneration of skeletal muscles. Satellite cells are located within a niche that includes myofibers and extracellular matrix. The function of specific extracellular matrix molecules in regulating SCs is poorly understood. Here we show that the extracellular matrix protein collagen VI is a key component of the satellite cell niche. Lack of collagen VI in Col6a1?/? mice causes impaired muscle regeneration and reduced satellite cell self-renewal capability after injury. Collagen VI null muscles display significant decrease of stiffness, which is able to compromise the in vitro and in vivo activity of wild-type satellite cells. When collagen VI is reinstated in vivo by grafting wild-type fibroblasts, the biomechanical properties of Col6a1?/? muscles are ameliorated and satellite cell defects rescued. Our findings establish a critical role for an extracellular matrix molecule in satellite cell self-renewal and open new venues for therapies of collagen VI-related muscle diseases.

Urciuolo, Anna; Quarta, Marco; Morbidoni, Valeria; Gattazzo, Francesca; Molon, Sibilla; Grumati, Paolo; Montemurro, Francesca; Tedesco, Francesco Saverio; Blaauw, Bert; Cossu, Giulio; Vozzi, Giovanni; Rando, Thomas A.; Bonaldo, Paolo

2013-01-01

79

Collagen VI regulates satellite cell self-renewal and muscle regeneration.  

PubMed

Adult muscle stem cells, or satellite cells have essential roles in homeostasis and regeneration of skeletal muscles. Satellite cells are located within a niche that includes myofibers and extracellular matrix. The function of specific extracellular matrix molecules in regulating SCs is poorly understood. Here, we show that the extracellular matrix protein collagen VI is a key component of the satellite cell niche. Lack of collagen VI in Col6a1(-/-) mice causes impaired muscle regeneration and reduced satellite cell self-renewal capability after injury. Collagen VI null muscles display significant decrease of stiffness, which is able to compromise the in vitro and in vivo activity of wild-type satellite cells. When collagen VI is reinstated in vivo by grafting wild-type fibroblasts, the biomechanical properties of Col6a1(-/-) muscles are ameliorated and satellite cell defects rescued. Our findings establish a critical role for an extracellular matrix molecule in satellite cell self-renewal and open new venues for therapies of collagen VI-related muscle diseases. PMID:23743995

Urciuolo, Anna; Quarta, Marco; Morbidoni, Valeria; Gattazzo, Francesca; Molon, Sibilla; Grumati, Paolo; Montemurro, Francesca; Tedesco, Francesco Saverio; Blaauw, Bert; Cossu, Giulio; Vozzi, Giovanni; Rando, Thomas A; Bonaldo, Paolo

2013-01-01

80

Six family genes control the proliferation and differentiation of muscle satellite cells  

SciTech Connect

Muscle satellite cells are essential for muscle growth and regeneration and their morphology, behavior and gene expression have been extensively studied. However, the mechanisms involved in their proliferation and differentiation remain elusive. Six1 and Six4 proteins were expressed in the nuclei of myofibers of adult mice and the numbers of myoblasts positive for Six1 and Six4 increased during regeneration of skeletal muscles. Six1 and Six4 were expressed in quiescent, activated and differentiated muscle satellite cells isolated from adult skeletal muscle. Overexpression of Six4 and Six5 repressed the proliferation and differentiation of satellite cells. Conversely, knockdown of Six5 resulted in augmented proliferation, and that of Six4 inhibited differentiation. Muscle satellite cells isolated from Six4{sup +/-}Six5{sup -/-} mice proliferated to higher cell density though their differentiation was not altered. Meanwhile, overproduction of Six1 repressed proliferation and promoted differentiation of satellite cells. In addition, Six4 and Six5 repressed, while Six1 activated myogenin expression, suggesting that the differential regulation of myogenin expression is responsible for the differential effects of Six genes. The results indicated the involvement of Six genes in the behavior of satellite cells and identified Six genes as potential target for manipulation of proliferation and differentiation of muscle satellite cells for therapeutic applications.

Yajima, Hiroshi [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan)] [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan); Motohashi, Norio; Ono, Yusuke [Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo (Japan)] [Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo (Japan); Sato, Shigeru; Ikeda, Keiko [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan)] [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan); Masuda, Satoru; Yada, Erica; Kanesaki, Hironori; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi [Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo (Japan)] [Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo (Japan); Kawakami, Kiyoshi, E-mail: kkawakam@jichi.ac.jp [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan)] [Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi (Japan)

2010-10-15

81

Pericytes of human skeletal muscle are myogenic precursors distinct from satellite cells  

Microsoft Academic Search

Cells derived from blood vessels of human skeletal muscle can regenerate skeletal muscle, similarly to embryonic mesoangioblasts. However, adult cells do not express endothelial markers, but instead express markers of pericytes, such as NG2 proteoglycan and alkaline phosphatase (ALP), and can be prospectively isolated from freshly dissociated ALP+ cells. Unlike canonical myogenic precursors (satellite cells), pericyte-derived cells express myogenic markers

Arianna Dellavalle; Maurilio Sampaolesi; Rossana Tonlorenzi; Enrico Tagliafico; Benedetto Sacchetti; Laura Perani; Anna Innocenzi; Beatriz G. Galvez; Graziella Messina; Roberta Morosetti; Sheng Li; Marzia Belicchi; Giuseppe Peretti; Jeffrey S. Chamberlain; Woodring E. Wright; Yvan Torrente; Stefano Ferrari; Paolo Bianco; Giulio Cossu

2007-01-01

82

The contribution of high resolution satellite images to the production of base-maps and cartographies for archaeological research in Turkey and Iraq  

Microsoft Academic Search

The paper concerns the contribution of high resolution satellite images to the production of base-maps and cartographies for archaeological research, using both during field work and in GIS dedicated to Cultural Heritage. Particularly, some experiences conducted during researches on Turkish and Iraqi archaeological sites are presented, where the use of satellite images was necessary because of both large scale cartographies

Giuseppe Scardozzi

2009-01-01

83

Turkey Trouble  

NSDL National Science Digital Library

Limiting factors are things that can limit the size of a population such as food, water, shelter, disease, nesting sites, predation, and parasitism. In this activity students will play a game to simulate changes in a turkey population and will learn about limiting factors.

Ross, Julie

2011-09-11

84

A simplified but robust method for the isolation of avian and mammalian muscle satellite cells  

PubMed Central

Background Current methods of isolation of muscle satellite cells from different animal species are highly variable making inter-species comparisons problematic. This variation mainly stems from the use of different proteolytic enzymes to release the satellite cells from the muscle tissue (sometimes a single enzyme is used but often a combination of enzymes is preferred) and the different extracellular matrix proteins used to coat culture ware. In addition, isolation of satellite cells is frequently laborious and sometimes may require pre-plating of the cell preparation on uncoated flasks or Percoll centrifugation to remove contaminating fibroblasts. The methodology employed to isolate and culture satellite cells in vitro can critically determine the fusion of myoblasts into multi-nucleated myotubes. These terminally differentiated myotubes resemble mature myofibres in the muscle tissue in vivo, therefore optimal fusion is a keystone of in vitro muscle culture. Hence, a simple method of muscle satellite cell isolation and culture of different vertebrate species that can result in a high fusion rate is highly desirable. Results We demonstrate here a relatively simple and rapid method of isolating highly enriched muscle satellite cells from different avian and mammalian species. In brief, muscle tissue was mechanically dissociated, digested with a single enzyme (pronase), triturated with a 10-ml pipette, filtered and directly plated onto collagen coated flasks. Following this method and after optimization of the cell culture conditions, excellent fusion rates were achieved in the duck, chicken, horse and cow (with more than 50% cell fusion), and to a lesser extent pig, pointing to pronase as a highly suitable enzyme to release satellite cells from muscle tissue. Conclusions Our simplified method presents a quick and simple alternative to isolating highly enriched muscle satellite cell cultures which can subsequently rapidly differentiate into well developed primary myotubes. The use of the same isolation protocol allows better inter-species comparisons of muscle satellite cells. Of all the farm animal species investigated, harvested chicken muscle cells showed the highest percentage of muscle satellite cells, and equine muscle cells presented the highest fusion index, an impressive???77%. Porcine cells displayed the lowest amount of satellite cells but still achieved a modest fusion rate of???41%.

2012-01-01

85

Satellite-cell pool size does matter: Defining the myogenic potency of aging skeletal muscle  

Microsoft Academic Search

The deteriorating in vivo environment is thought to play a major role in reduced stem cell function with age. The capacity of stem cells to support tissue maintenance depends not only on their response to cues from the surrounding niche, but also on their abundance. Here, we investigate satellite cell (myogenic stem cell) pool size and its potential to participate

Gabi Shefer; Daniel P. Van de Mark; Joshua B. Richardson; Zipora Yablonka-Reuveni

2006-01-01

86

Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation.  

PubMed

Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. PMID:24960577

Nagata, Yosuke; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

2014-08-01

87

Fractalkine mediates inflammatory pain through activation of satellite glial cells  

PubMed Central

The activation of the satellite glial cells (SGCs) surrounding the dorsal root ganglion (DRG) neurons appears to play a role in pathological pain. We tested the hypothesis that fractalkine, which is constitutively expressed by primary nociceptive neurons, is the link between peripheral inflammation and the activation of SGCs and is thus responsible for the genesis of the inflammatory pain. The injection of carrageenin into the rat hind paw induced a decrease in the mechanical nociceptive threshold (hypernociception), which was associated with an increase in mRNA and GFAP protein expression in the DRG. Both events were inhibited by anti-fractalkine antibody administered directly into the DRG (L5) [intraganglionar (i.gl.)]. The administration of fractalkine into the DRG (L5) produced mechanical hypernociception in a dose-, time-, and CX3C receptor-1 (CX3CR1)–dependent manner. Fractalkine’s hypernociceptive effect appears to be indirect, as it was reduced by local treatment with anti–TNF-? antibody, IL-1–receptor antagonist, or indomethacin. Accordingly, the in vitro incubation of isolated and cultured SGC with fractalkine induced the production/release of TNF-?, IL-1?, and prostaglandin E2. Finally, treatment with i.gl. fluorocitrate blocked fractalkine (i.gl.)- and carrageenin (paw)-induced hypernociception. Overall, these results suggest that, during peripheral inflammation, fractalkine is released in the DRG and contributes to the genesis of inflammatory hypernociception. Fractalkine’s effect appears to be dependent on the activation of the SGCs, leading to the production of TNF?, IL-1?, and prostanoids, which are likely responsible for the maintenance of inflammatory pain. Thus, these results indicate that the inhibition of fractalkine/CX3CR1 signaling in SGCs may serve as a target to control inflammatory pain.

Souza, Guilherme R.; Talbot, Jhimmy; Lotufo, Celina M.; Cunha, Fernando Q.; Cunha, Thiago M.; Ferreira, Sergio H.

2013-01-01

88

Proinflammatory-activated trigeminal satellite cells promote neuronal sensitization: relevance for migraine pathology  

PubMed Central

Background Migraine is a complex, chronic, painful, neurovascular disorder characterized by episodic activation of the trigeminal system. Increased levels of calcitonin gene-related peptide (CGRP) are found at different levels during migraine attacks. Interestingly, CGRP is also released within the trigeminal ganglia suggesting possible local effects on satellite cells, a specialized type of glia that ensheaths trigeminal neurons. CGRP was shown to enhance satellite-cell production of interleukin 1? (IL-1?), while trigeminal neurons express an activity-dependent production of nitric oxide (NO). Thus, in the present study we tested the hypothesis that IL-1? and NO induce trigeminal satellite cell activation, and that once activated these cells can influence neuronal responses. Results Primary cultures of rat trigeminal satellite cells isolated from neuronal cultures were characterized in vitro. Cyclooxygenase (COX) expression and activity were taken as a marker of glial pro-inflammatory activation. Most of the experiments were carried out to characterize satellite cell responses to the two different pro-inflammatory stimuli. Subsequently, medium harvested from activated satellite cells was used to test possible modulatory effects of glial factors on trigeminal neuronal activity. IL-1? and the NO donor diethylenetriamine/nitric oxide (DETA/NO) elevated PGE2 release by satellite cells. The stimulatory effect of IL-1? was mediated mainly by upregulation of the inducible form of COX enzyme (COX2), while NO increased the constitutive COX activity. Regardless of the activator used, it is relevant that short exposures of trigeminal satellite cells to both activators induced modifications within the cells which led to significant PGE2 production after removal of the pro-inflammatory stimuli. This effect allowed us to harvest medium from activated satellite cells (so-called 'conditioned medium') that did not contain any stimulus, and thus test the effects of glial factors on neuronal activation. Conditioned medium from satellite cells activated by either IL-1? or NO augmented the evoked release of CGRP by trigeminal neurons. Conclusion These findings indicate that satellite cells contribute to migraine-related neurochemical events and are induced to do so by autocrine/paracrine stimuli (such as IL-1? and NO). The responsiveness of IL-1? to CGRP creates the potential for a positive feedback loop and, thus, a plurality of targets for therapeutic intervention in migraine.

Capuano, Alessandro; De Corato, Alice; Lisi, Lucia; Tringali, Giuseppe; Navarra, Pierluigi; Dello Russo, Cinzia

2009-01-01

89

Thymidine-3H Uptake by Satellite Cells of Regenerating Skeletal Muscle.  

National Technical Information Service (NTIS)

To obtain more detailed information on the development of such satellite cells and their possible function as precursors of myoblasts, an electron microscopic radioautographic study was performed during experimental muscle regeneration in normal, adult, w...

M. Reznik

1968-01-01

90

Reduced satellite cell population may lead to contractures in children with cerebral palsy  

PubMed Central

AIM Satellite cells are the stem cells residing in muscle responsible for skeletal muscle growth and repair. Skeletal muscle in cerebral palsy (CP) has impaired longitudinal growth that results in muscle contractures. We hypothesized that the satellite cell population would be reduced in contractured muscle. METHOD We compared the satellite cell populations in hamstring muscles from participants with CP contracture (n=8; six males, two females; age range 6–15y; Gross Motor Function Classification System [GMFCS] levels II–V; 4 with hemiplegia, 4 with diplegia) and from typically developing participants (n=8; six males, two females, age range 15–18y). Muscle biopsies were extracted from the gracilis and semitendinosus muscles and mononuclear cells were isolated. Cell surface markers were stained with fluorescently conjugated antibodies to label satellite cells (neural cell adhesion molecule) and inflammatory and endothelial cells (CD34 and CD4 respectively). Cells were analyzed using flow cytometry to determine cell populations. RESULTS After gating for intact cells a mean of 12.8% (SD 2.8%) were determined to be satellite cells in typically developing children, but only 5.3% (SD 2.3%;p<0.05) in children with CP. Hematopoietic and endothelial cell types were equivalent in typically developing children and children with CP (p>0.05) suggesting the isolation procedure was valid. INTERPRETATION A reduced satellite cell population may account for the decreased longitudinal growth of muscles in CP that develop into fixed contractures or the decreased ability to strengthen muscle in CP. This suggests a unique musculoskeletal disease mechanism and provides a potential therapeutic target for debilitating muscle contractures.

SMITH, LUCAS R; CHAMBERS, HENRY G; LIEBER, RICHARD L

2014-01-01

91

Commitment of Satellite Cells Expressing the Calcium Channel ?2?1 Subunit to the Muscle Lineage  

PubMed Central

Satellite cells can maintain or repair muscle because they possess stem cell properties, making them a valuable option for cell therapy. However, cell transplants into skeletal muscle of patients with muscular dystrophy are limited by donor cell attachment, migration, and survival in the host tissue. Cells used for therapy are selected based on specific markers present in the plasma membrane. Although many markers have been identified, there is a need to find a marker that is expressed at different states in satellite cells, activated, quiescent, or differentiated cell. Furthermore, the marker has to be present in human tissue. Recently we reported that the plasma membrane ?2?1 protein is involved in cell attachment and migration in myoblasts. The ?2?1 subunit forms a part of the L-type voltage-dependent calcium channel in adult skeletal muscle. We found that the ?2?1 subunit is expressed in the majority of newly isolated satellite cells and that it appears earlier than the ?1 subunits and at higher levels than the ? or ? subunits. We also found that those cells that expressed ?2?1 would differentiate into muscle cells. This evidence indicates that the ?2?1 may be used as a marker of satellite cells that will differentiate into muscle.

Tamayo, Tammy; Grajales, Liliana; Garcia, Jesus

2012-01-01

92

Influence of estrogens and isoflavones on porcine muscle satellite cell growth  

Microsoft Academic Search

The role of estrogens and estrogen-like compounds, such as dietary phytoestrogens, in pig skeletal muscle growth is largely unknown. The aim of this study was therefore to investigate the in vitro effects of estrogens and isoflavones on porcine muscle satellite cell growth. Myogenic cells were derived from M. semimembranosus of newborn piglets, typified for muscle cell specific proteins (e.g. desmin)

MARCUS MAU; TORSTEN VIERGUTZ; CHARLOTTE REHFELDT

2006-01-01

93

Role of satellite cells in muscle growth and maintenance of muscle mass.  

PubMed

Changes in muscle mass may result from changes in protein turnover, reflecting the balance between protein synthesis and protein degradation, and changes in cell turnover, reflecting the balance between myonuclear accretion and myonuclear loss. Myonuclear accretion, i.e. increase in the number of myonuclei within the muscle fibers, takes place via proliferation and fusion of satellite cells, myogenic stem cells associated to skeletal muscle fibers and involved in muscle regeneration. In developing muscle, satellite cells undergo extensive proliferation and most of them fuse with myofibers, thus contributing to the increase in myonuclei during early postnatal stages. A similar process is induced in adult skeletal muscle by functional overload and exercise. In contrast, satellite cells and myonuclei may undergo apoptosis during muscle atrophy, although it is debated whether myonuclear loss occurs in atrophying muscle. An increase in myofiber size can also occur by changes in protein turnover without satellite cell activation, e.g. in late phases of postnatal development or in some models of muscle hypertrophy. The relative role of protein turnover and cell turnover in muscle adaptation and in the establishment of functional muscle hypertrophy remains to be established. The identification of the signaling pathways mediating satellite cell activation may provide therapeutic targets for combating muscle wasting in a variety of pathological conditions, including cancer cachexia, renal and cardiac failure, neuromuscular diseases, as well as aging sarcopenia. PMID:22621743

Pallafacchina, G; Blaauw, B; Schiaffino, S

2013-12-01

94

Myf5 expression during fetal myogenesis defines the developmental progenitors of adult satellite cells  

PubMed Central

Myf5 is a member of the muscle-specific determination genes and plays a critical role in skeletal muscle development. Whereas the expression of Myf5 during embryonic and fetal myogenesis has been extensively studied, its expression in progenitors that will ultimately give rise to adult satellite cells, the stem cells responsible for muscle repair, is still largely unexplored. To investigate this aspect, we have generated a mouse strain carrying a CreER coding sequence in the Myf5 locus. In this strain, Tamoxifen-inducible Cre activity parallels endogenous Myf5 expression. Combining Myf5CreER and Cre reporter alleles, we were able to evaluate the contribution of cells expressing Myf5 at distinct developmental stages to the pool of satellite cells in adult hindlimb muscles. Although it was possible to trace back the origin of some rare satellite cells to a subpopulation of Myf5+ve progenitors in the limb buds at the late embryonic stage (~E12), a significant number of satellite cells arise from cells which expressed Myf5 for the first time at the fetal stage (~E15). These studies provide direct evidence that adult satellite cells derive from progenitors that first express the myogenic determination gene Myf5 during fetal stages of myogenesis.

Biressi, Stefano; Bjornson, Christopher R.R.; Carlig, Poppy M.M.; Nishijo, Koichi; Keller, Charles; Rando, Thomas A.

2013-01-01

95

Super radiation tolerance of CIGS solar cells demonstrated in space by MDS-1 satellite  

Microsoft Academic Search

High radiation tolerance of CIGS solar cells is demonstrated in space for the first time by monitoring the performance of Cu(In,Ga)Se\\/sub 2\\/ thin-film solar cells on MDS-1 since February 2002. Short-circuit current of the CIGS cells did not degrade and open-circuit voltage of the cells degraded only about 1%. In contrast, the performance of other solar cells on the satellite,

S. Kawakita; M. Imaizumi; T. Sumita; K. Kushiya; T. Ohshima; M. Yamaguchi; S. Matsuda; S. Yoda; T. Kamiya

2003-01-01

96

Effects of insulin and insulin-like growth factors on satellite cell proliferation in vitro  

SciTech Connect

Primary cultures of skeletal muscle satellite cells were induced to proliferate by exposure to physiologic levels of somatomedins and pharmacologic levels of insulin. In the presence of insulin concentrations that promote maximum proliferation, addition of oSM did not produce an additive effect, whereas the addition of MSA/rIGF-II did produce a significant increase in satellite cell proliferation above that induced by insulin. A more, in depth, analysis of the interaction of MSA/rIGF-II with its satellite cell receptor under a variety of experimental conditions revealed that binding of /sup 175/I-MSA/rIGF-II was inhibited by oSm nd MSA/rIGF-II, but not by insulin. Migration, and localization of /sup 125/I-MSA/rIGF-II-receptor complexes in 7% sodium dodecyl sulfate polyacrylamide gels suggest that these complexes are Type II IGF receptors. In addition, this receptor system of satellite cells was shown to be modulated by other hormones; notably, pre-exposure of cells with insulin increased /sup 125/I-MSA/rIGF-II binding, while oSm, or MSA/rIGF-II preincubation decreased the binding of /sup 125/I-MSA/rIGF-II. Collectively, these data support the hypothesis that somatomedins lay an important role in the control of postnatal muscle growth by providing a link between these hormones and satellite cells, one of the significant target cells involved in the growth process.

Dodson, M.V.

1985-01-01

97

Isolation and Culture of Skeletal Muscle Myofibers as a Means to Analyze Satellite Cells  

PubMed Central

Summary Myofibers are the functional contractile units of skeletal muscle. Mononuclear satellite cells located between the basal lamina and the plasmalemma of the myofiber are the primary source of myogenic precursor cells in postnatal muscle. This chapter describes protocols used in our laboratory for isolation, culturing and immunostaining of single myofibers from mouse skeletal muscle. The isolated myofibers are intact and retain their associated satellite cells underneath the basal lamina. The first protocol discusses myofiber isolation from the flexor digitorum brevis (FDB) muscle. Myofibers are cultured in dishes coated with Vitrogen collagen and satellite cells remain associated with the myofibers undergoing proliferation and differentiation on the myofiber surface. The second protocol discusses the isolation of longer myofibers from the extensor digitorum longus (EDL). Different from the FDB myofibers, the longer EDL myofibers tend to tangle and break if cultured together; therefore, EDL myofibers are cultured individually. These myofibers are cultured in dishes coated with Matrigel. The satellite cells initially remain associated with the myofiber and later migrate away to its vicinity, resulting in extensive cell proliferation and differentiation. These culture protocols allow studies on the interplay between the myofiber and its associated satellite cells.

Shefer, Gabi; Yablonka-Reuveni, Zipora

2012-01-01

98

Pitx genes are redeployed in adult myogenesis where they can act to promote myogenic differentiation in muscle satellite cells.  

PubMed

Skeletal muscle retains a resident stem cell population called satellite cells. Although mitotically quiescent in mature muscle, satellite cells can be activated to produce myoblast progeny to generate myonuclei for skeletal muscle homoeostasis, hypertrophy and repair. Regulation of satellite cell function in adult requires redeployment of many of the regulatory networks fundamental to developmental myogenesis. Involved in such control of muscle stem cell fate in embryos are members of the Pitx gene family of bicoid-class homeodomain proteins. Here, we investigated the expression and function of all three Pitx genes in muscle satellite cells of adult mice. Endogenous Pitx1 was undetectable, whilst Pitx2a, Pitx2b and Pitx2c were at low levels in proliferating satellite cells, but increased during the early stages of myogenic differentiation. By contrast, proliferating satellite cells expressed robust amounts of Pitx3, with levels then decreasing as cells differentiated, although Pitx3 remained expressed in unfused myoblasts. To examine the role of Pitx genes in satellite cell function, retroviral-mediated expression of Pitx1, all Pitx2 isoforms or Pitx3, was used. Constitutive expression of any Pitx isoform suppressed satellite cell proliferation, with the cells undergoing enhanced myogenic differentiation. Conversely, myogenic differentiation into multinucleated myotubes was decreased when Pitx2 or Pitx3 levels were reduced using siRNA. Together, our results show that Pitx genes play a role in regulating satellite cell function during myogenesis in adult. PMID:23438814

Knopp, Paul; Figeac, Nicolas; Fortier, Mathieu; Moyle, Louise; Zammit, Peter S

2013-05-01

99

Ground deformation in an area later damaged by an earthquake: monitoring the Avcilar district of Istanbul, Turkey, by satellite radar interferometry 1992-1999  

Microsoft Academic Search

The Avcilar district of Istanbul was severely damaged by the M 7.4 Izmit (Kocaeli) earthquake of 1999. The same area underwent ground subsidence before the earthquake, as revealed by geodetic monitoring. Analysis of 14 synthetic aperture radar images acquired by the ERS-1 and ERS-2 satellites between 1992 and 1999 by interferometry (InSAR) measures the rate of subsidence. Using the General

Samuray Akarvardar; Kurt L. Feigl; Semih Ergintav

2009-01-01

100

Eph/ephrin interactions modulate muscle satellite cell motility and patterning  

PubMed Central

During development and regeneration, directed migration of cells, including neural crest cells, endothelial cells, axonal growth cones and many types of adult stem cells, to specific areas distant from their origin is necessary for their function. We have recently shown that adult skeletal muscle stem cells (satellite cells), once activated by isolation or injury, are a highly motile population with the potential to respond to multiple guidance cues, based on their expression of classical guidance receptors. We show here that, in vivo, differentiated and regenerating myofibers dynamically express a subset of ephrin guidance ligands, as well as Eph receptors. This expression has previously only been examined in the context of muscle-nerve interactions; however, we propose that it might also play a role in satellite cell-mediated muscle repair. Therefore, we investigated whether Eph-ephrin signaling would produce changes in satellite cell directional motility. Using a classical ephrin ‘stripe’ assay, we found that satellite cells respond to a subset of ephrins with repulsive behavior in vitro; patterning of differentiating myotubes is also parallel to ephrin stripes. This behavior can be replicated in a heterologous in vivo system, the hindbrain of the developing quail, in which neural crest cells are directed in streams to the branchial arches and to the forelimb of the developing quail, where presumptive limb myoblasts emigrate from the somite. We hypothesize that guidance signaling might impact multiple steps in muscle regeneration, including escape from the niche, directed migration to sites of injury, cell-cell interactions among satellite cell progeny, and differentiation and patterning of regenerated muscle.

Stark, Danny A.; Karvas, Rowan M.; Siegel, Ashley L.; Cornelison, D. D. W.

2011-01-01

101

Muscle satellite cell proliferation and association: new insights from myofiber time-lapse imaging  

PubMed Central

Background As the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter the cell cycle to proliferate and supply a population of myoblasts, which will repair or replace damaged myofibers by differentiating and fusing either with an existing myofiber or with each other. There is also evidence that the orientation of cell division with respect to the myofiber may indicate or convey asymmetry in the two daughter cells. Our recent studies with time-lapse imaging of myofiber-associated satellite cells in vitro have yielded new data on the timing and orientation of satellite cell divisions, and revealed persistent differences in the behavior of daughter cells from planar versus vertical divisions. Results We analyzed 244 individual fiber-associated satellite cells in time-lapse video from 24 to 48 hours after myofiber harvest. We found that initial cell division in fiber culture is not synchronous, although presumably all cells were activated by the initial trauma of harvest; that cell cycling time is significantly shorter than previously thought (as short as 4.8 hours, averaging 10 hours between the first and second divisions and eight hours between the second and third); and that timing of subsequent divisions is not strongly correlated with timing of the initial division. Approximately 65% of first and 80% of second cell divisions occur parallel to the axis of the myofiber, whereas the remainder occur outside the plane of the fiber surface (vertical division). We previously demonstrated that daughter cells frequently remain associated with each other after division or reassociate after a brief separation, and that unrelated cells may also associate for significant periods of time. We show in this paper that daughter cells resulting from a vertical division remain associated with one another several times longer than do daughters from a horizontal division. However, the total average time of association between sister cells is not significantly different from the total average time of association between unrelated cells. Conclusions These longitudinal characterizations of satellite cell behavior shortly after activation provide new insights into cell proliferation and association as a function of relatedness, and indicate significant and consistent heterogeneity within the population based on these metrics.

2011-01-01

102

IL-4 receptor blockade abrogates satellite cell: rhabdomyosarcoma fusion and prevents tumor establishment.  

PubMed

Tumor cells of the muscle-related cancer alveolar rhabdomyosarcoma (aRMS) have dysregulated terminal myogenic differentiation that is characterized by continuous proliferation, decreased capacity to express markers of terminal differentiation, and inability of tumor cells to fuse to one another in the manner seen for normal myoblasts. Whether aRMS tumor cells can fuse with normal myogenic progenitors such as skeletal muscle stem cells (satellite cells) or myoblasts is unknown, as is the biological effect of fusion events if the phenomenon occurs. To study this possibility, we isolated primary satellite cells harboring a lacZ Cre-LoxP reporter gene for coculture with murine aRMS primary tumor cells expressing Cre. Results of in vitro and in vivo experiments demonstrated tumor cell-muscle cell progenitor fusion events as well as accelerated rates of tumor establishment and progression when satellite cells and derived muscle progenitors were coinjected with tumor cells in an orthotopic allograft model. Interleukin 4 receptor (IL-4R) blocking antibody treatment reversed fusion events in vitro and blocked tumor initiation and progression in vivo. Taken together, this study supports a potential role of tumor cell-host cell fusion and the strong therapeutic potential of IL-4R blockade to prevent the establishment of RMS tumors at new anatomical sites. PMID:23897781

Li, Guangheng; Kikuchi, Ken; Radka, Megan; Abraham, Jinu; Rubin, Brian P; Keller, Charles

2013-11-01

103

Myostatin inhibition induces muscle fibre hypertrophy prior to satellite cell activation  

PubMed Central

Muscle fibres are multinucleated post-mitotic cells that can change dramatically in size during adulthood. It has been debated whether muscle fibre hypertrophy requires activation and fusion of muscle stem cells, the satellite cells. Myostatin (MSTN) is a negative regulator of skeletal muscle growth during development and in the adult, and MSTN inhibition is therefore a potential therapy for muscle wasting diseases, some of which are associated with a depletion of satellite cells. Conflicting results have been obtained in previous analyses of the role of MSTN on satellite cell quiescence. Here, we inhibited MSTN in adult mice with a soluble activin receptor type IIB and analysed the incorporation of new nuclei using 5?-bromo-2?-deoxyuridine (BrdU) labelling by isolating individual myofibres. We found that satellite cells are activated by MSTN inhibition. By varying the dose and time course for MSTN inhibition, however, we found that myofibre hypertrophy precedes the incorporation of new nuclei, and that the overall number of new nuclei is relatively low compared to the number of total myonuclei. These results reconcile some of the previous work obtained by other methods. In contrast with previous reports, we also found that Mstn null mice do not have increased satellite cell numbers during adulthood and are not resistant to sarcopaenia. Our results support a previously proposed model of hypertrophy in which hypertrophy can precede satellite cell activation. Studies of the metabolic and functional effects of postnatal MSTN inhibition are needed to determine the consequences of increasing the cytoplasm/myonuclear ratio after MSTN inhibition.

Wang, Qian; McPherron, Alexandra C

2012-01-01

104

Analytic studies on satellite detection of severe, two-cell tornadoes  

NASA Technical Reports Server (NTRS)

It is argued that a two-cell structure is likely to be the unique property, and potentially satellite-accessible observable, of the exceptionally severe tornado. Analysis elucidating the dynamic, thermodynamic, and geometric properties of this two-cell structure is described. The analysis ultimately will furnish instrumentation requirements.

Carrier, G. F.; Dergarabedian, P.; Fendell, F. E.

1979-01-01

105

Expression of Cd34 and Myf5 Defines the Majority of Quiescent Adult Skeletal Muscle Satellite Cells  

Microsoft Academic Search

Skeletal muscle is one of a several adult post- mitotic tissues that retain the capacity to regenerate. This relies on a population of quiescent precursors, termed satellite cells. Here we describe two novel markers of quiescent satellite cells: CD34, an established marker of hematopoietic stem cells, and Myf5, the earliest marker of myogenic commitment. CD34 1 ve myoblasts can be

Jonathan R. Beauchamp; Louise Heslop; David S. W. Yu; Shahragim Tajbakhsh; Robert G. Kelly; Anton Wernig; Margaret E. Buckingham; Terence A. Partridge; Peter S. Zammit

2000-01-01

106

Cell metabolism sets the differences between subpopulations of satellite cells (SCs)  

PubMed Central

Background We have recently characterized two distinct populations of Satellite Cells (SCs) that differ in proliferation, regenerative potential, and mitochondrial coupling efficiency and classified these in Low Proliferative Clones (LPC) and High Proliferative Clones (HPC). Herewith, we have investigated their cell metabolism and individuated features that remark an intrinsic difference in basal physiology but that are retrievable also at the initial phases of their cloning. Results Indeed, LPC and HPC can be distinguished for mitochondrial membrane potential (??m) just after isolation from the fiber. This is matched by mitochondrial redox state measured via NAD+/NADH analysis and alternative respiratory CO2 production in cloned cells. All these parameters are accountable for metabolic differences reflected indeed by alternative expression of the glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (Pfkfb3). Also Ca2+ handling by mitochondria is different together with the sensitivity to apoptosis triggered via this pathway. Finally, according to the above, we were able to determine which one among the clones represents the suitable stem cell. Conclusions These experimental observations report novel physiological features in the cell biology of SCs and refer to an intrinsic heterogeneity within which their stemness may reside.

2013-01-01

107

Fibre type-specific satellite cell response to aerobic training in sedentary adults.  

PubMed

In the present study, we sought to determine the effect of a traditional, 12 week aerobic training protocol on skeletal muscle fibre type distribution and satellite cell content in sedentary subjects. Muscle biopsies were obtained from the vastus lateralis [n = 23 subjects (six male and 17 female); body mass index 30.7 ± 1.2 kg m(-2)] before and after 12 weeks of aerobic training performed on a cycle ergometer. Immunohistochemical analyses were used to quantify myosin heavy chain (MyHC) isoform expression, cross-sectional area and satellite cell and myonuclear content. Following training, a decrease in MyHC hybrid type IIa/IIx fibre frequency occurred, with a concomitant increase in pure MyHC type IIa fibres. Pretraining fibre type correlated with body mass index, and the change in fibre type following training was associated with improvements in maximal oxygen consumption. Twelve weeks of aerobic training also induced increases in mean cross-sectional area in both MyHC type I and type IIa fibres. Satellite cell content was also increased following training, specifically in MyHC type I fibres, with no change in the number of satellite cells associated with MyHC type II fibres. With the increased satellite cell content following training, an increase in myonuclear number per fibre also occurred in MyHC type I fibres. Hypertrophy of MyHC type II fibres occurred without detectable myonuclear addition, suggesting that the mechanisms underlying growth in fast and slow fibres differ. These data provide intriguing evidence for a fibre type-specific role of satellite cells in muscle adaptation following aerobic training. PMID:24687582

Fry, Christopher S; Noehren, Brian; Mula, Jyothi; Ubele, Margo F; Westgate, Philip M; Kern, Philip A; Peterson, Charlotte A

2014-06-15

108

Stochastic cellular automata model of cell migration, proliferation and differentiation: validation with in vitro cultures of muscle satellite cells.  

PubMed

Cell migration and proliferation has been modelled in the literature as a process similar to diffusion. However, using diffusion models to simulate the proliferation and migration of cells tends to create a homogeneous distribution in the cell density that does not correlate to empirical observations. In fact, the mechanism of cell dispersal is not diffusion. Cells disperse by crawling or proliferation, or are transported in a moving ?uid. The use of cellular automata, particle models or cell-based models can overcome this limitation. This paper presents a stochastic cellular automata model to simulate the proliferation, migration and differentiation of cells. These processes are considered as completely stochastic as well as discrete. The model developed was applied to predict the behaviour of in vitro cell cultures performed with adult muscle satellite cells. Moreover, non homogeneous distribution of cells has been observed inside the culture well and, using the above mentioned stochastic cellular automata model, we have been able to predict this heterogeneous cell distribution and compute accurate quantitative results. Differentiation was also incorporated into the computational simulation. The results predicted the myotube formation that typically occurs with adult muscle satellite cells. In conclusion, we have shown how a stochastic cellular automata model can be implemented and is capable of reproducing the in vitro behaviour of adult muscle satellite cells. PMID:22954469

Garijo, N; Manzano, R; Osta, R; Perez, M A

2012-12-01

109

Isolation and Culture of Individual Myofibers and their Satellite Cells from Adult Skeletal Muscle  

PubMed Central

Muscle regeneration in the adult is performed by resident stem cells called satellite cells. Satellite cells are defined by their position between the basal lamina and the sarcolemma of each myofiber. Current knowledge of their behavior heavily relies on the use of the single myofiber isolation protocol. In 1985, Bischoff described a protocol to isolate single live fibers from the Flexor Digitorum Brevis (FDB) of adult rats with the goal to create an in vitro system in which the physical association between the myofiber and its stem cells is preserved 1. In 1995, Rosenblattmodified the Bischoff protocol such that myofibers are singly picked and handled separately after collagenase digestion instead of being isolated by gravity sedimentation 2, 3. The Rosenblatt or Bischoff protocol has since been adapted to different muscles, age or conditions 3-6. The single myofiber isolation technique is an indispensable tool due its unique advantages. First, in the single myofiber protocol, satellite cells are maintained beneath the basal lamina. This is a unique feature of the protocol as other techniques such as Fluorescence Activated Cell Sorting require chemical and mechanical tissue dissociation 7. Although the myofiber culture system cannot substitute for in vivo studies, it does offer an excellent platform to address relevant biological properties of muscle stem cells. Single myofibers can be cultured in standard plating conditions or in floating conditions. Satellite cells on floating myofibers are subjected to virtually no other influence than the myofiber environment. Substrate stiffness and coating have been shown to influence satellite cells' ability to regenerate muscles 8, 9 so being able to control each of these factors independently allows discrimination between niche-dependent and -independent responses. Different concentrations of serum have also been shown to have an effect on the transition from quiescence to activation. To preserve the quiescence state of its associated satellite cells, fibers should be kept in low serum medium 1-3. This is particularly useful when studying genes involved in the quiescence state. In serum rich medium, satellite cells quickly activate, proliferate, migrate and differentiate, thus mimicking the in vivo regenerative process 1-3. The system can be used to perform a variety of assays such as the testing of chemical inhibitors; ectopic expression of genes by virus delivery; oligonucleotide based gene knock-down or live imaging. This video article describes the protocol currently used in our laboratory to isolate single myofibers from the Extensor Digitorum Longus (EDL) muscle of adult mice (6-8 weeks old).

Pasut, Alessandra; Jones, Andrew E.; Rudnicki, Michael A.

2013-01-01

110

Isolation and culture of individual myofibers and their satellite cells from adult skeletal muscle.  

PubMed

Muscle regeneration in the adult is performed by resident stem cells called satellite cells. Satellite cells are defined by their position between the basal lamina and the sarcolemma of each myofiber. Current knowledge of their behavior heavily relies on the use of the single myofiber isolation protocol. In 1985, Bischoff described a protocol to isolate single live fibers from the Flexor Digitorum Brevis (FDB) of adult rats with the goal to create an in vitro system in which the physical association between the myofiber and its stem cells is preserved (1). In 1995, Rosenblattmodified the Bischoff protocol such that myofibers are singly picked and handled separately after collagenase digestion instead of being isolated by gravity sedimentation (2, 3). The Rosenblatt or Bischoff protocol has since been adapted to different muscles, age or conditions (3-6). The single myofiber isolation technique is an indispensable tool due its unique advantages. First, in the single myofiber protocol, satellite cells are maintained beneath the basal lamina. This is a unique feature of the protocol as other techniques such as Fluorescence Activated Cell Sorting require chemical and mechanical tissue dissociation (7). Although the myofiber culture system cannot substitute for in vivo studies, it does offer an excellent platform to address relevant biological properties of muscle stem cells. Single myofibers can be cultured in standard plating conditions or in floating conditions. Satellite cells on floating myofibers are subjected to virtually no other influence than the myofiber environment. Substrate stiffness and coating have been shown to influence satellite cells' ability to regenerate muscles (8, 9) so being able to control each of these factors independently allows discrimination between niche-dependent and -independent responses. Different concentrations of serum have also been shown to have an effect on the transition from quiescence to activation. To preserve the quiescence state of its associated satellite cells, fibers should be kept in low serum medium (1-3). This is particularly useful when studying genes involved in the quiescence state. In serum rich medium, satellite cells quickly activate, proliferate, migrate and differentiate, thus mimicking the in vivo regenerative process (1-3). The system can be used to perform a variety of assays such as the testing of chemical inhibitors; ectopic expression of genes by virus delivery; oligonucleotide based gene knock-down or live imaging. This video article describes the protocol currently used in our laboratory to isolate single myofibers from the Extensor Digitorum Longus (EDL) muscle of adult mice (6-8 weeks old). PMID:23542587

Pasut, Alessandra; Jones, Andrew E; Rudnicki, Michael A

2013-01-01

111

MASTR directs MyoD-dependent satellite cell differentiation during skeletal muscle regeneration  

PubMed Central

In response to skeletal muscle injury, satellite cells, which function as a myogenic stem cell population, become activated, expand through proliferation, and ultimately fuse with each other and with damaged myofibers to promote muscle regeneration. Here, we show that members of the Myocardin family of transcriptional coactivators, MASTR and MRTF-A, are up-regulated in satellite cells in response to skeletal muscle injury and muscular dystrophy. Global and satellite cell-specific deletion of MASTR in mice impairs skeletal muscle regeneration. This impairment is substantially greater when MRTF-A is also deleted and is due to aberrant differentiation and excessive proliferation of satellite cells. These abnormalities mimic those associated with genetic deletion of MyoD, a master regulator of myogenesis, which is down-regulated in the absence of MASTR and MRTF-A. Consistent with an essential role of MASTR in transcriptional regulation of MyoD expression, MASTR activates a muscle-specific postnatal MyoD enhancer through associations with MEF2 and members of the Myocardin family. Our results provide new insights into the genetic circuitry of muscle regeneration and identify MASTR as a central regulator of this process.

Mokalled, Mayssa H.; Johnson, Aaron N.; Creemers, Esther E.; Olson, Eric N.

2012-01-01

112

Total Solar Eclipse: Live from Turkey  

NSDL National Science Digital Library

On March 29, 2006, a team from the Exploratorium filmed and broadcast live the total eclipse of the Sun as seen from Side, Turkey. The web site created around this event includes streaming video of the eclipse, a slide show from first contact through totality and fourth contact, and an image gallery with photos of the eclipse and the chosen site in Turkey, a Roman-era amphitheater. There is also information about how the location was chosen, a map showing the path of totality, how the eclipse was filmed and broadcast live by satellite, and the mechanics of a solar eclipse.

2006-02-23

113

Sulforaphane causes a major epigenetic repression of myostatin in porcine satellite cells  

PubMed Central

Satellite cells function as skeletal muscle stem cells to support postnatal muscle growth and regeneration following injury or disease. There is great promise for the improvement of muscle performance in livestock and for the therapy of muscle pathologies in humans by the targeting of myostatin (MSTN) in this cell population. Human diet contains many histone deacetylase (HDAC) inhibitors, such as the bioactive component sulforaphane (SFN), whose epigenetic effects on MSTN gene in satellite cells are unknown. Therefore, we aimed to investigate the epigenetic influences of SFN on the MSTN gene in satellite cells. The present work provides the first evidence, which is distinct from the effects of trichostatin A (TSA), that SFN supplementation in vitro not only acts as a HDAC inhibitor but also as a DNA methyltransferase (DNMT) inhibitor in porcine satellite cells. Compared with TSA and 5-aza-2?-deoxycytidine (5-aza-dC), SFN treatment significantly represses MSTN expression, accompanied by strongly attenuated expression of negative feedback inhibitors of the MSTN signaling pathway. miRNAs targeting MSTN are not implicated in posttranscriptional regulation of MSTN. Nevertheless, a weakly enriched myoblast determination (MyoD) protein associated with diminished histone acetylation in the MyoD binding site located in the MSTN promoter region may contribute to the transcriptional repression of MSTN by SFN. These findings reveal a new mode of epigenetic repression of MSTN by the bioactive compound SFN. This novel pharmacological, biological activity of SFN in satellite cells may thus allow for the development of novel approaches to weaken the MSTN signaling pathway, both for therapies of human skeletal muscle disorders and for livestock production improvement.

Fan, Huitao; Zhang, Rui; Tesfaye, Dawit; Tholen, Ernst; Looft, Christian; Holker, Michael; Schellander, Karl; Cinar, Mehmet Ulas

2012-01-01

114

Myf5-Positive Satellite Cells Contribute to Pax7-Dependent Long-Term Maintenance of Adult Muscle Stem Cells  

PubMed Central

SUMMARY Skeletal muscle contains Pax7-expressing muscle stem or satellite cells, enabling muscle regeneration throughout most of adult life. Here, we demonstrate that induced inactivation of Pax7 in Pax7-expressing cells of adult mice leads to loss of muscle stem cells and reduced heterochromatin condensation in rare surviving satellite cells. Inactivation of Pax7 in Myf5-expressing cells revealed that the majority of adult muscle stem cells originate from myogenic lineages, which express the myogenic regulators Myf5 or MyoD. Likewise, the majority of muscle stem cells are replenished from Myf5-expressing myogenic cells during adult life, and inactivation of Pax7 in Myf5-expressing cells after muscle damage leads to a complete arrest of muscle regeneration. Finally, we demonstrate that a relatively small number of muscle stem cells are sufficient for efficient repair of skeletal muscles. We conclude that Pax7 acts at different levels in a nonhierarchical regulatory network controlling muscle-satellite-cell-mediated muscle regeneration.

Gunther, Stefan; Kim, Johnny; Kostin, Sawa; Lepper, Christoph; Fan, Chen-Ming; Braun, Thomas

2014-01-01

115

Multi-temporal land cover classification of the Konya Basin, south-central Turkey, based on a LANDSAT TM-derived NDVI/NDMI time series: satellite remote sensing in support of landscape-scale soil biogeochemistry research  

NASA Astrophysics Data System (ADS)

Recently, terrestrial biogeochemists and soil scientists have called for new approaches to study human impacts on soil biogeochemical properties at landscape-wide, 100-1000 km2 spatial scales (Trumbore and Czimczik 2008). Here, we use satellite remote sensing to map land cover across a 16,000 km2 region in the Konya Basin, south-central Turkey, in support of research into agricultural and pastoral land use impacts on soil biogeochemistry. Our land cover classification is based on time series analysis of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI) data, derived from eight LANDSAT TM images spanning the 2006-2007 growing seasons. Using a hierarchical, binary-split classification approach and a support vector machine (SVM) algorithm, we map five land cover classes that correspond with the following dominant land-use categories: 1) annual cultivated row-crops, 2) perennial orchards/cultivated woody vegetation, 3) fallow fields, 4) uncultivated woody vegetation, 5) steppe vegetation/rangeland. The final map has an overall classification accuracy of 87.4% (kappa = 0.842), determined via traditional confusion-matrix analysis and over 150 site visits during summer 2010. Classes 1 and 2, which have the highest per-pixel NDVI and NDMI sums across image dates, attain the highest producer and consumer accuracies (>95%). We also compare the relative contributions and efficacy of NDVI and NDMI in separating land cover classes, and the influence of radiometric correction and calibration across image dates on classification accuracies. Our results support previous research showing that NDVI time series can effectively classify agricultural landscapes in semi-arid to arid environments (Simonneaux et al. 2008; Pax-Lenny et al. 1996). By combining our land cover map with other geospatial information in a GIS, we demonstrate how satellite remote sensing can help expand spatial scales of terrestrial biogeochemistry research from experimental plots to landscapes. As an example, our final map proved to be a very practical tool for locating sites for soil sampling in the Konya Basin during the summer 2010 field season.

Mayes, M. T.; Ozdogan, M.; Marin-Spiotta, E.

2010-12-01

116

Sphingolipidoses in Turkey.  

PubMed

During the last 5 years 2057 children under the age of 5 with various neurologic symptoms with the suspected diagnosis of lysosomal storage diseases were referred to our hospital from different universities and state hospitals. We were able to separate sphingolipidoses by lysosomal enzyme screening. A total of 300 patients (15%) with sphingolipidoses were diagnosed; there were deficiencies of arylsulfatase A [metachromatic leukodystrophy (MLD)] in 93 (31%), hexosaminidase [Sandhoff disease (SHD)] in 62 (20.7%), hexosaminidase A [Tay-Sachs disease (TSD)] in 15 (5%), beta-galactosidase (GM1 gangliosidosis) in 35 (11.7%), alpha-galactosidase (Fabry disease) in one (0.3%) cerebroside beta-galactosidase (Krabbe disease) in 65 (21.7%) and glucosylceramidase (Gaucher disease) in 29 (9.6%). SHD (20.7%), MLD (31%) and Krabbe disease (21.7%) were common. Prenatal enzymatic diagnosis was made in 70 at risk pregnancies, 64 for TSD and SHD, three for MLD and three for GM1 gangliosidosis by using chorionic villus biopsy in 54, cord blood samples in 12 and cultured amniotic fluid cells in four. Seventeen fetuses were found to be affected. We have calculated the relative frequency and minimum incidence of sphingolipidoses in Turkey. The combined incidence of sphingolipidoses is 4.615 per 100,000 live births. The calculated incidences are 1.43, 0.95, 1, 0.23, 0.54, 0.45, 0.015 per 100,000 live births for MLD, SHD, Krabbe, Gaucher, TSD, GM1 gangliosidosis and Fabry diseases, respectively. The real incidence, which covers all subtypes of this group of diseases, should be greater than this number. The results suggested that, as a group, sphingolipidoses are relatively common and represent an important health problem in Turkey and some rare autosomal recessive diseases of Turkey are due to 'founder effect' created by consanguineous marriages. PMID:15275696

Ozkara, Hatice Asuman; Topçu, Meral

2004-09-01

117

Isolation and Culture of Skeletal Muscle Myofibers as a Means to Analyze Satellite Cells  

PubMed Central

Multinucleated myofibers are the functional contractile units of skeletal muscle. In adult muscle, mononuclear satellite cells, located between the basal lamina and the plasmalemma of the myofiber, are the primary myogenic stem cells. This chapter describes protocols for isolation, culturing and immunostaining of myofibers from mouse skeletal muscle. Myofibers are isolated intact and retain their associated satellite cells. The first protocol discusses myofiber isolation from the flexor digitorum brevis (FDB) muscle. These short myofibers are cultured in dishes coated with PureCol collagen (formerly known as Vitrogen) using a serum replacement medium. Employing such culture conditions, satellite cells remain associated with the myofibers, undergoing proliferation and differentiation on the myofiber surface. The second protocol discusses the isolation of longer myofibers from the extensor digitorum longus (EDL) muscle. Different from the FDB preparation, where multiple myofibers are processed together, the longer EDL myofibers are typically processed and cultured individually in dishes coated with Matrigel using a growth factor rich medium. Under these conditions, satellite cells initially remain associated with the parent myofiber and later migrate away, giving rise to proliferating and differentiating progeny. Myofibers from other types of muscles, such as diaphragm, masseter, and extraocular muscles can also be isolated and analyzed using protocols described herein. Overall, cultures of isolated myofibers provide essential tools for studying the interplay between the parent myofiber and its associated satellite cells. The current chapter provides background, procedural, and reagent updates, and step-by-step images of FDB and EDL muscle isolations, not included in our 2005 publication in this series.

Keire, Paul; Shearer, Andrew; Shefer, Gabi; Yablonka-Reuveni, Zipora

2012-01-01

118

Satellite cells isolated from aged or dystrophic muscle exhibit a reduced capacity to promote angiogenesis in vitro.  

PubMed

Deficits in skeletal muscle function exist during aging and muscular dystrophy, and suboptimal function has been related to factors such as atrophy, excessive inflammation and fibrosis. Ineffective muscle regeneration underlies each condition and has been attributed to a deficit in myogenic potential of resident stem cells or satellite cells. In addition to reduced myogenic activity, satellite cells may also lose the ability to communicate with vascular cells for coordination of myogenesis and angiogenesis and restoration of proper muscle function. Objectives of the current study were to determine the angiogenic-promoting capacity of satellite cells from two states characterized by dysfunctional skeletal muscle repair, aging and Duchenne muscular dystrophy. An in vitro culture model composed of satellite cells or their conditioned media and rat adipose tissue microvascular fragments (MVF) was used to examine this relationship. Microvascular fragments cultured in the presence of rat satellite cells from adult muscle donors (9-12 month of age) exhibited greater indices of angiogenesis (endothelial cell sprouting, tubule formation and extensive branching) than MVF co-cultured with satellite cells from aged muscle donors (24 month of age). We sought to determine if the differential degree of angiogenesis we observed in the co-culture setting was due to soluble factors produced by each satellite cell age group. Similar to the co-culture experiment, conditioned media produced by adult satellite cells promoted greater angiogenesis than that of aged satellite cells. Next, we examined differences in angiogenesis-stimulating ability of satellite cells from 12 mo old MDX mice or age-matched wild-type mice. A reduction in angiogenesis activity of media conditioned by satellite cells from dystrophic muscle was observed as compared to healthy muscle. Finally, we found reduced gene expression of hypoxia-inducible factor 1? (HIF-1?) and vascular endothelial growth factor (VEGF) in both aged and dystrophic satellite cells compared to their adult and normal counterparts, respectively. These results indicate that functional deficits in satellite cell activities during aging and diseased muscle may extend to their ability to communicate with other cells in their environment, in this case cells involved in angiogenesis. PMID:24070607

Rhoads, R P; Flann, K L; Cardinal, T R; Rathbone, C R; Liu, X; Allen, R E

2013-10-25

119

Muscle Atrophy Reversed by Growth Factor Activation of Satellite Cells in a Mouse Muscle Atrophy Model  

PubMed Central

Muscular dystrophies comprise a large group of inherited disorders that lead to progressive muscle wasting. We wanted to investigate if targeting satellite cells can enhance muscle regeneration and thus increase muscle mass. We treated mice with hepatocyte growth factor and leukemia inhibitory factor under three conditions: normoxia, hypoxia and during myostatin deficiency. We found that hepatocyte growth factor treatment led to activation of the Akt/mTOR/p70S6K protein synthesis pathway, up-regulation of the myognic transcription factors MyoD and myogenin, and subsequently the negative growth control factor, myostatin and atrophy markers MAFbx and MuRF1. Hypoxia-induced atrophy was partially restored by hepatocyte growth factor combined with leukemia inhibitory factor treatment. Dividing satellite cells were three-fold increased in the treatment group compared to control. Finally, we demonstrated that myostatin regulates satellite cell activation and myogenesis in vivo following treatment, consistent with previous findings in vitro. Our results suggest, not only a novel in vivo pharmacological treatment directed specifically at activating the satellite cells, but also a myostatin dependent mechanism that may contribute to the progressive muscle wasting seen in severely affected patients with muscular dystrophy and significant on-going regeneration. This treatment could potentially be applied to many conditions that feature muscle wasting to increase muscle bulk and strength.

Hauerslev, Simon; Vissing, John; Krag, Thomas O.

2014-01-01

120

An autoradiographic study of satellite cell differentiation into regenerating myotubes following transplantation of muscles in young rats  

Microsoft Academic Search

Satellite cells were traced autoradiographically during the regeneration of skeletal muscle in young Sprague-Dawley rats. Approximately 31% of the satellite cells in uninjured muscles appeared labelled after three injections of tritiated thymidine; none of the myonuclei were labelled in the same muscles. Four to six days after transplanting the radioactive muscles to non-radioactive littermates, regenerating myotube nuclei in the host

Mikel H. Snow

1978-01-01

121

Alkaline regenerative fuel cell energy storage system for manned orbital satellites  

NASA Technical Reports Server (NTRS)

It is pointed out that the alkaline regenerative fuel cell system represents a highly efficient, lightweight, reliable approach for providing energy storage in an orbiting satellite. In addition to its energy storage function, the system can supply hydrogen and oxygen for attitude control of the satellite and for life support. A summary is presented of the results to date obtained in connection with the NASA-sponsored fuel cell technology advancement program, giving particular attention to the requirements of the alkaline regenerative fuel cell and the low-earth mission. Attention is given to system design guidelines, weight considerations, gold-platinum cathode cell performance, matrix development, the electrolyte reservoir plate, and the cyclical load profile tests.

Martin, R. E.; Gitlow, B.; Sheibley, D. W.

1982-01-01

122

Ultrastructural aspects of DRG satellite cell involvement in experimental cisplatin neuronopathy.  

PubMed

Different substances may induce neurological impairment, clinically expressed as peripheral neuropathies, due to damage of the neuronal bodies (neuronopathy) of sensory or motor neurons. Neuronopathies have generally been studied referring to neurons, although other cellular components may also be damaged. Cisplatin (CDDP) is known to be neurotoxic to the neurons of the dorsal root ganglia (DRG). The scarcity of information as to the possible involvement and role played by dorsal root ganglion (DRG) satellite cells in neuronopathies prompted this study using the chronic DRG neuronopathy induced by the repeated administration of CDDP in rats as a model. Eighteen female Wistar rats were treated according to 3 different schedules of CDDP administration (6 rats for each group). Six further animals were used as controls. At the end of the experiment the L4-L5-L6 dorsal root ganglia were examined at the light and electron microscope. Ag-NOR reaction was also examined in 4 further CDDP-treated rats and 4 controls. Pathological changes in satellite cells of animals treated with CDDP were remarkable in the nucleus where heterochromatin clumps were reduced or even completely absent. Morphometric analysis of the area occupied by heterochromatin indicated that this nuclear component decreased in an exposure-time dependent manner. Frequently, nucleolar-like structures became apparent in the nucleus of the rats treated with the higher doses of CDDP. Ag-NOR positive regions in the nuclei of treated rats were increased with respect to the controls. Cytoplasmic changes in DRG satellite cells of CDDP treated rats were limited, being characterized by an increased electron-density of the matrix. In treated rats deep invaginations between satellite cells and the neuronal surface were evident, leading to the formation of vacuoli. The interstitial connective space often showed edematous areas. Our observations demonstrate that in chronic cisplatin neuronopathy, DRG satellite cells are also involved in the pathological changes induced by drug exposure, and that these changes may be interpreted as being mainly reactive. PMID:7585442

Cece, R; Petruccioli, M G; Pizzini, G; Cavaletti, G; Tredici, G

1995-10-01

123

Increased adipogenic conversion of muscle satellite cells in obese Zucker rats  

Microsoft Academic Search

Aims\\/hypothesis:Visceral and intermuscular adipose tissue (IMAT) depots account for most obesity-related metabolic and cardiovascular complications. Muscle satellite cells (SCs) are mesenchymal stem cells giving rise to myotubes and also to adipocytes, suggesting their possible contribution to IMAT origin and expansion. We investigated the myogenic differentiation of SCs and the adipogenic potential of both preadipocytes and SCs from genetically obese Zucker

A Scarda; C Franzin; G Milan; M Sanna; C Dal Prà; C Pagano; L Boldrin; M Piccoli; E Trevellin; M Granzotto; P Gamba; G Federspil; P De Coppi; R Vettor

2010-01-01

124

Expression of Cd34 and Myf5 Defines the Majority of Quiescent Adult Skeletal Muscle Satellite Cells  

PubMed Central

Skeletal muscle is one of a several adult post-mitotic tissues that retain the capacity to regenerate. This relies on a population of quiescent precursors, termed satellite cells. Here we describe two novel markers of quiescent satellite cells: CD34, an established marker of hematopoietic stem cells, and Myf5, the earliest marker of myogenic commitment. CD34+ve myoblasts can be detected in proliferating C2C12 cultures. In differentiating cultures, CD34+ve cells do not fuse into myotubes, nor express MyoD. Using isolated myofibers as a model of synchronous precursor cell activation, we show that quiescent satellite cells express CD34. An early feature of their activation is alternate splicing followed by complete transcriptional shutdown of CD34. This data implicates CD34 in the maintenance of satellite cell quiescence. In heterozygous Myf5nlacZ/+ mice, all CD34+ve satellite cells also express ?-galactosidase, a marker of activation of Myf5, showing that quiescent satellite cells are committed to myogenesis. All such cells are positive for the accepted satellite cell marker, M-cadherin. We also show that satellite cells can be identified on isolated myofibers of the myosin light chain 3F-nlacZ-2E mouse as those that do not express the transgene. The numbers of satellite cells detected in this way are significantly greater than those identified by the other three markers. We conclude that the expression of CD34, Myf5, and M-cadherin defines quiescent, committed precursors and speculate that the CD34?ve, Myf5?ve minority may be involved in maintaining the lineage-committed majority.

Beauchamp, Jonathan R.; Heslop, Louise; Yu, David S.W.; Tajbakhsh, Shahragim; Kelly, Robert G.; Wernig, Anton; Buckingham, Margaret E.; Partridge, Terence A.; Zammit, Peter S.

2000-01-01

125

Signal-dependent fra-2 regulation in skeletal muscle reserve and satellite cells  

PubMed Central

Activator protein-1 (AP-1) is a ubiquitous transcription factor that paradoxically also has some tissue-specific functions. In skeletal muscle cells, we document that the AP-1 subunit, Fra-2, is expressed in the resident stem cells (Pax7-positive satellite cells) and also in the analogous undifferentiated ‘reserve' cell population in myogenic cultures, but not in differentiated myofiber nuclei. Silencing of Fra-2 expression enhances the expression of differentiation markers such as muscle creatine kinase and myosin heavy chain, indicating a possible role of Fra-2 in undifferentiated myogenic progenitor cells. We observed that Fra-2 is a target of cytokine-mediated extracellular signal-regulated kinase-1/2 signaling in cultured muscle cells, and extensive mass spectrometry and mutational analysis identified S320 and T322 as regulators of Fra-2 protein stability. Interestingly, Fra-2 S320 phosphorylation occurs transiently in activated satellite cells and is extinguished in myogenin-positive differentiating cells. Thus, cytokine-mediated Fra-2 expression and stabilization is linked to regulation of myogenic progenitor cells having implications for the molecular regulation of adult muscle stem cells and skeletal muscle regeneration.

Alli, N S; Yang, E C; Miyake, T; Aziz, A; Collins-Hooper, H; Patel, K; McDermott, J C

2013-01-01

126

Human Metapneumovirus in Turkey Poults  

PubMed Central

This study was conducted to reexamine the hypothesis that human metapneumovirus (hMPV) will not infect turkeys. Six groups of 2-week-old turkeys (20 per group) were inoculated oculonasally with 1 of the following: noninfected cell suspension; hMPV genotype A1, A2, B1, or B2; or avian metapneumovirus (aMPV) subtype C. Poults inoculated with hMPV showed nasal discharge days 4–9 postexposure. Specific viral RNA and antigen were detected by reverse-transcription PCR and immunohistochemical evaluation, respectively, in nasal turbinates of birds exposed to hMPV. Nasal turbinates of hMPV-infected turkeys showed inflammatory changes and mucus accumulation. Each of the 4 hMPV genotypes caused a transient infection in turkeys as evidenced by clinical signs, detection of hMPV in turbinates, and histopathologic examination. Detailed investigation of cross-species pathogenicity of hMPV and aMPV and its importance for human and animal health is needed.

Velayudhan, Binu T.; Nagaraja, Kakambi V.; Thachil, Anil J.; Shaw, Daniel P.; Gray, Gregory C.

2006-01-01

127

Plasticity and recovery of skeletal muscle satellite cells during limb regeneration.  

PubMed

Salamander limb regeneration depends on local progenitors whose progeny are recruited to the new limb. We previously identified a Pax7(+) cell population in skeletal muscle whose progeny have the potential to contribute to the regenerating limb. However, the plasticity of individual Pax7(+) cells, as well as their recovery within the new limb, was unclear. Here, we show that Pax7(+) cells remain present after multiple rounds of limb amputation/regeneration. Pax7(+) cells are found exclusively within skeletal muscle in the regenerating limb and proliferate where the myofibers are growing. Pax7 is rapidly down-regulated in the blastema, and analyses of clonal derivatives show that Pax7(+) cell progeny are not restricted to skeletal muscle during limb regeneration. Our data suggest that the newt regeneration blastema is not entirely a composite of lineage-restricted progenitors. The results demonstrate that except for a transient and subsequently blunted increase, skeletal muscle satellite cells constitute a stable pool of reserve cells for multiple limb regeneration events.-Morrison, J. I., Borg, P., Simon, A. Plasticity and recovery of skeletal muscle satellite cells during limb regeneration. PMID:19887652

Morrison, Jamie I; Borg, Paula; Simon, András

2010-03-01

128

Natural infection of turkeys by infectious laryngotracheitis virus.  

PubMed

The infectious laryngotracheitis virus (ILTV) is an important respiratory pathogen of chickens that also infects pheasants and peafowl. Epidemiologically non-related commercial turkey flocks with clinical signs such as tracheitis, swollen sinuses, conjunctivitis and expectoration of bloody mucus were examined for the presence of the virus. Laboratory ILTV detection was performed by virus isolation in embryonated eggs and cell cultures, PCR and sequencing of amplification products, histopathology, indirect immunofluorescence and electron microscopy. One ILTV turkey isolate was also experimentally inoculated into susceptible chickens and turkeys, reproducing a mild respiratory disease. This is the first description of natural infections with ILTV in turkeys. PMID:18436397

Portz, Cristiana; Beltrão, Nilzane; Furian, Thales Quedi; Júnior, Alfredo Bianco; Macagnan, Marisa; Griebeler, Josiane; Lima Rosa, Carlos André Veiga; Colodel, Edson Moleta; Driemeier, David; Back, Alberto; Barth Schatzmayr, Ortrud Monika; Canal, Cláudio Wageck

2008-09-18

129

Infrared and visible satellite rain estimation. I - A grid cell approach. II - A cloud definition approach  

NASA Technical Reports Server (NTRS)

This study explores the relationships between satellite-viewed cloudy grid cells and the variability of the precipitation contained therein, together with the relationships between the satellite-IR clouds and rainfall and the IR-thresholded visible clouds and rainfall. In the grid cell approach, IR, visible, and radar data for five days of the Florida Area Cumulus Experiment were examined using a 32-km grid and 30-min interval; the results of this experiment indicated that useful, accurate rainfall estimates beyond rain/no rain discrimination are unlikely. In the cloud definition approach, it was found that the cloud IR area was highly correlated with the rain area and with the volume rain rate across the entire spectrum of cloud sizes. It was poorly correlated with mean cloud rain rate.

Negri, Andrew J.; Adler, Robert F.

1987-01-01

130

A Role for Nitric Oxide in Muscle Repair: Nitric Oxide-mediated Activation of Muscle Satellite Cells  

PubMed Central

Muscle satellite cells are quiescent precursors interposed between myofibers and a sheath of external lamina. Although their activation and recruitment to cycle enable muscle repair and adaptation, the activation signal is not known. Evidence is presented that nitric oxide (NO) mediates satellite cell activation, including morphological hypertrophy and decreased adhesion in the fiber-lamina complex. Activation in vivo occurred within 1 min after injury. Cell isolation and histology showed that pharmacological inhibition of nitric oxide synthase (NOS) activity prevented the immediate injury-induced myogenic cell release and delayed the hypertrophy of satellite cells in that muscle. Transient activation of satellite cells in contralateral muscles 10 min later suggested that a circulating factor may interact with NO-mediated signaling. Interestingly, satellite cell activation in muscles of mdx dystrophic mice and NOS-I knockout mice quantitatively resembled NOS-inhibited release of normal cells, in agreement with reports of displaced and reduced NOS expression in dystrophin-deficient mdx muscle and the complete loss of NOS-I expression in knockout mice. Brief NOS inhibition in normal and mdx mice during injury produced subtle alterations in subsequent repair, including apoptosis in myotube nuclei and myotube formation inside laminar sheaths. Longer NOS inhibition delayed and restricted the extent of repair and resulted in fiber branching. A model proposes the hypothesis that NO release mediates satellite cell activation, possibly via shear-induced rapid increases in NOS activity that produce “NO transients.”

Anderson, Judy E.

2000-01-01

131

Spaceflight performance of several types of silicon solar cells on the LIPS 3 satellite  

NASA Technical Reports Server (NTRS)

Results from exposure of several types of Solarex silicon cells to a space environment for nearly two years on the LIPS 3 satellite are presented. Experiments include standard thickness (10 mil) cells with and without back surface fields, and ultrathin (2 mil) cells also with and without back surface fields. A comparison between a widely used coverslide adhesive, DC 93-500 and a potential alternate is also presented. The major findings from the data are that the 2 mil cells without a back surface field show the smallest normalized short circuit current degradation and that the 10 mil back surface field cells show the greatest absolute power output for the radiation exposures and temperatures encountered. The new encapsulant (McGhan Nusil CV-2500) exhibits a degradation comparable to DC 93-500. A comparison is made with each of the cell types in this experiment with expectations based on JPL Radiation Handbook data.

Silver, J.; Warfield, D.

1991-01-01

132

On spatial distribution of proton radiation belt from solar cell degradation of Akebono satellite  

NASA Astrophysics Data System (ADS)

Solar cells on any satellite degrade gradually due to severe space radiation environment. We found a fair correlation between the decrease rate of solar cell output current of Akebono satellite orbiting in the inner magnetosphere and trapped proton flux from AP8 model between 1989 and 1992. After 1993, presumably as a result of long-term degradation, variation of solar cell output seems more susceptible to other causes such as high temperature effect, and simple monthly averaged data show no significant relation between them. One of possible causes for the temperature variation of the solar cells is terrestrial heat radiation with changing orientation of solar cell panels towards the earth and another is solar radiation varied with eccentric earth's orbit around the sun. In order to remove the possible temperature effect, we sort the data expected to be least affected by the terrestrial heat radiation from the orbit conditions, and also analyze difference of the output current for a month from that for the same month in the previous year. The analysis method leads us to successfully track a continuous correlation between the decease rate of solar cell output and energetic trapped proton flux up to 1996. We also discuss the best-fitted spatial distribution of energetic protons from comparison with model calculations.

Miyake, W.; Miyoshi, Y.; Matsuoka, A.

2013-12-01

133

CD13 Regulates Anchorage and Differentiation of the Skeletal Muscle Satellite Stem Cell Population in Ischemic Injury.  

PubMed

CD13 is a multifunctional cell surface molecule that regulates inflammatory and angiogenic mechanisms in vitro, but its contribution to these processes in vivo or potential roles in stem cell biology remains unexplored. We investigated the impact of loss of CD13 on a model of ischemic skeletal muscle injury that involves angiogenesis, inflammation, and stem cell mobilization. Consistent with its role as an inflammatory adhesion molecule, lack of CD13 altered myeloid trafficking in the injured muscle, resulting in cytokine profiles skewed toward a prohealing environment. Despite this healing-favorable context, CD13(KO) animals showed significantly impaired limb perfusion with increased necrosis, fibrosis, and lipid accumulation. Capillary density was correspondingly decreased, implicating CD13 in skeletal muscle angiogenesis. The number of CD45-/Sca1-/?7-integrin+/?1-integrin+ satellite cells was markedly diminished in injured CD13(KO) muscles and adhesion of isolated CD13(KO) satellite cells was impaired while their differentiation was accelerated. Bone marrow transplantation studies showed contributions from both host and donor cells to wound healing. Importantly, CD13 was coexpressed with Pax7 on isolated muscle-resident satellite cells. Finally, phosphorylated-focal adhesion kinase and ERK levels were reduced in injured CD13(KO) muscles, consistent with CD13 regulating satellite cell adhesion, potentially contributing to the maintenance and renewal of the satellite stem cell pool and facilitating skeletal muscle regeneration. Stem Cells 2014;32:1564-1577. PMID:24307555

Rahman, M Mamunur; Ghosh, Mallika; Subramani, Jaganathan; Fong, Guo-Hua; Carlson, Morgan E; Shapiro, Linda H

2014-06-01

134

Contribution to the mechanisms of compressing Prandtl Cell Model: The Karliova Triple Junction as a case study from Eastern Turkey  

NASA Astrophysics Data System (ADS)

The Prandtl Cell (PC) model consists of an ideally plastic material, which is compressed between two parallel rigid plates (Prandtl, 1924). In the original PC model the material is allowed to flow only in one direction in response to compressive stresses. The original PC setting has been modified to accommodate different boundary conditions in later studies. For example, the plastic material is allowed to flow either towards or away from the apex of the wedge, where non-parallel plates move towards or away from each other. Cummings (1976) set up four different boundary conditions and classified four different PC models according to the geometry of the slip lines, the relative movement along the slip lines, and the movement of the plastic material. But none of the models explain the exact features of the slip lines and which factors controlled them. In this study, we consider one of the models of Cummings (1976) and we use field data, morphotectonic indices and analogue model results to interpret the fault pattern near the Karliova Triple Junction in Eastern Turkey, where the North Anatolian Fault Zone (NAFZ) and the East Anatolian Fault Zone EAFZ) meet. Quantified geomorphic features are used to understand local tectonic signals. We analyzed the drainage patterns, long profiles and hypsometric integral of bedrock rivers that drain across and around secondary faults between the NAFZ and the EAFZ. Morphotectonic analysis of different river system, which are bounded by strike-slip faults show that not only morphotectonic features but also deformation styles vary along the slip lines. Analyzing fourty branches of two main river systems between the NAFZ and EAFZ reveal that secondary faults can be classified into two fault sets. The first and most prominent fault,that formed close to NAFZ, consists of strike-slip faults that change along strike into oblique normal-slip faults when the strike of the fault changes from from NW to SE: The second fault set is less clearly recognizable and has a sinistral sense of slip. The constructed analogy of long profile and hypsometric integral demonstrates that those faults which formed near the EAFZ are tectonically quiescent whereas those that formed close to NAFZ are tectonically active. Our analysis shows that rivers controlled by these latter faults are undergoing permanent response to continuous tectonic uplift. Furthermore, the change of motion from dominant strike-slip to normal faulting creates the classic stratigraphic landform-cuesta-. Orientation of the NAFZ, the EAFZ and secondary faults between them are very similar to the PC model of Cummings (1976; Fig. 2B). Combining analogue models and morphotectonic analysis suggest that secondary faults propagated from west to east. The compressive stress distribution in analogue models varies along the boundary plates and the open ends of NAFZ and EAFZ triangle. From west to east formation of faults is both confirmed by morphotectonic analysis and analogue model experiment. In summary, for the region between the most eastern NAFZ, and the most northern EAFZ, we show that the compressive PC model slip lines start to develop from west to east. The sense of motion, the magnitude of displacement, and the evolving landcapes along these slip lines are fully controlled by the velocities of the boundary faults.

Sançar, Taylan; Schreurs, Guido; Zabc?, Cengiz; Akyüz, H. Serdar

2013-04-01

135

Fabrication of glass gas cells for the HALOE and MAPS satellite experiments  

NASA Technical Reports Server (NTRS)

The Halogen Occultation Experiment (HALOE) and the Measurement of Air Pollution from Satellites (MAPS) experiment are satellite-borne experiments which measure trace constituents in the Earth's atmosphere. The instruments which obtain the data for these experiments are based on the gas filter correlation radiometer measurement technique. In this technique, small samples of the gases of interest are encapsulated in glass cylinders, called gas cells, which act as very selective optical filters. This report describes the techniques employed in the fabrication of the gas cells for the HALOE and MAPS instruments. Details of the method used to fuse the sapphire windows (required for IR transmission) to the glass cell bodies are presented along with detailed descriptions of the jigs and fixtures used during the assembly process. The techniques and equipment used for window inspection and for pairing the HALOE windows are discussed. Cell body materials and the steps involved in preparing the cell bodies for the glass-to-sapphire fusion process are given.

Sullivan, E. M.; Walthall, H. G.

1984-01-01

136

[Instability of repetitive units of foreign centromeric satellite DNA in transgenic mice and transfected cells].  

PubMed

Cytologically detectable instability of centromeric satellite DNA may cause hereditary disorders in human. To study the mechanisms of such instability, two transgenic mouse lines and 11 clones of transfected F9 mouse embryonic teratocarcinoma cells were obtained with the 3.8-kb repetitive unit (Sat) of Bos taurus satellite DNA IV. Intergeneration and somatic instability of exogenous satellite DNA (satDNA) was observed in transgenic mice and transfected cells as a change in nucleotide sequence of an internal Sat region approximately 1000 bp in size. Since Sat was in the hemizygous state in both cases by the experimental protocol, the instability was attributed to intra-allelic processes. Intergeneration instability probably took place in the premeiotic period of gametogenesis or in early embryo development and led to prenatal death of transgenic embryos after at least one generation. No direct or inverse correlation was observed between methylation and instability of Sat. The results testify that submicroscopic changes in highly repetitive noncoding DNA sequences may already affect the genome function in higher eukaryotes. PMID:15523841

Suchkova, I O; Slominskaia, N A; Kustova, M E; Baranova, T V; Golubkov, V I; Sorokin, A V; Vasil'ev, V B; Patkin, E L

2004-08-01

137

Bovine satellite DNA induces heterochromatinization of host chromosomal DNA in cells of trassatellite mouse embryonal carcinoma.  

PubMed

Embryonal teratocarcinoma F9 cells were transfected with a fragment (3.8 kb) of bovine satellite DNA IV (Sat), which is not homologous to mouse satellite DNA. FISH analysis revealed various chromosomal integration sites of integrated Sat in different transsatellite clones. After several passages, transsatellite had a tendency to spread along chromosome bearing Sat in one of the studied lines. The integrated transsatellites were enriched with prolonged single-strand DNA regions (SSR) revealed by FISH without previous chromosomal denaturation, and were unmethylated. The observed SSR are presumably supposed to represent intermediates of transsatellite DNA instability via unequal sister chromatid exchanges. DAPI staining demonstrated that the integrated Sat induced the formation of prominent ectopic neoheterochromatin blocks in regions adjacent to integrated Sat. These blocks were located exclusively between integrated Sat and centromeric heterochromatin. Thus, mouse repetitive centromeric DNA (AT-rich, DAPI-positive) "spreads" along the chromosome in response to integration of the bovine satellite GC-rich DNA. The results obtained are discussed in the context of possible position effect variegation mechanisms operating in undifferentiated cells. PMID:15112432

Suchkova, I O; Baranova, T V; Kustova, M E; Kisljakova, T V; Vassiliev, V B; Slominskaja, N O; Alenina, N V; Patkin, E L

2004-01-01

138

Hydropower potential in Turkey  

Microsoft Academic Search

Turkey has a total hydropower potential of 433 GW that is equal to 1.2% of the total hydropower potential of the world and to 14% of European hydropower potential. Only 125 GW of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 34% of the economically usable potential

Kamil Kaygusuz

1999-01-01

139

Floating islands of Turkey  

Microsoft Academic Search

Turkey abounds in both natural as well as cultural richness. Especially the natural assets located in developing regions have an important role to play in the economic life of such areas. The floating islands are one of these assets and have become an important research subject lately. Turkey is considered as a heaven of floating islands. Almost all geographical regions

Ihsan Bulut

2011-01-01

140

Turkey: Turkish Naval Industry.  

National Technical Information Service (NTIS)

It is critically important for Turkey to maintain sea border security against various types of threats and it is the mission of the Turkish Navy to contribute to Turkish defense policy by developing and maintaining a modern naval force in Turkey and abroa...

O. Cirika

2008-01-01

141

Transforming growth factor beta-1 facilitates establishing clonal populations of ovine muscle satellite cells.  

PubMed

Myogenic cells isolated from lamb fetuses (approximately mid-gestation) exhibited a concentration-dependent decrease in myogenic cell proliferation in response to transforming growth factor (TGF) beta-1 (P < .001). Half-maximal inhibition of proliferation occurred at approximately .05 ng of TGF beta-1/mL and maximal inhibition of proliferation occurred at approximately .1 ng of TGF beta-1/mL. The specificity of this inhibition was confirmed by neutralization of the activity following exposure to a TGF beta antibody. The TGF beta-1 also suppressed proliferation of ovine satellite cells isolated from 5-d-old lambs (P < .0035), but to a lesser extent than observed for embryonic cells. In contrast, TGF beta-1 did not significantly suppress serum-stimulated proliferation of ovine satellite cells isolated from 30- or 150-d-old lambs. Similarly, TGF beta-1 did not suppress proliferation of skeletal muscle fibroblast-like cells isolated from either fetal lambs or 150-d-old lambs. In fact, proliferation of fibroblast-like cells derived from embryonic ovine muscle was enhanced by exposure to TGF beta-1 at all levels tested; however, a concentration-dependent response was not observed. Media transfer experiments showed that conditioning of culture media by postnatally derived cells did not render TGF beta-1 inactive. The studies described in this manuscript suggest that sensitivity of ovine myogenic cells to the antiproliferative effect of TGF-beta may vary with the stage of development.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7982828

Hathaway, M R; Pampusch, M S; Hembree, J R; Dayton, W R

1994-08-01

142

Satellite Glial Cell Proliferation in the Trigeminal Ganglia After Chronic Constriction Injury of the Infraorbital Nerve  

PubMed Central

We have examined satellite glial cell (SGC) proliferation in trigeminal ganglia following chronic constriction injury of the infraorbital nerve. Using BrdU labeling combined with immunohistochemistry for SGC specific proteins we positively confirmed proliferating cells to be SGCs. Proliferation peaks at approximately 4 days after injury and dividing SGCs are preferentially located around neurons that are immunopositive for ATF-3, a marker of nerve injury. After nerve injury there is an increase GFAP expression in SGCs associated with both ATF-3 immunopositive and immunonegative neurons throughout the ganglia. SGCs also express the non-glial proteins, CD45 and CD163, which label resident macrophages and circulating leukocytes, respectively. In addition to SGCs, we found some Schwann cells, endothelial cells, resident macrophages, and circulating leukocytes were BrdU immunopositive.

Donegan, Macayla; Kernisant, Melanie; Cua, Criselda; Jasmin, Luc; Ohara, Peter T.

2014-01-01

143

The role of radiation hard solar cells in minimizing the costs of global satellite communications systems  

NASA Technical Reports Server (NTRS)

An analysis embodied in a PC computer program is presented which quantitatively demonstrates how the availability of radiation hard solar cells can minimize the cost of a global satellite communication system. The chief distinction between the currently proposed systems, such as Iridium Odyssey and Ellipsat, is the number of satellites employed and their operating altitudes. Analysis of the major costs associated with implementing these systems shows that operation within the earth's radiation belts can reduce the total system cost by as much as a factor of two, so long as radiation hard components including solar cells, can be used. A detailed evaluation of several types of planar solar cells is given, including commercially available Si and GaAs/Ge cells, and InP/Si cells which are under development. The computer program calculates the end of life (EOL) power density of solar arrays taking into account the cell geometry, coverglass thickness, support frame, electrical interconnects, etc. The EOL power density can be determined for any altitude from low earth orbit (LEO) to geosynchronous (GEO) and for equatorial to polar planes of inclination. The mission duration can be varied over the entire range planned for the proposed satellite systems. An algorithm is included in the program for determining the degradation of cell efficiency for different cell technologies due to proton and electron irradiation. The program can be used to determine the optimum configuration for any cell technology for a particular orbit and for a specified mission life. Several examples of applying the program are presented, in which it is shown that the EOL power density of different technologies can vary by an order of magnitude for certain missions. Therefore, although a relatively radiation soft technology can be made to provide the required EOL power by simply increasing the size of the array, the impact on the total system budget could be unacceptable, due to increased launch and hardware costs. In aggregate these factors can account for more than a 10% increase in the total system cost. Since the estimated total costs of proposed global coverage systems range from $1 Billion to $9 Billion, the availability of radiation hard solar cells could make a decisive difference in the selection of a particular constellation architecture.

Summers, Geoffrey P.; Walters, Robert J.; Messenger, Scott R.; Burke, Edward A.

1995-01-01

144

The Long, the Short and the Micro: A PolyA Tale of Pax3 in Satellite Cells  

PubMed Central

The use of alternative polyadenylation sites is emerging as an important regulator of gene expression. In this issue of Cell Stem Cell, Boutet and coworkers report that alternative 3'UTRs of the Pax3 transcript restrict its expression to axial satellite cells through miR-mediated targeting of one of the isoforms.

Pasut, Alessandra; Rudnicki, Michael A.

2012-01-01

145

The long, the short, and the micro: a polyA tale of Pax3 in satellite cells.  

PubMed

The use of alternative polyadenylation sites is emerging as an important regulator of gene expression. In this issue of Cell Stem Cell, Boutet et al. (2012) report that alternative 3'UTRs of the Pax3 transcript restrict its expression to axial satellite cells through miR-mediated targeting of one of the isoforms. PMID:22385651

Pasut, Alessandra; Rudnicki, Michael A

2012-03-01

146

Absence of a differentiation defect in muscle satellite cells from DM2 patients.  

PubMed

Myotonic dystrophy type 1 (DM1) and type II (DM2) are dominantly inherited multisystemic disorders. DM1 is triggered by the pathological expansion of a (CTG)(n) triplet repeat in the DMPK gene, whereas a (CCTG)(n) tetranucleotide repeat expansion in the ZNF9 gene causes DM2. Both forms of the disease share several features, even though the causative mutations and the loci involved differ. Important distinctions exist, such as the lack of a congenital form of DM2. The reason for these disparities is unknown. In this study, we characterized skeletal muscle satellite cells from adult DM2 patients to provide an in vitro model for the disease. We used muscle cells from DM1 biopsies as a comparison tool. Our main finding is that DM2 satellite cells differentiate normally in vitro. Myotube formation was similar to unaffected controls. In contrast, fetal DM1 cells were deficient in that ability. Consistent with this observation, the myogenic program in DM2 was intact but is compromised in fetal DM1 cells. Although expression of the ZNF9 gene was enhanced in DM2 during differentiation, the levels of the ZNF9 protein were substantially reduced. This suggests that the presence of a large CCTG tract impairs the translation of the ZNF9 mRNA. Additionally, DM2 muscle biopsies displayed the altered splicing of the insulin receptor mRNA, correlating with insulin resistance in the patients. Finally, CUGBP1 steady-state protein levels were unchanged in DM2 cultured muscle cells and in DM2 muscle biopsies relative to controls, whereas they are increased in DM1 muscle cells. Our findings suggest that the myogenic program throughout muscle development and tissue regeneration is intact in DM2. PMID:19632331

Pelletier, Richard; Hamel, Frederic; Beaulieu, Daniel; Patry, Lysanne; Haineault, Caroline; Tarnopolsky, Mark; Schoser, Benedikt; Puymirat, Jack

2009-10-01

147

Identification of self-renewing myoblasts in the progeny of single human muscle satellite cells.  

PubMed

We demonstrate that self-renewing myoblasts can be identified in the progeny of single human muscle satellite cells (HMSC) in culture. We show, using cytoskeletal proteins and cell size as markers, that self-renewing myoblasts are phenotypically different from other myoblasts, but similar to native HMSC. Native desmin-positive HMSC, cultured as single cells, yielded two major populations of myoblasts, alpha-sarcomeric (alpha-SR)-actin-positive myoblasts and desmin-positive myoblasts. In appropriate culture conditions, alpha-SR-actin-positive myoblasts fused into myotubes, whereas a population of desmin-positive non-fusing myoblasts (NFMB) persisted for weeks among the myotubes. Upon isolation from myotubes, some of the NFMB resumed proliferation and their progeny included fusing and non-fusing myoblasts, with the same cytoskeletal phenotypes as the progeny of native HMSC. This self-renewal cycle could be repeated, yielding four cohorts of myoblasts. The yield of self-renewing cells appeared to decrease with the number of cycles. These results suggest that stem cells are present among NFMB. Moreover, we find that these presumptive stem cells are already segregated during myoblast proliferation. They are small, phenotypically similar to native HMSC, and do not divide unless they are isolated from their sister progeny and cultured alone. Enriched preparations of cells with stem cell-like properties can be obtained from proliferating myoblasts by flow cytometry on the basis of size and nucleocytoplasmic ratio. PMID:8935928

Baroffio, A; Hamann, M; Bernheim, L; Bochaton-Piallat, M L; Gabbiani, G; Bader, C R

1996-03-01

148

MMP-14 is necessary but not sufficient for invasion of three-dimensional collagen by human muscle satellite cells.  

PubMed

The twenty-five known matrix metalloproteases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteases (TIMPs), mediate cell invasion through the extracellular matrix (ECM). In a comparative three-dimensional assay, we analyzed human and mouse satellite cells' competence to invade an artificial ECM (collagen I). We identified a single MMP that 1) is expressed by human muscle satellite cells; 2) is induced at the mRNA/protein level by adhesion to collagen I; and 3) is necessary for invasion into a collagen I matrix. Interestingly, murine satellite cells neither express this MMP, nor invade the collagen matrix. However, exogenous human MMP-14 is not sufficient to induce invasion of a collagen matrix by murine cells, emphasizing species differences. PMID:24898588

Lund, Dane K; Mouly, Vincent; Cornelison, Ddw

2014-07-15

149

Higher-order unfolding of satellite heterochromatin is a consistent and early event in cell senescence.  

PubMed

Epigenetic changes to chromatin are thought to be essential to cell senescence, which is key to tumorigenesis and aging. Although many studies focus on heterochromatin gain, this work demonstrates large-scale unraveling of peri/centromeric satellites, which occurs in all models of human and mouse senescence examined. This was not seen in cancer cells, except in a benign senescent tumor in vivo. Senescence-associated distension of satellites (SADS) occurs earlier and more consistently than heterochromatin foci formation, and SADS is not exclusive to either the p16 or p21 pathways. Because Hutchinson Guilford progeria syndrome patient cells do not form excess heterochromatin, the question remained whether or not proliferative arrest in this aging syndrome involved distinct epigenetic mechanisms. Here, we show that SADS provides a unifying event in both progeria and normal senescence. Additionally, SADS represents a novel, cytological-scale unfolding of chromatin, which is not concomitant with change to several canonical histone marks nor a result of DNA hypomethylation. Rather, SADS is likely mediated by changes to higher-order nuclear structural proteins, such as LaminB1. PMID:24344186

Swanson, Eric C; Manning, Benjamin; Zhang, Hong; Lawrence, Jeanne B

2013-12-23

150

Higher-order unfolding of satellite heterochromatin is a consistent and early event in cell senescence  

PubMed Central

Epigenetic changes to chromatin are thought to be essential to cell senescence, which is key to tumorigenesis and aging. Although many studies focus on heterochromatin gain, this work demonstrates large-scale unraveling of peri/centromeric satellites, which occurs in all models of human and mouse senescence examined. This was not seen in cancer cells, except in a benign senescent tumor in vivo. Senescence-associated distension of satellites (SADS) occurs earlier and more consistently than heterochromatin foci formation, and SADS is not exclusive to either the p16 or p21 pathways. Because Hutchinson Guilford progeria syndrome patient cells do not form excess heterochromatin, the question remained whether or not proliferative arrest in this aging syndrome involved distinct epigenetic mechanisms. Here, we show that SADS provides a unifying event in both progeria and normal senescence. Additionally, SADS represents a novel, cytological-scale unfolding of chromatin, which is not concomitant with change to several canonical histone marks nor a result of DNA hypomethylation. Rather, SADS is likely mediated by changes to higher-order nuclear structural proteins, such as LaminB1.

Swanson, Eric C.; Manning, Benjamin; Zhang, Hong

2013-01-01

151

Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/  

NASA Technical Reports Server (NTRS)

In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

Glaser, P. E.; Almgren, D. W.

1978-01-01

152

Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays  

NASA Technical Reports Server (NTRS)

The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

Glaser, P. E.

1974-01-01

153

Izmit, Turkey 1999 Earthquake Interferogram  

NASA Technical Reports Server (NTRS)

This image is an interferogram that was created using pairs of images taken by Synthetic Aperture Radar (SAR). The images, acquired at two different times, have been combined to measure surface deformation or changes that may have occurred during the time between data acquisition. The images were collected by the European Space Agency's Remote Sensing satellite (ERS-2) on 13 August 1999 and 17 September 1999 and were combined to produce these image maps of the apparent surface deformation, or changes, during and after the 17 August 1999 Izmit, Turkey earthquake. This magnitude 7.6 earthquake was the largest in 60 years in Turkey and caused extensive damage and loss of life. Each of the color contours of the interferogram represents 28 mm (1.1 inches) of motion towards the satellite, or about 70 mm (2.8 inches) of horizontal motion. White areas are outside the SAR image or water of seas and lakes. The North Anatolian Fault that broke during the Izmit earthquake moved more than 2.5 meters (8.1 feet) to produce the pattern measured by the interferogram. Thin red lines show the locations of fault breaks mapped on the surface. The SAR interferogram shows that the deformation and fault slip extended west of the surface faults, underneath the Gulf of Izmit. Thick black lines mark the fault rupture inferred from the SAR data. Scientists are using the SAR interferometry along with other data collected on the ground to estimate the pattern of slip that occurred during the Izmit earthquake. This then used to improve computer models that predict how this deformation transferred stress to other faults and to the continuation of the North Anatolian Fault, which extends to the west past the large city of Istanbul. These models show that the Izmit earthquake further increased the already high probability of a major earthquake near Istanbul.

2001-01-01

154

Presenilin-1 acts via Id1 to regulate the function of muscle satellite cells in a ?-secretase-independent manner  

PubMed Central

Summary Muscle satellite cells are the resident stem cells of adult skeletal muscle. Here, we have examined the role of the multifunctional protein presenilin-1 (PS1) in satellite cell function. PS1 acts as a crucial component of the ?-secretase complex, which is required to cleave single-pass transmembrane proteins such as Notch and amyloid-? precursor protein. PS1, however, also functions through ?-secretase-independent pathways. Activation of satellite cells was accompanied by induction of PS1, with PS1 knockdown enhancing their myogenic differentiation, but reducing their self-renewal. Transfection with siRNA against PS1 led to accelerated myogenic differentiation during muscle regeneration in vivo. Conversely, constitutive expression of PS1 resulted in the suppression of myogenic differentiation and promotion of the self-renewal phenotype. Importantly, we found that PS1 also acts independently of its role in ?-secretase activity in controlling myogenesis, which is mediated in part by Id1 (inhibitor of DNA binding 1), a negative regulator of the myogenic regulatory factor MyoD. PS1 can control Id1, which affects satellite cell fate by regulating the transcriptional activity of MyoD. Taken together, our observations show that PS1 is a key player in the choice of satellite cell fate, acting through both ?-secretase-dependent and ?-secretase-independent mechanisms.

Ono, Yusuke; Gnocchi, Viola F.; Zammit, Peter S.; Nagatomi, Ryoichi

2009-01-01

155

The depletion of skeletal muscle satellite cells with age is concomitant with reduced capacity of single progenitors to produce reserve progeny  

PubMed Central

Satellite cells are myogenic progenitors residing on the myofiber surface that support skeletal muscle repair. We used mice in which satellite cells were detected by GFP expression driven by nestin gene regulatory elements to define age-related changes in both numbers of satellite cells that occupy hindlimb myofibers and their individual performance. We demonstrate a reduction in satellite cells per myofiber with age that is more prominent in females compared to males. Satellite cell loss also persists with age in myostatin-null mice regardless of increased muscle mass. Immunofluorescent analysis of isolated myofibers from nestin-GFP/Myf5nLacZ/+ mice reveals a decline with age in the number of satellite cells that express detectable levels of ?gal. Nestin-GFP expression typically diminishes in primary cultures of satellite cells as myogenic progeny proliferate and differentiate, but GFP subsequently reappears in the Pax7+ reserve population. Clonal analysis of sorted GFP+ satellite cells from hindlimb muscles shows heterogeneity in the extent of cell density and myotube formation among colonies. Reserve cells emerge primarily within high-density colonies, and the number of clones that produce reserve cells is reduced with age. Thus, satellite cell depletion with age could be attributed to a reduced capacity to generate a reserve population.

Day, Kenneth; Shefer, Gabi; Shearer, Andrew; Yablonka-Reuveni, Zipora

2010-01-01

156

Characterization of myosin isoforms in satellite cell cultures from adult rat diaphragm, soleus and tibialis anterior muscles  

PubMed Central

Satellite cells were isolated by enzymatic dissociation and Percoll gradient centrifugation from adult rat diaphragm, soleus, and tibialis anterior muscles with fairly reproducible yields. Diaphragm and soleus muscle yielded approximately five times more satellite cells than tibialis anterior muscle. According to light microscopic criteria, no morphological differences existed between the satellite cell cultures of different origin. Contrary to the donor muscles, myotubes from the 10-day-cultured satellite cells contained a uniform myosin heavy chain (MHC) pattern with predominance of an immunochemically identified embryonic heavy chain. The three types of cultures displayed a typical embryonic light chain (LC) pattern with LC1emb, LC1f, LC2f, and traces of LC3f. The isomyosin pattern was characterized by four embryonic isomyosins, eMl–eM4, with similar distributions in the three cultures. In summary, these myosin analyses provide no evidence for the existence of satellite cell diversity among three rat muscles of different fiber-type composition, at least not under the applied in vitro conditions.

Dusterhoft, Sabine; Yablonka-Reuveni, Zipora; Pette, Dirk

2014-01-01

157

Earth-satellite path attenuation statistics influenced by orientation of rain cells  

NASA Technical Reports Server (NTRS)

It is examined whether there may be preferred azimuths for earth-satellite paths along which fading and space diversity statistics are influenced differently than along other azimuths. Such preferred directions may exist if individual rain cells are statistically elongated along them for the given climatological region. The analysis is performed using the rain reflectivity data base obtained at Wallops Island during June, July and August 1973 using a high resolution radar. It is found that in the vicinity of Wallops Island increased attenuation and poorer diversity gains exist along paths whose azimuths and base lines lie in the NE-SW quadrants as compared to the NW-SE sectors. This result suggests the dominance of the major axis of rain cells in these quadrants.

Goldhirsh, J.

1977-01-01

158

Label-free screening of niche-to-niche variation in satellite stem cells using functionalized pores  

NASA Astrophysics Data System (ADS)

Combinations of surface markers are currently used to identify muscle satellite cells. Using pores functionalized with specific antibodies and measuring the transit time of cells passing through these pores, we discovered remarkable heterogeneity in the expression of these markers in muscle (satellite) stem cells that reside in different single myofibers. Microniche-specific variation in stem cells of the same organ has not been previously described, as bulk analysis does not discriminate between separate myofibers or even separate hind-leg muscle groups. We found a significant population of Sca-1+ satellite cells that form myotubes, thereby demonstrating the myogenic potential of Sca-1+ cells, which are currently excluded in bulk sorting. Finally, using our label-free pore screening technique, we have been able to quantify directly surface expression of Notch1 without activation of the Notch pathway. We show for the first time Notch1-expression heterogeneity in unactivated satellite cells. The discovery of fiber-to-fiber variations prompts new research into the reasons for such diversity in muscle stem cells.

Chapman, Matthew R.; Balakrishnan, Karthik; Conboy, Michael J.; Mohanty, Swomitra; Jabart, Eric; Huang, Haiyan; Hack, James; Conboy, Irina M.; Sohn, Lydia L.

2012-02-01

159

Informatics in Turkey  

NASA Technical Reports Server (NTRS)

In the last twenty years the rapid change in the informatics sector has had economic and social impact on private and government activities. The Supreme Council for Science and Technology of Turkey assigned highest priority to the informatics in its meeting in February 1993. With this advice TUBITAK (The Scientific and Technical Research Council of Turkey) intends to give a strong impulse to development of a research policy in this field.

Cakir, Serhat

1994-01-01

160

Decreasing trend of groundwater in Turkey  

NASA Astrophysics Data System (ADS)

In these days the increasing demand for water has created problems for availability of its resources. Some recent issues like population growth, global warming and inefficient methods of water consumption, generated the need to find sources of water other than surface water such as ground water. Excess using of groundwater in most parts of the world causes depletion of ground water in those areas. Scientists are trying to find efficient means to quantify these trends. GRACE (Gravity Recovery and Climate Experiment) including two satellites launched in March 2002, is making measurements of the Earth's gravity field which is used to display the change of storage of the water on the Earth. GRACE makes it possible to find the trend of the change of storage all over the world.It can show specific areas in the world that have dramatic decreasing trend of water storage. One of these regions that have been considered in this study is Turkey in western Asia, as one of the countries deeply affected by global warming. Turkey is identified as one of the first places where desertification will start in Europe, according to estimates by the UN Environment Program (UNEP). Turkey has 25 underground water tables and they had a decrease in level of 27 meters in the past 25 years (Turkey water report 2009). In this paper the change of the ground water is evaluated by applying the GRACE storage anomalies and the mass conservation equation that concludes the reduction trend in groundwater. The results clarify that decreasing trend of groundwater is more noticeable during recent years, particularly since 2006. Our results show that in recent years the average decrease in ground water level is 2.5 cm per year and the maximum decrease occurred in May 2007 with the value of about 7.9 cm. KEY WORDS: water resources; Ground water; Turkey; GRACE

Sarachi, S.; Moghim, S.; Famiglietti, J. S.

2010-12-01

161

The role of radiation hard solar cells in minimizing the costs of global satellite communication systems  

NASA Technical Reports Server (NTRS)

An analysis embodied in a PC computer program is presented, which quantitatively demonstrates how the availability of radiation hard solar cells can help minimize the cost of a global satellite communications system. An important distinction between the currently proposed systems, such as Iridium, Odyssey and Ellipsat, is the number of satellites employed and their operating altitudes. Analysis of the major costs associated with implementing these systems shows that operation at orbital altitudes within the earth's radiation belts (10(exp 3) to 10(exp 4)km) can reduce the total cost of a system by several hundred percent, so long as radiation hard components including solar cells can be used. A detailed evaluation of the predicted performance of photovoltaic arrays using several different planar solar cell technologies is given, including commercially available Si and GaAs/Ge, and InP/Si which is currently under development. Several examples of applying the program are given, which show that the end of life (EOL) power density of different technologies can vary by a factor of ten for certain missions. Therefore, although a relatively radiation-soft technology can usually provide the required EOL power by simply increasing the size of the array, the impact upon the total system budget could be unacceptable, due to increased launch and hardware costs. In aggregate, these factors can account for more than a 10% increase in the total system cost. Since the estimated total costs of proposed global-coverage systems range from $1B to $9B, the availability of radiation-hard solar cells could make a decisive difference in the selection of a particular constellation architecture.

Summers, Geoffrey P.; Walters, Robert J.; Messenger, Scott R.; Burke, Edward A.

1996-01-01

162

Satellite cell heterogeneity revealed by G-Tool, an open algorithm to quantify myogenesis through colony-forming assays  

PubMed Central

Background Muscle growth and repair is accomplished by the satellite cell pool, a self-renewing population of myogenic progenitors. Functional heterogeneity within the satellite cell compartment and changes in potential with experimental intervention can be revealed by in vitro colony-forming cell (CFC) assays, however large numbers of colonies need to be assayed to give meaningful data, and manually quantifying nuclei and scoring markers of differentiation is experimentally limiting. Methods We present G-Tool, a multiplatform (Java) open-source algorithm that analyzes an ensemble of fluorescent micrographs of satellite cell-derived colonies to provide quantitative and statistically meaningful metrics of myogenic potential, including proliferation capacity and propensity to differentiate. Results We demonstrate the utility of G-Tool in two applications: first, we quantify the response of satellite cells to oxygen concentration. Compared to 3% oxygen which approximates tissue levels, we find that 21% oxygen, the ambient level, markedly limits the proliferative potential of transit amplifying progeny but at the same time inhibits the rate of terminal myogenic differentiation. We also test whether satellite cells from different muscles have intrinsic differences that can be read out in vitro. Compared to masseter, dorsi, forelimb and hindlimb muscles, we find that the diaphragm satellite cells have significantly increased proliferative potential and a reduced propensity to spontaneously differentiate. These features may be related to the unique always-active status of the diaphragm. Conclusions G-Tool facilitates consistent and reproducible CFC analysis between experiments and individuals. It is released under an open-source license that enables further development by interested members of the community.

2012-01-01

163

Wild Turkey Populations and Management.  

National Technical Information Service (NTIS)

Study Objective: Determine the perceived and actual magnitude of crop damage by wild turkeys and the consequences of expanded hunting opportunity for turkeys in the primary range. Performance: Technology Transfer and Reports. Conduct technology transfer, ...

J. F. Kubisiak

1996-01-01

164

Sodium and potassium currents in freshly isolated and in proliferating human muscle satellite cells.  

PubMed

1. Human muscle satellite cells (SC) were studied either immediately after dissociation of muscle biopsies or later, as they proliferated in culture. A purification procedure combined with clonal cultures ensured that electrophysiological recordings were done in myogenic cells. Hoechst staining for the DNA attested that cells were mononucleated. 2. The goals of this study were to examine (i) whether the electrophysiological properties of freshly isolated SC resembled those of SC that proliferated in culture for several weeks, (ii) whether freezing and thawing affected these properties, and (iii) whether SC constituted a homogeneous population. 3. We found that there were only subtle differences between the electrophysiological results obtained in freshly isolated SC and in proliferating SC with or without previous freezing and thawing. Most SC expressed two voltage-gated currents, a TTX-resistant Na+ current and a calcium-activated potassium current (IK, Ca). 4. The level of expression of the Na+ current and of IK, Ca was affected in a different way by cellular proliferation; the normalized Na+ conductance (pS pF-1) of proliferating cells resembled that of freshly isolated SC, whereas the IK, Ca conductance increased 10 times. The analysis of the amplitude distributions of the Na+ current and of IK, Ca in the various SC preparations suggested that there was only one class of SC. PMID:8021836

Hamann, M; Widmer, H; Baroffio, A; Aubry, J P; Krause, R M; Kaelin, A; Bader, C R

1994-03-01

165

Sodium and potassium currents in freshly isolated and in proliferating human muscle satellite cells.  

PubMed Central

1. Human muscle satellite cells (SC) were studied either immediately after dissociation of muscle biopsies or later, as they proliferated in culture. A purification procedure combined with clonal cultures ensured that electrophysiological recordings were done in myogenic cells. Hoechst staining for the DNA attested that cells were mononucleated. 2. The goals of this study were to examine (i) whether the electrophysiological properties of freshly isolated SC resembled those of SC that proliferated in culture for several weeks, (ii) whether freezing and thawing affected these properties, and (iii) whether SC constituted a homogeneous population. 3. We found that there were only subtle differences between the electrophysiological results obtained in freshly isolated SC and in proliferating SC with or without previous freezing and thawing. Most SC expressed two voltage-gated currents, a TTX-resistant Na+ current and a calcium-activated potassium current (IK, Ca). 4. The level of expression of the Na+ current and of IK, Ca was affected in a different way by cellular proliferation; the normalized Na+ conductance (pS pF-1) of proliferating cells resembled that of freshly isolated SC, whereas the IK, Ca conductance increased 10 times. The analysis of the amplitude distributions of the Na+ current and of IK, Ca in the various SC preparations suggested that there was only one class of SC.

Hamann, M; Widmer, H; Baroffio, A; Aubry, J P; Krause, R M; Kaelin, A; Bader, C R

1994-01-01

166

Micro space power system using MEMS fuel cell for nano-satellites  

NASA Astrophysics Data System (ADS)

A micro space power system using micro fuel cell was developed for nano-satellites. The power system was fabricated using microelectromechanical system (MEMS) fabrication technologies. Polymer electrolyte membrane (PEM) fuel cell was selected in consideration of space environment. Sodium borohydride (NaBH4) was selected as a hydrogen source while hydrogen peroxide (H2O2) was selected as an oxygen source. The power system consists of a micro fuel cell, micro-reactor, micro-pump, and fuel cartridges. The micro fuel cell was fabricated on a light-weight and corrosion-resistant glass plates. The micro-reactor was used to generate hydrogen from NaBH4 alkaline solution via a catalytic hydrolysis reaction. All components such as micro-pump, fuel cartridges, and auxiliary battery were integrated for a complete power system. The storability of NaBH4 solution was evaluated at -25 °C and the performance of the micro power system was measured at various operating conditions. The power output of micro power system reasonably followed up the given electric load conditions.

Lee, Jongkwang; Kim, Taegyu

2014-08-01

167

Satellite glial cells in dorsal root ganglia are activated in experimental autoimmune encephalomyelitis.  

PubMed

Pain is a serious and common problem with patients suffering from multiple sclerosis (MS). Very little has been done to investigate the peripheral mechanisms of pain in MS. Here we used a mouse model of experimental autoimmune encephalomyelitis (EAE) to investigate the possible contribution of satellite glial cells (SGCs) to pain in MS. EAE mice had reduced pain thresholds 10 days after disease induction. We examined dorsal root ganglia and found increased expression of glial fibrillary acidic protein in SGCs, a marker of SGC activation, and increased coupling among SGCs, a known component of activated SGCs. Activated SGCs have previously been shown to contribute to pain in other classical neuropathic pain models, suggesting that pain in multiple sclerosis has a peripheral component. PMID:24686185

Warwick, Rebekah A; Ledgerwood, Craig J; Brenner, Talma; Hanani, Menachem

2014-05-21

168

Analytic studies on satellite detection of severe, two-cell tornadoes  

NASA Technical Reports Server (NTRS)

From funnel-cloud-length interpretation, the severe tornado is characterized by peak swirl speed relative to the axis of rotation of about 90 m/s. Thermohydrodynamic achievement of the pressure deficit from ambient necessary to sustain such swirls requires that a dry, compressionally heated, non-rotating downdraft of initially tropopause-level air lie within an annulus of rapidly swirling, originally low-level air ascending on a near-moist-adiabatic locus of thermodynamic states. The two-cell structure furnishes an observable parameter possibly accessible to a passively instrumented, geosynchronous meteorological satellite with mesoscale resolution, for early detection of a severe tornado. Accordingly, the low-level turnaround region, in which the surface inflow layer separates to become a free ascending layer and for which inviscid modeling suffices, is examined quantitatively. Preliminary results indicate that swirl overshoot, i.e., swirl speeds in the turnaround region in excess of the maximum achieved in the potential vortex, is modest.

Carrier, G. F.; Dergarabedian, P.; Fendell, F. E.

1979-01-01

169

Systemic inflammation alters satellite glial cell function and structure. A possible contribution to pain.  

PubMed

Local peripheral injury activates satellite glial cells (SGCs) in sensory ganglia, which may contribute to chronic pain. We hypothesized that systemic inflammation affects sensory ganglia like local injury. We induced systemic inflammation in mice by injecting lipopolysaccharide (LPS) intraperitoneally, and characterized SGCs and neurons in dorsal root ganglia (DRG), using dye injection, calcium imaging, electron microscopy (EM), immunohistochemistry, and electrical recordings. Several days post-LPS, SGCs were activated, and dye coupling among SGCs increased 3-4.5-fold. EM showed abnormal growth of SGC processes and the formation of new gap junctions. Sensitivity of SGCs to ATP increased twofold, and neuronal excitability was augmented. Blocking gap junctions reduced pain behavior in LPS-treated mice. Thus, changes in DRG due to systemic inflammation are similar to those due to local injury, which may explain the pain in sickness behavior and in other systemic diseases. PMID:24875177

Blum, E; Procacci, P; Conte, V; Hanani, M

2014-08-22

170

Primary culture of trigeminal satellite glial cells: a cell-based platform to study morphology and function of peripheral glia  

PubMed Central

Primary cell culture provides an experimental platform in which morphology, physiology, and cell-cell communication pathways can be studied under a well-controlled environment. Primary cell cultures of peripheral and central glia offer unique possibilities to clarify responses and pathways to different stimuli. Peripheral glia, satellite glial cells (SGCs), which surround neuronal cell bodies within sensory ganglia, have recently been known as key players in inflammation and neuronal sensitization. The objectives of this study were 1) to establish a cell-based platform of cultured trigeminal SGCs to study glial marker expression and functions under control conditions; 2) to validate the cell-based platform by prostaglandin E2 (PGE2) release response following administration of Cisplatin; and 3) to investigate inhibition of PGE2 release by glial modulators, Ibudilast and SKF86002. Primary cell cultures of SGCs from rat trigeminal ganglia were established following enzymatically and mechanically dissociation of the ganglia. Cultures were characterized in vitro for up to 21 days post isolation for morphological and immunocytochemical characteristics. PGE2 release, determined by ELISA, was used as a pro-inflammatory marker to characterize SGCs response to chemotherapeutic agent, Cisplatin, known to contribute in chemotherapy-induced peripheral neuropathy. Our results indicate that 1) isolated SGCs maintained their characteristics in vitro for up to 21 days; 2) Cisplatin enhanced PGE2 release from the SGCs, which was attenuated by Ibudilast and SKF86002. These findings confirm the utility and validity of the cultured trigeminal SGCs platform for glial activation and modulation; and suggest further investigation on Ibudilast and SKF86002 in prevention of chemotherapy-induced pain.

Poulsen, Jeppe N; Larsen, Frederik; Duroux, Meg; Gazerani, Parisa

2014-01-01

171

Sequence-specific microscopic visualization of DNA methylation status at satellite repeats in individual cell nuclei and chromosomes  

PubMed Central

Methylation-specific fluorescence in situ hybridization (MeFISH) was developed for microscopic visualization of DNA methylation status at specific repeat sequences in individual cells. MeFISH is based on the differential reactivity of 5-methylcytosine and cytosine in target DNA for interstrand complex formation with osmium and bipyridine-containing nucleic acids (ICON). Cell nuclei and chromosomes hybridized with fluorescence-labeled ICON probes for mouse major and minor satellite repeats were treated with osmium for crosslinking. After denaturation, fluorescent signals were retained specifically at satellite repeats in wild-type, but not in DNA methyltransferase triple-knockout (negative control) mouse embryonic stem cells. Moreover, using MeFISH, we successfully detected hypomethylated satellite repeats in cells from patients with immunodeficiency, centromeric instability and facial anomalies syndrome and 5-hydroxymethylated satellite repeats in male germ cells, the latter of which had been considered to be unmethylated based on anti-5-methylcytosine antibody staining. MeFISH will be suitable for a wide range of applications in epigenetics research and medical diagnosis.

Li, Yufeng; Miyanari, Yusuke; Shirane, Kenjiro; Nitta, Hirohisa; Kubota, Takeo; Ohashi, Hirofumi; Okamoto, Akimitsu; Sasaki, Hiroyuki

2013-01-01

172

High Energy Instrumentation Efforts in Turkey  

SciTech Connect

This work summarizes the efforts in Turkey to build a laboratory capable of building and testing high energy astrophysics detectors that work in space. The EC FP6 ASTRONS project contributed strongly to these efforts, and as a result a fully operational laboratory at Sabanci University have been developed. In this laboratory we test and develop Si and CdZnTe based room temperature semiconductor strip detectors and develop detector and electronics system to be used as a payload on potential small Turkish satellites.

Kalemci, Emrah [Sabanci University, Tuzla, Istanbul (Turkey)

2011-09-21

173

Molecular basis of the myogenic profile of aged human skeletal muscle satellite cells during differentiation.  

PubMed

Sarcopenia is the age-related loss of muscle mass, strength and function. Human muscle proteins are synthesized at a slower rate in the elderly than in young adults, leading to atrophy and muscle mass loss with a decline in the functional capability. Additionally, aging is accompanied by a decrease in the ability of muscle tissue to regenerate following injury or overuse due to the impairment of intervening satellite cells, in which we previously reported oxidative damage evidences. The aim of the present study was to determine the effects of aging on myoblasts and myotubes obtained from human skeletal muscle, and characterize the transcriptional profile as molecular expression patterns in relation to age-dependent modifications in their regenerative capacity. Our data show that the failure to differentiate does not depend on reduced myogenic cell number, but difficulty to complete the differentiation program. Data reported here suggested the following findings: (i) oxidative damage accumulation in molecular substrates, probably due to impaired antioxidant activity and insufficient repair capability, (ii) limited capability of elderly myoblasts to execute a complete differentiation program; restricted fusion, possibly due to altered cytoskeleton turnover and extracellular matrix degradation and (iii) activation of atrophy mechanism by activation of a specific FOXO-dependent program. PMID:19457451

Pietrangelo, Tiziana; Puglielli, Cristina; Mancinelli, Rosa; Beccafico, Sara; Fanò, Giorgio; Fulle, Stefania

2009-08-01

174

Expression of a voltage-dependent potassium current precedes fusion of human muscle satellite cells (myoblasts).  

PubMed

Using the whole-cell recording patch clamp technique in clonal cultures of human muscle satellite cells (SC), we studied a voltage-gated potassium current analogous to the delayed rectifier current (IKdr) described in adult human skeletal muscle. This current was absent in proliferating SC cultured in a growth medium containing 15% serum, except when the SC approached the end of their replicative life (between 77 and 124 days in culture); at that time, approximately 50% of the SC possessed IKdr. In contrast, IKdr was expressed within less than 4 days in approximately 70% of the SC cultured in a serum-free medium (SFM) and within 24 h in differentiating medium. We believe that IKdr may be a characteristic feature of fusion-component SC and that it may be involved in the fusion process for the following reasons: 1) after the transfer in differentiating medium, cultures of SC in which the expression of IKdr was previously promoted by exposure to SFM were found to fuse immediately, without the initial 24 h lag time observed in control sister cultures; 2) in the latter "naive" SC, IKdr was expressed during the first day in differentiating medium, before SC began to fuse; 3) most of the SC that did not fuse even after weeks of exposure to differentiating medium did not express IKdr; 4) TEA, at a concentration of 3 mM, reduces the amplitude of IKdr by 55% and the fusion index by 55-67%. PMID:7814451

Widmer, H; Hamann, M; Baroffio, A; Bijlenga, P; Bader, C R

1995-01-01

175

Nitric Oxide Sustains Long-Term Skeletal Muscle Regeneration by Regulating Fate of Satellite Cells Via Signaling Pathways Requiring Vangl2 and Cyclic GMP  

PubMed Central

Satellite cells are myogenic precursors that proliferate, activate, and differentiate on muscle injury to sustain the regenerative capacity of adult skeletal muscle; in this process, they self-renew through the return to quiescence of the cycling progeny. This mechanism, while efficient in physiological conditions does not prevent exhaustion of satellite cells in pathologies such as muscular dystrophy where numerous rounds of damage occur. Here, we describe a key role of nitric oxide, an important signaling molecule in adult skeletal muscle, on satellite cells maintenance, studied ex vivo on isolated myofibers and in vivo using the ?-sarcoglycan null mouse model of dystrophy and a cardiotoxin-induced model of repetitive damage. Nitric oxide stimulated satellite cells proliferation in a pathway dependent on cGMP generation. Furthermore, it increased the number of Pax7+/Myf5? cells in a cGMP-independent pathway requiring enhanced expression of Vangl2, a member of the planar cell polarity pathway involved in the Wnt noncanonical pathway. The enhanced self-renewal ability of satellite cells induced by nitric oxide is sufficient to delay the reduction of the satellite cell pool during repetitive acute and chronic damages, favoring muscle regeneration; in the ?-sarcoglycan null dystrophic mouse, it also slowed disease progression persistently. These results identify nitric oxide as a key messenger in satellite cells maintenance, expand the significance of the Vangl2-dependent Wnt noncanonical pathway in myogenesis, and indicate novel strategies to optimize nitric oxide-based therapies for muscular dystrophy. Stem Cells 2012; 30:197–209.

Buono, Roberta; Vantaggiato, Chiara; Pisa, Viviana; Azzoni, Emanuele; Bassi, Maria Teresa; Brunelli, Silvia; Sciorati, Clara; Clementi, Emilio

2012-01-01

176

Terrorism in Turkey.  

National Technical Information Service (NTIS)

Turkey has been fighting against the PKK (Kurdistan Worker Party) since 1985. The purpose of this study is to define what the PKK is, to explain origin of the Kurdish citizen, to define differences between the PKK and the Kurdish citizen and to try to fin...

Y. Oztekin

2000-01-01

177

Astronomy in Modern Turkey  

NASA Astrophysics Data System (ADS)

Present-day astronomy and its development in the recent history of Turkey are described. Current astronomy education in modern-day Turkish Republic from primary to high schools, including modern-day university education is discussed. Astronomical and space research together with the existing observatories and present-day Turkish astronomy in the global state is presented.

Eker, Zeki; Demircan, Osman, Kirbiyik, Halil; Bilir, Selcuk

2013-01-01

178

Special education in Turkey  

Microsoft Academic Search

Special education has been gaining intense attention from governments and educators throughout the world. As a developing country, and official candidate for the European Union, Turkey has been working on issues related to special education provision and inclusive education to improve the quality of services for citizens with disabilities. This article presents the developments and current status of special education

Macid A. Melekoglu; Orhan Cakiroglu; Kimber W. Malmgren

2009-01-01

179

Wind energy in Turkey  

Microsoft Academic Search

Wind and wind energy has always played an important role in the historical and economical development of Asia Minor and the geographical area covered by the Republic of Turkey today. The ancient city of Troia probably became rich with harbor fees from commercial vessels, which could not sail up the Dardanelles because of strong north-easterly winds and swift currents. As

Mehmet Hana?asio?lu

1999-01-01

180

Special Education in Turkey  

ERIC Educational Resources Information Center

The quality and the prevalence of education are the major indicators of the development of a society. It is a kind of human right to every person living in the society to be educated in a sufficient way. The education of the disabled people, a social reality in Turkey, is not sufficiently carried out. This paper aims at the education of the…

Eres, Figen

2010-01-01

181

Wind energy and Turkey.  

PubMed

The global energy requirement for sustaining economic activities, meeting social needs and social development is increasing daily. Environmentally friendly, renewable energy resources are an alternative to the primary non-renewable energy resources, which devastate ecosystems in order to meet increasing demand. Among renewable energy sources such as hydropower, biopower, geothermal power and solar power, wind power offers distinct advantages to Turkey. There is an increasing tendency toward wind globally and the European Union adjusted its legal regulations in this regard. As a potential EU Member state, Turkey is going through a similar process. The number of institutional and legal regulations concerning wind power has increased in recent years; technical infrastructure studies were completed, and some important steps were taken in this regard. This study examines the way in which Turkey has developed support for wind power, presents a SWOT analysis of the wind power sector in Turkey and a projection was made for the concrete success expected to be accomplished in the future. PMID:21479556

Coskun, Aynur Aydin; Türker, Yavuz Özhan

2012-03-01

182

Special Education in Turkey  

ERIC Educational Resources Information Center

Special education has been gaining intense attention from governments and educators throughout the world. As a developing country, and official candidate for the European Union, Turkey has been working on issues related to special education provision and inclusive education to improve the quality of services for citizens with disabilities. This…

Melekoglu, Macid A.; Cakiroglu, Orhan; Malmgren, Kimber W.

2009-01-01

183

Educational Reform in Turkey  

ERIC Educational Resources Information Center

There are a number of reform initiatives underway in Turkey but some of these, which are concerned with curricular and structural changes, have encountered serious difficulties. This paper begins with a brief summary of school effectiveness and school improvement research guiding many educational reforms. It then gives some information about…

Aksit, Necmi

2007-01-01

184

NATO and Turkey.  

National Technical Information Service (NTIS)

NATO has provided a general balance of power and European stability since the late 1940's. The Southern flank is vital to NATO not only from a military standpoint but also economically. Turkey plays a vital role in defending the Southern flank of NATO by ...

I. Gurdal

1987-01-01

185

Cloning Creationism in Turkey.  

ERIC Educational Resources Information Center

Defines how political balances and changes in Turkey effect creation-evolution relation. Describes the influences of Bilim Arastirma Vakfi (BAV) on these changes, which are directly targeted to public education, and discusses the content of creationism. Questions why Islamic creationism is a copy of that of the Institute for Creation Research…

Edis, Taner

1999-01-01

186

Informatics in Turkey.  

National Technical Information Service (NTIS)

In the last twenty years the rapid change in the informatics sector has had economic and social impact on private and government activities. The Supreme Council for Science and Technology of Turkey assigned highest priority to the informatics in its meeti...

S. Cakir

1994-01-01

187

Country Profiles, Turkey.  

ERIC Educational Resources Information Center

A profile of Turkey is sketched in this paper. Emphasis is placed on the nature, scope, and accomplishments of population activities in the country. Topics and sub-topics include: location and description of the country; population (size, growth patterns, age structure, urban/rural distribution, ethnic and religious composition, migration,…

Anderson, Lewis S.

188

Neuronal soma-satellite glial cell interactions in sensory ganglia and the participation of purinergic receptors  

PubMed Central

It has been known for some time that the somata of neurons in sensory ganglia respond to electrical or chemical stimulation and release transmitters in a Ca2+-dependent manner. The function of the somatic release has not been well delineated. A unique characteristic of the ganglia is that each neuronal soma is tightly enwrapped by satellite glial cells (SGCs). The somatic membrane of a sensory neuron rarely makes synaptic contact with another neuron. As a result, the influence of somatic release on the activity of adjacent neurons is likely to be indirect and/or slow. Recent studies of neuron-SGC interactions have demonstrated that ATP released from the somata of dorsal root ganglion neurons activates SGCs. They in turn exert complex excitatory and inhibitory modulation of neuronal activity. Thus, SGCs are actively involved in the processing of afferent information. In this review, we summarize our understanding of bidirectional communication between neuronal somata and SGCs in sensory ganglia and its possible role in afferent signaling under normal and injurious conditions. The participation of purinergic receptors is emphasized because of their dominant roles in the communication.

Gu, Yanping; Chen, Yong; Zhang, Xiaofei; Li, GuangWen; Wang, Cong Ying; Huang, Li-Yen Mae

2011-01-01

189

Satellite cell activation and populations on single muscle-fiber cultures from adult zebrafish (Danio rerio).  

PubMed

Satellite cells (SCs), stem cells in skeletal muscle, are mitotically quiescent in adult mammals until activated for growth or regeneration. In mouse muscle, SCs are activated by nitric oxide (NO), hepatocyte growth factor (HGF) and the mechanically induced NO-HGF signaling cascade. Here, the SC population on fibers from the adult, ectothermic zebrafish and SC responsiveness to activating stimuli were assessed using the model system of isolated fibers cultured at 27 and 21°C. SCs were identified by immunostaining for the HGF receptor, c-met, and activation was determined using bromodeoxyuridine uptake in culture or in vivo. In dose-response studies, SC activation was increased by treatment with the NO-donor drug isosorbide dinitrate (1 mmol l(-1)) or HGF (10 ng ml(-1)) to maximum activation at lower concentrations of both than in previous studies of mouse fibers. HGF-induced activation was blocked by anti-c-met antibody, and reduced by culture at 21°C. The effect of cyclical stretch (3 h at 4 cycles per minute) increased activation and was blocked by nitric oxide synthase inhibition and reduced by culture at 21°C. The number of c-met+ SCs per fiber increased rapidly (by 3 h) after stretching. The character of signaling in SC activation on zebrafish fibers, in particular temperature-dependent responses to HGF and stretch, gives new insights into the influence of ectothermy on regulation of muscle growth in teleosts and suggests the use of the single-fiber model system to explore the basis of fiber hyperplasia and the conservation of regulatory pathways between species. PMID:24577448

Zhang, Helia; Anderson, Judy E

2014-06-01

190

S1P lyase in skeletal muscle regeneration and satellite cell activation: Exposing the hidden lyase?  

PubMed Central

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid whose actions are essential for many physiological processes including angiogenesis, lymphocyte trafficking and development. In addition, S1P serves asamuscle trophic factor that enables efficient muscle regeneration. This is due in part to S1P's ability to activate quiescent muscle stem cells called satellite cells (SCs) that are needed for muscle repair. However, the molecular mechanism by which S1P activates SCs has not been well understood. Further, strategies for harnessing S1P signaling to recruit SCs for therapeutic benefit have been lacking. S1P is irreversibly catabolized by S1P lyase (SPL), a highly conserved enzyme that catalyzes the cleavage of S1P at carbon bond C2–3, resulting in formation of hexadecenal and ethanolamine-phosphate. SPL enhances apoptosis through substrate- and product-dependent events, thereby regulating cellular responses to chemotherapy, radiation and ischemia. SPL is undetectable in resting murine skeletal muscle. However, we recently found that SPL is dynamically upregulated in skeletal muscle after injury. SPL upregulation occurred in the context of a tightly orchestrated genetic program that resulted in a transient S1P signal in response to muscle injury. S1P activated quiescent SCs via a sphingosine-1-phosphate receptor 2 (S1P2)/signal transducer and activator of transcription 3 (STAT3)-dependent pathway, thereby facilitating skeletal muscle regeneration. Mdx mice, which serve as a model for muscular dystrophy (MD), exhibited skeletal muscle SPL upregulation and S1P deficiency. Pharmacological SPL inhibition raised skeletal muscle S1P levels, enhanced SC recruitment and improved mdx skeletal muscle regeneration. These findings reveal how S1P can activate SCs and indicate that SPL suppression may provide a therapeutic strategy for myopathies. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.

Saba, Julie D.; de la Garza-Rodea, Anabel S.

2013-01-01

191

A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle.  

PubMed

Androgens have well-established anabolic actions on skeletal muscle, although the direct effects of the androgen receptor (AR) in muscle remain unclear. We generated satellite cell-specific AR-knockout (satARKO) mice in which the AR is selectively ablated in satellite cells, the muscle precursor cells. Total-limb maximal grip strength is decreased by 7% in satARKO mice, with soleus muscles containing ?10% more type I fibers and 10% less type IIa fibers than the corresponding control littermates. The weight of the perineal levator ani muscle is markedly reduced (-52%). Thus, muscle AR is involved in fiber-type distribution and force production of the limb muscles, while it is a major determinant of the perineal muscle mass. Surprisingly, myostatin (Mstn), a strong inhibitor of skeletal muscle growth, is one of the most androgen-responsive genes (6-fold reduction in satARKO) through direct transcription activation by the AR. Consequently, muscle hypertrophy in response to androgens is augmented in Mstn-knockout mice. Our finding that androgens induce Mstn signaling to restrain their own anabolic actions has implications for the treatment of muscle wasting disorders.-Dubois, V., Laurent, M. R., Sinnesael, M., Cielen, N., Helsen, C., Clinckemalie, L., Spans, L., Gayan-Ramirez, G., Deldicque, L., Hespel, P., Carmeliet, G., Vanderschueren, D., and Claessens, F. A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle. PMID:24671706

Dubois, Vanessa; Laurent, Michaël R; Sinnesael, Mieke; Cielen, Nele; Helsen, Christine; Clinckemalie, Liesbeth; Spans, Lien; Gayan-Ramirez, Ghislaine; Deldicque, Louise; Hespel, Peter; Carmeliet, Geert; Vanderschueren, Dirk; Claessens, Frank

2014-07-01

192

MicroRNA-133 controls brown adipose determination in skeletal muscle satellite cells by targeting Prdm16.  

PubMed

Brown adipose tissue (BAT) is an energy-dispensing thermogenic tissue that plays an important role in balancing energy metabolism. Lineage-tracing experiments indicate that brown adipocytes are derived from myogenic progenitors during embryonic development. However, adult skeletal muscle stem cells (satellite cells) have long been considered uniformly determined toward the myogenic lineage. Here, we report that adult satellite cells give rise to brown adipocytes and that microRNA-133 regulates the choice between myogenic and brown adipose determination by targeting the 3'UTR of Prdm16. Antagonism of microRNA-133 during muscle regeneration increases uncoupled respiration, glucose uptake, and thermogenesis in local treated muscle and augments whole-body energy expenditure, improves glucose tolerance, and impedes the development of diet-induced obesity. Finally, we demonstrate that miR-133 levels are downregulated in mice exposed to cold, resulting in de novo generation of satellite cell-derived brown adipocytes. Therefore, microRNA-133 represents an important therapeutic target for the treatment of obesity. PMID:23395168

Yin, Hang; Pasut, Alessandra; Soleimani, Vahab D; Bentzinger, C Florian; Antoun, Ghadi; Thorn, Stephanie; Seale, Patrick; Fernando, Pasan; van Ijcken, Wilfred; Grosveld, Frank; Dekemp, Robert A; Boushel, Robert; Harper, Mary-Ellen; Rudnicki, Michael A

2013-02-01

193

MicroRNA-133 Controls Brown Adipose Determination in Skeletal Muscle Satellite Cells by Targeting Prdm16  

PubMed Central

SUMMARY Brown adipose tissue (BAT) is an energy-dispensing thermogenic tissue that plays an important role in balancing energy metabolism. Lineage-tracing experiments indicate that brown adipocytes are derived from myogenic progenitors during embryonic development. However, adult skeletal muscle stem cells (satellite cells) have long been considered uniformly determined toward the myogenic lineage. Here, we report that adult satellite cells give rise to brown adipocytes and that microRNA-133 regulates the choice between myogenic and brown adipose determination by targeting the 3?UTR of Prdm16. Antagonism of microRNA-133 during muscle regeneration increases uncoupled respiration, glucose uptake, and thermogenesis in local treated muscle and augments whole-body energy expenditure, improves glucose tolerance, and impedes the development of diet-induced obesity. Finally, we demonstrate that miR-133 levels are downregulated in mice exposed to cold, resulting in de novo generation of satellite cell-derived brown adipocytes. Therefore, microRNA-133 represents an important therapeutic target for the treatment of obesity.

Yin, Hang; Pasut, Alessandra; Soleimani, Vahab D.; Bentzinger, C. Florian; Antoun, Ghadi; Thorn, Stephanie; Seale, Patrick; Fernando, Pasan; van IJcken, Wilfred; Grosveld, Frank; Dekemp, Robert A.; Boushel, Robert; Harper, Mary-Ellen; Rudnicki, Michael A.

2013-01-01

194

Charge efficiency of Ni/H2 cells during transfer orbit of Telstar 4 satellites  

NASA Technical Reports Server (NTRS)

The TELSTAR 4 communication satellites being manufactured by Martin Marietta Astro Space (Astro Space) for AT&T are three axis stabilized spacecraft scheduled to be launched on expendable vehicles such as the Atlas or Ariane rockets. Typically, these spacecraft consist of a box that holds the electronics and supports the antenna reflectors and the solar array wings. The wings and reflectors are folded against the sides of the box during launch and the spacecraft is spun for attitude control in that phase; they are then deployed after achieving the final orbit. The launch phase and transfer orbits required to achieve the final geosynchronous orbit typically take 4 to 5 days during which time the power required for command, telemetry, attitude control, heaters, etc., is provided by two 50 AH nickel hydrogen batteries augmented by the exposed outboard solar panels. In the past, this situation has presented no problem since there was a considerable excess of power available from the array. In the case of large high powered spacecraft such as TELSTAR 4, however, the design power levels in transfer orbit approach the time-averaged power available from the exposed surface area of the solar arrays, resulting in a very tight power margin. To compound the difficulty, the array output of the spinning spacecraft in transfer orbit is shaped like a full wave rectified sine function and provides very low charging rates to the batteries during portions of the rotation. In view of the typically low charging efficiency of alkaline nickel batteries at low rates, it was decided to measure the efficiency during a simulation of the TELSTAR 4 conditions at the expected power levels and temperatures on three nickel hydrogen cells of similar design. The unique feature of nickel hydrogen cells that makes the continuous measurement of efficiency possible is that hydrogen is one of the active materials and thus, cell pressure is a direct measure of the state of charge or available capacity. The pressure is measured with a calibrated strain gage mounted on the outside of the pressurized cell.

Fang, W. C.; Maurer, Dean W.; Vyas, B.; Thomas, M. N.

1994-01-01

195

A morphologic study of bronchus-associated lymphoid tissue in turkeys.  

PubMed

Bronchus-associated lymphoid tissue (BALT) in normal turkeys of ages 1 day and 1, 2, 3, 4, 8, and 18 weeks was examined by light microscopy and by scanning and transmission electron microscopy. Turkey BALT resembled other mucosa-associated lymphoid tissues; it was made up of a population of lymphocytes covered by a specialized epithelium different from typical pseudostratified ciliated columnar bronchial epithelium. There were distinct age-related differences in BALT structure. Bronchus-associated lymphoid nodules were larger and more numerous in older turkeys. In 1-day- to 2-week-old turkeys, the primary cell type of BALT epithelium was nonciliated cuboidal; in 2-week old turkeys it was squamous; and in turkeys older than 4-weeks of age, the epithelium was primarily ciliated columnar. In 1- to 4-week old turkeys, large numbers of intraepithelial lymphocytes disrupted the normal organization of the epithelium. In older turkeys, epithelial and lymphoid cells were in discrete compartments separated by connective tissue. Lymphocytes in 1-day-old turkeys were found in loose aggregates around venules and within the epithelium. In 1-week old turkeys, lymphocytes were organized into compartments of morphologically similar cells. By 3-weeks of age, lymphocytes were present in distinct germinal centers. Epithelial cells of BALT did not have large numbers of apical vesicles and thus were not structurally specialized for antigen uptake by endocytosis. However, the epithelial barrier appeared to be disrupted over lymphoid nodules, suggesting that antigen would be readily available to lymphocytes and phagocytes in BALT. Age-related differences in turkey BALT structure may have functional consequences with respect to the respiratory immune response. PMID:2239743

Fagerland, J A; Arp, L H

1990-09-01

196

Family practice in Turkey.  

PubMed

The national project 'Transformation in Health' was started in 2005 to provide expert primary care by family physicians, and decrease expenses in Turkey. The number of family physicians was far below the need, so public physicians were promoted to family physician status after a 10-day intensive course. The government declared some satisfactory results, but privately paid family physicians were not accepted into the system. Furthermore, the government stopped paying for their services from private settings. Some family physicians became unemployed as the major payer for all forms of medical care in Turkey denied their services. The process showed it's value in time. Nevertheless, family physicians should be the core of this transformation as family medicine is an academic and a scientific discipline and a primary care-oriented specialty with its own specific educational content, research and base of evidence, which cannot be achieved through standard medical education. PMID:24682837

Ozsahin, Akatli Kursad

2014-03-01

197

Terrorism in Turkey  

Microsoft Academic Search

Over the past two decades, terrorism has exacted an enormous toll on the Republic of Turkey, a secular democracy with a 99.8% Muslim population. From 1984 to 2000, an estimated 30,000 to 35,000 Turkish citizens were killed by a nearly continuous stream of terrorism-related events. During this period, the Partiya Karekeren Kurdistan (PKK), a Kurdish separatist group (re-named KADEK in

Ulkumen Rodoplu; Jeffrey Arnold; Gurkan Ersoy

198

Suicide terrorism in Turkey  

Microsoft Academic Search

With the PKK's suicide attacks in Turkey of summer 1999 still fresh in people's minds, Prof. Do?u Ergil draws on the few Turkish?language accounts about the subject, one only newly?available, to profile the organisation's approach to suicide terrorism. He does this by examining the culture to which those chosen to be ‘live bombs’ are part of and places all within

Do?u Ergil

2000-01-01

199

Nursing in Turkey.  

PubMed

The current discussion on the nursing shortage needs to focus as much on nursing job satisfaction and retention as on nursing recruitment and education. Selected aspects of the motivational psychology of Abraham Maslow, Mihaly Csikszentmihalyi, and Frederick Hertzberg are here discussed in light of the challenges-opportunities of nursing in Turkey and elsewhere. Also discussed is an innovative program to support the application of nursing theory and professional development in Toronto, Canada. PMID:16982724

Baumann, Steven L

2006-10-01

200

The molecular responses of skeletal muscle satellite cells to continuous expression of IGF-1: implications for the rescue of induced muscular atrophy in aged rats  

NASA Technical Reports Server (NTRS)

Approximately 50% of humans older than 85 years have physical frailty due to weak skeletal muscles. This indicates a need for determining mechanisms to combat this problem. A critical cellular factor for postnatal muscle growth is a population of myogenic precursor cells called satellite cells. Given the complex process of sarcopenia, it has been postulated that, at some point in this process, a limited satellite cell proliferation potential could become rate-limiting to the regrowth of old muscles. It is conceivable that if satellite cell proliferative capacity can be maintained or enhanced with advanced age, sarcopenia could potentially be delayed or prevented. Therefore, the purposes of this paper are to describe whether IGF-I can prevent muscular atrophy induced by repeated cycles of hindlimb immobilization, increase the in vitro proliferation in satellite cells from these muscles and, if so, the molecular mechanisms by which IGF-I mediates this increased proliferation. Our results provide evidence that IGF-I can enhance aged muscle regrowth possibly through increased satellite cell proliferation. The results also suggest that IGF-I enhances satellite cell proliferation by decreasing the cell cycle inhibitor, p27Kip1, through the PI3'-K/Akt pathway. These data provide molecular evidence for IGF-I's rescue effect upon aging-associated skeletal muscle atrophy.

Chakravarthy, M. V.; Booth, F. W.; Spangenburg, E. E.

2001-01-01

201

Epidermal growth factor receptor is required for estradiol-stimulated bovine satellite cell proliferation.  

PubMed

The objective of this study was to assess the role of the epidermal growth factor receptor (EGFR) in estradiol-17? (E2)-stimulated proliferation of cultured bovine satellite cells (BSCs). Treatment of BSC cultures with AG1478 (a specific inhibitor of EGFR tyrosine kinase activity) suppresses E2-stimulated BSC proliferation (P < 0.05). In addition, E2-stimulated proliferation is completely suppressed (P < 0.05) in BSCs in which EGFR expression is silenced by treatment with EGFR small interfering RNA (siRNA). These results indicate that EGFR is required for E2 to stimulate proliferation in BSC cultures. Both AG1478 treatment and EGFR silencing also suppress proliferation stimulated by LR3-IGF-1 (an IGF1 analogue that binds normally to the insulin-like growth factor receptor (IGFR)-1 but has little or no affinity for IGF binding proteins) in cultured BSCs (P < 0.05). Even though EGFR siRNA treatment has no effect on IGFR-1? mRNA expression in cultured BSCs, IGFR-1? protein level is substantially reduced in BSCs treated with EGFR siRNA. These data suggest that EGFR silencing results in post-transcriptional modifications that result in decreased IGFR-1? protein levels. Although it is clear that functional EGFR is necessary for E2-stimulated proliferation of BSCs, the role of EGFR is not clear. Transactivation of EGFR may directly stimulate proliferation, or EGFR may function to maintain the level of IGFR-1? which is necessary for E2-stimulated proliferation. It also is possible that the role of EGFR in E2-stimulated BSC proliferation may involve both of these mechanisms. PMID:24906928

Reiter, B C; Kamanga-Sollo, E; Pampusch, M S; White, M E; Dayton, W R

2014-07-01

202

Reduced masticatory function is related to lower satellite cell numbers in masseter muscle.  

PubMed

The physiology of masseter muscles is known to change in response to functional demands, but the effect on the satellite cell (SC) population is not known. In this study, the hypothesis is tested that a decreased functional demand of the masseter muscle causes a reduction of SCs. To this end, twelve 5-week-old male Sprague-Dawley rats were put on a soft diet (SD, n = 6) or a hard diet (HD, n = 6) and sacrificed after 14 days. Paraffin sections of the superficial masseter and the m. digastricus (control muscle) were stained with haematoxylin and eosin for tissue survey and with anti-myosin heavy chain (MHC) for slow and fast fibres. Frozen sections of both muscles were double-stained for collagen type IV and Pax7. Slow MHC fibres were equally distributed in the m. digastricus but only localized in a small area of the m. masseter. No differences between HD or SD for the m. digastricus were found. The m. masseter had more SCs per fibre in HD than in SD (0.093 ± 0.007 and 0.081 ± 0.008, respectively; P = 0.027). The m. masseter had more fibres per surface area than the m. digastricus in rats with an SD group (758.1 ± 101.6 and 568.4 ± 85.6, P = 0.047) and a HD group (737.7 ± 32.6 and 592.2 ± 82.2; P = 0.007). The m. digastricus had more SCs per fibre than the m. masseter in the SD group (0.094 ± 0.01 and 0.081 ± 0.008; P = 0.039). These results suggest that reduced masseter muscle function is related to a lower number of SCs. Reduced muscle function might decrease microdamage and hence the requirement of SCs in the muscle fibres. PMID:22828080

Kuijpers, M A R; Grefte, S; Bronkhorst, E M; Carels, C E L; Kiliaridis, S; Von den Hoff, J W

2014-06-01

203

Effect of trenbolone acetate on protein synthesis and degradation rates in fused bovine satellite cell cultures.  

PubMed

Although androgenic and estrogenic steroids are widely used to enhance muscle growth and increase feed efficiency in feedlot cattle, their mechanism of action is not well understood. Although in vivo studies have indicated that androgens affect protein synthesis and protein degradation rate in muscle, results from in vitro studies have been inconsistent. We have examined the effects of trenbolone acetate (TBA), a synthetic androgen, on protein synthesis and degradation rates in fused bovine satellite cell (BSC) cultures. Additionally, we have examined the effects of compounds that interfere with binding of TBA or insulin-like growth factor-1 (IGF-1) to their respective receptors on TBA-induced alterations in protein synthesis and degradation rates in BSC cultures. Treatment of fused BSC cultures with TBA results in a concentration-dependent increase (P < 0.05) in protein synthesis rate and a decrease (P < 0.05) in degradation rate, establishing that TBA directly affects these parameters. Flutamide, a compound that prevents androgen binding to the androgen receptor, suppresses (P < 0.05) TBA-induced alterations in protein synthesis and degradation in fused BSC cultures, indicating the androgen receptor is involved. JB1, a competitive inhibitor of IGF-1 binding to the type 1 IGF receptor (IGF1R), suppresses (P < 0.05) TBA-induced alterations in protein synthesis and degradation, indicating that this receptor also is involved in the actions of TBA on both synthesis and degradation. In summary, our data show that TBA acts directly to alter both protein synthesis and degradation rates in fused BSC cultures via mechanisms involving both the androgen receptor and IGF1R. PMID:20961723

Kamanga-Sollo, E; White, M E; Hathaway, M R; Weber, W J; Dayton, W R

2011-01-01

204

Epidemiology of pityriasis versicolor in Adana, Turkey.  

PubMed

Pityriasis versicolor is a common superficial mycoses of the skin. It is now recognized that the causative organisms of this infection are different species of Malassezia. The aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor in Adana, Turkey. In total, 97 patients positive for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All samples were inoculated in plates containing modified Dixon's medium. However, only 44 of the patients (45.4%) showed Malassezia spp. in culture. Malassezia globosa (47.7%) was the most commonly isolated species followed by Malassezia furfur (36.4%) and Malassezia slooffiae (15.9%). Mixed Malassezia species were not isolated. In conclusion, M. globosa was found to be the predominant PV isolate in Adana, Turkey. PMID:19583685

Karaka?, Mehmet; Turaç-Biçer, Aygül; Ilkit, Macit; Durdu, Murat; Seydao?lu, Gül?ah

2009-07-01

205

Identification of the STAC3 gene as a skeletal muscle-specifically expressed gene and a novel regulator of satellite cell differentiation in cattle.  

PubMed

Recent studies in mice and zebrafish suggest that the unannotated Src homology 3 and cysteine rich domain 3 (STAC3) gene plays an important role in skeletal muscle development and contraction. The objective of this study was to determine the tissue specificity of the bovine STAC3 gene and its potential role in the proliferation and differentiation of bovine satellite cells. The STAC3 mRNA was detected only in skeletal muscle among 18 bovine tissues examined by reverse transcription PCR. Western blotting revealed the expression of STAC3 protein in bovine skeletal muscle and the absence of it in 6 bovine tissues analyzed. Transfection of the bovine satellite cells with a pool of 2 STAC3 small interfering RNA (siRNA) caused a 90% reduction in STAC3 mRNA. Cell proliferation assays revealed that STAC3 knockdown had no effect on the proliferation rate of bovine satellite cells. Approximately 60% of bovine satellite cells transfected with STAC3 siRNA formed myotubes by 72 h of differentiation, whereas that percentage was 40% for those transfected with negative control siRNA (P < 0.05). At 24, 48, and 72 h of differentiation, bovine satellite cells transfected with STAC3 siRNA had greater mRNA expression of myogenin, myosin heavy chain 3, and myosin heavy chain 7, markers of myotubes, than those transfected with negative control siRNA (P < 0.05). These results suggest that the STAC3 gene is a negative regulator of the differentiation and fusion of bovine satellite cells into myotubes. However, STAC3 expression was increased during the differentiation of bovine satellite cells into myotubes. This suggests that STAC3 might have different functions in bovine myotubes than in bovine satellite cells. PMID:24948655

Zhang, Y; Cong, X; Wang, A; Jiang, H

2014-08-01

206

Impedances of Li/SO2 cells retrieved from the Long Duration Exposure Facility (LDEF satellite) and comparison with cells stored terrestrially  

NASA Technical Reports Server (NTRS)

Impedances were measured on several Li/SO2 cells retrieved from the Long Duration Exposure Facility (LDEF) satellite. These cells were used to power instruments and recorders and had all been partially or fully discharged. Impedances were also measured on several cells that were stored in cold storage since manufacture. Unfortunately, none of the cells stored terrestrially had undergone any discharge, whereas all of the cells on the satellite were at least partially discharged early in the mission and then remained on orbit for about 5 years further. It has been observed by others that storage of an Li/SO2 cell after partial discharge, increases the resistance and thickness of the passive film on the Li electrode, as indicated by an increase in the time for recovery of voltage when a load is applied (voltage lag), or in some cases by an inability of a cell to sustain a normal current after such storage. Since the cells stored terrestrially were not discharged in the same manner as the LDEF cells, a direct comparison cannot be made. Thus, the effects of the space environment cannot be separated from the effects of storage after partial discharge. It is believed that the increases in impedance in the LDEF cells are largely due to the storage upon partial discharge rather than the effects of the space environment.

Reid, Margaret A.

1991-01-01

207

Neotectonics of Turkey – a synthesis  

Microsoft Academic Search

Turkey forms one of the most actively deforming regions in the world and has a long history of devastating earthquakes. The better understanding of its neotectonic features and active tectonics would provide insight, not only for the country but also for the entire Eastern Mediterranean region. Active tectonics of Turkey is the manifestation of collisional intracontinental convergence- and tectonic escape-related

Erdin Bozkurt

2001-01-01

208

Turkey: Informatics and Economic Modernization.  

National Technical Information Service (NTIS)

During the 1980s, Turkey laid the foundation for its transition to an information-based economy (IBE). Nevertheless, when compared to peer-group countries that targeted informatics as a catalyst for economic modernization, Turkey has not yet adequately de...

1993-01-01

209

Turkey's energy demand and supply  

SciTech Connect

The aim of the present article is to investigate Turkey's energy demand and the contribution of domestic energy sources to energy consumption. Turkey, the 17th largest economy in the world, is an emerging country with a buoyant economy challenged by a growing demand for energy. Turkey's energy consumption has grown and will continue to grow along with its economy. Turkey's energy consumption is high, but its domestic primary energy sources are oil and natural gas reserves and their production is low. Total primary energy production met about 27% of the total primary energy demand in 2005. Oil has the biggest share in total primary energy consumption. Lignite has the biggest share in Turkey's primary energy production at 45%. Domestic production should be to be nearly doubled by 2010, mainly in coal (lignite), which, at present, accounts for almost half of the total energy production. The hydropower should also increase two-fold over the same period.

Balat, M. [Sila Science, Trabzon (Turkey)

2009-07-01

210

The effects of clenbuterol on satellite cell activation and the regeneration of skeletal muscle: an autoradiographic and morphometric study of whole muscle transplants in mice.  

PubMed Central

The beta-2 agonist clenbuterol was tested for its effect on the proliferation of satellite cells in transplanted skeletal muscles. Using autoradiographic techniques it was found that satellite cells in clenbuterol treated transplants began proliferating earlier than in control animals. The effect of clenbuterol on the growth of regenerating muscle fibres was also examined using morphometric techniques, which manifested itself as hypertrophy of the fibres when compared with the controls. Images Fig. 2 Fig. 3

Roberts, P; McGeachie, J K

1992-01-01

211

Early-age feed restriction affects viability and gene expression of satellite cells isolated from the gastrocnemius muscle of broiler chicks  

PubMed Central

Background Muscle growth depends on the fusion of proliferate satellite cells to existing myofibers. We reported previously that 0–14 day intermittent feeding led to persistent retardation in myofiber hypertrophy. However, how satellite cells respond to such nutritional insult has not been adequately elucidated. Results One-day-old broiler chicks were allocated to control (Con, ad libitum feeding), intermittent feeding (IF, feed provided on alternate days) and re-feeding (RF, 2 days ad libitum feeding after 12 days of intermittent feeding) groups. Chickens were killed on Day 15 and satellite cells were isolated. When cultured, satellite cells from the IF group demonstrated significant retardation in proliferation and differentiation potential, while RF partly restored the proliferation rate and differentiation potential of the satellite cells. Significant up-regulation of insulin like growth factor I receptor (IGF-IR) (P<0.05) and thyroid hormone receptor ? (TR?) (P<0.05), and down-regulation of growth hormone receptor (GHR) (P<0.01) and IGF-I (P<0.01) mRNA expression was observed in freshly isolated IF satellite cells when compared with Con cells. In RF cells, the mRNA expression of IGF-I was higher (P<0.05) and of TR? was lower (P<0.01) than in IF cells, suggesting that RF restored the mRNA expression of TR? and IGF-I, but not of GHR and IGF-IR. The Bax/Bcl-2 ratio tended to increase in the IF group, which was reversed in the RF group (P<0.05), indicating that RF reduced the pro-apoptotic influence of IF. Moreover, no significant effect of T3 was detected on cell survival in IF cells compared with Con (P<0.001) or RF (P<0.05) cells. Conclusions These data suggest that early-age feed restriction inhibits the proliferation and differentiation of satellite cells, induces changes in mRNA expression of the GH/IGF-I and thyroid hormone receptors in satellite cells, as well as blunted sensitivity of satellite cells to T3, and that RF partially reverses these effects. Thus, a moderate nutritional strategy for feed restriction should be chosen in early chick rearing systems.

2012-01-01

212

Movement ecology of migration in turkey vultures.  

PubMed

We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change. PMID:19060195

Mandel, J T; Bildstein, K L; Bohrer, G; Winkler, D W

2008-12-01

213

Satellites Harming Other Satellites.  

National Technical Information Service (NTIS)

A strategy is developed for assessing the harm that one satellite can do to another. A total of 29 modes are identified through which this harm can transpire, and the parameters and characteristics of each are explained. An overall, quantitative index of ...

P. C. Hughes

1991-01-01

214

Solar cell degradation observed by the Advanced Photovoltaic and Electronics experiments (APEX) satellite  

Microsoft Academic Search

This paper presents results from the Photovoltaic Array Space Power Plus Diagnostics (PASP Plus) experiment flown on board the Advanced Photovoltaic and Electronics experiment (APEX) satellite launched on 3 August 1994 into a 2552 km×363 km orbit with a 70° inclination. Results presented are based on 4576 orbits of data from 3 August 1994 to 11 August 1995. Fifteen solar

K. P. Ray; D. E. Delorey; E. G. Mullen; D. A. Guidice; D. C. Marvin; H. B. Curtis; M. F. Piszczor

1996-01-01

215

Dynamic between National Identity and Foreign Policy in Turkey.  

National Technical Information Service (NTIS)

Recently, Turkey's foreign policy has undergone some considerable changes. In order to understand why this has occurred, and where Turkey's foreign policy will likely go in the future, one must examine Turkey's national identity. Today, Turkey's dominant ...

I. W. Bullen

2009-01-01

216

Juxtacrine and Paracrine Interactions of Rat Marrow-Derived Mesenchymal Stem Cells, Muscle-Derived Satellite Cells, and Neonatal Cardiomyocytes with Endothelial Cells in Angiogenesis Dynamics  

PubMed Central

Research into angiogenesis has contributed to progress in the fast-moving field of regenerative medicine. Designing coculture systems is deemed a helpful method to understand the dynamic interaction of various cells involved in the angiogenesis process. We investigated the juxtacrine and paracrine interaction between 3 different cells, namely rat marrow-derived mesenchymal stem cells (rMSCs), rat muscle-derived satellite cells (rSCs), and rat neonatal cardiomyocytes (rCMs), and endothelial cells (ECs) during angiogenesis process. In vitro Matrigel angiogenesis assay was performed whereby ECs were monocultured or cocultured with rMSCs, rSCs, and rCMs or their conditioned media (CM). In addition, in vivo Matrigel plug assay for angiogenesis was conducted to assess the angiogenic potential of the rCM-, rMSC-, and rSC-derived CM. Our results demonstrated that the rMSCs, rSCs, and rCMs elongated along the EC tubules, whereas the rMSCs formed tube-like structures with sprouting tip cells, leading to improved angiogenesis in the coculture system. Moreover, the rMSC- and rSC-derived CM significantly improved angiogenesis tube formation on Matrigel, accelerated EC chemotaxis, and increased the arteriolar density, vascularization index, and vascularization flow index in the Matrigel plug in vivo. Western blotting showed that rMSCs secreted a high level of vascular endothelial growth factor, basic fibroblast growth factor, and stromal-derived factor-1-alpha. Tie2 is also shed from rMSCs. This study demonstrated that stem cells interact with ECs in the juxtacrine and paracrine manner during angiogenesis, and marrow MSCs have superior angiogenic properties.

Rahbarghazi, Reza; Khazraiinia, Parvaneh; Kajbafzadeh, Abdol-Mohammad; Ahmadi, Seyed Hossein; Mohammadi, Elham; Molazem, Mohammad; Zamani-Ahmadmahmudi, Mohamad

2013-01-01

217

Impaired Macrophage and Satellite Cell Infiltration Occurs in a Muscle-Specific Fashion Following Injury in Diabetic Skeletal Muscle  

PubMed Central

Background Systemic elevations in PAI-1 suppress the fibrinolytic pathway leading to poor collagen remodelling and delayed regeneration of tibialis anterior (TA) muscles in type-1 diabetic Akita mice. However, how impaired collagen remodelling was specifically attenuating regeneration in Akita mice remained unknown. Furthermore, given intrinsic differences between muscle groups, it was unclear if the reparative responses between muscle groups were different. Principal Findings Here we reveal that diabetic Akita muscles display differential regenerative responses with the TA and gastrocnemius muscles exhibiting reduced regenerating myofiber area compared to wild-type mice, while soleus muscles displayed no difference between animal groups following injury. Collagen levels in TA and gastrocnemius, but not soleus, were significantly increased post-injury versus controls. At 5 days post-injury, when degenerating/necrotic regions were present in both animal groups, Akita TA and gastrocnemius muscles displayed reduced macrophage and satellite cell infiltration and poor myofiber formation. By 10 days post-injury, necrotic regions were absent in wild-type TA but persisted in Akita TA. In contrast, Akita soleus exhibited no impairment in any of these measures compared to wild-type soleus. In an effort to define how impaired collagen turnover was attenuating regeneration in Akita TA, a PAI-1 inhibitor (PAI-039) was orally administered to Akita mice following cardiotoxin injury. PAI-039 administration promoted macrophage and satellite cell infiltration into necrotic areas of the TA and gastrocnemius. Importantly, soleus muscles exhibit the highest inducible expression of MMP-9 following injury, providing a mechanism for normative collagen degradation and injury recovery in this muscle despite systemically elevated PAI-1. Conclusions Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed regeneration is an impairment in macrophage infiltration and satellite cell recruitment to degenerating areas; a phenomena that occurs differentially between muscle groups.

Krause, Matthew P.; Al-Sajee, Dhuha; D'Souza, Donna M.; Rebalka, Irena A.; Moradi, Jasmin; Riddell, Michael C.; Hawke, Thomas J.

2013-01-01

218

Potential of adipose-derived mesenchymal stem cells and skeletal muscle-derived satellite cells for somatic cell nuclear transfer mediated transgenesis in Arbas Cashmere goats.  

PubMed

Somatic cell nuclear transfer is used to generate genetic models for research and new, genetically modified livestock varieties. Goat fetal fibroblast cells (gFFCs) are the predominant nuclear donors in Cashmere goat transgenic cloning, but have disadvantages. We evaluated the potential of goat adipose-derived mesenchymal stem cells (gADSCs) and goat skeletal muscle-derived satellite cells (gMDSCs) for somatic cell nuclear transfer, evaluating their proliferation, pluripotency, transfection efficiency and capacity to support full term development of embryos after additive gene transfer or homologous recombination. gADSCs and gMDSCs were isolated by enzyme digestion and differentiated into neurocytes, myotube cells and insulin-producing cells. Neuron-specific enolase, fast muscle myosin and insulin expression were determined by immunohistochemistry. Following somatic cell nuclear transfer with donor cells derived from gADSCs, gMDSCs and gFFCs, transfection and cloning efficiencies were compared. Red fluorescent protein levels were determined by quantitative PCR and western blotting. 5-Methylcytosine, H4K5, H4K12 and H3K18 were determined immunohistochemically. gADSCs and gMDSCs were maintained in culture for up to 65 passages, whereas gFFCs could be passaged barely more than 15 times. gADSCs and gMDSCs had higher fluorescent colony forming efficiency and greater convergence (20%) and cleavage (10%) rates than gFFCs, and exhibited differing H4K5 histone modification patterns after somatic cell nuclear transfer and in vitro cultivation. After transfection with a pDsRed2-1 expression plasmid, the integrated exogenous genes did not influence the pluripotency of gADSCs-pDsRed2-1 or gMDSCs-pDsRed2-1. DsRed2 mRNA expression by cloned embryos derived from gADSCs-pDsRed2-1 or gMDSCs-pDsRed2-1 was more than twice that of gFFCs-pDsRed2-1 embryos (P<0.01). Pregnancy rates of gADSCs-pDsRed2-1 and gMDSCs-pDsRed2-1 recipients were higher than those of gFFCs-pDsRed2-1 recipients (P<0.01). With their high proliferative capacity and transfection efficiency, gADSCs and gMDSCs are a valuable cell source for breeding new, genetically modified varieties of livestock by somatic cell nuclear transfer. PMID:24699686

Ren, Yu; Wu, Haiqing; Ma, Yuzhen; Yuan, Jianlong; Liang, Hao; Liu, Dongjun

2014-01-01

219

Potential of Adipose-Derived Mesenchymal Stem Cells and Skeletal Muscle-Derived Satellite Cells for Somatic Cell Nuclear Transfer Mediated Transgenesis in Arbas Cashmere Goats  

PubMed Central

Somatic cell nuclear transfer is used to generate genetic models for research and new, genetically modified livestock varieties. Goat fetal fibroblast cells (gFFCs) are the predominant nuclear donors in Cashmere goat transgenic cloning, but have disadvantages. We evaluated the potential of goat adipose-derived mesenchymal stem cells (gADSCs) and goat skeletal muscle-derived satellite cells (gMDSCs) for somatic cell nuclear transfer, evaluating their proliferation, pluripotency, transfection efficiency and capacity to support full term development of embryos after additive gene transfer or homologous recombination. gADSCs and gMDSCs were isolated by enzyme digestion and differentiated into neurocytes, myotube cells and insulin-producing cells. Neuron-specific enolase, fast muscle myosin and insulin expression were determined by immunohistochemistry. Following somatic cell nuclear transfer with donor cells derived from gADSCs, gMDSCs and gFFCs, transfection and cloning efficiencies were compared. Red fluorescent protein levels were determined by quantitative PCR and western blotting. 5-Methylcytosine, H4K5, H4K12 and H3K18 were determined immunohistochemically. gADSCs and gMDSCs were maintained in culture for up to 65 passages, whereas gFFCs could be passaged barely more than 15 times. gADSCs and gMDSCs had higher fluorescent colony forming efficiency and greater convergence (20%) and cleavage (10%) rates than gFFCs, and exhibited differing H4K5 histone modification patterns after somatic cell nuclear transfer and in vitro cultivation. After transfection with a pDsRed2-1 expression plasmid, the integrated exogenous genes did not influence the pluripotency of gADSCs–pDsRed2-1 or gMDSCs–pDsRed2-1. DsRed2 mRNA expression by cloned embryos derived from gADSCs–pDsRed2-1 or gMDSCs–pDsRed2-1 was more than twice that of gFFCs–pDsRed2-1 embryos (P<0.01). Pregnancy rates of gADSCs–pDsRed2-1 and gMDSCs–pDsRed2-1 recipients were higher than those of gFFCs–pDsRed2-1 recipients (P<0.01). With their high proliferative capacity and transfection efficiency, gADSCs and gMDSCs are a valuable cell source for breeding new, genetically modified varieties of livestock by somatic cell nuclear transfer.

Yuan, Jianlong; Liang, Hao; Liu, Dongjun

2014-01-01

220

Hierarchical structure of Turkey’s foreign trade  

NASA Astrophysics Data System (ADS)

We examine the hierarchical structures of Turkey’s foreign trade by using real prices of their commodity export and import move together over time. We obtain the topological properties among the countries based on Turkey’s foreign trade during the 1996-2010 period by using the concept of hierarchical structure methods (minimal spanning tree, (MST) and hierarchical tree, (HT)). These periods are divided into two subperiods, such as 1996-2002 and 2003-2010, in order to test various time-window and observe the temporal evolution. We perform the bootstrap techniques to investigate a value of the statistical reliability to the links of the MSTs and HTs. We also use a clustering linkage procedure in order to observe the cluster structure much better. From the structural topologies of these trees, we identify different clusters of countries according to their geographical location and economic ties. Our results show that the DE (Germany), UK (United Kingdom), FR (France), IT (Italy) and RU (Russia) are more important within the network, due to a tighter connection with other countries. We have also found that these countries play a significant role for Turkey’s foreign trade and have important implications for the design of portfolio and investment strategies.

Kantar, Ersin; Deviren, Bayram; Keskin, Mustafa

2011-10-01

221

Extrachromosomal circles of satellite repeats and 5S ribosomal DNA in human cells  

Microsoft Academic Search

BACKGROUND: Extrachomosomal circular DNA (eccDNA) is ubiquitous in eukaryotic organisms and was detected in every organism tested, including in humans. A two-dimensional gel electrophoresis facilitates the detection of eccDNA in preparations of genomic DNA. Using this technique we have previously demonstrated that most of eccDNA consists of exact multiples of chromosomal tandemly repeated DNA, including both coding genes and satellite

Sarit Cohen; Neta Agmon; Olga Sobol; Daniel Segal

2010-01-01

222

TNF/p38?/polycomb signaling to Pax7 locus in satellite cells links inflammation to the epigenetic control of muscle regeneration.  

PubMed

How regeneration cues are converted into the epigenetic information that controls gene expression in adult stem cells is currently unknown. We identified an inflammation-activated signaling in muscle stem (satellite) cells, by which the polycomb repressive complex 2 (PRC2) represses Pax7 expression during muscle regeneration. TNF-activated p38? kinase promotes the interaction between YY1 and PRC2, via threonine 372 phosphorylation of EZH2, the enzymatic subunit of the complex, leading to the formation of repressive chromatin on Pax7 promoter. TNF-? antibodies stimulate satellite cell proliferation in regenerating muscles of dystrophic or normal mice. Genetic knockdown or pharmacological inhibition of the enzymatic components of the p38/PRC2 signaling--p38? and EZH2--invariably promote Pax7 expression and expansion of satellite cells that retain their differentiation potential upon signaling resumption. Genetic knockdown of Pax7 impaired satellite cell proliferation in response to p38 inhibition, thereby establishing the biological link between p38/PRC2 signaling to Pax7 and satellite cell decision to proliferate or differentiate. PMID:20887952

Palacios, Daniela; Mozzetta, Chiara; Consalvi, Silvia; Caretti, Giuseppina; Saccone, Valentina; Proserpio, Valentina; Marquez, Victor E; Valente, Sergio; Mai, Antonello; Forcales, Sonia V; Sartorelli, Vittorio; Puri, Pier Lorenzo

2010-10-01

223

TNF/p38 alpha/Polycomb signalling to Pax7 locus in satellite cells links inflammation to the epigenetic control of muscle regeneration  

PubMed Central

How regeneration cues are converted into the epigenetic information that controls gene expression in adult stem cells is currently unknown. We identified a novel inflammation-activated signalling in muscle stem (satellite) cells, by which the Polycomb Repressive Complex 2 (PRC2) represses Pax7 expression during muscle regeneration. TNF-activated p38alpha kinase promotes the interaction between YY1 and PRC2, via threonine 372 phosphorylation of EzH2, the enzymatic sub-unit of the complex, leading to the formation of repressive chromatin on Pax7 promoter. Anti-TNF antibodies stimulate satellite cell proliferation in regenerating muscles of dystrophic or normal mice. Genetic knockdown or pharmacological inhibition of the enzymatic components of the p38/PRC2 signalling – p38alpha and EzH2 - invariably promote Pax7 expression and expansion of satellite cells that retain their differentiation potential upon signalling resumption. Genetic knockdown of Pax7 impaired satellite cell proliferation in response to p38 inhibition, thereby establishing the biological link between p38/PRC2 signalling to Pax7 and satellite cell decision to proliferate or differentiate.

Palacios, Daniela; Mozzetta, Chiara; Consalvi, Silvia; Caretti, Giuseppina; Saccone, Valentina; Proserpio, Valentina; Marquez, Victor E.; Valente, Sergio; Mai, Antonello; Forcales, Sonia V.; Sartorelli, Vittorio; Puri, Pier Lorenzo

2010-01-01

224

Turkey's foreign dependence on energy  

SciTech Connect

Turkey becomes more dependent on the external countries in energy production every year. As an average of the period 1994-2002 the total primary energy production has been 27.9 Mtoe, and consumption has been 73.06 Mtoe, so Turkey is dependent on external countries in petroleum, natural gas, and hard coal consumption. The external dependency rate of these fuels has been at levels of 89.3%, 96.6%, and 82%, respectively. In the projections of Turkey for 2020, the primary energy consumption is estimated to be 298 Mtoe, production is estimated to be 70 Mtoe, the ratio of production to consumption will be reduced to 23.5%, and this situation will cause serious risks for sustainable development. In other words, Turkey will have to import 76.5% of the energy that it consumes in the 2020s.

Uslu, T. [Karadeniz Technical University, Trabzon (Turkey). Dept. of Mining Engineering

2008-07-01

225

Applied Material Science in Turkey.  

National Technical Information Service (NTIS)

This report covers visits to several of Turkey's leading technical institutions and provides a survey of some of their facilities and ongoing research in applied material science; primarily with minerals, ceramics, polymers, and elastic constants. The ins...

L. Cartz

1987-01-01

226

Focal Degenerative Myopathy in Turkeys.  

National Technical Information Service (NTIS)

Approximately 10% of a large flock of Broad-Breasted White tom turkeys was clinically affected by lameness, varying degrees of locomotor incoordination, and poor weight gains. Some of the affected birds also exhibited torticollis. Muscle tissue from turke...

R. R. Maronpot T. J. Bucci M. A. Stedham

1968-01-01

227

Dual Oxidase Maturation factor 1 (DUOXA1) overexpression increases reactive oxygen species production and inhibits murine muscle satellite cell differentiation  

PubMed Central

Background Dual oxidase maturation factor 1 (DUOXA1) has been associated with the maturation of the reactive oxygen species (ROS) producing enzyme, dual oxidase 1 (DUOX1) in the adult thyroid. However, ROS have also been implicated in the development of several tissues. We found that activated muscle satellite cells and primary myoblasts isolated from mice express robust levels of DUOXA1 and that its levels are altered as cells differentiate. Results To determine whether DUOXA1 levels affect muscle differentiation, we used an adenoviral construct (pCMV5-DUOXA1-GFP) to drive constitutive overexpression of this protein in primary myoblasts. High levels of DUOXA1 throughout myogenesis resulted in enhanced H2O2 production, fusion defects, reduced expression of early (myogenin) and late (myosin heavy chain) markers of differentiation, and elevated levels of apoptosis compared to control cells infected with an empty adenoviral vector (pCMV5-GFP). DUOXA1 knockdown (using a DUOXA1 shRNA construct) resulted in enhanced differentiation compared to cells subjected to a control shRNA, and subjecting DUOXA1 overexpressing cells to siRNAs targeting DUOX1 or apoptosis signal-regulating kinase 1 (ASK1) rescued the phenotype. Conclusions This study represents the first to demonstrate the importance of DUOXA1 in skeletal muscle myoblasts and that DUOXA1 overexpression in muscle stem cells induces apoptosis and inhibits differentiation through DUOX1 and ASK1.

2014-01-01

228

Flight Data of a Cu(In,Ga)Se2 Thin-Film Solar Cell Module without a Coverglass by a Nano Satellite  

Microsoft Academic Search

A CIGS solar cell module without a coverglass was demonstrated by a small satellite since October 2005. A coverglass is normally used to protect the cell performance from low-energy (<3MeV) protons in space. This mission evaluates the model to assess the cell performance of CIGS solar cells, which thus far exhibited no degradation by thermal annealing effect in space. Flight

Shirou Kawakita; Mitsuru Imaizumi; Koichi Kibe; Yuya Nakamura; Shinichi Nakasuka

2009-01-01

229

Flight Data of a Cu(In,Ga)Se2 Thin-Film Solar Cell Module without a Coverglass by a Nano Satellite  

NASA Astrophysics Data System (ADS)

A CIGS solar cell module without a coverglass was demonstrated by a small satellite since October 2005. A coverglass is normally used to protect the cell performance from low-energy (<3MeV) protons in space. This mission evaluates the model to assess the cell performance of CIGS solar cells, which thus far exhibited no degradation by thermal annealing effect in space. Flight data indicates that the performance has showed no degradation for about 900 days.

Kawakita, Shirou; Imaizumi, Mitsuru; Kibe, Koichi; Nakamura, Yuya; Nakasuka, Shinichi

230

Devastating Earthquake in Turkey  

NSDL National Science Digital Library

The death toll will pass 10,000 today from Tuesday's earthquake, which measured 7.4 on the Richter scale and shattered a 400-mile stretch from northwestern Turkey to areas near central Ankara. Relief officials have publicly stated that they fear the worst for the estimated 35,000 people who remain trapped beneath rubble, as most will now have been without water for more than 72 hours. In addition to locating and rescuing survivors, the Turkish Government and international aid workers are working feverishly to organize relief efforts, prevent the spread of disease, repair damaged infrastructure, and contain a massive fire at the country's largest oil refinery. The sites listed provide information about this horrible act of nature

De Nie, Michael W.

231

Solar power satellite system definition study. Volume 4: Silicon solar cell annealing test, phase 1  

NASA Technical Reports Server (NTRS)

Laser annealing tests were conducted on ten 50 micron cells. Two were control cells that were not irradiated. These showed no loss in output due to exposure to the laser. Two cells were broken in handling. Six cells were successfully tested. All cells tested without breakage showed some recovery. One cell was subjected to two cycles and showed recovery on both cycles. Cells that were moderately degraded appeared to recover more completely than those more severly degraded. Exposure times ranged from two to ten seconds at 500 degrees centigrade. There was some indication that longer exposure was beneficial.

Walker, F.

1979-01-01

232

Self-renewal and differentiation of muscle satellite cells are regulated by the Fas-associated death domain.  

PubMed

Making the decision between self-renewal and differentiation of adult stem cells is critical for tissue repair and homeostasis. Here we show that the apoptotic adaptor Fas-associated death domain (FADD) regulates the fate decisions of muscle satellite cells (SCs). FADD phosphorylation was specifically induced in cycling SCs, which was high in metaphase and declined in later anaphase. Furthermore, phosphorylated FADD at Ser-191 accumulated in the uncommitted cycling SCs and was asymmetrically localized in the self-renewing daughter SCs. SCs containing a phosphoryl-mimicking mutation at Ser-191 of FADD (FADD-D) expressed higher levels of stem-like markers and reduced commitment-associated markers. Moreover, a phosphoryl-mimicking mutation at Ser-191 of FADD suppressed SC activation and differentiation, which promoted the cycling SCs into a reversible quiescent state. Therefore, these data indicate that FADD regulates the fate determination of cycling SCs. PMID:24375410

Cheng, Wei; Wang, Lu; Yang, Bingya; Zhang, Rong; Yao, Chun; He, Liangqiang; Liu, Zexu; Du, Pan; Hammache, Kahina; Wen, Juan; Li, Huang; Xu, Qiang; Hua, Zichun

2014-02-21

233

NOAA's Satellites  

NSDL National Science Digital Library

The National Oceanic & Atmospheric Administration (NOAA) maintains this centralized resource on NOAA satellites, of interest to life and physical scientists alike. Featured and described here are NOAA's National Environmental Satellite, Data and Information Service (NESDIS); NOAA's CoastWatch Program; and hundreds of Archived Satellite Images, Storm Animations and Special Events. Each section of the site points users to wealth of further information, spanning the technology of satellites to real-time satellite images. For users ranging from the curious student to the driven researcher, this site plays a central role in organizing NOAA satellite information.

234

Satellite reconnaissance  

NASA Astrophysics Data System (ADS)

The potential of the observation equipment in remote sensing satellites is described. United States meteorology, land use and oceanography satellites and the major US Earth observation programs are listed. Imaging satellite systems are described such as: visible light and near infrared, thermal IR window, and microwave window. It is concluded that a geometrical resolution between 10 and 40 m can be expected. In order to reduce the data flow from the satellite system the input side of the system (the object-sensor interaction) has to be known. Satellites with synthetic aperture radar are increasingly important, but satellites can never fully replace observations with aircraft and drones.

Deloor, G. P.

1984-06-01

235

Defects in glycosylation impair satellite stem cell function and niche composition in the muscles of the dystrophic Large(myd) mouse.  

PubMed

The dystrophin-associated glycoprotein complex (DGC) is found at the muscle fiber sarcolemma and forms an essential structural link between the basal lamina and internal cytoskeleton. In a set of muscular dystrophies known as the dystroglycanopathies, hypoglycosylation of the DGC component ?-dystroglycan results in reduced binding to basal lamina components, a loss in structural stability, and repeated cycles of muscle fiber degeneration and regeneration. The satellite cells are the key stem cells responsible for muscle repair and reside between the basal lamina and sarcolemma. In this study, we aimed to determine whether pathological changes associated with the dystroglycanopathies affect satellite cell function. In the Large(myd) mouse dystroglycanopathy model, satellite cells are present in significantly greater numbers but display reduced proliferation on their native muscle fibers in vitro, compared with wild type. However, when removed from their fiber, proliferation in culture is restored to that of wild type. Immunohistochemical analysis of Large(myd) muscle reveals alterations to the basal lamina and interstitium, including marked disorganization of laminin, upregulation of fibronectin and collagens. Proliferation and differentiation of wild-type satellite cells is impaired when cultured on substrates such as collagen and fibronectin, compared with laminins. When engrafted into irradiated tibialis anterior muscles of mdx-nude mice, wild-type satellite cells expanded on laminin contribute significantly more to muscle regeneration than those expanded on fibronectin. These results suggest that defects in ?-dystroglycan glycosylation are associated with an alteration in the satellite cell niche, and that regenerative potential in the dystroglycanopathies may be perturbed. PMID:22887880

Ross, Jacob; Benn, Abigail; Jonuschies, Jacqueline; Boldrin, Luisa; Muntoni, Francesco; Hewitt, Jane E; Brown, Susan C; Morgan, Jennifer E

2012-10-01

236

Satellite battery testing status  

NASA Technical Reports Server (NTRS)

Because of the large numbers of satellite cells currently being tested and anticipated at the Naval Weapons Support Center (NAVWPNSUPPCEN) Crane, Indiana, satellite cell testing is being integrated into the Battery Test Automation Project (BTAP). The BTAP, designed to meet the growing needs for battery testing at the NAVWPNSUPPCEN Crane, will consist of several Automated Test Stations (ATSs) which monitor batteries under test. Each ATS will interface with an Automation Network Controller (ANC) which will collect test data for reduction.

Haag, R.; Hall, S.

1986-01-01

237

Country Analysis Briefs: Turkey, April 17, 2014.  

National Technical Information Service (NTIS)

Turkey's importance in world energy markets is growing, both as a regional energy transit hub and as a growing consumer. Turkey's energy demand has increased rapidly over the past few years and likely will continue to grow in the future.

2014-01-01

238

Meteorological Satellites.  

National Technical Information Service (NTIS)

An overview is presented of the meteorological satellite programs that have been evolving from 1958 to the present, and plans for the future meteorological and environmental satellite systems that are scheduled to be placed into service in the early 1980'...

A. Schnapf A. Schwalb B. C. Diesen L. J. Allison P. S. Martin

1980-01-01

239

Tadpole Satellite.  

National Technical Information Service (NTIS)

A low cost synchronous orbit satellite to evaluate small mercury bombardment ion thruster applications is described. The ion thrusters provide the satellite with precise north-south and east-west stationkeeping capabilities. In addition, the thrusters are...

1974-01-01

240

Influence of Pasteurella multocida and high and low environmental temperatures on adrenals and bursa of Fabricius in turkeys  

SciTech Connect

The morphologic changes in the adrenals and bursa of Fabricius were evaluated from turkeys inoculated with Pasteurella multocida either in the palatine air spaces or via drinking water and maintained at high (33.4-37.4 C), low (2.6-5.3 C), and moderate (19.8-22.4 C) temperatures in temperature-controlled chambers. There was a slight hyperplasia of the adrenal cortical cells and a hypertrophy of the nuclei in the uninoculated turkeys maintained at both high and low temperatures, but these changes were more marked in turkeys maintained at low temperatures. Regardless of the temperature to which the turkeys were exposed, there was an increase in adrenal weight, hyperplasia of the cortical cells, hypertrophy of the nuclei of the cortical cells, and depletion of lipid in the cortical cells in the turkeys that became depressed after inoculation with P. multocida. In the uninoculated turkeys exposed to high temperatures there was a reduction in the weight of the bursa of Fabricius, atrophy of the follicles, and a reduction in the number of lymphocytes within the follicle, which did not occur in the bursae from uninoculated turkeys maintained at low temperatures. In the turkeys inoculated with P. multocida, there was a marked reduction in bursal weight, atrophy of the follicles, and reduction in the number of lymphocytes within the follicles.

Simensen, E.; Olson, L.D.; Hahn, G.L.

1980-01-01

241

Isolation and serological studies with infectious bursal disease viruses from fowl, turkeys and ducks: Demonstration of a second serotype  

Microsoft Academic Search

The isolation of a number of strains of infectious bursal disease (IBD) virus from fowl, turkeys and ducks is described. These isolates could be grouped into two serotypes using the neutralisation test. It is proposed that the cell culture adapted vaccine strain from fowl should be the prototype virus for serotype 1 and that the TY89 isolate from a turkey

J. B. McFerran; M. S. McNulty; E. R. McKillop; T. J. Connor; R. M. McCracken; D. S. Collins; G. M. Allan

1980-01-01

242

Insulin-like growth factor-I extends in vitro replicative life span of skeletal muscle satellite cells by enhancing G1/S cell cycle progression via the activation of phosphatidylinositol 3'-kinase/Akt signaling pathway  

NASA Technical Reports Server (NTRS)

Interest is growing in methods to extend replicative life span of non-immortalized stem cells. Using the insulin-like growth factor I (IGF-I) transgenic mouse in which the IGF-I transgene is expressed during skeletal muscle development and maturation prior to isolation and during culture of satellite cells (the myogenic stem cells of mature skeletal muscle fibers) as a model system, we elucidated the underlying molecular mechanisms of IGF-I-mediated enhancement of proliferative potential of these cells. Satellite cells from IGF-I transgenic muscles achieved at least five additional population doublings above the maximum that was attained by wild type satellite cells. This IGF-I-induced increase in proliferative potential was mediated via activation of the phosphatidylinositol 3'-kinase/Akt pathway, independent of mitogen-activated protein kinase activity, facilitating G(1)/S cell cycle progression via a down-regulation of p27(Kip1). Adenovirally mediated ectopic overexpression of p27(Kip1) in exponentially growing IGF-I transgenic satellite cells reversed the increase in cyclin E-cdk2 kinase activity, pRb phosphorylation, and cyclin A protein abundance, thereby implicating an important role for p27(Kip1) in promoting satellite cell senescence. These observations provide a more complete dissection of molecular events by which increased local expression of a growth factor in mature skeletal muscle fibers extends replicative life span of primary stem cells than previously known.

Chakravarthy, M. V.; Abraha, T. W.; Schwartz, R. J.; Fiorotto, M. L.; Booth, F. W.

2000-01-01

243

Time's Up, Turkey--Pop-Up Thermometers  

ERIC Educational Resources Information Center

Meat thermometers can be awkward to use in terms of placement and avoidance of bones. Because of these problems, each year 30 million Thanksgiving turkeys have a built-in thermometer that pops up when the turkey is properly cooked. Turkey timers are an example of how engineering solved a common, everyday problem. The following 5E learning cycle…

Moyer, Richard; Everett, Susan

2009-01-01

244

Coal as an Energy Source in Turkey  

Microsoft Academic Search

The objective of this study is to investigate many aspects of coal as an energy source in Turkey, giving the structure of the Turkish coal industry, Turkey's coal reserves, and environmental concerns. Turkey has mainly hard coal (HC) and lignite (LG) reserves with 1,126 million tons (Mt) and 8,375 Mt as of 1999, respectively. Rich LG deposits are spread all

ARIF HEPBASLI

2004-01-01

245

Management Plan for Wild Turkeys in Pennsylvania.  

National Technical Information Service (NTIS)

The wild turkey (Meleagris gallopavo) is native to North America. Of six subspecies, the eastern wild turkey (M. g. silvestris) is the only one to have occurred in Pennsylvania. Wild turkeys are our largest gallinaceous game bird. The males, or gobblers, ...

W. E. Drake

1999-01-01

246

Development works on nickel/hydrogen cells. [for satellite energy storage  

NASA Technical Reports Server (NTRS)

Experiments were performed to reduce the costs for NI/H2 cells by using nickel oxide electrodes with high capacity per unit area. No maintenance requirements, long cycle life, insensitivity to overcharge and cell reversal, and high power capability were revealed.

Gutmann, G.

1982-01-01

247

Absence of exogenous satellite cell contribution to regeneration of frozen skeletal muscle  

Microsoft Academic Search

Summary Rat extensor digitorum longus (EDL) muscles were repeatedly frozen and thawed to kill completely all cellular constituents. Within four days, blood vessels and phagocytic cells invaded the muscles. Migrating or circulating myoblasts were not among the invading cells, and could be induced to invade the frozen muscle only when a physical bridge was created with an adjacent intact muscle.

E. Schultz; D. L. Jaryszak; M. C. Gibson; D. J. Albright

1986-01-01

248

On the spatial extent of the proton radiation belt from solar cell output variation of the Akebono satellite  

NASA Astrophysics Data System (ADS)

Output current of silicon solar cells of Akebono satellite orbiting in the inner magnetosphere decreased from 13 A in 1989 to about 7 A in 2009, due to accumulated damage by energetic particles. A fair correlation between the monthly decrease rate of solar cell output current and trapped proton flux was found between 1989 and 1992, indicating that trapped energetic protons are responsible for the solar cell degradation. Simple variation from month to month was dominated by a fluctuation with one-year period and the correlation was not discernible after 1993. On the other hand, during orbiting the earth, another kind of decrease of output current emerged at low altitude above the sub-solar point, i.e., in the midst of sunlit condition. The decrease was larger in later years. The fact indicates more prominent temperature effect in the later years because of progress of the degradation. By removing data affected by the orbit condition above, variation from the same month in the previous year shows a clear oscillation due to orbit precession correlated with trapped energetic proton flux up to 1996. The amplitude of the annual variation oscillation tends to be larger than that expected from a degradation model based on energetic proton distribution of the NASA’s AP8 model. The larger oscillation amplitude suggests that the proton radiation belt was more sharply localized than given by the AP8 model throughout the early half of 1990s.

Miyake, W.; Miyoshi, Y.; Matsuoka, A.

2014-06-01

249

A comparison of virulence of influenza A virus isolates from mallards in experimentally inoculated turkeys.  

PubMed

Low pathogenic avian influenza viruses (LPAIV) from wild waterfowl can and do cross species barriers, infecting and sometimes becoming established in domestic poultry. Turkeys are naturally highly susceptible to LPAIV infections, especially with viruses from ducks. In this study, we describe clinical signs and lesions in experimentally inoculated commercial turkeys produced by a LPAIV, A/mallard/MN/1714/09 (H7N1), isolated from a mallard duck. Our results demonstrate that this H7N1 isolate produced clinical signs, including severe edema of the head and face because of an early inflammatory response in both inoculated and contact turkeys. In comparison, an isolate, A/mallard/MN/2749/09 (H6N8) from the same mallard population, infected and was transmitted between naive turkeys but did not cause clinical disease or lesions. Our data indicate that proinflammatory (IL-1beta, TNF-alpha, and IL-6) and antiviral (IFN-gamma and IL-2) cytokines are expressed at different levels in H7N1- and H6N8-infected turkey peripheral blood mononuclear cells. These differences correlate inversely with clinical lesions, suggesting that differences in host responses result in variances in viral pathogenesis and in virulence of LPAIV in commercial turkeys. Based on these results, we can conclude that turkeys may exhibit variable immunologic responses to infection with different AIV strains. PMID:24597123

Mondal, Shankar; Xing, Zheng; Cardona, Carol

2013-12-01

250

Turkey vulture surveys in Cuba  

USGS Publications Warehouse

Turkey Vultures (Cathartes aura), were surveyed monthly in Cuba from March 1982-January 1983. A total of 25371 vultures were tallied in 7186 km (3.5 vultures/transect km) of roadside counting along main highways leading from the city of La Habana (northwestern Cuba) to the city of Las Tunas (southeast). Numbers of vultures counted declined substantially beyond 200 m from the transect road. Density of vultures observed within 200 m of the road along the transect route was 0.06/ha. Highest counts were obtained in March, April and June. Turkey Vulture flying activity was greatest during the periods 0900-1200 H and 1400-1700 H.

Wotzkow, C.; Wiley, J.W.

1988-01-01

251

Evaluation of solar cells and arrays for potential solar power satellite applications  

NASA Technical Reports Server (NTRS)

Proposed solar array designs and manufacturing methods are evaluated to identify options which show the greatest promise of leading up to the develpment of a cost-effective SPS solar cell array design. The key program elements which have to be accomplished as part of an SPS solar cell array development program are defined. The issues focussed on are: (1) definition of one or more designs of a candidate SPS solar array module, using results from current system studies; (2) development of the necessary manufacturing requirements for the candidate SPS solar cell arrays and an assessment of the market size, timing, and industry infrastructure needed to produce the arrays for the SPS program; (3) evaluation of current DOE, NASA and DOD photovoltaic programs to determine the impacts of recent advances in solar cell materials, array designs and manufacturing technology on the candidate SPS solar cell arrays; and (4) definition of key program elements for the development of the most promising solar cell arrays for the SPS program.

Almgren, D. W.; Csigi, K.; Gaudet, A. D.

1978-01-01

252

Turkey’s Kurdish Problem: Steps Toward a Solution  

Microsoft Academic Search

Deep Kurdish and Turkish mistrust for each other, continuing PKK terrorist activity, the inadequacy of the government's reform measures, and the divided leadership of the Kurdish community are among many factors inhibiting a democratic solution of Turkey's Kurdish problem. This article recommends several measures for immediate implementation, including: “civic action” training for Turkish military and security personnel; open-ended conversations between

Emrullah Uslu

2007-01-01

253

Satellite telemetry  

NASA Astrophysics Data System (ADS)

Hydrologic application of satellite data collection systems in Brazil is discussed. The Data Collection Platform (DCP) is a telemetry station used for the acquisition of environmental parameters. Artificial satellites are employed to relay the data to receiving centers. Two meteorologic satellite data collection systems are in operation in Brazil: the ARGOS system, on board low-orbit (850 km) satellites of the TIROS-NOAA series, and the Geostationary Operational Satellite (GOES) system, on board geostationary satellites (36,000 km) of the SMS/GOES series. DCPs have been used mainly in the field of hydrology to obtain timely data, to make decisions, and to compose historical records. The first DCP network established in Brazil was in the Tocantins Basin, which has 10 telemetry stations. Other networks are currently being planned. Prototypes of ARGOS and GOES DCPs are being developed that are aimed at further industrialization and improved supply of national demand.

Deolveira, J. R.

1983-08-01

254

Activation State of Muscle Satellite Cells Isolated from Steers Implanted with a Combined Trenbolone Acetate and Estradiol Implant1,2  

Microsoft Academic Search

Muscle satellite cells were isolated from seven yearling steers implanted for 31 d with a combined implant that contained 120 mg of trenbolone acetate (TBA) and 24 mg of estradiol (E 2) and from seven nonimplanted, control steers. Implanted steers had a 28% greater ADG and a 23% greater feed efficiency than did nonimplanted steers. Implanted steers had increased (

B. J. Johnson; N. Halstead; M. E. White; M. R. Hathaway; A. DiCostanzo; W. R. Dayton

2010-01-01

255

Healthy satellites provide quality service  

NASA Astrophysics Data System (ADS)

The procedures used by Telesat Canada to ensure the performance of Anik satellites is described. At the Satellite Telemetry, Tracking and Command station, each Anik satellite has its own dedicated antenna. Telemetered information from the satellites is received, processed and forwarded to the Satellite Control Center. There the satellite controllers issue all commands to the satellites, and continually monitor the telemetered data. These data, describing the state of health of the satellites, are then analyzed by engineering specialists. The satellites are held in their precise orbital positions by means of specially developed software. The Anik C and D satellites employ travelling wave tube amplifiers (TWTAs) in the transpounder channels. The TWTA saturated flux density (SFD) and equivalent isotropic radiated power (EIRP) are regularly measured and their trends scrutinized. This ensures that customers receive the radio frequency power needed for high-quality service. The satellite electrical power is supplied by the solar cell array and batteries. Power system performance is evaluated regularly to ensure that power is available to operate the required number of TWTAs. In addition to rain-fades, short service interruptions can be caused by high voltage trip-offs of TWTAs, and by electrostatic discharge related anomalies. To minimize these interruptions, Telesat ensures that the satellite controllers are fully trained and prepared for any eventuality, and the relevant operational procedures are continually refined. A fully trained staff of satellite controllers keep interruptions caused by high voltage trip-offs of TWTAs and by electrostatic discharge to a minimum.

Margittai, Paul

256

Labour migration from Turkey.  

PubMed

This study is concerned with Turkish labor migration to Western Europe. Earlier and recent patterns of labor migration, characteristics of migrants by occupation, area of destination, and by geographical origins are discussed. Economic and demographic consequences of labor migration are also analyzed. It is estimated that Turkey's population will reach 73 million at the year 2000 with the present growth rate of 2.48% annually. Considering the efforts made to slow down the present high fertility rates and assuming that the decrease in labor force participation during 1970-1980 continues, the author concludes that the labor supply will increase with a growth rate of 2% annually for the next 13-15 years. Thus, the labor supply will reach 26.6 million people in the year 2000 from the 1980 level of 17.8 million. Assuming also that the income/employment elasticity of .25 which was observed throughout the period of 1960-1980 will not change until 2000, the annual growth rate of employment may be estimated as 1.5%. Thus, the number of people employed will reach 20 million in the year 1990 and 23.2 million in the year 2000. 8.8 million people will join the labor market as new entrants between 1980 and 2000. Only 6 million people out of 8.8 million will be employed. Thus, in the year 2000, it is estimated that 2.8 million new unemployed people will be added to the already open unemployment figure 1980 census data give the number of unemployed as .6 million people. Adding the 2.8 million new unemployed to this figure totals 3.4 million unemployed in 2000. The State Planning Organization's estimate of labor surplus for 1980 was 2.5 million people. When 2.8 million unemployed people are added to this figure, the labor surplus for the year 2000 reaches 5.3 million people. PMID:12342136

Uner, S

1988-01-01

257

Regenerative fuel cell systems for mid- to high-orbit satellites  

NASA Technical Reports Server (NTRS)

An assessment of the present and projected capabilities of selected hydrogen-oxygen and hydrogen-halogen fuel cell and electrolyzer combinations for energy storage systems (ESS) in configurations useful for spacecraft missions operating in the 10- to 50-kW range for many years in midaltitude to geosynchronous orbits has recently been completed. Results of the study indicate that regenerative fuel cell ESS are feasible for the intended application. A computer model was used to provide tradeoff analyses for optimizing the various ESS fuel cell concepts. When appropriately configured to be compatible with the mission needs of the selected model spacecraft, the specific energy for these ESS are intermediate between that presently available for nickel-hydrogen batteries and that expected for the newly emerging sodium-sulfur technology.

Taenaka, R. K.; Adler, E.; Stofel, E. J.; Clark, K. B.

1987-01-01

258

Community effect triggers terminal differentiation of myogenic cells derived from muscle satellite cells by quenching Smad signaling  

SciTech Connect

A high concentration of bone morphogenetic proteins (BMPs) stimulates myogenic progenitor cells to undergo heterotopic osteogenic differentiation. However, the physiological role of the Smad signaling pathway during terminal muscle differentiation has not been resolved. We report here that Smad1/5/8 was phosphorylated and activated in undifferentiated growing mouse myogenic progenitor Ric10 cells without exposure to any exogenous BMPs. The amount of phosphorylated Smad1/5/8 was severely reduced during precocious myogenic differentiation under the high cell density culture condition even in growth medium supplemented with a high concentration of serum. Inhibition of the Smad signaling pathway by dorsomorphin, an inhibitor of Smad activation, or noggin, a specific antagonist of BMP, induced precocious terminal differentiation of myogenic progenitor cells in a cell density-dependent fashion even in growth medium. In addition, Smad1/5/8 was transiently activated in proliferating myogenic progenitor cells during muscle regeneration in rats. The present results indicate that the Smad signaling pathway is involved in a critical switch between growth and differentiation of myogenic progenitor cells both in vitro and in vivo. Furthermore, precocious cell density-dependent myogenic differentiation suggests that a community effect triggers the terminal muscle differentiation of myogenic cells by quenching the Smad signaling.

Yanagisawa, Michiko [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan) [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan); Aging Research, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550 (Japan); Mukai, Atsushi; Shiomi, Kosuke [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan)] [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan); Song, Si-Yong [Institute of Neuroscience, Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, 1314-1 Shido, Sanuki-shi, Kagawa 769-2193 (Japan)] [Institute of Neuroscience, Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, 1314-1 Shido, Sanuki-shi, Kagawa 769-2193 (Japan); Hashimoto, Naohiro, E-mail: nao@ncgg.go.jp [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan)] [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan)

2011-01-15

259

9 CFR 146.43 - Terminology and classification; meat-type turkey slaughter plants.  

Code of Federal Regulations, 2010 CFR

...Terminology and classification; meat-type turkey slaughter plants. 146.43 Section...meat-type turkey slaughter plants. Participating meat-type turkey slaughter...meat-type turkey slaughter plant. A participating meat-type turkey...

2010-01-01

260

9 CFR 146.43 - Terminology and classification; meat-type turkey slaughter plants.  

Code of Federal Regulations, 2010 CFR

...Terminology and classification; meat-type turkey slaughter plants. 146.43 Section...meat-type turkey slaughter plants. Participating meat-type turkey slaughter...meat-type turkey slaughter plant. A participating meat-type turkey...

2009-01-01

261

Sciatic nerve injury induces apoptosis of dorsal root ganglion satellite glial cells and selectively modifies neurosteroidogenesis in sensory neurons.  

PubMed

Neurosteroids are synthesized either by glial cells, by neurons, or within the context of neuron-glia cross-talk. Various studies suggested neurosteroid involvement in the control of neurodegeneration but there is no evidence showing that the natural protection of nerve cells against apoptosis directly depends on their own capacity to produce neuroprotective neurosteroids. Here, we investigated the interactions between neurosteroidogenesis and apoptosis occurring in sensory structures of rats subjected to neuropathic pain generated by sciatic nerve chronic constriction injury (CCI). Using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), we observed no apoptotic cells in the spinal cord up to 30 days after CCI although pain symptoms such as mechano-allodynia, thermal and mechanical hyperalgesia were evidenced with the Hargreaves's behavioral and von Frey filament tests. In contrast, double-labeling experiments combining TUNEL and immunostaining with antibodies against glutamine synthetase or neuronal nuclei protein revealed apoptosis occurrence in satellite glial cells (SGC) (not in neurons) of CCI rat ipsilateral dorsal root ganglia (DRG) at day 30 after injury. Pulse-chase experiments coupled with high performance liquid chromatography and flow scintillation detection showed that, among numerous biosynthetic pathways converting [(3)H]pregnenolone into various [(3)H]neurosteroids, only [(3)H]estradiol formation was selectively modified and upregulated in DRG of CCI rats. Consistently, immunohistochemical investigations localized aromatase (estradiol-synthesizing enzyme) in DRG neurons but not in SGC. Pharmacological inhibition of aromatase caused apoptosis of CCI rat DRG neurons. Altogether, our results suggest that endogenously produced neurosteroids such as estradiol may be pivotal for the protection of DRG sensory neurons against sciatic nerve CCI-induced apoptosis. PMID:19565659

Schaeffer, Véronique; Meyer, Laurence; Patte-Mensah, Christine; Eckert, Anne; Mensah-Nyagan, Ayikoe G

2010-01-15

262

Sphingosine-1-Phosphate Enhances Satellite Cell Activation in Dystrophic Muscles through a S1PR2/STAT3 Signaling Pathway  

PubMed Central

Sphingosine-1-phosphate (S1P) activates a widely expressed family of G protein-coupled receptors, serves as a muscle trophic factor and activates muscle stem cells called satellite cells (SCs) through unknown mechanisms. Here we show that muscle injury induces dynamic changes in S1P signaling and metabolism in vivo. These changes include early and profound induction of the gene encoding the S1P biosynthetic enzyme SphK1, followed by induction of the catabolic enzyme sphingosine phosphate lyase (SPL) 3 days later. These changes correlate with a transient increase in circulating S1P levels after muscle injury. We show a specific requirement for SphK1 to support efficient muscle regeneration and SC proliferation and differentiation. Mdx mice, which serve as a model for muscular dystrophy (MD), were found to be S1P-deficient and exhibited muscle SPL upregulation, suggesting that S1P catabolism is enhanced in dystrophic muscle. Pharmacological SPL inhibition increased muscle S1P levels, improved mdx muscle regeneration and enhanced SC proliferation via S1P receptor 2 (S1PR2)-dependent inhibition of Rac1, thereby activating Signal Transducer and Activator of Transcription 3 (STAT3), a central player in inflammatory signaling. STAT3 activation resulted in p21 and p27 downregulation in a S1PR2-dependent fashion in myoblasts. Our findings suggest that S1P promotes SC progression through the cell cycle by repression of cell cycle inhibitors via S1PR2/STAT3-dependent signaling and that SPL inhibition may provide a therapeutic strategy for MD.

Carlson, Morgan E.; Oskouian, Babak; Kumar, Ashok; Fyrst, Henrik; Zhang, Meng; Proia, Richard L.; Hoffman, Eric P.; Saba, Julie D.

2012-01-01

263

Relaxin Regulates MMP Expression and Promotes Satellite Cell Mobilization During Muscle Healing in Both Young and Aged Mice  

PubMed Central

The polypeptide hormone relaxin has been proven to be effective in promoting both the remodeling and regeneration of various tissues, including cardiac muscle. In addition, our previous study demonstrated that relaxin is beneficial to skeletal muscle healing by both promoting muscle regeneration and preventing fibrosis formation. However, the molecular and cellular mechanisms of relaxin in regulating both myogenic cell differentiation and muscle healing process are still unclear. In this study, C2C12 mouse myoblasts and primary human myoblasts were treated with relaxin to investigate its potential effect in vitro; relaxin was also injected intramuscularly into the injured site of the mouse on the second day after injury to observe its function in vivo, especially in the aged muscle. Results showed that relaxin promoted myogenic differentiation, migration, and activation of matrix metalloproteinases (MMPs) of cultured myoblasts in vitro. In the injured muscle, relaxin administration promoted the activation of Pax7-positive skeletal muscle satellite cells and increased its local population compared with nontreated control muscles. Meanwhile, both angiogenesis and revascularization were increased, while the extended inflammatory reaction was repressed in the relaxin-treated injured muscle. Moreover, relaxin similarly promoted muscle healing in mice with aged muscle. These results revealed the multiple effects of relaxin in systematically improving muscle healing as well as its potential for clinical applications in patients with skeletal muscle injuries and diseases.

Mu, Xiaodong; Urso, Maria L.; Murray, Kiley; Fu, Freddie; Li, Yong

2010-01-01

264

Artificial Satellites  

NSDL National Science Digital Library

Over 2,000 man-made satellites are currently orbiting the Earth, providing a wide range of services like communications, remote sensing, and global positioning. As more are launched and new technologies are developed, they will play an increasingly important role in everyday life.The Tech Museum offers this site (1) dedicated to the basics of satellites and their functions. A Java program complements the Satellite Anatomy section, which illustrates the standard components of three different categories of satellites. More information specific to satellite launches and their orbits can be found here (2). Most of the material is composed of fun experiments that demonstrate satellite operation. One of the most interesting features on this NASA site (3) is the Live 3D Java Tracking Display, which shows hundreds of different satellites and their current position in orbit. A few selected news articles and a separate section on satellite applications are also provided. The European Space Agency provides a look at solar power satellites (4), which could essentially "beam" energy to Earth. While it is not a new concept, the sheer magnitude of a project to construct a solar power satellite has thus far been too great to justify an attempt. At a conference held in December 2002 (5), representatives from the satellite industry convened to discuss current developments. Although many of the articles only address industry outlooks, some are more technology-oriented. For instance, one considers a new navigation system that could improve overall coverage and signal availability. A lesson plan (6) for grades K-5 teaches children how satellites are launched and some basic terminology. The activity uses different sized marbles, clay, and some other items to demonstrate fundamental concepts. Satellites of the Global Positioning System are being used for more than they were originally intended in England. This news article (7) describes how they are used to study earthquakes and corresponding movements in the Earth's crust. In other news (8), the largest communications satellite ever built was lost in November 2002. The failure of one of its launching rockets resulted in the satellite falling in a decaying orbit until it fell into the sea.

Leske, Cavin.

2003-01-01

265

Suicide in Batman, Southeastern Turkey  

ERIC Educational Resources Information Center

The southeastern part of Turkey has comparatively high female suicide rates. We aimed to research social, economic, cultural, and psychiatric reasons of suicides in Batman in a case-controlled psychological autopsy study comparing suicides with matched community controls. The female suicide rate was 9.3 per 100.000 and the female/male ratio was…

Altindag, Abdurrahman; Ozkan, Mustafa; Oto, Remzi

2005-01-01

266

Internet financial reporting in Turkey  

Microsoft Academic Search

Purpose – This paper aims to investigate internet financial reporting following major regulatory changes in Turkey. Although these regulations only cover publicly listed firms, large unlisted firms also use the internet to disseminate financial information. Design\\/methodology\\/approach – The study surveys the top 500 Turkish industrial firms on the “Istanbul Chamber of Industry 500” (ICI500) to determine whether the regulatory changes

Aslihan E. Bozcuk; Sinan Aslan; S. Burak Arzova

2011-01-01

267

Self-Study Guide: Turkey.  

National Technical Information Service (NTIS)

The purpose of this self-study guide is to provide basic background information on Turkey for persons being assigned there. The guide tries to present the information in a way that individuals can obtain a better understanding of the country and, as a res...

2010-01-01

268

Renewable energy policies in Turkey  

Microsoft Academic Search

Achieving solution to environmental problems that we face today requires long-term potential actions for sustainable development. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions. Although, Turkey has substantial reserves of renewable energy resources, actual utilization of these resources are quite low.The aim of this study is to investigate the renewable

Durmus Kaya

2006-01-01

269

Women in physics in Turkey  

NASA Astrophysics Data System (ADS)

This study tries to tackle improving women's participation in physics in Turkey, and at the same time gather statistical data that could be evaluated against other nations' progress on this issue. The most important aim of this discussion is to prevent the underutilization of potentially qualified women in science.

Er, Zuhal; U?ur, ?aziye; Akta?, Demet Kaya

2013-03-01

270

Soaring Satellites  

NSDL National Science Digital Library

Working in small teams, learners try to build a satellite that can float for at least five seconds in the marked area of a vertical wind tube. Learners think about and explore the concepts of lift and weight as they try to adapt their satellite to hover between the lines.

Museum Of Science, Boston

2010-01-01

271

Satellite Tracker  

NSDL National Science Digital Library

Students use satellite tracking software available on the Internet to monitor a very large satellite, the International Space Station. Using information from this online resource, students predict and graph the motion of the space station at their location and create a 3-D display of its path through the sky.

Integrated Teaching And Learning Program

272

Fluid satellite  

Microsoft Academic Search

Rotating planet and satellite systems with large mass ratios are examined in terms of the stability of the systems, particularly for conditions which result in the formation of planet-moon systems such as Pluto-Charon. The planet is modeled as a Maclaurin spheroid massive enough to experience little influence by the satellite. Several equilibrium sequences are calculated for the shapes which can

I. Hachisu; Y. Eriguchi

1985-01-01

273

Meteorological satellites  

NASA Technical Reports Server (NTRS)

An overview is presented of the meteorological satellite programs that have been evolving from 1958 to the present, and plans for the future meteorological and environmental satellite systems that are scheduled to be placed into service in the early 1980's are reviewed. The development of the TIROS family of weather satellites, including TIROS, ESSA, ITOS/NOAA, and the present TIROS-N (the third generation operational system) is summarized. The contribution of the Nimbus and ATS technology satellites to the development of the operational-orbiting and geostationary satellites is discussed. Included are descriptions of both the TIROS-N and the DMSP payloads currently under development to assure a continued and orderly growth of these systems into the 1980's.

Allison, L. J. (editor); Schnapf, A.; Diesen, B. C., III; Martin, P. S.; Schwalb, A.; Bandeen, W. R.

1980-01-01

274

Essential environmental cues from the satellite cell niche: optimizing proliferation and differentiation.  

PubMed

The use of muscle progenitor cells (MPCs) for regenerative medicine has been severely compromised by their decreased proliferative and differentiative capacity after being cultured in vitro. We hypothesized the loss of pivotal niche factors to be the cause. Therefore, we investigated the proliferative and differentiative response of passage 0 murine MPCs to varying substrate elasticities and protein coatings and found that proliferation was influenced only by elasticity, whereas differentiation was influenced by both elasticity and protein coating. A stiffness of 21 kPa optimally increased the proliferation of MPCs. Regarding differentiation, we demonstrated that fusion of MPCs into myotubes takes place regardless of elasticity. However, ongoing maturation with cross-striations and contractions occurred only on elasticities higher than 3 kPa. Furthermore, maturation was fastest on poly-d-lysine and laminin coatings. PMID:19321742

Boonen, K J M; Rosaria-Chak, K Y; Baaijens, F P T; van der Schaft, D W J; Post, M J

2009-06-01

275

Monitoring and Measures on Pops in Turkey  

Microsoft Academic Search

Turkey signed the Stockholm Convention on May 23, 2001, with the objective of protecting human health and environment, focusing\\u000a on eliminating or reducing releases of 12 POPs, the “Dirty Dozen”. Turkey has developed its National Implementation Plan (NIP)\\u000a as a Party to the Stockholm Convention. The NIP sets out how the Stockholm Convention is being implemented in Turkey and outlines

Özcan Ceylan

276

Landslide susceptibility mapping for Ayvalik (Western Turkey) and its vicinity by multicriteria decision analysis  

Microsoft Academic Search

This paper presents the results of geographical information system (GIS)-based landslide susceptibility mapping in Ayval?k,\\u000a western Turkey using multi-criteria decision analysis. The methodology followed in the study includes data production, standardization,\\u000a and analysis stages. A landslide inventory of the study area was compiled from aerial photographs, satellite image interpretations,\\u000a and detailed field surveys. In total, 45 landslides were recorded and

Aykut Akgun; Necdet Türk

2010-01-01

277

Heat shock factor 1 binds to and transcribes satellite II and III sequences at several pericentromeric regions in heat-shocked cells  

SciTech Connect

Cells respond to stress by activating the synthesis of heat shock proteins (HSPs) which protect the cells against the deleterious effects of stress. This mechanism is controlled by the heat shock factor 1 (HSF1). In parallel to HSP gene transcription, in human cells, HSF1 also binds to and transcribes satellite III repeated sequences present in numerous copies in the 9q12 pericentromeric region of chromosome 9. These HSF1 accumulation sites are termed nuclear stress bodies (nSBs). In tumor cells, however, the number of nSBs is higher than the number of 9q12 copies, suggesting the existence of other HSF1 targets. In this paper, we were interested in characterizing these other HSF1 binding sites. We show that HSF1 indeed binds to the pericentromeric region of 14 chromosomes, thereby directing the formation of 'secondary nSBs'. The appearance of secondary nSBs depends on the number of satellite sequences present in the target locus, and on the cellular amount of HSF1 protein. Moreover, secondary nSBs also correspond to transcription sites, thus demonstrating that heat shock induces a genome-wide transcription of satellite sequences. Finally, by analyzing published transcriptomic data, we show that the derepression of these large heterochromatic blocks does not significantly affect the transcription of neighboring genes.

Eymery, Angeline, E-mail: aeymery@gmail.com [Universite Joseph Fourier-Grenoble I (France) [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Souchier, Catherine, E-mail: catherine.souchier@ujf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France) [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Vourc'h, Claire, E-mail: claire.vourch@ujf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France) [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France); Jolly, Caroline, E-mail: caroline.jolly@upmf-grenoble.fr [Universite Joseph Fourier-Grenoble I (France) [Universite Joseph Fourier-Grenoble I (France); INSERM Institut Albert Bonniot U823, La Tronche, F-38700 (France)

2010-07-01

278

[Plant poisoning cases in Turkey].  

PubMed

In Turkey, the majority of the population live in rural areas where they use wild plants as food and medicine. The confusion of an edible plant with a poisonous one give rise to serious poisoning which may even result in death. The incidence of plant poisoning in Turkey is about 6% and especially high among children between ages of 2 and 11 living in rural areas. The number of species that cause poisoning is around twenty and Hyoscyamus niger (Solanaceae), Colchicum species (Liliaceae), Conium maculatum (Umbelliferae) and Prunus species (Rosaceae) are the most important. Mushroom poisoning is more frequent in spring and fall. The main reasons are their widespread usage as food and the inexperience of the gatherers in distinguishing the edibles from the poisonous. Amanita phalloides, A. verna, A. muscaria, A. pantherina are responsible for severe cases of poisoning. PMID:7857034

Oztekin-Mat, A

1994-01-01

279

Turkey: World Oil Report 1991  

SciTech Connect

This paper reports on a marked oil production increase, an exploration program in the Black Sea and the planned development of an offshore gas field in the Sea of Mamara in Turkey. The production increase stems from development of new fields in southeastern Turkey by Turkiye Petrolleri Anonim Ortakligi (TPAO), the national oil company. Discovered in 1989, development of Kahta, Karakus, Cendere and several other nearby finds have pushed Turkish crude output to the highest level in 14 years. Last May, BP entered into a three-year joint venture with TPAO to explore a 29,344 sq mi area in the Black Sea in waters to 6,500+ ft deep. The three-year program calls for BP to run seismic this year followed by its Airborne Laser Fluorosensor survey technique. Drilling will depend on survey results.

Not Available

1991-08-01

280

Cerebral encephalomalacia in commercial turkeys.  

PubMed

A flock of 9 1/2-week-old commercial tom turkeys experienced high mortality after consuming a complete feed containing an unidentified toxic substance. Initially, turkeys were found dead. Clinically, the birds were calm and still but became hyperexcitable with noise. A small percentage of birds exhibited torticollis, opisthotonos, circling, ataxia, and blindness. Findings at necropsy and upon microscopic examination were bilaterally symmetrical areas of necrosis of the cerebral hemispheres in the area of the neostriatum that were well demarcated from the surrounding normal neuropil. A feeding trial with the suspect feed in twelve 4-week-old turkey hens induced clinical disease and gross and microscopic brain changes similar to those observed in the field case. Analyses for the following substances in the suspect feed were either negative or within acceptable limits: salt, selenium, furazolidone, monensin, amprolium, 3-nitro-4-hydroxyphenylarsonic acid, aflatoxin, deoxynivalenol, zearalenone, T-2 toxin, ochratoxin, fumonisin, organophosphates, chlorinated hydrocarbons, and carbamates. The toxic component of the feed remains unidentified. PMID:8257395

Ficken, M D; Cummings, T S; Wages, D P

1993-01-01

281

Effect of ractopamine-hydrochloride and trenbolone acetate on longissimus muscle fiber area, diameter, and satellite cell numbers in cull beef cows1  

Microsoft Academic Search

The objective of this study was to evalu- ate the effects of coadministration of ractopamine-HCl (RAC) and trenbolone acetate plus estradiol (TBA) on LM fiber cross-sectional area (CSA), diameter, fiber- associated myonuclei, and satellite cell number. Culled crossbred beef cows (n = 98; 11 ± 1.8 yr old; BCS 4.3 ± 0.03) from a single ranch in south Florida were

J. M. Gonzalez; J. N. Carter; D. D. Johnson; S. E. Ouellette; S. E. Johnson

2010-01-01

282

Small satellites  

NASA Technical Reports Server (NTRS)

Satellites smaller than Mimas (r = 195 km) are distinguished by irregular overall shapes and by rough limb topography. Material properties and impact cratering dominate the shaping of these objects. Long fragmentation histories can produce a variety of internal structures, but so far there is no direct evidence that any small satellite is an equilibrium ellipsoid made up of noncohesive gravitationally bound rubble. One many bodies that orbit close to their primary the tidal and rotational components of surface gravity strongly affect the directions of local g and thereby affect the redistribution of regolith by mass wasting. Downslope movement of regolith is extensive on Deimos, and is probably effective on many other small satellites. It is shown that in some cases observed patterns of downslope mass wasting cold produce useful constraints on the satellite's mean density. The diversity of features seen in the few high-resolution images of small satellites currently available suggests that these objects have undergone complex histories of cratering, fragmentation, and regolith evolution.

Thomas, P.; Veverka, J.; Dermott, S.

1986-01-01

283

Turkey's Political Identity: East vs. West?  

Microsoft Academic Search

As a secular Islamic nation, Turkey has not only been an ally of the West but also the bridge to relations with the East. Turkey's secular nature is attributed to Mustafa Kemal Ataturk's political, economic, and cultural reforms, which took place during the establishment of the Turkish Republic in the early 1920s. Since then, the Turkish army has been the

Tervanda Ayrapetyan

2007-01-01

284

Rise of Political Islam in Turkey.  

National Technical Information Service (NTIS)

As a Muslim-majority country that is also a secular democratic state, a member of NATO, and a long-standing U.S. ally, Turkey is pivotal to U.S. strategy to shape the Middle Eastern security environment. Turkey also is a key test case for the role of Isla...

A. Rabasa F. S. Larrabee

2008-01-01

285

Rights of the Child in Turkey.  

ERIC Educational Resources Information Center

This report to the United Nations Convention on the Rights of the Child contains observations of the World Organisation Against Torture (OMCT) concerning the application of the Convention by Turkey and observations regarding violence against girls in Turkey. The report is presented in three major parts. Part 1 asserts that despite the considerable…

Naqvi, Yasmin

286

RABIES EMERGENCE AMONG FOXES IN TURKEY  

Microsoft Academic Search

Sixteen rabies isolates recently collected from mainland Turkey and two isolates held within a British archive were used to form a representative cohort from a range of vectors, and were analyzed to identify potential causes for an increase of rabies within the fox (Vulpes vulpes) population in Turkey. Each isolate was characterized by sequence analysis of the nucleoprotein gene and

Nicholas Johnson; Colin Black; Jemma Smith; Hikmet Un; Lorraine M. McElhinney; Orhan Aylan; Anthony R. Fooks

287

Government Publications and Gray Literature in Turkey  

ERIC Educational Resources Information Center

This paper investigates bibliographic control of government publications and gray literature in Turkey, in order to determine what further measures are needed to support researchers in both Turkey and abroad. It reports the circumstances surrounding the creation of "The Bibliography of Government Publications" prepared in 1971, and outlines how…

Anameric, Hakan

2009-01-01

288

Extreme Forms of Child Labour in Turkey  

ERIC Educational Resources Information Center

Two little known forms of child labour in Turkey are examined. The process through which these children are made to work has parallels with the experiences of slaves. First, a long-standing practice from Northwestern Turkey of parents hiring children to better-off farmers is examined. Further, a more recent problem is examined where children are…

Degirmencioglu, Serdar M.; Acar, Hakan; Acar, Yuksel Baykara

2008-01-01

289

Turkeys Raised (Released August 23, 2007).  

National Technical Information Service (NTIS)

The preliminary estimate of turkeys raised in the United States during 2007 is 272 million, up 4 percent from the number raised during 2006. The following six States are expected to account for about two-thirds of the turkeys produced in the United States...

2007-01-01

290

Turkeys Raised (Released September 25, 2009).  

National Technical Information Service (NTIS)

Turkeys raised in the United States during 2009 is 250 million, down 8 percent from the number raised during 2008. The following six States are expected to account for about two-thirds of the turkeys produced in the United States during 2009: Minnesota, a...

2009-01-01

291

Turkeys Raised (Released August 25, 2008).  

National Technical Information Service (NTIS)

The preliminary estimate of turkeys raised in the United States during 2008 is 271 million, down slightly from the number raised during 2007. The following six States are expected to account for about two-thirds of the turkeys produced in the United State...

2008-01-01

292

Citizenship Education in Turkey: Inclusive or Exclusive  

ERIC Educational Resources Information Center

This paper scrutinises citizenship education in Turkey from the foundation of the Turkish Republic (1923) to the present and explores the extent to which it encourages inclusive or exclusive concepts of national identity and citizenship. In Turkey, where there are citizens belonging to ethnic and religious minorities, civic education plays a…

Ince, Basak

2012-01-01

293

Turkey's Oil and Natural Gas Pipelines System  

Microsoft Academic Search

Turkey's natural gas (NG) production is very small and is almost all imported. Turkish natural gas production in 2000, 23 billion cubic feet (Bcf), met around 4% of domestic natural gas consumption requirements. NG consumption is estimated at around 700 Bcf in year 2002, accounting for around 17% of Turkey's total energy consumption. Turkish natural gas demand had been projected

Mustafa Balat; Nuray Ozdemir

2005-01-01

294

Epizootic Hemorrhagic Disease in Cattle, Western Turkey  

PubMed Central

In 2007, an outbreak of epizootic hemorrhagic disease (EHD) occurred in Turkey. On the basis of clinical investigation, 41 cattle were suspected to have EHD. Reverse transcription–PCR and sequence analyses indicated that the virus belonged to EHD virus serotype 6, thus confirming EHD virus infection of cattle in Turkey.

Yesilbag, Kadir; Batten, Carrie; Senturk, Sezgin; Maan, Narender S.; Mertens, Peter Paul Clement; Batmaz, Hasan

2009-01-01

295

Epidemiological investigations on Q fever in Turkey  

PubMed Central

Q fever is endemic in Turkey in both human beings and animals. Cows, sheep, goats, and dogs may play a role as reservoirs of Coxiella burnetii. Ornithodorus lahorensis ticks also harbour the agent. The disease is disseminated throughout Turkey; epidemics among human beings are relatively rare.

Payzin, Sabahattin

1953-01-01

296

Ultrastructural pathology of Bordetella avium infection in turkeys.  

PubMed

One-day-old turkeys were infected intranasally with Bordetella avium, and tracheas were examined by scanning and transmission electron microscopy at 1 to 5 weeks post-inoculation (PI). The predominant ultrastructural lesions were progressive loss of ciliated epithelium with replacement by nonciliated cells, bacterial colonization of ciliated cells, membrane-bound crystalline inclusions in cytoplasma of epithelial cells, depletion of mucous granules, and distortion of tracheal rings and the mucosal surface. Tracheal surface exudates consisted of mucus, necrotic cells, heterophils, and fibrin. Ciliated cells were replaced by immature cuboidal cells characterized by abundant rough endoplasmic reticulum with small numbers of electron-dense mucous granules in the apical cytoplasm. Bacterial surfaces were rough and contained numerous pleomorphic, knob-like structures, 20-50 nm in diameter. Other changes included enlarged mucosal gland openings, cell extrusion marks, pleomorphic microvilli, and cells with small numbers of short cilia. PMID:3672806

Arp, L H; Fagerland, J A

1987-09-01

297

Satellite Winds  

NSDL National Science Digital Library

In this online, interactive module, students learn about the using successive satellite observations of clouds to determine wind direction and speed. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

298

The history of liver transplantation in Turkey.  

PubMed

Liver transplantation is the definitive treatment for end-stage liver diseases. The first successful liver transplant was performed in the United States by Thomas Starzl in 1967. The first successful solid organ transplant in Turkey was a living-related kidney transplant performed by Dr. Haberal in 1975. After much effort by Dr. Haberal, the Turkish parliament enacted a law about organ transplantation in 1979. After clinical and experimental studies, the first liver transplant in Turkey was performed by Dr. Haberal in 1988. The first successful partial living-donor liver transplant in children in Turkey was performed by the same team on March 15, 1990. On April 24, 1990, the first living-donor liver transplant was performed on a child in Turkey using a left lateral segment by Dr. Haberal and coworkers. On May 16, 1992, Dr. Haberal performed a simultaneous living-donor liver and kidney transplantation to an adult from the same donor. There currently are 30 liver transplantation centers in Turkey. According to data from the Ministry of Health, there presently are 2065 patients in Turkey who are waiting for a liver transplantation. From January 2002 to June 2013, there were 6091 liver transplants performed in Turkey (4020 living-donor [66% ] and 2071 deceased donor liver transplants [34% ]). From January 2011 to June 2013, there were 2514 patients who had liver transplants in Turkey, and 437 patients (17%) died. The number of liver transplants per year in Turkey reached 1000 transplants in 2012 and more than 1150 transplants in 2013 (15.1/million/y). Therefore, Turkey has one of the highest volumes of liver transplantation per population worldwide, with 90% survival within 1 year after transplantation. PMID:24635786

Moray, Gökhan; Arslan, Gülnaz; Haberal, Mehmet

2014-03-01

299

Satellite Telecommunications.  

ERIC Educational Resources Information Center

This issue of a quarterly publication of the Council of Europe covers aspects of the history, technology, policies, and impact of telecommunications in Europe, with an emphasis on European television. The following articles are included: (1) "Man and the World of Telecommunications" (Piet Stoffelen); (2) "The European Communications Satellite

Forum, 1986

1986-01-01

300

The contribution of Saharan dust in PM10 concentration levels in Anatolian Peninsula of Turkey.  

PubMed

Sahara-originated dust is the most significant natural source of particulate matter; however, this contribution is still unclear in the Eastern Mediterranean especially in Western Turkey, where significant industrial sources and metropolitan areas are located. The Real-time Air Quality Modeling System (RAQMS) is utilized to explore the possible effects of Saharan dust on high levels of PM10 measured in Turkey. RAQMS model is compared with 118-air quality stations distributed throughout Turkey (81 cities) for April 2008. MODIS aerosol product (MOD04 for Terra and MYD04 for Aqua) is used to see columnar aerosol loading of the atmosphere at 550nm (Aerosol optical depth (AOD) values found to be between 0.6 and 0.8 during the episode). High-resolution vertical profiles of clouds and aerosols are provided from CALIOP, on board of CALISPO satellite. The results suggest a significant contribution of Sahara dust to high levels of PM10 in Turkey with RAQMS and in situ time series showing similar patterns. The two data sets are found to be in agreement with a correlation of 0.87. PMID:24485280

Kabatas, B; Unal, A; Pierce, R B; Kindap, T; Pozzoli, L

2014-08-01

301

General Ecological Characteristics Based on GIS Methods in Poyrazlar Lake, Turkey  

NASA Astrophysics Data System (ADS)

General Ecological Characteristics Based on GIS Methods in Poyrazlar Lake, Turkey Cercis Ikiel Derya Evrim Kilic• Ayse Atalay Dutucu Sakarya University, Art and Science Faculty, Department of Geography, Sakarya, Turkey In this research, general ecological features in Poyrazlar lake is investigated. The study area is located in the east part of Marmara region and north-western part of the Adapazari plain (north-western part of Turkey) between the coordinates of 40°48'-40°52' N and 30°23'-30°30' E. Research area is within phytogeographical region of Euro-Siberian that is among flora and phytogeographical region of Turkey. The main element of vegetation consists Humid-Mild Deciduous forests (especially Quercus spp.) and hydrophyte plants (such as reeds and Nymphaea alba L.). Poyrazlar lake, that's water is fresh, is one of the important wetland areas in the region with its ecological characteristics. Especially the research area is haunted by various migratory birds and it is an important recreation area. The objective of this study is to analyze particularly the formation of Poyrazlar lake, ecological features of this area and negative influence of surrounding human activities in the area. For this purpose topography, geology, soil maps, forest arrangement plan, Spot 5 (2010 period) satellite image for current land use map and field observations data are used. These images are analyzed by utilizing data image processing techniques in ERDAS Imagine© 10.0 and ArcGIS© 10.0 software. Keywords: Ecology; Ecological Features; GIS; Alluvial Dam Lake; Poyrazlar Lake

Ikiel, C.; Kilic, D. E.; Atalay Dutucu, A.

2012-04-01

302

[The urbanization rate in Turkey].  

PubMed

Data from the annual statistical report on Turkey for 1990 and the results of research from 1985 and 1990 were utilized and compared with the trends of urbanization observed in the 1969 work of Z. Siemek on Turkey. In 1990, Turkey had about 56.5 million people with an average annual natural growth rate of 2.6% and an unemployment rate of 16%. The rural population made up 41% of the total populace. Urbanization was on the increase, from 47% in 1980, to 55% in 1985, and 59% in 1990. Urbanization in Ankara, because of its location in the center of Turkey, was particularly active in the regions of Anatolia, although it was still isolated in terms of intensified development. Istanbul's The population of Istanbul numbered 6,754,000 people in 1990. It is the major industrial center of the country with about 20% of industrial plants and 17% of the work force in the manufacturing industry. The largest degree of urbanization was demonstrated by Ankara: in 1927 its population numbered only 74,500 people, in 1965 about 902,000 inhabitants, and in 1990 about 2,837,000 people. During the period 1985-90, only 2 out of 73 provinces experienced a decline of the urban population: Kirikkale from 70.4% to 69.7% (because of the dynamic development of the Central region) and Istanbul from 95.4% to 92.4%. During this same period, Kirikkale's urban population, compared with the nation's total urban population, also declined from 0.9% to 0.7% because of immigration of both urban and rural people to other, more attractive provinces. The growth of urban population in the province of Istanbul varied from 1% to 10% during the period and made up 20.3% of the entire urban population. The Central region underwent a large degree of urbanization characterized by industrial-agricultural development. The city of Sivas became a center of communication. In the Central and Kurd regions, urbanization proceeded fast owing to the development of the Black Sea region and the immigration of Kurds from Iraq and Iran. PMID:12291543

Widy-kwiatkowska, J

1994-01-01

303

Turkey Operation - Year Round Production (VHS 3/4 inch) (Video).  

National Technical Information Service (NTIS)

Turkey operations are at greater risk since turkeys are more sensitive to disease than other commercial poultry. Turkeys also require longer to mature and need more contact with people. Range turkeys require different biosecurity procedures since it is ha...

1989-01-01

304

Virus shedding and serum antibody responses during experimental turkey coronavirus infections in young turkey poults  

Microsoft Academic Search

The course of turkey coronavirus (TCoV) infection in young turkey poults was examined using a field isolate (TCoV-MG10) from a diarrhoeal disease outbreak on a commercial turkey farm in Ontario, Canada. Two-day-old and 28-day-old poults were inoculated orally with TCoV-MG10 to examine the effect of age on viral shedding and serum antibody responses to the virus. The presence of coronavirus

M. H. Gomaa; D. Yoo; D. Ojkic; J. R. Barta

2009-01-01

305

TDRS satellite over African Rift Valley, Kenya, Africa  

NASA Technical Reports Server (NTRS)

This post deploy view of a TDRS satellite shows a segment of the African Rift Valley near Lake Baringo, Kenya, Africa (3.0S, 36.0E). The African Rift Valley system is a geologic fault having its origins in southern Turkey, through the near east forming the bed of the Jordan River, Gulf of Aqaba, the Red Sea and down through east Africa. The line of lakes and valleys of east Africa are the result of the faulting activity.

1983-01-01

306

Radiological maps for Trabzon, Turkey.  

PubMed

The activity concentrations and absorbed gamma dose rates due to primordial radionuclides and (137)Cs have been ascertained in 222 soil samples in 18 counties of the Trabzon province of Turkey using a HPGe detector. The mean activity concentrations of (238)U, (232)Th, (40)K and (137)Cs in soil samples were 41, 35, 437 and 21 Bq kg(-1), respectively. Based on the measured concentrations of these radionuclides, the mean absorbed gamma dose in air was calculated as 59 nGy h(-1) and hence, the mean annual effective dose due to terrestrial gamma radiation was calculated as 72 ?Sv y(-1). In addition, outdoor in situ gamma dose rate (D) measurements were performed in the same 222 locations using a portable NaI detector and the annual effective dose was calculated to be 66 ?Sv y(-1) from these results. The results presented in this study are compared with other parts of Turkey. Radiological maps of the Trabzon province were composed using the results obtained from the study. PMID:21382657

Kurnaz, A; Kucukomeroglu, B; Damla, N; Cevik, U

2011-04-01

307

MIMOSA satellite  

NASA Astrophysics Data System (ADS)

MIMOSA microsatellite is sixth satellite of the Czech Republic and it is dedicated to yield new experimental data on total atmosphere density of the upper ionosphere. The complex verification of total density analytical model (TD88) is the main project objective. The only payload on board is a highly sensitive accelerometer MACEK. Moreover, designed accelerometer accuracy (10 -9 ms -2) enables to study a weak forces like reflected solar radiation pressure or pressure of the thermal radiation dissipated by the Earth. Presented paper describes payload properties, satellite and subsystem features, budgets and mission performance. The project is at C/D phase presently. The launch is scheduled for the second half of 2000 and expected lifetime is at least two years.

Peresty, R.; Sehnal, L.; Chvojka, M.; Dostal, P.

2000-03-01

308

Managing Satellites  

NASA Technical Reports Server (NTRS)

Integral Systems, Inc.'s EPOCH 2000 forms the core of NASA's Near Earth Asteroid Rendezvous (NEAR) mission's command and control center. EPOCH 2000, which allows ground operators to monitor and control satellites over a wide area network, owes part of its heritage from work completed to support Goddard Space Flight Center. The software automates telemetry processing, commanding, anomaly detection, and archiving collected data. The NEAR spacecraft, launched in February 1996, will rendezvous in early 1999 and orbit the Asteroid Eros for a year. Integral Systems also provided Low Earth Orbit Autonomous Ground Terminals (LEO-Ts) to NASA. The LEO-T is designed to make it easier and less expensive for principal investigators to obtain telemetry, tracking and control services for their science missions. The company products have supported well over 70 satellite missions aimed at scientific research, meteorology, or communications applications.

1997-01-01

309

Comparison of MAP and tyrosine kinase signaling in heterophils from commercial and wild-type turkeys.  

PubMed

Protein tyrosine and mitogen-activated kinases are crucial mediators of the host innate immune response, conferring signals from surface receptors on the host cell to the nucleus of the cell where gene expression occurs. Heterophils were isolated from wild-type Rio Grande turkeys and a commercial line of turkeys (Line A) on days 4 and 7 post-hatch. Heterophils were stimulated for 1h with Salmonella enteritidis (SE) or opsonized SE (OPSE). After stimulation, cells were lysed and lysates were tested for mitogen-activated protein kinase (MAPK) activity. Specifically, phosphorylation of extracellular signal-regulated protein kinase (ERK1/2) and p38 MAPK phosphorylation were assayed using commercially available ELISA kits. Total protein tyrosine kinase (PTK) activity was also assayed. On both days 4 and 7 post-hatch, heterophils from Rio Grande turkeys had significantly higher levels of ERK 1/2 and p38 MAPK kinase activity upon stimulation with either SE or OPSE (p<0.001). Likewise, PTK values on days 4 and 7 in Rio Grande turkey heterophils were significantly higher upon stimulation with SE than with OPSE and were significantly (p<0.001) higher than PTK levels in Line A upon SE and OPSE stimulation. The data presented supports previous heterophil functional comparison studies wherein heterophils from Rio Grande turkeys had higher levels of oxidative burst and degranulation activities as compared to the activity observed in commercial Line A heterophils. This suggests that the regulation and control of these functions are mediated by protein tyrosine and mitogen-activated kinases. Furthermore, the data suggest that selection of commercial lines of turkeys for larger, heavier bodies, and faster growth may be associated with subsequent selection for decreased innate immune functions related to intracellular signaling mechanisms and possibly a subsequent increase in susceptibility to disease. PMID:17241661

Genovese, Kenneth J; He, Haiqi; Lowry, Virginia K; Kogut, Michael H

2007-01-01

310

The Turkey Ig-Like Receptor Family: Identification, Expression and Function  

PubMed Central

The chicken leukocyte receptor complex located on microchromosome 31 encodes the chicken Ig-like receptors (CHIR), a vastly expanded gene family which can be further divided into three subgroups: activating CHIR-A, bifunctional CHIR-AB and inhibitory CHIR-B. Here, we investigated the presence of CHIR homologues in other bird species. The available genome databases of turkey, duck and zebra finch were screened with different strategies including BLAST searches employing various CHIR sequences, and keyword searches. We could not identify CHIR homologues in the distantly related zebra finch and duck, however, several partial and complete sequences of CHIR homologues were identified on chromosome 3 of the turkey genome. They were designated as turkey Ig-like receptors (TILR). Using cDNA derived from turkey blood and spleen RNA, six full length TILR could be amplified and further divided according to the typical sequence features into one activating TILR-A, one inhibitory TILR-B and four bifunctional TILR-AB. Since the TILR-AB sequences all displayed the critical residues shown to be involved in binding to IgY, we next confirmed the IgY binding using a soluble TILR-AB1-huIg fusion protein. This fusion protein reacted with IgY derived from various gallinaceous birds, but not with IgY from other bird species. Finally, we tested various mab directed against CHIR for their crossreactivity with either turkey or duck leukocytes. Whereas no staining was detectable with duck cells, the CHIR-AB1 specific mab 8D12 and the CHIR-A2 specific mab 13E2 both reacted with a leukocyte subpopulation that was further identified as thrombocytes by double immunofluorescence employing B-cell, T-cell and thrombocyte specific reagents. In summary, although the turkey harbors similar LRC genes as the chicken, their distribution seems to be distinct with predominance on thrombocytes rather than lymphocytes.

Windau, Katharina; Viertlboeck, Birgit C.; Gobel, Thomas W.

2013-01-01

311

The Turkey Ig-like receptor family: identification, expression and function.  

PubMed

The chicken leukocyte receptor complex located on microchromosome 31 encodes the chicken Ig-like receptors (CHIR), a vastly expanded gene family which can be further divided into three subgroups: activating CHIR-A, bifunctional CHIR-AB and inhibitory CHIR-B. Here, we investigated the presence of CHIR homologues in other bird species. The available genome databases of turkey, duck and zebra finch were screened with different strategies including BLAST searches employing various CHIR sequences, and keyword searches. We could not identify CHIR homologues in the distantly related zebra finch and duck, however, several partial and complete sequences of CHIR homologues were identified on chromosome 3 of the turkey genome. They were designated as turkey Ig-like receptors (TILR). Using cDNA derived from turkey blood and spleen RNA, six full length TILR could be amplified and further divided according to the typical sequence features into one activating TILR-A, one inhibitory TILR-B and four bifunctional TILR-AB. Since the TILR-AB sequences all displayed the critical residues shown to be involved in binding to IgY, we next confirmed the IgY binding using a soluble TILR-AB1-huIg fusion protein. This fusion protein reacted with IgY derived from various gallinaceous birds, but not with IgY from other bird species. Finally, we tested various mab directed against CHIR for their crossreactivity with either turkey or duck leukocytes. Whereas no staining was detectable with duck cells, the CHIR-AB1 specific mab 8D12 and the CHIR-A2 specific mab 13E2 both reacted with a leukocyte subpopulation that was further identified as thrombocytes by double immunofluorescence employing B-cell, T-cell and thrombocyte specific reagents. In summary, although the turkey harbors similar LRC genes as the chicken, their distribution seems to be distinct with predominance on thrombocytes rather than lymphocytes. PMID:23527222

Windau, Katharina; Viertlboeck, Birgit C; Göbel, Thomas W

2013-01-01

312

CENP-A, B, and -C Chromatin Complex That Contains the I-Type  Satellite Array Constitutes the Prekinetochore in HeLa Cells  

Microsoft Academic Search

CENP-A is a component of centromeric chromatin and defines active centromere regions by forming cen- tromere-specific nucleosomes. We have isolated centromeric chromatin containing the CENP-A nucleosome, CENP-B, and CENP-C from HeLa cells using anti-CENP-A and\\/or anti-CENP-C antibodies and shown that the CENP-A\\/B\\/C complex is predominantly formed on -satellite DNA that contains the CENP-B box (I-type array). Mapping of hypersensitive sites

Satoshi Ando; Hua Yang; Naohito Nozaki; Tuneko Okazaki; Kinya Yoda

2002-01-01

313

The turkey, compared to the chicken, fails to mount an effective early immune response to Histomonas meleagridis in the gut.  

PubMed

Histomonosis is a disease of poultry caused by Histomonas meleagridis. Chickens usually recover while the mortality rate in turkeys is high. The immunological response of both species towards H. meleagridis was investigated. Parasites migrated in greater numbers to the turkey liver compared with that of chicken. Chicken mounted an effective caecal innate response, with increased expression of IL-1beta, CXCLi2 and IL-6 mRNA, resulting in control of parasite numbers. The turkey failed to mount such an effective innate response in the caecal tonsil, allowing greater numbers to migrate to the liver, where a sustained, uncontrolled immune response was mounted, evidenced by the upregulation of mRNA for IL-1beta, CXCLi2, IFN-gamma, IL-13, IL-4 and IL-10. Expression levels of mRNA of the chicken and turkey beta-defensin AvBD2 suggest that this response was not limited to the cytokines. There was an influx of CD4+, CD8alpha+, CD28+ and CD44+ cells into the livers of both species, coinciding with parasite movement. These influxes were more pronounced in the turkey, correlating with a decrease in numbers of the same cells in the spleen, which was not observed in the chicken. Antibody levels in the chicken increased more than those in the turkey, supporting evidence of an adaptive response. PMID:19493211

Powell, F L; Rothwell, L; Clarkson, M J; Kaiser, P

2009-06-01

314

The pathogenicity of avian metapneumovirus subtype C wild bird isolates in domestic turkeys  

PubMed Central

Background Avian metapneumovirus subtype C (aMPV/C) causes severe upper respiratory disease in turkeys. Previous report revealed the presence of aMPV/C in wild birds in the southeast regions of the U.S. Methods In this study, aMPV/C positive oral swabs from American coots (AC) and Canada geese (CG) were passaged three times in the respiratory tract of specific pathogen free (SPF) turkeys and used as aMPV/C P3 virus isolates in subsequent studies. Results Wild bird P3 isolates showed similar growth characteristics when compared to virulent aMPV/C in chicken embryo fibroblast ( CEF) cell cultures and their glycoprotein G gene sequence was closely related to the G gene of aMPV/C Colorado reference virus. Three-day-old commercial or SPF turkeys were inoculated oculonasally with wild bird aMPV/C P3 isolates. At 5 and 7 days post-inoculation (DPI), severe clinical signs were observed in both of the AC and CG virus-exposed groups. Viral RNA was detected in tracheal swabs by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, immunohistochemistry showed virus replication in the nasal turbinate and trachea. All virus-exposed turkeys developed positive antibody response by 14 DPI. Conclusions Our data demonstrate that aMPV/C wild bird isolates induced typical aMPV/C disease in the domestic turkeys.

2013-01-01

315

Energy related environmental policies in Turkey  

SciTech Connect

There is increasing consensus in both the scientific and political communities that significant reductions in greenhouse gas (GHG) emissions are necessary to limit the magnitude and extent of climate change. Renewable energy systems already reduce GHG emissions from the energy sector, although on a modest scale. Turkey is heavily dependent on expensive imported energy resources (oil, gas, and coal) that place a big burden on the economy, and air pollution is becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. This article presents a review of the energy related environmental policies in Turkey.

Kaygusuz, K.; Bilgen, S. [Karadeniz Technical University, Trabzon (Turkey). Dept. of Chemistry

2008-07-01

316

How Satellites Work  

NSDL National Science Digital Library

Collection of seven classroom activities that focus on satellite technology. Topics include: coordinated universal time (UTC); satellite pass prediction; satellite design; satellite orbits; satellite launching; and, use of satellites in at-sea rescues. Each activity provides list of materials needed, background information, and procedure.

317

Pathogenic and immunogenic responses in turkeys following in ovo exposure to avian metapneumovirus subtype C.  

PubMed

Commercial turkey eggs, free of antibodies to avian metapneumovirus subtype C (aMPV/C), were inoculated with aMPV/C at embryonation day (ED) 24. There was no detectable effect of virus inoculation on the hatchability of eggs. At 4 days post inoculation (DPI) (the day of hatch (ED 28)) and 9 DPI (5 days after hatch), virus replication was detected by quantitative RT-PCR in the turbinate, trachea and lung but not in the thymus or spleen. Mild histological lesions characterized by lymphoid cell infiltration were evident in the turbinate mucosa. Virus exposure inhibited the mitogenic response of splenocytes and thymocytes and upregulated gene expression of IFN-? and IL-10 in the turbinate tissue. Turkeys hatching from virus-exposed eggs had aMPV/C-specific IgG in the serum and the lachrymal fluid. At 3 week of age, in ovo immunized turkeys were protected against a challenge with pathogenic aMPV/C. PMID:21146877

Cha, Ra Mi; Khatri, Mahesh; Mutnal, Manohar; Sharma, Jagdev M

2011-03-15

318

Injectable thermosensitive chitosan/?-glycerophosphate/collagen hydrogel maintains the plasticity of skeletal muscle satellite cells and supports their in vivo viability.  

PubMed

A cell carrier plays an important role in the maintenance, growth and engraftment of specific cells aimed for defined therapeutic uses in many tissue engineering strategies. A suitable microenvironment for the cells allows for the maximum efficacy of the hybrid device. We have prepared an injectable thermosensitive chitosan/?-glycerophosphate/collagen (C/GP/Co) gel and investigated its potential application as a support for the culture of skeletal muscle satellite cells (SMSCs). A cell viability assay was used to evaluate the in vitro cytocompatibility of the gel. Cell growth was assessed by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and histological analysis. The influence of the C/GP/Co gel on the plasticity of SMSCs seeded at the surface of the gel was assessed by induction of the myogenic, osteogenic and adipogenic differentiation. C/GP/Co gel provided the appropriate environment for the culture of SMSCs in vitro. In addition, the C/GP/Co gel supported SMSC plasticity. In vivo testing of the SMSC-seeded gel was investigated by subcutaneous injection into the dorsum of nude mice. Cell viability was assessed both by in vivo imaging and histological examination of the explants. In conclusion, C/GP/Co hydrogel is a cytocompatible carrier for the in vivo delivery of SMSCs and supportive for SMSC plasticity. Thus, this gel has potential applications in tissue engineering and regenerative medicine. PMID:23620126

Ding, Ke; Yang, Zhong; Zhang, Yu-Long; Xu, Jian-Zhong

2013-09-01

319

Dressing the Thanksgiving Turkey: Using Measurement?  

NSDL National Science Digital Library

This blog post presents a Thanksgiving activity that engages learners as they practice measuring with nonstandard units and comparing lengths. Learners use unifix cubes to measure the heights of four turkeys then compare and arrange them in order from shortest to tallest. The last part of the activity has students measuring Tom Turkey to determine which clothing he should be dressed in for dinner. The lesson plan and all student worksheets can be downloaded to a PDF.

Mitchell, Myrna

2013-11-15

320

Long-term insulin-like growth factor-I expression in skeletal muscles attenuates the enhanced in vitro proliferation ability of the resident satellite cells in transgenic mice  

NASA Technical Reports Server (NTRS)

Insulin-like growth factor-I (IGF-I) overexpression for 1-month in mouse skeletal muscle increases satellite cell proliferation potential. However, it is unknown whether this beneficial enhancement by IGF-I expression would persist over a longer-term duration in aged mice. This is an important issue to address if a prolonged course of IGF-I is to be used clinically in muscle-wasting conditions where satellite cells may become limiting. Using the IGF-I transgenic (IGF-I Tg) mouse that selectively expresses the IGF-I transgene in striated muscles, we found that 18-months of continuous IGF-I overexpression led to a loss in the enhanced in vitro proliferative capacity of satellite cells from Tg skeletal muscles. Also 18-month-old IGF-I Tg satellite cells lost the enhanced BrdU incorporation, greater pRb and Akt phosphorylations, and decreased p27(Kip1) levels initially observed in cells from 1-month-old IGF-I Tg mice. The levels of those biochemical markers reverted to similar values seen in the 18-months WT littermates. These findings, therefore, suggest that there is no further beneficial effect on enhancing satellite cell proliferation ability with persistent long-term expression of IGF-I in skeletal muscles of these transgenic mice.

Chakravarthy, M. V.; Fiorotto, M. L.; Schwartz, R. J.; Booth, F. W.

2001-01-01

321

Characterization of extremely halophilic Archaea isolated from the Ayvalik Saltern, Turkey  

Microsoft Academic Search

Seven extremely halophilic strains were isolated from the Ayvalik Saltern in the north-eastern part of Turkey. Chemical analyses of the brine and salt samples were performed to measure their salt content, hardness and pH. Isolated strains were tested for their antibiotic sensitivities; cell and colony morphologies; hydrolysis of casein, starch, gelatin, Tween 20 and Tween 80; and oxidase and catalase

Rahel Elevi; Parvaneh Assa; Meral Birbir; Ayse Ogan; Aharon Oren

2004-01-01

322

Turkey vulture and California condor  

USGS Publications Warehouse

Populations of turkey vultures in the western states appear stable, with no evidence of recent significant changes in distribution. Turkey vultures occupy a variety of habitats, nest in diverse situations and utilize a wide variety of carrion. Consequently, no particular limiting factor is likely to have a major effect on the total population. California condor numbers, in contrast, have continued to decline. With the capture of the last wild bird in 1987, the species has been extirpated from the wild. Reestablishment will depend on production and introduction of captive-reared birds, hopefully within the next 10 years. In the 18th century, condors inhabited areas along the Pacific coast from British Columbia to Baja California. Since 1950, the range has been restricted to a six county area adjacent to the southern San Joaquin Valley of California. Within this area, there appears to be no shortage of suitable nest sites; all recently used nest sites are within federally-controlled lands. Suitable foraging grounds have continued to diminish and are now largely limited to private rangelands and some Bureau of Land Management rangelands within the foothills of the San Joaquin Valley. Only these areas continue to supply the large mammal carcasses that the California condor needs for survival. The habitat of the condor is subject to a variety of land use practices and development pressures. Excessive mortality, coupled with low reproductive potential, continues to threaten the recovery of the species. Development of management practices to reduce mortality, particularly those that are contaminant-related, and of a preserve design to insure adequate habitat for the reintroduced population are still necessary for eventual recovery of the species.

Pattee, O.H.; Wilbur, S.R.

1989-01-01

323

Policy Options for Turkey: A Critique of the Interpretation and Utilization of PISA Results in Turkey  

ERIC Educational Resources Information Center

In this article we provide a critique of the interpretation and utilization of Programme for International Student Assessment (PISA) results by the National Education Authorities in Turkey. First, we define and explain what OECD's PISA is. Second, we make an overview of the media coverage in Turkey of the PISA 2003 and 2006 results. Third, we…

Gur, Bekir S.; Celik, Zafer; Ozoglu, Murat

2012-01-01

324

Characterization of muscle morphology and satellite cells, and expression of muscle-related genes in skeletal muscle of juvenile and adult Megalobrama amblycephala.  

PubMed

Hyperplasia and hypertrophy are two distinct processes of skeletal muscle growth regulated by four myogenic regulatory factors (MRFs, contains MyoD, Myf5, Mrf4 and myogenin (MyoG)) and myostatin (MSTN). In this study, characterization of muscle morphology and satellite cells in juvenile (1-year-old) and adult (2-year-old) Megalobrama amblycephala was described. Compared with 1-year-old M. amblycephala, the diameter scope of epaxial, horizontal septum and hypaxial muscle fibers including red and white muscle in 2-year-old fish exhibited broader with dramatic reduction in frequency distribution of <20?m diameter, nevertheless observable increase in frequency distribution of >50?m diameter. Intermyofibrillar (IM) nuclei were also found except numerous subsarcolemmal (SS) nuclei in 2-year-old fish, whereas only SS nuclei were observed in 1-year-old fish. Immunofluorescence results showed that more satellite cells existed in red muscle than white muscle in 1-year-old fish, rather than 2-year-old fish. Moreover, we observed predominant increase in the mRNA levels of MyoD, Myf5, Mrf4, and MSTN during muscle development of fish in 2-year-old fish except MyoG. PMID:24981216

Zhu, Kecheng; Wang, Huanling; Wang, Huijuan; Gul, Yasmeen; Yang, Min; Zeng, Cong; Wang, Weimin

2014-09-01

325

Antimuscle atrophy effect of nicotine targets muscle satellite cells partly through an ?7 nicotinic receptor in a murine hindlimb ischemia model.  

PubMed

We have recently identified that donepezil, an anti-Alzheimer drug, accelerates angiogenesis in a murine hindlimb ischemia (HLI) model. However, the precise mechanisms are yet to be fully elucidated, particularly whether the effects are derived from endothelial cells alone or from other nonvascular cells. Further investigation of the HLI model revealed that nicotine accelerated angiogenesis by activation of vascular endothelial cell growth factor (VEGF) synthesis through nicotinic receptors in myogenic cells, that is, satellite cells, in vivo and upregulated the expression of angiogenic factors, for example, VEGF and fibroblast growth factor 2, in vitro. As a result, nicotine prevented skeletal muscle from ischemia-induced muscle atrophy and upregulated myosin heavy chain expression in vitro. The in vivo anti-atrophy effect of nicotine on muscle was also observed in galantamine, another anti-Alzheimer drug, playing as an allosteric potentiating ligand. Such effects of nicotine were attenuated in ?7 nicotinic receptor knockout mice. In contrast, PNU282987, an ?7 nicotinic receptor agonist, comparably salvaged skeletal muscle, which was affected by HLI. These results suggest that cholinergic signals also target myogenic cells and have inhibiting roles in muscle loss by ischemia-induced muscle atrophy. PMID:24811002

Kakinuma, Yoshihiko; Noguchi, Tatsuya; Okazaki, Kayo; Oikawa, Shino; Iketani, Mitsue; Kurabayashi, Mutsumi; Furihata, Mutsuo; Sato, Takayuki

2014-07-01

326

Histomonas meleagridis: immunohistochemical localization of parasitic cells in formalin-fixed, paraffin-embedded tissue sections of experimentally infected turkeys demonstrates the wide spread of the parasite in its host.  

PubMed

In the present investigation, a polyclonal antibody-based immunohistochemical technique was developed to localize Histomonas meleagridis in formalin-fixed, paraffin-embedded tissues of experimentally infected turkeys. The developed technique was highly specific for histomonads as no immunohistochemical reaction was observed with cultures of Tetratrichomonas gallinarum, Trichomonas gallinae and Blastocystis sp. In addition, tissues positive for various other protozoan parasites and fungi were also tested to evaluate the specificity of the technique. It was possible to detect immunohistochemically histomonad antigens in all the tested samples (n=5) of caecum, liver, spleen and lung from infected turkeys, 3 out of 5 bursa of Fabricius, 1 out of 2 bone marrow, 2 out of 5 heart and 1 out of 5 each of proventriculus, pancreas and cerebellum. An immunohistochemical reaction indicative of presence of histomonads was also detected in blood vessels of various organs that indicated a possible hematogenous route of spread of the parasite in the host. A comparative study with routine diagnostic staining techniques indicated a high sensitivity and specificity of the newly developed immunohistochemical technique. Altogether, the technique developed can be used to study the sequential pathogenesis of histomonosis in turkeys and to obtain new insights into the mechanisms of interaction with the host tissues. PMID:18155698

Singh, Amarjit; Weissenböck, Herbert; Hess, Michael

2008-04-01

327

78 FR 55095 - Certain Pasta From Italy and Turkey  

Federal Register 2010, 2011, 2012, 2013

...Review)] Certain Pasta From Italy and Turkey Determinations On the basis of the record...orders on certain pasta from Italy and Turkey would be likely to lead to continuation...respect to imports of certain pasta from...

2013-09-09

328

Feasibility and acceptability of a text messaging-based smoking cessation program in ankara, Turkey.  

PubMed

Data from high-income countries suggest that cell phone-based smoking cessation programs have the potential to affect cessation rates. There is a paucity of research, however, about the feasibility of cell phone-based smoking cessation programs in lower income countries that have higher smoking prevalence rates. A one-arm feasibility and acceptability pilot study of SMS Turkey, a text messaging-based smoking cessation program, was conducted in Ankara, the capital of Turkey. The authors recruited 75 daily smokers who were seriously thinking about quitting in the subsequent 30 days into the 6-week SMS Turkey program. Recruitment was completed in 4 months. Participant retention was high: Almost all (96%) completed the program, and 84% provided 12-week follow-up data. Most (89%) of the respondents who completed the 4-week follow-up measures (n = 38, 51%) said that the text messages were easy to understand and referred to what they were experiencing and feeling during the quitting process (78%). On the basis of intention to treat, 13% of participants (n = 10) reported, at 12-week follow-up, continuous abstinence since their quit date, confirmed by carbon monoxide readings. The cell phone text messaging-based smoking cessation intervention appears feasible and acceptable in Ankara, Turkey. PMID:23627304

Ybarra, Michele L; Holtrop, Jodi S; Ba?ci Bosi, A Tülay; Bilir, Nazmi; Korchmaros, Josephine D; Salih Emri, A K

2013-08-01

329

Rapid transmission of the protozoan parasite Histomonas meleagridis in turkeys and specific pathogen free chickens following cloacal infection with a mono-eukaryotic culture.  

PubMed

In the present investigation, the pathogenicity and transmission of a mono-eukaryotic culture of Histomonas meleagridis for commercial turkeys and specific pathogen free (SPF) chickens is described for the first time. Two separate trials with the same kind of experimental design were performed, one with commercial turkeys and one with SPF chickens. In each experiment, two different groups were included, which were housed in separate rooms. The first group contained four control birds, whereas the second group consisted of 10 infected and four in-contact birds. The birds were infected via the cloaca at 14 days of age with 380,000 cells of a mono-eukaryotic culture of H. meleagridis consisting of a cloned isolate (Turkey/Austria/2922-66/04). Reisolation of the parasite from turkeys and chickens under experimental conditions was performed for the first time. The infected birds started to excrete the parasite as soon as 2 days post infection. Rapid spread of the parasite to in-contact turkeys and chickens was noticed, based on reisolation of live parasites. Reisolation of the pathogen was impossible from two of the four in-contact SPF chickens at any time, whereas all of the infected turkeys were found positive. Intermittent shedding of the parasite was noticed in infected turkeys and SPF chickens, but the phenomenon was much more severe in the SPF chickens as these birds survived the infection. All of the infected and in-contact turkeys died between days 11 and 14 post infection, whereas no death was recorded in the SPF chickens, which were killed 6 weeks after the infection. Typical lesions were recorded in the caeca and livers of the infected turkeys. In addition, a heavy destruction of the bursa of Fabricius was seen in all of the infected and one of the in-contact turkeys. Altogether, the present investigations are of importance for an understanding of the pathogenicity and transmission of H. meleagridis in poultry. PMID:16854640

Hess, M; Grabensteiner, E; Liebhart, D

2006-08-01

330

Small Glacier Area Studies: A New Approach for Turkey  

NASA Technical Reports Server (NTRS)

Many regions of Earth have glaciers that have been neglected for study because they are small. We report on a new approach to overcome the problem of studying small glaciers, using Turkey as an example. Prior to our study, no reliable estimates of Turkish glaciers existed because of a lack of systematic mapping, difficulty in using Landsat data collected before 1982, snowpack vs. glacier ice differentiation using existing satellite data and aerial photography, the previous high cost of Landsat images, and a lack of high-resolution imagery of small Turkish glaciers. Since 2008, a large number of < 1 m satellite images have become available at no cost to the research community. In addition, Landsat data are now free of charge from the U.S. Geological Survey, enabling the use of multiple images. We used 174 Landsat and eight high-resolution satellite images to document the areal extent of Turkish glaciers from the 1970s to 2007-2011. Multiple Landsat images, primarily Thematic Mapper (TM) data from 1984 to 2011, enabled us to minimize differentiation problems between snow and glacier ice, a potential source of error. In addition, we used Ikonos, Quickbird, and World View-1 & -2 very high-resolution imagery to evaluate our TM accuracies and determine the area of nine smaller glaciers in Turkey. We also used five Landsat-3 Return Beam Videcon (RBV) 30 m pixel resolution images, all from 1980, for six glaciers. The total area of Turkish glaciers decreased from 23 km2 in the 1970s to 10.1 km2 in 2007-2011. By 2007-2011, six Turkish glaciers disappeared, four were < 0.3 km2, and only three were 1.0 km2 or larger. No trends in precipitation from 1970 to 2006 and cloud cover from 1980 to 2010 were found, while surface temperatures increased, with summer minimum temperatures showing the greatest increase. We conclude that increased surface temperatures during the summer were responsible for the 56% recession of Turkish glaciers from the 1970s to 2006-2011.

Yavasli, Dogukan D.; Tucker, Compton J.

2012-01-01

331

Satellite altimetry  

NASA Technical Reports Server (NTRS)

Since altimetry data are not really old enough to use the term data archaeology, Mr. Cheney referred to the stewardship of these data. He noted that it is very important to document the basis for an altimetry data set as the algorithms and corrections used to arrive at the Geophysical Data Record (GDR) have been improving and are continuing to improve the precision of sea level data derived from altimetry. He noted that the GEOSAT Exact Repeat Mission (ERM) data set has recently been reprocessed by his organization in the National Ocean Service of NOAA and made available to the scientific community on CD/ROM disks by the National Oceanographic Data Center of the U.S. (NODC). The new data set contains a satellite orbit more precise by an order of magnitude together with an improved water vapor correction. A new, comprehensive GDR Handbook has also been prepared.

Cheney, Robert E.

1992-01-01

332

Rural settlement policies in Turkey and the Kurdish areas  

Microsoft Academic Search

The adament refusal of Turkey to admit to a Kurdish question is a major source of human rights violations, social tension, political and economic instability, and an irritant in Turkey's relations with neighboring countries and the European Union. In the 1980s and 1990s Turkey, and in particular the areas predominantly populated by Kurds, was the scene of an increasingly bitter

J. P. Jongerden

2003-01-01

333

Renewable and sustainable energy use in Turkey: a review  

Microsoft Academic Search

Turkey is an energy importing nation with more than half of our energy requirements met by imported fuels. Air pollution is becoming a significant environmental concern in the country. In this regard, renewable energy resources are becoming attractive for sustainable energy development and environmental pollution mitigation in Turkey. Turkey's geographical location has several advantages for extensive use of most of

Kamil Kaygusuz

2002-01-01

334

Androgen Receptor in Human Skeletal Muscle and Cultured Muscle Satellite Cells: Up-Regulation by Androgen Treatment  

Microsoft Academic Search

Androgens stimulate myogenesis, but we do not know what cell types within human skeletal muscle express the androgen receptor (AR) protein and are the target of androgen action. Because testosterone promotes the commitment of pluripo- tent, mesenchymal cells into myogenic lineage, we hypothe- sized that AR would be expressed in mesenchymal precursor cells in the skeletal muscle. AR expression was

INDRANI SINHA-HIKIM; WAYNE E. TAYLOR; NESTOR F. GONZALEZ-CADAVID; WEI ZHENG; SHALENDER BHASIN

335

Satellite cells attract monocytes and use macrophages as a support to escape apoptosis and enhance muscle growth  

Microsoft Academic Search

nce escaped from the quiescence niche, precursor cells interact with stromal components that support their survival, proliferation, and differentiation. We examined interplays between human myogenic precursor cells (mpc) and monocyte\\/macrophages (MP), the main stromal cell type observed at site of muscle regeneration. mpc selectively and specifically attracted monocytes in vitro after their release from quiescence, chemotaxis declining with differentiation. A

Bénédicte Chazaud; Corinne Sonnet; Peggy Lafuste; Guillaume Bassez; Anne-Cécile Rimaniol; Françoise Poron; François-Jérôme Authier; Patrick A. Dreyfus; Romain K. Gherardi

2003-01-01

336

Outer planet satellites  

NASA Technical Reports Server (NTRS)

Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon.

Schenk, Paul M.

1991-01-01

337

Turkey opens electricity markets as demand grows  

SciTech Connect

Turkey's growing power market has attracted investors and project developers for over a decade, yet their plans have been dashed by unexpected political or financial crises or, worse, obstructed by a lengthy bureaucratic approval process. Now, with a more transparent retail electricity market, government regulators and investors are bullish on Turkey. Is Turkey ready to turn the power on? This report closely examine Turkey's plans to create a power infrastructure capable of providing the reliable electricity supplies necessary for sustained economic growth. It was compiled with on-the-ground research and extensive interview with key industrial and political figures. Today, hard coal and lignite account for 21% of Turkey's electricity generation and gas-fired plants account for 50%. The Alfin Elbistan-B lignite-fired plant has attracted criticism for its lack of desulfurization units and ash dam facilities that have tarnished the industry's image. A 1,100 MW hard-coal fired plant using supercritical technology is under construction. 9 figs., 1 tab.

McKeigue, J.; Da Cunha, A.; Severino, D. [Global Business Reports (United States)

2009-06-15

338

Turkey liver - a chromium enriched food source  

SciTech Connect

There are presently no known foods for humans that are particularly good sources of chromium. As a means of obtaining Cr enriched foods, turkeys were fed diets containing various levels of supplemental chromium. Four groups of 6-month old turkey hens were fed either the basal diet for laying hens or this diet supplemented with 25, 100 or 200 ..mu..g of chromium as chromium chloride per g of diet. Liver Cr concentration of the turkeys sacrificed after 1 week increased from 7 ng/g (wet wt) while consuming the basal diet to 15, 48 and 68 ng/g, respectively, while consuming the diets with supplemental chromium. Comparable values for the turkeys sacrificed after 5 weeks were 2, 43, 170 and 325 ng/g. Similar trends but higher chromium values were observed for kidney samples. The chromium contents of the dark and white meat and eggs were not altered significantly. Chromium concentrations of the pancreas, gizzard and heart increased marginally; final chromium concentrations were less than 23 ng/g even after 5 weeks on the highest level of supplemental chromium. Chromium content of spleen and lungs was approximately 2-fold higher than that of the pancreas, gizzard or heart. Therefore, turkey liver is a food source suitable for Cr enrichment while the eggs, dark and white meat and other edible parts do not appear to be enriched following chromium supplementation.

Polansky, M.M.; Bryden, N.A.; Richards, M.; Anderson, R.A.

1986-03-01

339

Satellite cells in slow and fast rat muscles differ in respect to acetylcholinesterase regulation mechanisms they convey to their descendant myofibers during regeneration.  

PubMed

The hypothesis of satellite cell diversity in slow and fast mammalian muscles was tested by examining acetylcholinesterase (AChE) regulation in muscles regenerating 1) under conditions of muscle disuse (tenotomy, leg immobilization) in which the pattern of neural stimulation is changed, and 2) after cross-transplantation when the regenerating muscle develops under a foreign neural stimulation pattern. Soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat were allowed to regenerate after ischemic-toxic injury either in their own sites or had been cross-transplanted to the site of the other muscle. Molecular forms of AChE in regenerating muscles were analyzed by velocity sedimentation in linear sucrose gradients. Neither tenotomy nor limb immobilization significantly affected the characteristic pattern of AChE molecular forms in regenerating SOL muscles, suggesting that the neural stimulation pattern is probably not decisive for its induction. During an early phase of regeneration, the general pattern of AChE molecular forms in the cross-transplanted regenerating muscle was predominantly determined by the type of its muscle of origin, and much less by the innervating nerve which exerted only a modest modifying effect. However, alkali-resistant myofibrillar ATPase activity on which the separation of muscle fibers into type I and type II is based, was determined predominantly by the motor nerve innervating the regenerating muscle. Mature regenerated EDL muscles (13 weeks after injury) which had been innervated by the SOL nerve became virtually indistinguishable from the SOL muscles in regard to their pattern of AChE molecular forms. However, AChE patterns of mature regenerated SOL muscles that had been innervated by the EDL nerve still displayed some features of the SOL pattern. In regard to AChE regulation, muscle satellite cells from slow or fast rat muscles convey to their descendant myotubes the information shifting their initial development in the direction of either slow or fast muscle, respectively. The satellite cells in fast or slow muscles are, therefore, intrinsically different. Intrinsic information is expressed mostly during an early phase of regeneration whereas later on the regulatory influence of the motor nerve more or less predominates. PMID:8151731

Dolenc, I; Crne-Finderle, N; Erzen, I; Sketelj, J

1994-02-01

340

First micro-satellite and new enhanced small satellite series in DFH Satellite Co. Ltd.  

NASA Astrophysics Data System (ADS)

As one important department of CAST (Chinese Academy of Space Technology), with responsibility for small and micro-satellite development, DFH Satellite Co. Ltd. (DFHSat) manufactured and launched six small satellites from 2000 to 2004. Nowadays, DFHSat is developing micro-satellite and new enhanced small satellite series. The first micro-satellite as a basic type is named HummerSat-1. HummerSat-1 is three-axis stabilized with orbit control capability. Information and power control are implemented through an on-board network, GaAs solar cell and Li-ion battery are adopted to obtain and storage power, S-band TT&C and data transmission works are used. The payload of HummerSat-1 has a weight of 60 kg and power consumption of 200 W. The enhanced small satellite series based on technology of HummerSat-1 is planned by DFHSat. It would be aiming to form a continuative product spectrum of 80-200 kg. The enhanced series is focused on satisfying different missions, including earth remote sensing, communication, science exploration, etc.

Zhang, Xiaomin; Xie, Bin; Dai, Shoulun; Zhang, Weiwen; Hu, Gefeng; Lan, Ding

2007-06-01

341

IMAGE Satellite Scaling  

NSDL National Science Digital Library

This is an activity about satellite size. Learners will calculate the volume of the IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) satellite, the first satellite mission to image the Earth's magnetosphere. They will then determine the effect of doubling and tripling the satellite dimensions on the satellite's mass and cost. This is the first activity in the Solar Storms and You: Exploring Satellite Design educator guide.

342

Passive solar reflector satellite revisited  

NASA Technical Reports Server (NTRS)

Passive light weight reflectors in space which direct the incident solar energy to a specified location on the Earth surface are proposed as an alternative system for the solar power satellite to overcome conversion losses and to avoid the need for photovoltaic cells. On Earth, either photovoltaic cells or a steam turbine alternator on a solar tower, or a similar conventional, relatively high efficiency cycle are used for electricity generation. The constraints which apply to the design of the optical system if a single satellite is placed in geostationary orbit are outlined. A single lens and a two lens system are discussed.

Polk, C.; Daly, J. C.

1980-01-01

343

Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management.  

National Technical Information Service (NTIS)

The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA s...

M. A. Shamma

2004-01-01

344

[Reoccurrence of histomonosis in turkey breeder farm].  

PubMed

Histomonosis is a severe disease caused by the protozoan parasite Histomonas (H.) meleagridis, which can lead to high losses in turkeys. The present report describes the reoccurrence of histomonosis in a turkey breeder farm. The first outbreak occurred in 2005 in 17 weeks old hens, the second in 2009 in 8 weeks old hens. The disease remained restricted in one house and one compartment, respectively. Mortality rose to 26 and 65% respectively within few days in spite of therapy with various compounds. Both flocks had to be euthanized. In both cases H. meleagridis belonging to genotype A was detected. The source of infection remained unclear in both cases. PMID:21309161

Aka, Johannes; Hauck, Rüdiger; Blankenstein, Petra; Balczulat, Stefanie; Hafez, Hafez Mohamed

2011-01-01

345

Space Solar Power: Satellite Concepts  

NASA Technical Reports Server (NTRS)

Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

Little, Frank E.

1999-01-01

346

Epidemiology of a Herpesvirus of Turkeys: Possible Sources and Spread of Infection in Turkey Flocks  

PubMed Central

Parameters of turkey herpesvirus (HVT) infection were followed sequentially from hatching through 20 weeks in two commercial turkey flocks. Maternal antibody was uniformly present at hatching but decreased below detectable levels by the 3rd week. Virus was first isolated at the 5th and 6th weeks and thereafter spread rapidly within the flocks. Development of active antibody followed that of viremia by 1 week. Both virus and antibody were present in virtually all turkeys after the 7th or 10th week; however, the incidence of tumors was negligible. Dust and litter from infected flocks were negative for HVT by poult bioassay, but the infection was easily transmitted by exposure of poults to dirty isolation cages or air from HVT-infected turkeys. Attempts to demonstrate congenital transmission of HVT by direct virus isolation from embryos of infected breeders or by isolation rearing procedures were unsuccessful. Images

Witter, R. L.; Solomon, J. J.

1971-01-01

347

UHF and L band propagation measurements to obtain log-normal shadowing parameters for mobile satellite link design  

Microsoft Academic Search

Tree shadowing is significant for mobile satellite radio propagation investigation and must be known for successful link design. Therefore, there are limited data on the relevant problem. For this purpose, propagation measurements at L and UHF band were performed in Trabzon, Turkey, in 1993 and 1996, respectively. These experiments were executed with a transmitter on the top of a high

I. Hakki Cavdar

2003-01-01

348

Differential gene expression between normal and pale, soft, and exudative turkey meat.  

PubMed

In response to high consumer demand, turkeys have been intensively selected for rapid growth rate and breast muscle mass and conformation. The success in breeding selection has coincided with an increasing incidence of pale, soft, and exudative (PSE) meat defect, especially in response to heat stress. We hypothesized that the underlying mechanism responsible for the development of PSE meat arises from differences in expression of several critical genes. The objective of this study was to determine differential gene expression between normal and PSE turkey meat using a 6K turkey skeletal muscle long oligonucleotide microarray. Breast meat samples were collected from Randombred Control Line 2 turkeys at 22 wk of age, and classified as normal or PSE primarily based on marinade uptake (high = normal, low = PSE). Total RNA was isolated from meat samples with the highest (normal, n = 6) and the lowest (PSE, n = 6) marinade uptake. Microarray data confirmation was conducted using quantitative real-time PCR. Selection of differentially expressed genes for pathway analysis was performed using a combination of fold change (FC) ranking (FC < -1.66, FC >1.66) and false discovery rate (<0.35) as criteria. The calcium signaling pathway was highlighted as the top canonical pathway associated with differential gene expression between normal and PSE turkey. Dramatic downregulation of fast-twitch myosin heavy chain coupled with upregulation of slow-twitch myosin and troponin C suggested a switch of skeletal muscle isoforms, which may alter muscle fiber arrangement and formation of actin-myosin complexes. Changes in expression of genes in the actin cytoskeleton signaling pathway also suggest altered structures of actin filaments that may affect cell motility as well as strength and flexibility of muscle cells. Substantial downregulation of pyruvate dehydrogenase kinase, isozyme 4 was observed in PSE samples, suggesting altered regulation of the aerobic metabolic pathway in the birds that developed PSE meat defect. PMID:23687159

Malila, Y; Tempelman, R J; Sporer, K R B; Ernst, C W; Velleman, S G; Reed, K M; Strasburg, G M

2013-06-01

349

Limited transmission of turkey coronavirus in young turkeys by adult Alphitobius diaperinus (Coleoptera: Tenebrionidae).  

PubMed

We examined the role of lesser mealworm, Alphitobius diaperinus (Panzer), in the transmission of an enteric disease of turkeys caused by a coronavirus. Turkey coronavirus (TCV) from two sources was studied, one isolate (NC95) was embryo propagated, the second was TCV infected material from turkeys diagnosed with poult enteritis mortality syndrome (PEMS). Beetles were fed virus-infected feces mixed with chicken feed. Transmission of virus was effectively halted by surface sterilization of the beetles. Turkey poults administered beetle homogenates infected with TCV+ PEMS that had not been surface sterilized had reduced weight gains and 50% mortality. Mortality and weight gains were not effected in the NC95 group. Virus isolation procedures were performed to determine NC95 viability at varying time intervals. Beetles were dissected and the guts removed 1, 12, and 24 h after the initial viral feeding. Whole beetles were also examined for comparison. Whole beetles and beetle guts were homogenized and injected into turkey eggs for embryo propagation. Direct immunofluorescence was used to determine the presence of TCV. A. diaperinus were capable of mechanical transmission of TCV. However, only turkey embryos receiving whole beetle and beetle gut homogenates within 1 h of feeding on the virus were positive for TCV. Laboratory studies demonstrating PEMS transmission by A. diaperinus are continuing. PMID:15535597

Watson, D W; Guy, J S; Stringham, S M

2000-05-01

350

Interaction between turkey monocytes and avian Chlamydia psittaci in the presence of Mycoplasma sp.: the importance of nitric oxide.  

PubMed

The interaction between Chlamydia psittaci and turkey monocytes was studied in vitro. Purified monocytes were inoculated with C. psittaci, in the presence or absence of Mycoplasma hyorhinis. Whereas turkey monocytes produced high amounts of nitric oxide (NO) following the inoculation with M. hyorhinis, inoculation with C. psittaci did not induce NO production in these phagocytes. The monocytes strongly supported chlamydial growth, as demonstrated by the presence of inclusion forming units, the positive direct immunofluorescence staining and transmission electron microscopy. In contrast, upon co-inoculation of the monocytes with C. psittaci and M. hyorhinis, a reduced replication rate of C. psittaci was observed. N(G)-monomethyl-L-Arginine, a competitive inhibitor for the enzyme NO-synthase, inhibited the NO production and reversed the antichlamydial activity of the M. hyorhinis co-inoculated turkey monocytes. These results imply two considerations. First, as chlamydiae are obligate intracellular bacteria, special care should be taken to guard chlamydial cultures from mycoplasmal contamination, in order to prevent false results when investigating the response of immunomodulating cells to chlamydial infection. Secondly, as a mycoplasmal co-infection in vitro has the capacity of inducing antichlamydial activity in turkey monocytes, through the action of NO, it could be suggested that a similar interaction might take place in vivo. Moreover, it was shown that avian M. gallisepticum strains were also able to induce NO in turkey monocytes. Considering the high prevalence of both C. psittaci and Mycoplasma sp. in turkeys, this interaction, through the pivotal role of NO, might influence the outcome of respiratory diseases in turkeys. PMID:10736525

Van Nerom, A; Ducatelle, R; Charlier, G; Haesebrouck, F

2000-06-01

351

Broadband Satellite Systems  

Microsoft Academic Search

Recently, the interest in broadband satellite multimedia (BSM) systems has grown rapidly. Advancements in transmission technology have led to the availability of low-cost satellite earth terminals. The superior remote access capabilities of satellite networks are foreseen to provide broadband services to geographically diverse user groups. The desire to support a wide range of broadband services in satellite networks implies that

Daniel Jozef Bem; Tadeusz W. Wieckowski; Ryszard J. Zielinski

2000-01-01

352

The Satellites of Jupiter  

Microsoft Academic Search

The objective of this paper is to deduce the revolution of the four Galilean satellites and the distances of those satellites from Jupiter. Galileo discovered Jupiter's four largest satellites, Io, Callisto, Ganymede and Europa, in 1610 with a telescope that would be regarded by today's standard as rudimentary (Kaufmann & Freedman 1999). The Galilean satellites, as they were to be

RONALD E. MICKLE

1931-01-01

353

The Determinants of Student Achievement in Turkey  

ERIC Educational Resources Information Center

Recent achievement test results show that Turkish students have been performing poorly compared to students from other countries. Using science literacy results from the PISA 2006 survey, we aim to measure the determinants of student achievement in Turkey within the education production function framework. We find that program types have large…

Dincer, M. A.; Uysal, G.

2010-01-01

354

The nature of PKK terrorism in Turkey  

Microsoft Academic Search

This study is undertaken to evaluate the profile of the PKK (Kurdish Workers Party) and Kurdish political behavior separately in an attempt to distinguish the Kurdish issue from terrorism. PKK's profile has changed between 1978, when it was founded and now, depending on Turkey's internal politics as well as the changing international environment. Basically, it started out as a Marxist?Leninist

Nur Bilge Criss

1995-01-01

355

Turkey Hatchery (Released January 15, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on January 1, 2010, in the United States totaled 27.5 million, down 7 percent from January 1, 2009. Eggs in incubators were up 4 percent from the December 1, 2009 total of 26.6 million eggs. Regional changes from the previous yea...

2010-01-01

356

Turkey Hatchery (Released June 15, 2009).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on June 1, 2009, in the United States totaled 29.2 million, down 8 percent from June 1, 2008. Eggs in incubators were up 2 percent from the May 1, 2009 total of 28.8 million eggs. Regional changes from the previous year were: Eas...

2009-01-01

357

Turkey Hatchery (Released April 15, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on April 1, 2010, in the United States totaled 28.3 million, down 5 percent from April 1, 2009. Eggs in incubators were up 6 percent from the March 1, 2010 total of 26.8 million eggs. Regional changes from the previous year were:...

2010-01-01

358

Turkey Hatchery (Released December 15, 2009).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on December 1, 2009, in the United States totaled 25.8 million, down 7 percent from December 1, 2008. Eggs in incubators were down 1 percent from the November 1, 2009 total of 26.0 million eggs. Regional changes from the previous...

2009-01-01

359

Turkey Hatchery (Released May 14, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on May 1, 2010, in the United States totaled 28.7 million, down slightly from May 1, 2009. Eggs in incubators were down slightly from the April 1, 2010 total of 28.8 million eggs. Regional changes from the previous year were: Eas...

2010-01-01

360

Turkey Hatchery (Released June 16, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on June 1, 2010, in the United States totaled 28.2 million, down 3 percent from June 1, 2009. Eggs in incubators were down 2 percent from the May 1, 2010 total of 28.7 million eggs. Regional changes from the previous year were: E...

2010-01-01

361

Turkey Hatchery (Released March 15, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on March 1, 2010, in the United States totaled 26.9 million, down 4 percent from March 1, 2009. Eggs in incubators were up 1 percent from the February 1, 2010 total of 26.8 million eggs. Regional changes from the previous year we...

2010-01-01

362

Turkey Hatchery (Released May 15, 2009).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on June 1, 2009, in the United States totaled 29.2 million, down 8 percent from June 1, 2008. Eggs in incubators were up 2 percent from the May 1, 2009 total of 28.8 million eggs. Regional changes from the previous year were: Eas...

2009-01-01

363

Turkey Hatchery (Released July 15, 2009).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on July 1, 2009, in the United States totaled 29.8 million, down 9 percent from July 1, 2008. Eggs in incubators were up 2 percent from the June 1, 2009 total of 29.2 million eggs. Regional changes from the previous year were: Ea...

2009-01-01

364

Turkey Hatchery (Released July 15, 2010).  

National Technical Information Service (NTIS)

Turkey eggs in incubators on July 1, 2010, in the United States totaled 29.7 million, down 1 percent from July 1, 2009. Eggs in incubators were up 4 percent from the June 1, 2010 total of 28.7 million eggs. Regional changes from the previous year were: Ea...

2010-01-01

365

Turkey devastated by another major earthquake  

NASA Astrophysics Data System (ADS)

The total number of dead from the disastrous earthquake that struck northwestern Turkey on August 17 could reach 40,000 and the property loss could be $40 billion, according to some reports. A week after the quake, relief efforts focused primarily on helping the tens of thousands injured and the hundreds of thousands homeless.

Showstack, Randy

366

The Legal Status of Transsexuals in Turkey  

Microsoft Academic Search

The development of the legal regulations concerning transsexuals in Turkey can be analysed in three phases. The first phase was prior to 1988 when there were no legal parameters at all. The second phase started in 1988 when certain changes made in the Turkish Civil Code (TCC) for the first time gave people who had already undergone sex reassignment surgery

Yesim M. Atamer

2005-01-01

367

Teachers' Attitudes towards Inclusion in Turkey  

ERIC Educational Resources Information Center

This study investigated the opinions of general education teachers working in public elementary schools in Turkey regarding the inclusion of students with disabilities into their classrooms and their willingness also to include students with more severe learning disabilities. One hundred and ninety-four general education teachers completed the…

Rakap, Salih; Kaczmarek, Louise

2010-01-01

368

Soil liquefaction potential in Eskisehir, NW Turkey  

Microsoft Academic Search

Liquefaction is one of the critical problems in geotechnical engineering. High ground water levels and alluvial soils have a high potential risk for damage due to liquefaction, especially in seismically active regions. Eskisehir urban area, studied in this article, is situated within the second degree earthquake region on the seismic hazard zonation map of Turkey and is surrounded by Eskisehir,

H. Tosun; E. Seyrek; A. Orhan; H. Savas; M. Türköz

2011-01-01

369

Factors Influencing Teaching Choice in Turkey  

ERIC Educational Resources Information Center

Why choose to become a teacher in Turkey? The authors examined motivations and perceptions among preservice teachers (N = 1577) encompassing early childhood, primary and secondary education. The Factors Influencing Teaching Choice (FIT-Choice) instrument was translated into Turkish and its construct validity and reliability assessed. Altruistic…

Kilinc, Ahmet; Watt, Helen M. G.; Richardson, Paul W.

2012-01-01

370

Transition to Family Practice in Turkey  

ERIC Educational Resources Information Center

Introduction: Turkey's primary health care (PHC) system was established in the beginning of the 1960s and provides preventive and curative basic medical services to the population. This article describes the experience of the Turkish health system, as it tries to adapt to the European health system. It describes the current organization of primary…

Gunes, Evrim Didem; Yaman, Hakan

2008-01-01

371

Developments in Concrete Dam Construction in Turkey.  

National Technical Information Service (NTIS)

Economic exploitation of Turkey's water resources requires construction of about 600 dams. One-fifth of them are in operation, one-tenth under construction, one-eighth are at the stage of final design and more than half of them are only at the planning st...

U. Oezis M. Alsan

1990-01-01

372

Turkey's Role in the Greater Middle East.  

National Technical Information Service (NTIS)

For much of the last five decades, Turkey has been regarded by many European observers as a strategic ally but not as a front line NATO member. Its status in the Alliance--as a developing Islamic state with a strong Ottoman tradition that is nonetheless l...

J. C. Snyder

1995-01-01

373

Re-examination of Turkey red.  

PubMed

Cotton yarn was dyed in Turkey red using madder through a special method. Amount of the dyestuffs bound to mordanted cotton fibre and the oiling numbers of the cotton yarn was investigated by using TLC (thin layer chromatography) and spectrophotometry. Sn(II) in the bright red cotton yarn was analysed by X-ray diffraction method. PMID:17867541

Karadag, Recep; Dolen, Emre

2007-07-01

374

Risk and Career Choice: Evidence from Turkey  

ERIC Educational Resources Information Center

In this paper, we examine the college major choice decision in a risk and return framework using university entrance exam data from Turkey. Specifically we focus on the choice between majors with low income risk such as education and health and others with riskier income streams. We use a unique dataset that allows us to control for the choice set…

Caner, Asena; Okten, Cagla

2010-01-01

375

Curie-point depth map of Turkey  

Microsoft Academic Search

A Curie-point isotherm map of the whole of Turkey has been prepared from aeromagnetic data by means of a spectral analysis technique. The most characteristic signature of this map is that the shallow depths generally correlated with the young volcanic rocks and the thinned crustal thicknesses in the west reveal geothermal fields and several hot springs. The orogenic Pontide belt

Ibrahim Aydin; Halil I. Karat; Ali Koçak

2005-01-01

376

Changing Emphasis: Rethinking Turkey's Early Literacy Instruction  

ERIC Educational Resources Information Center

The Ministry of National Education in Turkey initiated a new early reading instruction method in 2004. Analytical approach (Whole Language), as defined in the curriculum, was abandoned and phoneme based approach (Phonics) was introduced. This research has a two year longitudinal perspective and aims to collect the opinions of teachers about the…

Sahin, Ismet

2006-01-01

377

Teachers’ attitudes towards inclusion in Turkey  

Microsoft Academic Search

This study investigated the opinions of general education teachers working in public elementary schools in Turkey regarding the inclusion of students with disabilities into their classrooms and their willingness also to include students with more severe learning disabilities. One hundred and ninety?four general education teachers completed the survey package. The analysis of data showed that the sample possessed slightly negative

Salih Rakap; Louise Kaczmarek

2010-01-01

378

Elementary School Curriculum Reform in Turkey  

ERIC Educational Resources Information Center

This paper aims to examine the nature of the new elementary school curriculum in Turkey. In particular, the authors provide a coherent picture of the fundamentals, basic elements and the classroom implications of the new curriculum development initiative in five content areas: mathematics, science, social science, life science, and Turkish. This…

Koc, Yusuf; Isiksal, Mine; Bulut, Safure

2007-01-01

379

Global attention to Turkey due to desertification.  

PubMed

Desertification has recognized as an environmental problem by many international organizations such as UN, NATO and FAO. Desertification in Turkey is generally caused by incorrect land use, excessive grazing, forest fires, urbanization, industry, genetic erosion, soil erosion, salinization, and uncontrolled wild type plants picking. Due to anthropogenic destruction of forest, steppe flora gradually became dominant in Anatolia. In terms of biodiversity, Turkey has a significant importance in Europe and Middle East. Nine thousands plant species naturally grown in Turkey, one third of them are endemic. Also, endemic species of vertebrates, thrive in the lakes and marshy areas. The studies of modelling simulation of vegetation on the effects of Mediterranean climate during the Roman Classical period by using vegetation history showed that, in 2000 years BP, Mediterranean countries were more humid than today. Turkey is a special place on the global concern in terms of desertification because of biodiversity, agricultural potential, high population, social and economical structure, topographical factors and strategic regional location. Communication among scientists, decision makers and international non-profit organizations must be improved. PMID:17057981

Camci Cetin, S; Karaca, A; Haktanir, K; Yildiz, H

2007-05-01

380

Shadow Prices for Project Appraisal in Turkey.  

National Technical Information Service (NTIS)

This paper is a study of the shadow prices to be used for project appraisal in Turkey. It arrives at estimates of various efficiency pricing and social pricing parameters taking into account the Turkish import and export regime and the objectives of the G...

A. Mashayekhi

1980-01-01

381

Multigrade Schooling in Turkey: An Overview  

ERIC Educational Resources Information Center

This paper reviews multigrade schooling in Turkey, with an emphasis on its status in the education system, as well as the curriculum practices, teacher training and problems associated with it. It is viewed by the State as an "inevitable" practice that arises through limited number of pupils and classrooms in small and scattered settlement areas…

Aksoy, Naciye

2008-01-01

382

Early Childhood Education: The Case of Turkey  

ERIC Educational Resources Information Center

It is now widely recognized that early childhood education has paramount significance for the well-being of societies. In this study, the current situation of early childhood education in Turkey is discussed mainly in terms of its perception by the government, the school enrollment rate and the quality of early childhood education programs. The…

Usakli, Hakan

2010-01-01

383

Clopidogrel, Turkey and a red herring?  

PubMed Central

The authors present the case of acute hepatitis E in a 61-year-old Edinburgh man who had returned from a holiday in Turkey 6 weeks previously. Diagnosis was ambiguous with his presentation initially attributed to a drug-induced liver injury.

Leighton, SP; Gordon, C; Shand, A

2011-01-01

384

Fundamentalist Bedfellows: Political Creationism in Turkey.  

ERIC Educational Resources Information Center

Defines Islamic creationism and anti-evolutionism in Turkey, provides information about political and cultural changes starting from the 1920s, and discusses Islamic movements at this time. Presents examples of politicians' approaches to this issue and points out the effects of Christian creationism and the Institute for Creation Research (ICR) on…

Shapiro, Arthur M.

1999-01-01

385

Internet Censorship in Turkey: University Students' Opinions  

ERIC Educational Resources Information Center

The aim of this paper is to study university students' opinions toward online censorship with references to their socio-political and economic variables. Considering the upwards trend and the increasing number of online restrictions in Turkey, the opinions of university students (n=138) are thought to give significant findings. The questionnaire…

Ozkan, Hasan; Arikan, Arda

2009-01-01

386

Educational Research in Turkey, 1973-1974.  

ERIC Educational Resources Information Center

Summaries of 62 educational research projects, completed or in progress in Turkey during 1973-74, are contained in this survey. Information is outlined in 12 major categories. Included in the categories are title, organization, researcher(s), progress status, bibliographic references, background and aims, size and composition of sample, methods,…

Ozgentas, Ibrahim, Ed.

387

Educational Research in Turkey, 1971-1972.  

ERIC Educational Resources Information Center

Summaries of 34 educational research projects, completed or in progress in Turkey during 1971-72, are contained in this survey. Information is outlined in 12 major categories: title, organization, researcher(s), progress status, bibliographic references, background and aim(s), size and composition of sample, methods, main findings, number of…

Ozgentas, Ibrahim, Ed.

388

Probabilistic Ontology Learner in Semantic Turkey  

Microsoft Academic Search

In this paper we present the Semantic Turkey Ontology Learner (ST-OL), an incremental ontology learning system, that follows\\u000a two main ideas: (1) putting final users in the learning loop; (2) using a probabilistic ontology learning model that exploits\\u000a transitive relations for inducing better extraction models.

Francesca Fallucchi; Noemi Scarpato; Armando Stellato; Fabio Massimo Zanzotto

2009-01-01

389

Globalization and English Language Policy in Turkey  

ERIC Educational Resources Information Center

It is widely acknowledged that globalization has made a considerable impact on multidimensional aspects of human life including the language policies of many countries. This article examines the adjustment of Turkey's language policy in response to the global influence of English at different levels of Turkish national education, including its…

Kirkgoz, Yasemin

2009-01-01

390

Vocational and Technical Education Reform in Turkey  

ERIC Educational Resources Information Center

Turkey is a country where individual rights and freedom of people are improving. It is known that a free market economy is in its infancy. There is a strong relationship between developed human resources and the production sector. In this sense, vocational and technical education is very important. It cannot be said that the efforts for…

Kilic, Abdurrahman

2006-01-01

391

Electric power for space satellites  

NASA Technical Reports Server (NTRS)

The development of electric power systems for satellites is discussed as an evolutionary process requiring the integration of power generation, power storage, and power control and distribution. The growth of space electric power systems is traced. The capabilities and limitations of the various elements (i.e. silicon solar cells) are discussed together with their impact on future technological growth.

Mackenzie, C. M.

1974-01-01

392

Outer planet satellites  

SciTech Connect

Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon. 210 refs.

Schenk, P.M. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

393

a Survey of Landnet Sites Focusing on Tuz GÖLÜ Salt Lake, Turkey  

NASA Astrophysics Data System (ADS)

Radiometric calibration is critical to ensure the accuracy, veracity, continuity and reliability of satellite data measured from multiple sensors and platforms, and is thus recognized as a key activity by all satellite operators. For imaging sensors, vicarious methods using natural targets (such as salt lakes, deserts, or flatlands that are well-characterized and preferably temporally and spatially stable) as a reference are similarly well established. However, while selecting a target site, it is important that its quality and location are selected to minimize sources of uncertainty for any given sensor. To maximize the benefit from limited resources and minimize the impact on satellite operators, the Infrared Visible Optical Sensor (IVOS) sub-group of Committee on Earth Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV) has selected a few, well-characterized, regularly instrumented target sites, which have since become known as LANDNET sites. Currently, there are eight LANDNET sites: 1) Dome C, Antarctica; 2) Dunhuang, China, Asia; 3) Lspec Frenchman Flat, NV, USA, North America; 4) Ivanpah, NV/CA, USA, North America; 5) La Crau, France, Europe; 6) Negev, Southern Israel, Asia; 7) Railroad Valley Playa, NV, USA, North America; 8) Tuz Gölü, Central Anatolia, Turkey, Asia. This work summarizes the key characteristics, and areas of application of each of the LANDNET sites, especially that of Tuz Gölü, to guide and inform researchers on site selection, and increase international awareness and collaboration in this field. Additionally, detailed information about the Tuz Gölü, Turkey test site is provided, including geographical characteristics, spatial uniformity qualities, and opportunities for international researchers to conduct experiments and measurements. Practical, technical, and logistical experience gained through the international field campaigns organized over the last few years at Tuz Gölü is also shared in detail.

Gürbüz, S. Z.; Özen, H.; Chander, G.

2012-07-01

394

9 CFR 381.68 - Maximum inspection rates-New turkey inspection system.  

Code of Federal Regulations, 2010 CFR

...false Maximum inspection rates-New turkey inspection system. 381.68 Section...68 Maximum inspection ratesâNew turkey inspection system. (a) The maximum inspection rates for one inspector New Turkey Inspection (NTI-1 and NTI-1...

2010-01-01

395

78 FR 56865 - Certain Oil Country Tubular Goods From India and Turkey: Postponement of Preliminary...  

Federal Register 2010, 2011, 2012, 2013

...Oil Country Tubular Goods From India and Turkey: Postponement of Preliminary Determination...Shane Subler at (202) 482-0189 (Turkey), AD/CVD Operations, Import Administration...oil country tubular goods from India and Turkey.\\1\\ Currently, the preliminary...

2013-09-16

396

Turkey's Membership in the European Union: Analyzing Potential Benefits and Drawbacks.  

National Technical Information Service (NTIS)

Relations between Turkey and European integration institutions began with Turkey's application for associate membership in the European Economic Community (EEC) in 1959. Turkey applied for full membership in the EEC in 1987 but did not gain candidate stat...

A. Pehlivan

2008-01-01

397

75 FR 44766 - Certain Welded Carbon Steel Standard Pipe from Turkey: Final Results of Countervailing Duty...  

Federal Register 2010, 2011, 2012, 2013

...Welded Carbon Steel Standard Pipe from Turkey: Final Results of Countervailing Duty...welded carbon steel standard pipe from Turkey for the January 1, 2008, through December...Welded Carbon Steel Standard Pipe From Turkey: Preliminary Results of...

2010-07-29

398

78 FR 77420 - Certain Oil Country Tubular Goods From the Republic of Turkey: Preliminary Negative...  

Federal Register 2010, 2011, 2012, 2013

...Certain Oil Country Tubular Goods From the Republic of Turkey: Preliminary Negative Countervailing Duty Determination...certain oil tubular goods (OCTG) from the Republic of Turkey (Turkey). The period of investigation is January 1,...

2013-12-23

399

9 CFR 381.68 - Maximum inspection rates-New turkey inspection system.  

Code of Federal Regulations, 2010 CFR

...false Maximum inspection rates-New turkey inspection system. 381.68 Section...68 Maximum inspection ratesâNew turkey inspection system. (a) The maximum inspection rates for one inspector New Turkey Inspection (NTI-1 and NTI-1...

2009-01-01

400

78 FR 73838 - Steel Concrete Reinforcing Bar From Turkey: Postponement of Preliminary Determination in the...  

Federal Register 2010, 2011, 2012, 2013

...Administration [C-489-819] Steel Concrete Reinforcing Bar From Turkey: Postponement...countervailing duty investigation on steel concrete reinforcing bar from Turkey.\\1\\ The...1\\ See Steel Concrete Reinforcing Bar from Turkey:...

2013-12-09

401

76 FR 48802 - Certain Steel Concrete Reinforcing Bars From Turkey; Notice of Amended Final Results of...  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-489-807] Certain Steel Concrete Reinforcing Bars From Turkey; Notice...antidumping duty order on certain steel concrete reinforcing bars (rebar) from Turkey. See Certain Steel Concrete Reinforcing Bars From Turkey;...

2011-08-09

402

The Genome of Turkey Herpesvirus  

PubMed Central

Here we present the first complete genomic sequence of Marek's disease virus serotype 3 (MDV3), also known as turkey herpesvirus (HVT). The 159,160-bp genome encodes an estimated 99 putative proteins and resembles alphaherpesviruses in genomic organization and gene content. HVT is very similar to MDV1 and MDV2 within the unique long (UL) and unique short (US) genomic regions, where homologous genes share a high degree of colinearity and their proteins share a high level of amino acid identity. Within the UL region, HVT contains 57 genes with homologues found in herpes simplex virus type 1 (HSV-1), six genes with homologues found only in MDV, and two genes (HVT068 and HVT070 genes) which are unique to HVT. The HVT US region is 2.2 kb shorter than that of MDV1 (Md5 strain) due to the absence of an MDV093 (SORF4) homologue and to differences at the UL/short repeat (RS) boundary. HVT lacks a homologue of MDV087, a protein encoded at the UL/RS boundary of MDV1 (Md5), and it contains two homologues of MDV096 (glycoprotein E) in the RS. HVT RS are 1,039 bp longer than those in MDV1, and with the exception of an ICP4 gene homologue, the gene content is different from that of MDV1. Six unique genes, including a homologue of the antiapoptotic gene Bcl-2, are found in the RS. This is the first reported Bcl-2 homologue in an alphaherpesvirus. HVT long repeats (RL) are 7,407 bp shorter than those in MDV1 and do not contain homologues of MDV1 genes with functions involving virulence, oncogenicity, and immune evasion. HVT lacks homologues of MDV1 oncoprotein MEQ, CxC chemokine, oncogenicity-associated phosphoprotein pp24, and conserved domains of phosphoprotein pp38. These significant genomic differences in and adjacent to RS and RL regions likely account for the differences in host range, virulence, and oncogenicity between nonpathogenic HVT and highly pathogenic MDV1.

Afonso, C. L.; Tulman, E. R.; Lu, Z.; Zsak, L.; Rock, D. L.; Kutish, G. F.

2001-01-01

403

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 6.0 ampere hour nickle cadmium spacecraft cells for the dynamic explorer satellite program  

NASA Technical Reports Server (NTRS)

Evaluation tests of 10 nickel cadmium cells are described. Although pressures were greater than what normally was exhibited by General Electric cells in the past, it is recommended that these cells be placed on life test simulating the predicted Dynamic Explorer flight profiles.

Harkness, J. D.

1980-01-01

404

DNA Methylation at a Bovine Alpha Satellite I Repeat CpG Site during Development following Fertilization and Somatic Cell Nuclear Transfer  

PubMed Central

Incomplete epigenetic reprogramming is postulated to contribute to the low developmental success following somatic cell nuclear transfer (SCNT). Here, we describe the epigenetic reprogramming of DNA methylation at an alpha satellite I CpG site (?satI-5) during development of cattle generated either by artificial insemination (AI) or in vitro fertilization (IVF) and SCNT. Quantitative methylation analysis identified that SCNT donor cells were highly methylated at ?satI-5 and resulting SCNT blastocysts showed significantly more methylation than IVF blastocysts. At implantation, no difference in methylation was observed between SCNT and AI in trophoblast tissue at ?satI-5, however, SCNT embryos were significantly hyper-methylated compared to AI controls at this time point. Following implantation, DNA methylation at ?satI-5 decreased in AI but not SCNT placental tissues. In contrast to placenta, the proportion of methylation at ?satI-5 remained high in adrenal, kidney and muscle tissues during development. Differences in the average proportion of methylation were smaller in somatic tissues than placental tissues but, on average, SCNT somatic tissues were hyper-methylated at ?satI-5. Although sperm from all bulls was less methylated than somatic tissues at ?satI-5, on average this site remained hyper-methylated in sperm from cloned bulls compared with control bulls. This developmental time course confirms that epigenetic reprogramming does occur, at least to some extent, following SCNT. However, the elevated methylation levels observed in SCNT blastocysts and cellular derivatives implies that there is either insufficient time or abundance of appropriate reprogramming factors in oocytes to ensure complete reprogramming. Incomplete reprogramming at this CpG site may be a contributing factor to low SCNT success rates, but more likely represents the tip of the iceberg in terms of incompletely reprogramming. Until protocols ensure the epigenetic signature of a differentiated somatic cell is reset to a state resembling totipotency, the efficiency of SCNT is likely to remain low.

Couldrey, Christine; Wells, David N.

2013-01-01

405

DNA methylation at a bovine alpha satellite I repeat CpG site during development following fertilization and somatic cell nuclear transfer.  

PubMed

Incomplete epigenetic reprogramming is postulated to contribute to the low developmental success following somatic cell nuclear transfer (SCNT). Here, we describe the epigenetic reprogramming of DNA methylation at an alpha satellite I CpG site (?satI-5) during development of cattle generated either by artificial insemination (AI) or in vitro fertilization (IVF) and SCNT. Quantitative methylation analysis identified that SCNT donor cells were highly methylated at ?satI-5 and resulting SCNT blastocysts showed significantly more methylation than IVF blastocysts. At implantation, no difference in methylation was observed between SCNT and AI in trophoblast tissue at ?satI-5, however, SCNT embryos were significantly hyper-methylated compared to AI controls at this time point. Following implantation, DNA methylation at ?satI-5 decreased in AI but not SCNT placental tissues. In contrast to placenta, the proportion of methylation at ?satI-5 remained high in adrenal, kidney and muscle tissues during development. Differences in the average proportion of methylation were smaller in somatic tissues than placental tissues but, on average, SCNT somatic tissues were hyper-methylated at ?satI-5. Although sperm from all bulls was less methylated than somatic tissues at ?satI-5, on average this site remained hyper-methylated in sperm from cloned bulls compared with control bulls. This developmental time course confirms that epigenetic reprogramming does occur, at least to some extent, following SCNT. However, the elevated methylation levels observed in SCNT blastocysts and cellular derivatives implies that there is either insufficient time or abundance of appropriate reprogramming factors in oocytes to ensure complete reprogramming. Incomplete reprogramming at this CpG site may be a contributing factor to low SCNT success rates, but more likely represents the tip of the iceberg in terms of incompletely reprogramming. Until protocols ensure the epigenetic signature of a differentiated somatic cell is reset to a state resembling totipotency, the efficiency of SCNT is likely to remain low. PMID:23383311

Couldrey, Christine; Wells, David N

2013-01-01

406

Characterization of extremely halophilic Archaea isolated from saline environment in different parts of Turkey  

Microsoft Academic Search

Ninety-five extremely halophilic strains were isolated from six distinct saline regions of Turkey by using complex medium\\u000a containing 25% NaCl. The selected regions are Tuz Golu (salt lake), Ankara; Aci Lake, Denizli; Salda Lake, Denizli; Seyfe\\u000a Lake, Kyrsherhir; Tuzla Lake, Kayseri; and Bolluk Lake, Konya. The isolated strains were tested for motility, gram reaction,\\u000a cell and colony morphologies, pigmentation, biochemical

B. Ozcan; C. Cokmus; A. Coleri; M. Caliskan

2006-01-01

407

Groundwater contamination and its effect on health in Turkey  

Microsoft Academic Search

The sources of groundwater pollution in Turkey are identified, and pathways of contaminants to groundwater are first described.\\u000a Then, the effects of groundwater quality on health in Turkey are evaluated. In general, sources of groundwater contamination\\u000a fall into two main categories: natural and anthropogenic sources. Important sources of natural groundwater pollution in Turkey\\u000a include geological formations, seawater intrusion, and geothermal

Alper Baba; Gokmen Tayfur

408

Use of energy and labour in apricot agriculture in Turkey  

Microsoft Academic Search

Turkey is the biggest apricot producer in the world with 538,000t production per annum and 20.15% market share. Moreover, 83% of the dried apricots in world markets are produced in Turkey. In this research; the energy budget of traditionally applied apricot agriculture—one of the means of subsistence in Malatya region of Turkey—is evaluated. Total yield, apricot mass\\/pit mass ratio and

Ibrahim Gezer; Mustafa Acaro?lu; Haydar Hacisefero?ullari

2003-01-01

409

Satellite orbit predictor  

NASA Technical Reports Server (NTRS)

An analog aid to determine satellite coverage of Emergency Locator Transmitters Emergency Position Indicating Radio Beacon (ELT/EPIRB) distress incidence is discussed. The satellite orbit predictor is a graphical aid for determining the relationship between the satellite orbit, antenna coverage of the spacecraft and coverage of the Local User Terminal. The predictor allows the user to quickly visualize if a selected position will probably be detected and is composed of a base map and a satellite track overlay for each satellite.A table of equator crossings for each satellite is included.

Friedman, Morton l.; Garrett, James, Major

410

What are Satellites?  

NSDL National Science Digital Library

In this activity, students differentiate between natural satellites and artificial satellites, and are challenged to create a model of an artificial satellite, including calculating the amount of energy required to power the satellite and the size of the solar array required to generate that power. Student worksheets, answer sheet, illustrations of satellites, teacher tips and Web links are included. This is Lesson 2 in What are Satellites, part of IMAGERS, Interactive Media Adventures for Grade School Education using Remote Sensing. The website provides hands-on activities in the classroom supporting the science content in two interactive media books, The Adventures of Echo the Bat and Amelia the Pigeon.

411

The Mexican national satellite system  

NASA Astrophysics Data System (ADS)

The satellites, tracking, telemetry, command, and monitoring facilities, and the earth station complex for the Mexican national satellite system, Morelos, are described. The spacecraft are intended to provide educational television, rural telephony, data transmission, and business and industrial services. Scheduled for 1985 launch, the satellites will be placed in GEO and use the C and Ku bands with 12 narrow band and six wideband transponders. Spin-stabilized and solar cell powered, the functional mass will be 666 kg, including propellant. The solar panels will provide 940 W of power and 830 W will be available from NiCd batteries during eclipse conditions. The earth station will be located at Iztapalapa, which will have a 12 m antenna, redundant uplink and downlink radios, and command and ranging equipment. Back-up capability will be provided by a station at Tulancingo. Ku band and C band stations are in planning.

Sanchez Ruiz, M. E.; Briskman, R. D.

1983-10-01

412

West Nile virus studies in the Sanliurfa Province of Turkey.  

PubMed

We attempted to isolate West Nile virus from mosquitoes collected in the field for the first time in Turkey. A total of 6,457 mosquito specimens from Culex pipiens Linnaeus, Ochlerotatus caspius (Pallas) and Aedes spp. species were included in this study. Culex pipiens samples made up 56% of the total species, O. caspius 24% and Aedes spp 20%. There were no positive results after studying mosquito samples using Real-time PCR, VecTest, and Vero cell culture. In serological tests of 181 human serum samples, 29 (16%) were found to be West Nile positive. On the basis of these results, we intend to collect more mosquito samples especially from those areas from which positive serum samples were obtained. PMID:18260509

Ozer, Nurdan; Ergünay, Koray; Simsek, Fatih; Kaynas, Sinan; Alten, Bülent; Caglar, Selim S; Ustacelebi, Semsettin

2007-12-01

413

Satellite Imaging Corporation: IKONOS Satellite Images  

NSDL National Science Digital Library

Satellite Imaging Corporation (SIC) acquires and processes imagery from the IKONOS satellite as well as others and makes the products available through their website. The images in the gallery are arranged in several categories based on what applications the images might be useful for, such as Agriculture, Coastal Management, or Sports and Tourism.

Corporation, Satellite I.

414

Satellite diversity in mobile satellite CDMA systems  

Microsoft Academic Search

The paper addresses the exploitation of satellite diversity in a satellite mobile network. In particular, we focus on the impact of diversity on service availability and on system capacity, considering the forward link of a CDMA system with a multisatellite and multibeam architecture. The analysis includes the effects of path blockage, intrabeam and interbeam interference, imperfect power control, and fading

Carlo Caini; Giovanni Emanuele Corazza

2001-01-01

415

Barx2 and pax7 have antagonistic functions in regulation of wnt signaling and satellite cell differentiation.  

PubMed

The canonical Wnt signaling pathway is critical for myogenesis and can induce muscle progenitors to switch from proliferation to differentiation; how Wnt signals integrate with muscle-specific regulatory factors in this process is poorly understood. We previously demonstrated that the Barx2 homeobox protein promotes differentiation in cooperation with the muscle regulatory factor (MRF) MyoD. Pax7, another important muscle homeobox factor, represses differentiation. We now identify Barx2, MyoD, and Pax7 as novel components of the Wnt effector complex, providing a new molecular pathway for regulation of muscle progenitor differentiation. Canonical Wnt signaling induces Barx2 expression in muscle progenitors and perturbation of Barx2 leads to misregulation of Wnt target genes. Barx2 activates two endogenous Wnt target promoters as well as the Wnt reporter gene TOPflash, the latter synergistically with MyoD. Moreover, Barx2 interacts with the core Wnt effectors ?-catenin and T cell-factor 4 (TCF4), is recruited to TCF/lymphoid enhancer factor sites, and promotes recruitment of ?-catenin. In contrast, Pax7 represses the Wnt reporter gene and antagonizes the activating effect of Barx2. Pax7 also binds ?-catenin suggesting that Barx2 and Pax7 may compete for interaction with the core Wnt effector complex. Overall, the data show for the first time that Barx2, Pax7, and MRFs can act as direct transcriptional effectors of Wnt signals in myoblasts and that Barx2 and Wnt signaling participate in a regulatory loop. We propose that antagonism between Barx2 and Pax7 in regulation of Wnt signaling may help mediate the switch from myoblast proliferation to differentiation. Stem Cells 2014;32:1661-1673. PMID:24753152

Zhuang, Lizhe; Hulin, Julie-Ann; Gromova, Anastasia; Tran Nguyen, Thi Diem; Yu, Ruth T; Liddle, Christopher; Downes, Michael; Evans, Ronald M; Makarenkova, Helen P; Meech, Robyn

2014-06-01

416

Satellite RNAs and Satellite Viruses of Plants  

PubMed Central

The view that satellite RNAs (satRNAs) and satellite viruses are purely molecular parasites of their cognate helper viruses has changed. The molecular mechanisms underlying the synergistic and/or antagonistic interactions among satRNAs/satellite viruses, helper viruses, and host plants are beginning to be comprehended. This review aims to summarize the recent achievements i