Comparative analysis of morphometric characters of juvenile sterlet Acipenser ruthenus L. from natural population and aquaculture

Czech Academy of Sciences Publication Activity Database

Lenhardt, M.; Prokeš, Miroslav; Jaric, I. Z.; Baruš, Vlastimil; Kolarevic, J.; Krupka, I.; Cvijanovic, G.; Cakic, Z.; Gacic, Z.

2004-01-01

Roč. 65, Suppl.A (2004), s. 320 ISSN 0022-1112. [Nature and culture: comparative biology and interactions of wild and farmed fish. London, 19.07.2004-23.07.2004] R&D Projects: GA MZe(CZ) QF3028 Institutional research plan: CEZ:AV0Z6093917 Keywords : Acipenser ruthenus * morphometric characters Subject RIV: GL - Fishing Impact factor: 1.198, year: 2004

Individual Variation in Life History Characteristics Can Influence Extinction Risk

Energy Technology Data Exchange (ETDEWEB)

Jager, H I

2001-01-01

The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

Individual variation in life history characteristics can influence extinction risk (vol 144, pg 61, 2001) Correction

Energy Technology Data Exchange (ETDEWEB)

Jager, Yetta [ORNL

2009-01-01

The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

Mezinárodní obchod s jeseterem sibiřským (Acipenser baerii)

OpenAIRE

KORUNKOVÁ, Eva

2015-01-01

Sturgeon fish (Acipenseriformes) is commercially used to produce high quality fish meat and highly priced caviar. In fact, all species of Sturgeon fish are integrated into CITES appendix. Sturgeon (Acipenser baerii) is the most frequently bred/reared and the most commercial representative of its kind, not only in Europe but also in Asia. The aim of this final project is to evaluate international sturgeon trade while using CITES references from 1998-2012. The source of data(s) was commercial d...

Ultrastructure and morphology of spermatozoa in Chinese sturgeon (Acipenser sinensis Gray 1835) using scanning and transmission elektron microscopy

Czech Academy of Sciences Publication Activity Database

Wei, Q.; Li, P.; Pšenička, M.; Hadi Alavi, S.M.; Shen, L.; Liu, J.; Pěknicová, Jana; Linhart, O.

2007-01-01

Roč. 67, č. 7 (2007), s. 1269-1278 ISSN 0093-691X R&D Projects: GA ČR GA524/06/0817; GA MŠk LC06073 Grant - others:GA MŠk 1P05ME742 Institutional research plan: CEZ:AV0Z50520514 Keywords : Acipenser sinensis * spermatozoon * acrosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.911, year: 2007

Dispersal and survival of stocked juvenile hatchery-reared Atlantic sturgeon (Acipenser oxyrinchus

Directory of Open Access Journals (Sweden)

Kapusta Andrzej

2016-12-01

Full Text Available The post-stocking dispersal of juvenile Atlantic sturgeon (Acipenser oxyrinchus Mitchill in the Wis3oka River (southern Poland was investigated using biotelemetry. Thirty-five hatchery-reared juvenile A. oxyrinchus were tagged with radio or acoustic transmitters and tracked using mobile surveys and fixed receivers. Daily movement patterns were similar in 2009 and 2010. The sturgeon migrated with a mean speed of 1.42 km h-1 in 2009 and of 2.06 km h-1 in 2010. Migration rate was not regarded as being dependent on juvenile sturgeon size. The confirmed survival of individuals from the two field seasons differed slightly over the course of this study. Short-term survival of A. oxyrinchus was 86.7 and 90% in 2009 and 2010, respectively.

Effects of lecithin on growth and hematological indices in juveniles of Siberian sturgeon (Acipenser baeri Brandet 1869)

OpenAIRE

Najafipour Moghadam, E.; Falahatkar, B.; Kalbassi, M.R.

2011-01-01

This study was carried out to evaluate the effects of dietary lecithin on growth performance and hematological indices in juveniles of Siberian sturgeon (Acipenser baeri). Fish with initial average weight of 32.9±0.3 grams were fed five isoproteic and isolipidic formulated diets with different soybean lecithin levels including 0, 2.5, 5, 7.5 and 10% in triplicate groups for 8 weeks. Results showed that lecithin supplementation to 7.5% significantly increased some growth indices such as body w...

Status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Volume 2: Supplemental papers and data documentation; Final report

International Nuclear Information System (INIS)

Beamesderfer, R.C.; Nigro, A.A.

1995-01-01

This is the final report for research on white sturgeon Acipenser transmontanus from 1986--92 and conducted by the National Marine Fisheries Service (NMFS), Oregon Department of Fish and Wildlife (ODFW), US Fish and Wildlife Service (USFWS), and Washington Department of Fisheries (WDF). Findings are presented as a series of papers, each detailing objectives, methods, results, and conclusions for a portion of this research. This volume includes supplemental papers which provide background information needed to support results of the primary investigations addressed in Volume 1. This study addresses measure 903(e)(1) of the Northwest Power Planning Council's 1987 Fish and Wildlife Program that calls for ''research to determine the impact of development and operation of the hydropower system on sturgeon in the Columbia River Basin.'' Study objectives correspond to those of the ''White Sturgeon Research Program Implementation Plan'' developed by BPA and approved by the Northwest Power Planning Council in 1985. Work was conducted on the Columbia River from McNary Dam to the estuary

Radionuclide concentrations in white sturgeon from the Columbia River

Energy Technology Data Exchange (ETDEWEB)

Dauble, D.D.; Price, K.R.; Poston, T.M.

1992-09-01

Although radioactive releases from the US Department of Energy`s Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

Radionuclide concentrations in white sturgeon from the Columbia River

Energy Technology Data Exchange (ETDEWEB)

Dauble, D.D.; Price, K.R.; Poston, T.M.

1992-09-01

Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

Radionuclide concentrations in white sturgeon from the Columbia River

International Nuclear Information System (INIS)

Dauble, D.D.; Price, K.R.; Poston, T.M.

1992-09-01

Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River

Columbia River White Sturgeon (Acipenser Transmontanus) Early Life History and Genertics Study, August 1, 1984 to December 31, 1985 Final Report.

Energy Technology Data Exchange (ETDEWEB)

Brannon, Ernest L.

1985-12-01

Research on Columbia River white sturgeon has been directed at their early life history as it may apply to production and enhancement strategies for management of the species. The river environment in which sturgeon historically migrated, spawned, and reared has changed through development. Habitat changes are expected to precipitate genetic changes in the fish, as well as reduce the fitness in populations. Genetic analysis of samples taken from various locations over the length of the Columbia River have indicated that observed gene frequencies in all areas sampled were not in Hardy-Weinburg equilibrium, which could suggest that the general population is experiencing perturbation in the system. Analysis thus far has exposed few differences between samples from the lower, middle, and upper portions of the system. Allelic differences were identified in fish from the Roosevelt Lake, which may be evidence of unique characteristics among fish from that general area.

Morphological development and allometric growth patterns of Acipenser persicus Borodin, 1897 (Actinopterygii, Acipenseridae during early development

Directory of Open Access Journals (Sweden)

Soheil Eagderi

2017-06-01

Full Text Available Morphological development and allometric growth patterns of reared Persian sturgeon, Acipenser persicus, were studied from hatching to 50 days post-hatching (dph. The larvae were sampled, their left sides photographed and seven morphometric characters, including total length, head length, tail length, trunk length, snout length, caudal peduncle and predorsal length were measured. Allometric growth patterns were calculated as a power function of total length and described using the growth coefficient to find important steps in early life history. The total length of the newly hatched larvae and fry were 10.59±0.8 and 38.8±2.9 mm at 1 and 50 dph, respectively. Morphogenesis and differentiation were the highest rates during the first 11 days of early development, i.e. endogenous feeding period. There were higher growth rate of head, snout and tail regions compared with those of other organs from the hatch up to yolk sac absorption, followed by positive or almost isometric patterns, after the begin of exogenous feeding, showing priority to enhance the feeding and swimming capabilities. This study confirmed that most of morphological changes of this species are occurred from hatching until the onset of exogenous feeding i.e. during the lecithotrophic phase.

Columbia River White Sturgeon (Acipenser Transmontanus) Population Genetics and Early Life History Study, January 1, 1986 to December 31, 1986, Final Report.

Energy Technology Data Exchange (ETDEWEB)

Brannon, Ernest L.

1986-12-01

The 1986 Columbia River white sturgeon investigations continued to assess genetic variability of sturgeon populations isolated in various areas of the Columbia River, and to examine environmental factors in the habitat that may affect early life history success. Baseline data have been collected for three character sets. Twenty-eight loci have been analyzed for differences using electrophoresis, snout shapes were assessed for multivariate distinction, and scute counts have been examined as an index of variability. Fish that reside in the mid-Columbia and lower river have been sufficiently characterized by electrophoresis to compare with up-river areas. To date, few electrophoretic differences have been identified. However, Lake Roosevelt sturgeon sample size will be increased to determine if some of the observed differences from lower river fish are significant. Snout shape has been shown to be easily quantifiable using the digitizing technique. Scute count data initially indicate that variability exists within as well as between areas. Patterns of differentiation of one or more of these data sets may be used to formulate stock transplant guidelines essential for proper management or enhancement of this species. The historical habitat available to sturgeon in the Columbia River has changed through the development of hydroelectric projects. Dams have reduced the velocity and turbulence, and increased light penetration in the water column from less silt. These changes have affected the ability of sturgeon to feed and have made them more vulnerable to predation, which appear to have altered the ability of populations isolated in the reservoirs to sustain themselves. Present studies support the theory that both the biological and physical habitat characteristics of the Columbia River are responsible for reduced sturgeon survival, and justify consideration of enhancement initiatives above Bonneville to improve sturgeon reproductive success.

Inheritance of microsatellite loci in the polyploid lake sturgeon (Acipenser fulvescens)

Science.gov (United States)

Pyatskowit, J.D.; Krueger, C.C.; Kincaid, H.L.; May, B.

2001-01-01

Inheritance in the expression of amplicons for four microsatellite primer pairs was determined using 10 families created from gametes of wild lake sturgeon (Acipenser fulvescens). Loci Afu34 and Afu68 expressed a maximum of two even-intensity bands per individual and had progeny genotype ratios that fit disomic inheritance (P > 0.05). Some variation exhibited at Afu34 and Afu68 was attributable to a null allele. Genotype expression at both loci also indicated that one female parent had transmitted unreduced gametes. Primer Afu39 amplified products that exhibited four gene doses, where genotype counts fit expected ratios for disomic inheritance (P > 0.05) indicating amplification of products from two disomic loci that share alleles. Meiotic drive was evident at the Afu39 loci based on a test for random segregation (P inheritance based on a single progeny potentially produced by a double reduction gamete. No evidence for proposed octoploid inheritance was observed.

Assessment of the impacts of the Salem and Hope Creek Stations on shortnose sturgeon, 'Acipenser brevirostrum' lesueur. Technical report

International Nuclear Information System (INIS)

Masnik, M.T.; Wilson, J.H.

1980-04-01

Acipenser brevirostrum, a federally recognized endangered species, is known from the Delaware River in the vicinity of the Salem and Hope Creek Nuclear Stations. The potential for adverse impact to this species due to the completion of construction and the operation of these stations is assessed. A review of the literature pertaining to the distribution, life history, and tolerance of this species is presented. Both historical records and current status of the shortnose sturgeon population in the Delaware River are discussed

Transcriptome Sequencing, De Novo Assembly and Differential Gene Expression Analysis of the Early Development of Acipenser baeri.

Directory of Open Access Journals (Sweden)

Wei Song

Full Text Available The molecular mechanisms that drive the development of the endangered fossil fish species Acipenser baeri are difficult to study due to the lack of genomic data. Recent advances in sequencing technologies and the reducing cost of sequencing offer exclusive opportunities for exploring important molecular mechanisms underlying specific biological processes. This manuscript describes the large scale sequencing and analyses of mRNA from Acipenser baeri collected at five development time points using the Illumina Hiseq2000 platform. The sequencing reads were de novo assembled and clustered into 278167 unigenes, of which 57346 (20.62% had 45837 known homologues proteins in Uniprot protein databases while 11509 proteins matched with at least one sequence of assembled unigenes. The remaining 79.38% of unigenes could stand for non-coding unigenes or unigenes specific to A. baeri. A number of 43062 unigenes were annotated into functional categories via Gene Ontology (GO annotation whereas 29526 unigenes were associated with 329 pathways by mapping to KEGG database. Subsequently, 3479 differentially expressed genes were scanned within developmental stages and clustered into 50 gene expression profiles. Genes preferentially expressed at each stage were also identified. Through GO and KEGG pathway enrichment analysis, relevant physiological variations during the early development of A. baeri could be better cognized. Accordingly, the present study gives insights into the transcriptome profile of the early development of A. baeri, and the information contained in this large scale transcriptome will provide substantial references for A. baeri developmental biology and promote its aquaculture research.

Effect of dietary estradiol-17β on growth performance, body composition and blood indices in Stellate sturgeon, Acipenser stellatus

OpenAIRE

Khara, H.; Meknatkhah, B.; Falahatkar, B.; Ahmadnezhad, M.; Poursaeid, S.

2014-01-01

This study was investigated the effects of dietary estradiol-17β (E2) on growth, body composition and blood indices in Acipenser stellatus. Fish (40.9 ± 1.1 g average initial weight; n = 60 per group) were fed with three different diets containing 0 (control), 25 and 50 mg kg-1 dietary estradiol contents to apparent satiation for seven months. The results suggested that growth rate were decreased as the E2 level was increased. No significant difference was observed in condition factor among d...

Quantification of egg proteome changes during fertilization in sterlet Acipenser ruthenus.

Science.gov (United States)

Niksirat, Hamid; Andersson, Liselotte; Golpour, Amin; Chupani, Latifeh; James, Peter

2017-08-19

Eggs of sterlet are discharged outside into ambient aquatic environment where egg activation and fertilization occur. Effects of different activation media including freshwater and clay suspension on protein abundances of egg were quantified in sterlet Acipenser ruthenus. In-gel digestion and high resolution mass spectrometry were used for label-free protein quantification in the eggs of five females. No significant (p > 0.05) difference was found between protein abundances in eggs activated with different media. However, results showed significant (p eggs as control. The fact that abundance of proteasome subunit alpha significantly reduced only in eggs which were activated by clay suspension suggests that activation medium can somehow intervene with protein regulation during fertilization. In conclusion, external fertilization in sturgeon egg is accompanied by huge release of proteins into the external environment that may participate in the construction of a transient microenvironment around egg for attraction and protection of spermatozoa to ensure ensuing fertilization. Data are available via ProteomeXchange with identifier PXD006232. Copyright © 2017 Elsevier Inc. All rights reserved.

Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the Potomac River

Science.gov (United States)

Kieffer, Micah

2009-01-01

We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: a saltwater/freshwater reach at river km (rkm) 63-141 was the foraging-wintering concentration area, and one female migrated to spawn at rkm 187 in Washington, DC. The spawning migration explained the life history context of an adult captured 122 years ago in Washington, DC, supporting the idea that a natal population once lived in the river. Repeated homing migrations to foraging and wintering areas suggested the adults were residents, not transient coastal migrants. All habitats that adults need to complete life history are present in the river. The Potomac River shortnose sturgeon offers a rare opportunity to learn about the natural rebuilding of a sturgeon population.

Vulnerability of larval and juvenile white sturgeon to barotrauma: can they handle the pressure?

Energy Technology Data Exchange (ETDEWEB)

Brown, Richard S.; Cook, Katrina V.; Pflugrath, Brett D.; Rozeboom, Latricia L.; Johnson, Rachelle C.; McLellan, Jason; Linley, Timothy J.; Gao, Yong; Baumgartner, Lee J.; Dowell, Frederick E.; Miller, Erin A.; White, Timothy A.

2013-07-01

Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91 days post hatch; dph), were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma related injury and mortality were first observed 9 dph, on the same day as initial exogenous feeding. However, barotrauma related injury did not occur again until swim bladder inflation 75 dph (visible from necropsy and x-ray radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91 dph. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61-153 mm at 91 dph. The use of a combination of decompression tests and x-ray radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life history stages would help to determine fish susceptibility to hydroturbine passage and aid in fish conservation.

Status and Habitat Requirements of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam Volume II; Supplemental Papers and Data Documentation, 1986-1992 Final Report.

Energy Technology Data Exchange (ETDEWEB)

Beamesderfer, Raymond C.; Nigro, Anthony A. [Oregon Dept. of Fish and Wildlife, Clackamas, OR (US)

1995-01-01

This is the final report for research on white sturgeon Acipenser transmontanus from 1986--92 and conducted by the National Marine Fisheries Service (NMFS), Oregon Department of Fish and Wildlife (ODFW), US Fish and Wildlife Service (USFWS), and Washington Department of Fisheries (WDF). Findings are presented as a series of papers, each detailing objectives, methods, results, and conclusions for a portion of this research. This volume includes supplemental papers which provide background information needed to support results of the primary investigations addressed in Volume 1. This study addresses measure 903(e)(1) of the Northwest Power Planning Council's 1987 Fish and Wildlife Program that calls for ''research to determine the impact of development and operation of the hydropower system on sturgeon in the Columbia River Basin.'' Study objectives correspond to those of the ''White Sturgeon Research Program Implementation Plan'' developed by BPA and approved by the Northwest Power Planning Council in 1985. Work was conducted on the Columbia River from McNary Dam to the estuary.

The influence of dietary fatty acid composition on the respiratory and cardiovascular physiology of Adriatic sturgeon (Acipenser naccarii): a review

DEFF Research Database (Denmark)

McKenzie, DJ; Piraccini, G; Agnisola, C

1999-01-01

as 15% of dry feed weight), with an elevated content of highly unsaturated fatty acids of the co3 series (¿3 HUFA), had a significantly lower standard metabolic rate (SMR) and routine oxygen consumption (Mo2) than those fed a diet enriched with the same quantity of hydrogenated coconut oil......This paper reviews evidence that the fatty acid composition of dietary lipids influences the respiratory and cardiovascular physiology of Adriatic sturgeon {Acipenser naccarii) and, thereby, their tolerance of the stress of hypoxia. Sturgeon fed a commercial diet enriched in fish oil (menhaden oil...

Růstové vlastnosti a problematika chovu jesetera sibiřského (Acipenser baerii) v podmínkách České republiky

Czech Academy of Sciences Publication Activity Database

Prokeš, Miroslav; Baruš, Vlastimil; Peňáz, Milan; Baránek, V.

2003-01-01

Roč. 39, 1-2 (2003), s. 99-103 ISSN 0007-389X. [Nové technologie a nové druhy v akvakultuře. Vodňany, 24.04.2003-25.04.2003] R&D Projects: GA AV ČR IAA6093104; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : Acipenser baerii * growth rate Subject RIV: GL - Fishing

Lake Sturgeon, Acipenser fulvescens, movements in Rainy Lake, Minnesota and Ontario

Science.gov (United States)

Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

2006-01-01

Rainy Lake, Minnesota-Ontario, contains a native population of Lake Sturgeon (Acipenser fulvescens) that has gone largely unstudied. The objective of this descriptive study was to summarize generalized Lake Sturgeon movement patterns through the use of biotelemetry. Telemetry data reinforced the high utilization of the Squirrel Falls geographic location by Lake Sturgeon, with 37% of the re-locations occurring in that area. Other spring aggregations occurred in areas associated with Kettle Falls, the Pipestone River, and the Rat River, which could indicate spawning activity. Movement of Lake Sturgeon between the Seine River and the South Arm of Rainy Lake indicates the likelihood of one integrated population on the east end of the South Arm. The lack of re-locations in the Seine River during the months of September and October may have been due to Lake Sturgeon moving into deeper water areas of the Seine River and out of the range of radio telemetry gear or simply moving back into the South Arm. Due to the movements between Minnesota and Ontario, coordination of management efforts among provincial, state, and federal agencies will be important.

Site heteroplasmy in the mitochondrial cytochrome b gene of the sterlet sturgeon Acipenser ruthenus

Directory of Open Access Journals (Sweden)

Andreea Dudu

2012-01-01

Full Text Available Sturgeons are fish species with a complex biology. They are also characterized by complex aspects including polyploidization and easiness of hybridization. As with most of the Ponto-Caspian sturgeons, the populations of Acipenser ruthenus from the Danube have declined drastically during the last decades. This is the first report on mitochondrial point heteroplasmy in the cytochrome b gene of this species. The 1141 bp sequence of the cytb gene in wild sterlet sturgeon individuals from the Lower Danube was determined, and site heteroplasmy evidenced in three of the 30 specimens collected. Two nucleotide sequences were identified in these heteroplasmic individuals. The majority of the heteroplasmic sites are synonymous and do not modify the sequence of amino acids in cytochrome B protein. To date, several cases of point heteroplasmy have been reported in animals, mostly due to paternal leakage of mtDNA. The presence of specific point heteroplasmic sites might be interesting for a possible correlation with genetically distinct groups in the Danube River.

Penicillin improves the milt quality of Persian sturgeon, Acipenser persicus during short-term storage

Directory of Open Access Journals (Sweden)

Mostafa Halimi

2014-04-01

Full Text Available This study was conducted to examine the effects of antibiotic (5000 units of penicillin on sperm quality of Persian sturgeon, Acipenser persicus during 9 days in vitro storage of milt. For this purpose, the milt samples were stored in the presence and absence of 5000 units of penicillin. Freshwater was used as sperm activator. The milt samples were stored at 4°C and the motility indices were measured 0, 3, 6 and 9 days after storage. The sperm duration and percentage of sperm motility decreased after 6 days of storage both in the presence and absence of antibiotic, although this decrease was more significant in the absence of antibiotic. After 9 days of storage, the lowest values of sperm motility indices was recorded for antibiotic receiving milt samples while no motile spermatozoa observed for antibiotic-free milt samples. In conclusion, our results demonstrated that 5000 units of penicillin improve the Persian sturgeon milt quality during short-term storage.

Effects of thermal regime on ovarian maturation and plasma sex steroids in farmed white sturgeon, Acipenser transmontanus

Science.gov (United States)

Webb, M.A.H.; Van Eenennaam, J. P.; Feist, G.W.; Linares-Casenave, J.; Fitzpatrick, M.S.; Schreck, C.B.; Doroshov, S.I.

2001-01-01

Recently, commercial aquaculture farms in Northern California have exposed gravid, cultured white sturgeon females to cold water (12 ?? 1??C) throughout the late phase of vitellogenesis and ovarian follicle maturation resulting in improved ovulation rates and egg quality. However, the optimum timing for transfer of broodfish to the cold water and the capacity of transferred broodfish to maintain reproductive competence over an extended time in cold water had not been evaluated. Gravid white sturgeon females that have been raised at water temperatures of 16-20??C were transported to either cold water (12 ?? 1??C; Group 1) in November 1997 or maintained in ambient water temperatures (10-19??C; Group 2) until early spring. In March 1998, half of the fish in Group 2 had regressed ovaries, but the remaining females had intact ovarian follicles and were transported to the cold water. Ovarian follicles and blood were collected from females until they reached the stage of spawning readiness (determined by germinal vesicle position and an oocyte maturation assay) or underwent ovarian regression. Exposure of gravid sturgeon females to ambient water temperatures (14.5 ?? 2.3??C, mean ?? S.D.) from October to March led to a decrease in plasma sex steroids and a high incidence of ovarian regression in fish with a more advanced stage of oocyte development. Transfer of females with intact ovarian follicles to cold water (12 ?? 1??C) in the fall or early spring resulted in normal ovarian development in the majority of females. Holding females in cold water does not seem to override their endogenous reproductive rhythms but extends their capacity to maintain oocyte maturational competence over a longer period of time. A temperature-sensitive phase in ovarian development may occur during the transition from vitellogenic growth to oocyte maturation, and the degree and timing of sensitivity to environmental temperature are dependent on the female's endogenous reproductive rhythm. ?? 2001 Elsevier Science B.V. All Rights reserved.

Determination of hematology and plasma chemistry reference intervals for 3 populations of captive Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus).

Science.gov (United States)

Matsche, Mark A; Arnold, Jill; Jenkins, Erin; Townsend, Howard; Rosemary, Kevin

2014-09-01

The imperiled status of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), a large, long-lived, anadromous fish found along the Atlantic coast of North America, has prompted efforts at captive propagation for research and stock enhancement. The purpose of this study was to establish hematology and plasma chemistry reference intervals of captive Atlantic sturgeon maintained under different culture conditions. Blood specimens were collected from a total of 119 fish at 3 hatcheries: Lamar, PA (n = 36, ages 10-14 years); Chalk Point, MD (n = 40, siblings of Lamar); and Horn Point, Cambridge, MD (n = 43, mixed population from Chesapeake Bay). Reference intervals (using robust techniques), median, mean, and standard deviations were determined for WBC, RBC, thrombocytes, PCV, HGB, MCV, MCH, MCHC, and absolute counts for lymphocytes (L), neutrophils (N), monocytes, and eosinophils. Chemistry analytes included concentrations of total proteins, albumin, glucose, urea, calcium, phosphate, sodium, potassium, chloride, and globulins, AST, CK, and LDH activities, and osmolality. Mean concentrations of total proteins, albumin, and glucose were at or below the analytic range. Statistical comparisons showed significant differences among hatcheries for each remaining plasma chemistry analyte and for PCV, RBC, MCHC, MCH, eosinophil and monocyte counts, and N:L ratio throughout all 3 groups. Therefore, reference intervals were calculated separately for each population. Reference intervals for fish maintained under differing conditions should be established per population. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

Quantifying fish swimming behavior in response to acute exposure of aqueous copper using computer assisted video and digital image analysis

Science.gov (United States)

Calfee, Robin D.; Puglis, Holly J.; Little, Edward E.; Brumbaugh, William G.; Mebane, Christopher A.

2016-01-01

Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors.

Vulnerability of larval and juvenile white sturgeon to barotrauma: can they handle the pressure?

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Brown, Richard S; Cook, Katrina V; Pflugrath, Brett D; Rozeboom, Latricia L; Johnson, Rachelle C; McLellan, Jason G; Linley, Timothy J; Gao, Yong; Baumgartner, Lee J; Dowell, Frederick E; Miller, Erin A; White, Timothy A

2013-01-01

Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae, and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91 days post hatch; d.p.h.) were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma-related injury and mortality were first observed 9 d.p.h., on the same day as initial exogenous feeding. However, barotrauma-related injury did not occur again until swim bladder inflation 75 d.p.h. (visible at necropsy and on radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91 d.p.h. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61 to 153 mm at 91 d.p.h. The use of a combination of decompression tests and radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life-history stages would help to determine the susceptibility of fish to hydro turbine passage and aid in fish conservation.

Status and Habitat Requirements of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam, 1990-1991 Annual Report.

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Nigro, Anthony A. (Oregon Department of Fish and Wildlife, Portland, OR)

1991-09-01

We report on our effort from April 1990 to March 1991 to describe the life history and population dynamics of white sturgeon Acipenser transmontanus in.John Day Reservoir. We set 1188 set lines and 26 gill nets. We caught 623 white sturgeon with set lines and 236 with gill nets. Catch per unit effort was much higher in areas near the tailrace than in downstream sites. Our setlines were size selective. We recaptured 3 fish released in John Day Reservoir in 1989 and 28 fish released in 1990. Sport and commercial fishermen recovered 62 tags from fish we tagged in Bonneville, The Dalles and John Day reservoirs, 1987-1990. We observed extensive movements of marked sturgeon within the reservoirs. We completed aging of available samples from all three reservoirs from 1987-1990. We aged fish as old as 46 years. Bone marks were observed on 74 of 78 fish previously injected with oxytetracycline and annulus formation was generally complete after June. We estimated parameters in a length-weight equation. About 1.5% of the female white sturgeon we examined to date had early or late vitellogenic eggs and would be expected to spawn the following year.

Biotransformation and detoxication of molinate (Ordram) in fish

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Tjeerdema, R.S.

1987-01-01

Bioconcentration, deputation, and biotransformation of molinate were compared in common carp (cyprinus carpio), striped bass (Morone saxatilis), and white sturgeon (acipenser transmontanus) using a flow-through metabolism system. When compared to static conditions, flowing water improved oxygenation, decreased chemical volatilization and remetabolism, and run through a macroreticular resin, improved waste-product collection. Metabolite analysis employed gradient high-pressure liquid chromatography. Exposure to 100 μg L -1 [ring- 14 C]molinate for 24 h resulted in bioconcentration factors of 30.5 (carp), 25.3 (bass), and 19.7 (sturgeon); differences were not significant (all, P > 0.05). 14 C depuration by common carp was significantly slower than that by either striped bass or white sturgeon (both, P < 0.01). All three species oxidized molinate to a number of products and hydrolyzed, or conjugated with glutathione (GSH), the sulfoxide or sulfone, ultimately producing the mercapturic acid; carp and sturgeon also formed a D-glucuronic acid conjugate. Common carp were significantly less capable of sulfoxidation and GSH conjugation than either striped bass (P < 0.05) or white sturgeon (P < 0.01). Therefore, the selective toxicity of molinate in carp may be due to less efficient depuration and metabolic deactivation

The antioxidant system of seminal fluid during in vitro storage of sterlet Acipenser ruthenus sperm.

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Dzyuba, Viktoriya; Cosson, Jacky; Dzyuba, Borys; Yamaner, Gunes; Rodina, Marek; Linhart, Otomar

2016-04-01

The role of the seminal fluid antioxidant system in protection against damage to spermatozoa during in vitro sperm storage is unclear. This study investigated the effect of in vitro storage of sterlet Acipenser ruthenus spermatozoa together with seminal fluid for 36 h at 4 °C on spermatozoon motility rate and curvilinear velocity, thiobarbituric acid reactive substance level, and components of enzyme and non-enzyme antioxidant system (superoxide dismutase and catalase activity and uric acid concentration) in seminal fluid. Spermatozoon motility parameters after sperm storage were significantly decreased, while the level of thiobarbituric acid reactive substances, activity of superoxide dismutase and catalase, and uric acid concentration did not change. Our findings suggest that the antioxidant system of sterlet seminal fluid is effective in preventing oxidative stress during short-term sperm storage and prompt future investigations of changes in spermatozoon homeostasis and in spermatozoon plasma membrane structure which are other possible reasons of spermatozoon motility deterioration upon sperm storage.

Metallothionein as potential biomarker of cadmium exposure in Persian sturgeon (Acipenser persicus).

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Shariati, Fatemeh; Esaili Sari, Abbas; Mashinchian, Ali; Pourkazemi, Mohammad

2011-10-01

Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l(-1)) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l(-1) Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.

Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus larvae using Artemia nauplii and formulated diet

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Naser Agh

2013-07-01

Full Text Available High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate of first-feeding larvae were fed according to four main feeding regimes: (1 live food (live nauplii of brine shrimp Artemia urmiana; (2 indirect transition (5 days live food followed by gradual transition to formulated diet; (3 direct transition (using different combinations of live and formulated diet from the start feeding onwards; (4 formulated feed (FD from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food.

PHYSICO-CHEMICAL LIMITATIVE FACTORS FOR GROWTH AND DEVELOPMENT IN STERLET (ACIPENSER RUTHENUS LINNAEUS, 1758 IN EXTENSIVELY SYSTEM

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R. C. DIMA

2009-10-01

Full Text Available The oldest and most common method of increasing fish is a fish breeding ponds in which the supervision of nutrition and growth of biological material. Sterlet (Acipenser ruthenus ruthenus Linnaeus 1785 is the 4th of sturgeon scale and economic importance as a share of production of these fish .Monitoring of physicochemical parameters of sturgeons ponds has a crucial role to obtain satisfactory yields both in qualitative and quantitative. Chemical characteristics of water were determined in laboratory ecosystems Chemistry of the Institute of Research and Development for Ecology Aquaculture, Fisheries and Aquaculture Galaţi for the samples have been taken of the total water. Determination of the chemical characteristics was performed by standardized methods. Physic-chemical parameters of water were determined according to norm on the classification of surface water quality in order to establish the ecological status of water (Order no. 161/2006, for Class II of quality.

Phylogeography of the European sturgeon (Acipenser sturio): A critically endangered species.

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Chassaing, Olivier; Desse-Berset, Nathalie; Hänni, Catherine; Hughes, Sandrine; Berrebi, Patrick

2016-01-01

The European sturgeon (Acipenser sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species. Copyright © 2015 Elsevier Inc. All rights reserved.

Structuring decisions for managing threatened and endangered species in a changing climate.

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Gregory, Robin; Arvai, Joseph; Gerber, Leah R

2013-12-01

The management of endangered species under climate change is a challenging and often controversial task that incorporates input from a variety of different environmental, economic, social, and political interests. Yet many listing and recovery decisions for endangered species unfold on an ad hoc basis without reference to decision-aiding approaches that can improve the quality of management choices. Unlike many treatments of this issue, which consider endangered species management a science-based problem, we suggest that a clear decision-making process is equally necessary. In the face of new threats due to climate change, managers' choices about endangered species require closely linked analyses and deliberations that identify key objectives and develop measurable attributes, generate and compare management alternatives, estimate expected consequences and key sources of uncertainty, and clarify trade-offs across different dimensions of value. Several recent cases of endangered species conservation decisions illustrate our proposed decision-focused approach, including Gulf of Maine Atlantic salmon (Salmo salar) recovery framework development, Cultus Lake sockeye salmon (Oncorhynchus nerka) management, and Upper Columbia River white sturgeon (Acipenser transmontanus) recovery planning. Estructuración de Decisiones para Manejar Especies Amenazadas y en Peligro en un Clima Cambiante. © 2013 Society for Conservation Biology No claim to original US government works.

Influence of a weak field of pulsed DC electricity on the behavior and incidence of injury in adult Steelhead and Pacific Lamprey

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Mesa, Matthew G.; Copeland, Elizabeth S.

2009-01-01

Predation by pinnipeds, such as California sea lions Zalophus californianus, Pacific harbor seals Phoca vitulina, and Stellar sea lions Eumetopias jubatus on adult Pacific salmon Oncorhynchus spp in the lower Columbia River has become a serious concern for fishery managers trying to conserve and restore runs of threatened and endangered fish. As a result, Smith-Root, Incorporated (SRI; Vancouver, Washington), manufacturers of electrofishing and closely-related equipment, proposed a project to evaluate the potential of an electrical barrier to deter marine mammals and reduce the amount of predation on adult salmonids (SRI 2007). The objectives of their work were to develop, deploy, and evaluate a passive, integrated sonar and electric barrier that would selectively inhibit the upstream movements of marine mammals and reduce predation, but would not injure pinnipeds or impact anadromous fish migrations. However, before such a device could be deployed in the field, concerns by regional fishery managers about the potential effects of such a device on the migratory behavior of Pacific salmon, steelhead O. mykiss, Pacific lampreys Entoshpenus tridentata, and white sturgeon Acipenser transmontanus, needed to be addressed. In this report, we describe the results of laboratory research designed to evaluate the effects of prototype electric barriers on adult steelhead and Pacific lampreys.

Sediment cores and chemistry for the Kootenai River White Sturgeon Habitat Restoration Project, Boundary County, Idaho

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Barton, Gary J.; Weakland, Rhonda J.; Fosness, Ryan L.; Cox, Stephen E.; Williams, Marshall L.

2012-01-01

The Kootenai Tribe of Idaho, in cooperation with local, State, Federal, and Canadian agency co-managers and scientists, is assessing the feasibility of a Kootenai River habitat restoration project in Boundary County, Idaho. This project is oriented toward recovery of the endangered Kootenai River white sturgeon (Acipenser transmontanus) population, and simultaneously targets habitat-based recovery of other native river biota. Projects currently (2010) under consideration include modifying the channel and flood plain, installing in-stream structures, and creating wetlands to improve the physical and biological functions of the ecosystem. River restoration is a complex undertaking that requires a thorough understanding of the river. To assist in evaluating the feasibility of this endeavor, the U.S. Geological Survey collected and analyzed the physical and chemical nature of sediment cores collected at 24 locations in the river. Core depths ranged from 4.6 to 15.2 meters; 21 cores reached a depth of 15.2 meters. The sediment was screened for the presence of chemical constituents that could have harmful effects if released during restoration activities. The analysis shows that concentrations of harmful chemical constituents do not exceed guideline limits that were published by the U.S. Army Corps of Engineers in 2006.

Understanding the basis of shortnose sturgeon (Acipenser brevirostrum) partial migration in the Gulf of Maine

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Altenritter, Matthew E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

2018-01-01

Movement of shortnose sturgeon (Acipenser brevirostrum) among major river systems in the Gulf of Maine is common and has implications for the management of this endangered species. Directed movements of 61 telemetered individuals monitored between 2010 and 2013 were associated with the river of tagging and individual characteristics. While a small proportion of fish tagged in the Kennebec River moved to the Penobscot River (5%), a much higher proportion of fish tagged in the Penobscot River moved to the Kennebec River (66%), during probable spawning windows. This suggests that Penobscot River fish derive from a migratory contingent within a larger Kennebec River population. Despite this connectivity, fish captured in the Penobscot River were larger (∼100 mm fork length) and had higher condition factors (median Fulton’s K: 0.76) than those captured in the Kennebec River (median Fulton’s K: 0.61). Increased abundance and resource limitation in the Kennebec River may be constraining growth and promoting migration to the Penobscot River by individuals with sufficient initial size and condition. Migrants could experience an adaptive reproductive advantage relative to nonmigratory individuals.

Comparison of select hematology and serum chemistry analtyes between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens)

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DiVincenti, Louis; Priest, Heather; Walker, Kyle J.; Wyatt, Jeffrey D.; Dittman, Dawn

2013-01-01

Hematology and serum chemistry analytes were compared between wild-caught and aquarium-housed lake sturgeon (Acipenser fulvescens) to potentially improve understanding of medical issues in lake sturgeon. Blood samples were taken from 30 lake sturgeon exhibited in 11 institutions in the United States and from 23 experimentally stocked lake sturgeon caught in gill nets in the lower Genesee River in Rochester, New York, USA. For hematology, only segmented neutrophil count was significantly different, with wild-caught fish having a higher number of circulating neutrophils. For clinical chemistry analytes, chloride, uric acid, calcium, phosphate, glucose, aspartate aminotransferase, triglycerides, and creatine kinase were significantly different between the two cohorts. These differences are likely not clinically significant and are attributable to handling stress, variability in environmental parameters, or differences in nutritional status. This is the first report of hematology and serum chemistry values in aquarium-housed lake sturgeon and provides useful reference intervals for clinicians.

Development of polysomic microsatellite markers for characterization of population structuring and phylogeography in the shortnose sturgeon (Acipenser brevirostrum)

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Henderson, Anne P.; King, Tim L.

2012-01-01

Shortnose sturgeon Acipenser brevirostrum is an endangered polyploid fish species for which no nuclear DNA markers previously existed. To address this need, 86 polysomic loci were developed and characterized in 20 A. brevirostrum from five river systems and eight members (parents and six progeny) of a captive-bred family. All markers proved to be polymorphic, polysomic, and demonstrated direct inheritance when tested in a captive family. Eleven loci were included in a range-wide survey of 561 fish sampled from 17 geographic collections. Allelic diversity at these markers ranged from 7 to 24 alleles/locus and averaged 16.5 alleles/locus; sufficient diversity to produce unique multilocus genotypes. In the range-wide survey, a Mantel comparison of an ecological (1-Jaccard’s) and genetic (ΦPT; an analog to FST) distance metrics, identified a strong positive correlation (r = 0.98, P PT represents a viable metric for assessing genetic relatedness using this class of marker.

Genomic Organization and Physical Mapping of Tandemly Arranged Repetitive DNAs in Sterlet (Acipenser ruthenus).

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Biltueva, Larisa S; Prokopov, Dimitry Y; Makunin, Alexey I; Komissarov, Alexey S; Kudryavtseva, Anna V; Lemskaya, Natalya A; Vorobieva, Nadezhda V; Serdyukova, Natalia A; Romanenko, Svetlana A; Gladkikh, Olga L; Graphodatsky, Alexander S; Trifonov, Vladimir A

2017-01-01

Acipenseriformes represent a phylogenetically basal clade of ray-finned fish characterized by unusual genomic traits, including paleopolyploid states of extant genomes with high chromosome numbers and slow rates of molecular evolution. Despite a high interest in this fish group, only a limited number of studies have been accomplished on the isolation and characterization of repetitive DNA, karyotype standardization is not yet complete, and sex chromosomes are still to be identified. Here, we applied next-generation sequencing and cluster analysis to characterize major fractions of sterlet (Acipenser ruthenus) repetitive DNA. Using FISH, we mapped 16 tandemly arranged sequences on sterlet chromosomes and found them to be unevenly distributed in the genome with a tendency to cluster in particular regions. Some of the satellite DNAs might be used as specific markers to identify individual chromosomes and their paralogs, resulting in the unequivocal identification of at least 18 chromosome pairs. Our results provide an insight into the characteristic genomic distribution of the most common sterlet repetitive sequences. Biased accumulation of repetitive DNAs in particular chromosomes makes them especially interesting for further search for cryptic sex chromosomes. Future studies of these sequences in other acipenserid species will provide new perspectives regarding the evolution of repetitive DNA within the genomes of this fish order. © 2017 S. Karger AG, Basel.

Accelerometer-derived activity correlates with volitional swimming speed in lake sturgeon (Acipenser fulvescens)

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Thiem, J.D.; Dawson, J.W.; Gleiss, A.C.; Martins, E.G.; Haro, Alexander J.; Castro-Santos, Theodore R.; Danylchuk, A.J.; Wilson, R.P.; Cooke, S.J.

2015-01-01

Quantifying fine-scale locomotor behaviours associated with different activities is challenging for free-swimming fish.Biologging and biotelemetry tools can help address this problem. An open channel flume was used to generate volitionalswimming speed (Us) estimates of cultured lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and these were paired withsimultaneously recorded accelerometer-derived metrics of activity obtained from three types of data-storage tags. This studyexamined whether a predictive relationship could be established between four different activity metrics (tail-beat frequency(TBF), tail-beat acceleration amplitude (TBAA), overall dynamic body acceleration (ODBA), and vectorial dynamic body acceleration(VeDBA)) and the swimming speed of A. fulvescens. Volitional Us of sturgeon ranged from 0.48 to 2.70 m·s−1 (0.51–3.18 bodylengths (BL) · s−1). Swimming speed increased linearly with all accelerometer-derived metrics, and when all tag types werecombined, Us increased 0.46 BL·s−1 for every 1 Hz increase in TBF, and 0.94, 0.61, and 0.94 BL·s−1 for every 1g increase in TBAA,ODBA, and VeDBA, respectively. Predictive relationships varied among tag types and tag-specific parameter estimates of Us arepresented for all metrics. This use of acceleration data-storage tags demonstrated their applicability for the field quantificationof sturgeon swimming speed.

Microsatellites variation in sterlet sturgeon, Acipenser ruthenus from the Lower Danube

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Andreea Dudu

2013-05-01

Full Text Available Sturgeons represent an ancient group of fish with an important scientific and commercial value. The economical significance of these species is due to their meat and roes that are considered to be a gastronomic delicacy. Unfortunately, precisely due to their economical value the sturgeons have been overexploited by fishing and poaching and nowadays are facing extinction. Currently, in the Ponto-Caspian region is found the greatest diversity of acipenserid species and the Lower Danube is the last refuge for the sturgeons from the Black Sea. Acipenser ruthenus (sterlet is a fresh water sturgeon species which has undergone a large population decline, but local populations are still surviving in most parts of the rivers draining to Black, Azov and Caspian Seas. In order to have successful conservation programs of this species is essential to evaluate its genetic diversity. Microsatellites represent valuable markers for genetic analyses aiming the assessment of genetic variability of population. In our study we analyzed the cross-amplification and the polymorphism in A. ruthenus population from the Lower Danube of seven microsatellite loci (LS-19, LS-34, LS-54, LS-57, LS-68, Aox23 and Aox45, originally isolated in North-American sturgeon species. Among the seven loci, three (LS57, Aox23 and Aox45 have showed a tetrasomic profile. The most polymorphic loci were LS-57 with 12 alleles in population, followed by Aox23 and Aox45 with 11 alleles and LS-68 with 10 alleles. Four loci (LS-19, LS-34 and LS-54 presented a lower level of polymorphism, only three alleles being identified for the analyzed individuals.

Identification of a new mineralized tissue in the notochord of reared Siberian sturgeon (Acipenser baerii).

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Leprévost, Amandine; Azaïs, Thierry; Trichet, Michael; Sire, Jean-Yves

2017-11-01

In a study aiming to improve knowledge on the mineralization of the axial skeleton in reared Siberian sturgeon (Acipenser baerii Brandt, 1869), we discovered a new mineralized tissue within the notochord. To our knowledge, such a structure has never been reported in any vertebrate species with the exception of the pathological mineralization of the notochord remains in degenerative intervertebral disks of mammals. Here, we describe this enigmatic tissue using X-ray microtomography, histological analyses and solid state NMR-spectroscopy. We also performed a 1-year monitoring of the mineral content (MC) of the notochord in relation with seasonal variations of temperature. In all specimens studied from 2-year-old juveniles onwards, this mineralized structure was found within a particular region of the notochord called funiculus. This feature first appears in the abdominal region then extends posteriorly with ageing, while the notochord MC also increases. The mineral phase is mainly composed of amorphous calcium phosphate, a small amount of which changes into hydroxyapatite with ageing. The putative role of this structure is discussed as either a store of minerals available for the phosphocalcic metabolism, or a mechanical support in a species with a poorly mineralized axial skeleton. A pathological feature putatively related to rearing conditions is also discussed. © 2017 Wiley Periodicals, Inc.

Electronic archival tags provide first glimpse of bathythermal habitat use by free-ranging adult lake sturgeon Acipenser fulvescens

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Briggs, Andrew S.; Hondorp, Darryl W.; Quinlan, Henry R.; Boase, James C.; Mohr, Lloyd C.

2016-01-01

Information on lake sturgeon (Acipenser fulvescens) depth and thermal habitat use during non-spawning periods is unavailable due to the difficulty of observing lake sturgeon away from shallow water spawning sites. In 2002 and 2003, lake sturgeon captured in commercial trap nets near Sarnia, Ontario were implanted with archival tags and released back into southern Lake Huron. Five of the 40 tagged individuals were recaptured and were at large for 32, 57, 286, 301, and 880 days. Temperatures and depths recorded by archival tags ranged from 0 to 23.5 ºC and 0.1 to 42.4 m, respectively. For the three lake sturgeon that were at large for over 200 days, temperatures occupied emulated seasonal fluctuations. Two of these fish occupied deeper waters during winter than summer while the other occupied similar depths during non-spawning periods. This study provides important insight into depth and thermal habitat use of lake sturgeon throughout the calendar year along with exploring the feasibility of using archival tags to obtain important physical habitat attributes during non-spawning periods.

Annual variation of hematology and plasma chemistry in shortnose sturgeon, Acipenser brevirostrum, during a dam-impeded spawning run.

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Matsche, Mark A; Gibbons, Jarrett

2012-12-01

Shortnose sturgeon (Acipenser brevirostrum) spawning migrations on the Cooper River are impeded by Pinopolis Dam, Lake Moultrie, South Carolina. Sturgeon and other species aggregate below the dam in late winter/early spring and are subjected to a variety of stressors stemming from crowding, poor habitat quality, and injuries that appear to be caused by boat propeller or turbine strikes. Spawning has been documented in the tailrace, but reproductive success has not been verified as no juveniles have been captured. Fish within the dam tailrace were captured by gill net during winter, 2005 and 2007-2011, and physiological condition was assessed using a panel of hematologic and biochemical indices. Plasma phosphorus and calcium were significantly higher in females, while PCV and aspartate aminotransferase were significantly higher in males, indicating sex-specific physiological changes triggered during maturity. A marked leucopenia, accompanied by lymphopenia and neutrophilia, was evident in both sexes and was consistent across years, indicating that these fish were under chronic stress. Testosterone and estradiol levels and hematologic and biochemical reference intervals are provided for comparative purposes.

Metric Characters and Body Indices of Juvenile Sterlet Acipenser ruthenus Raised in a Recirculating Aquaculture System (RAS

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Mărioara Nicula

2015-05-01

Full Text Available Our research was performed on juvenile sterlets (Acipenser ruthenus, aged between 346-431 days, maintained in five round pools (Ø=3 m, V=6 m3, h-100 cm and fed with a commercial extruded pellet (3 mm granulation, 48% CP, and 10% EE. Body weight and total body length on 30 individuals from each tank were determined every two weeks. Weighing and somatic measurements achieved at the end of experimental period (standard length-l, body weight-G, maximum body high–H, maximum body perimeter (Pmax, head length–lh,, caudal peduncle length-lp allowed us to calculate the following body indices: profile index, thickness index, Fulton index, Kiselev index, meat index. Statistical analysis was performed by using the SPPS IBM 22 and Minitab 16 software. Data were reported as Mean±Sx at a significant level of p<0.05. Testing differences between means was realized by ANOVA completed with post-hoc Tukey test. Results obtained led to conclude that specimens analyzed had a good maintenance and feeding, an adequate development, a high proportion of meat, an elongated body and a straight back, and they are eligible for selection.

Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1998 Annual Report.

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Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

2002-03-01

In 1998 white sturgeon (Acipenser transmontanus) were captured, marked, and population data were collected in the Snake River between Lower Granite Dam and the mouth of the Salmon River. A total of 13,785 hours of setline effort and 389 hours of hook-and-line effort was employed in 1998. Of the 278 white sturgeon captured in the Snake River, 238 were marked for future identification. Three sturgeon were captured in the Salmon River and none were captured in the Clearwater River. Since 1997, 6.9% of the tagged fish have been recovered. Movement of recaptured white sturgeon ranged from 98.5 kilometers downstream to 60.7 kilometers upstream, however, less than 25% of the fish moved more than 16 kilometers (10 miles). In the Snake River, white sturgeon ranged in total length from 51.5 cm to 286 cm and averaged 118.9 cm. Differences were detected in the length frequency distributions of sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). In addition, the proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 37% since the 1970's. Analysis of the length-weight relationship indicated that white sturgeon in Lower Granite Reservoir were slightly larger than white sturgeon in the free-flowing Snake River.

Substrate and flow characteristics associated with White Sturgeon recruitment in the Columbia River Basin

Science.gov (United States)

Hatten, James R.; Parsley, Michael; Barton, Gary; Batt, Thomas; Fosness, Ryan L.

2018-01-01

A study was conducted to identify habitat characteristics associated with age 0+ White Sturgeon (Acipenser transmontanus Richardson, 1863) recruitment in three reaches of the Columbia River Basin: Skamania reach (consistent recruitment), John Day reach (intermittent/inconsistent recruitment), and Kootenai reach (no recruitment). Our modeling approach involved numerous steps. First, we collected information about substrate, embeddedness, and hydrodynamics in each reach. Second, we developed a set of spatially explicit predictor variables. Third, we built two habitat (probability) models with Skamania reach training data where White Sturgeon recruitment was consistent. Fourth, we created spawning maps of each reach by populating the habitat models with in-reach physical metrics (substrate, embeddedness, and hydrodynamics). Fifth, we examined model accuracy by overlaying spawning locations in Skamania and Kootenai reaches with habitat predictions obtained from probability models. Sixth, we simulated how predicted habitat changed in each reach after manipulating physical conditions to more closely match Skamania reach. Model verification confirmed White Sturgeon generally spawned in locations with higher model probabilities in Skamania and Kootenai reaches, indicating the utility of extrapolating the models. Model simulations revealed significant gains in White Sturgeon habitat in all reaches when spring flow increased, gravel/cobble composition increased, or embeddedness decreased. The habitat models appear well suited to assist managers when identifying reach-specific factors limiting White Sturgeon recruitment in the Columbia River Basin or throughout its range.

Influence of environmentally relevant concentrations of vinclozolin on quality, DNA integrity, and antioxidant responses of sterlet Acipenser ruthenus spermatozoa.

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Gazo, Ievgeniia; Linhartova, Pavla; Shaliutina, Anna; Hulak, Martin

2013-04-25

The effects of vinclozolin (VIN), an anti-androgenic fungicide, on quality, oxidative stress, DNA integrity, and ATP level of sterlet (Acipenser ruthenus) spermatozoa were investigated in vitro. Fish spermatozoa were incubated with different concentrations of vinclozolin (0.5, 2, 10, 15, 20 and 50 μg/l) for 2 h. A dose-dependent reduction in spermatozoa motility and velocity was observed at concentrations of 2-50 μg/l. A dramatic increase in DNA fragmentation was recorded at concentrations 10 μg/l and above. After 2 h exposure at higher test concentrations (10-50 μg/l), oxidative stress was apparent, as reflected by significantly higher levels of protein and lipid oxidation and significantly greater superoxide dismutase activity. Intracellular ATP content of spermatozoa decreased with increasing concentrations of VIN. The results demonstrated that VIN can induce reactive oxygen species stress in fish spermatozoa, which could impair the sperm quality, DNA integrity, ATP content, and the antioxidant defense system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Fine-scale habitat preference of green sturgeon (Acipenser medirostris) within three spawning locations in the Sacramento River, California

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Wyman, Megan T.; Thomas, Michael J.; McDonald, Richard R.; Hearn, Alexander R.; Battleson, Ryan D.; Chapman, Eric D.; Kinzel, Paul J.; Minear, J. Tobey; Mora, Ethan A.; Nelson, Jonathan M.; Pagel, Matthew D.; Klimley, A. Peter

2018-01-01

Vast sections of the Sacramento River have been listed as critical habitat by the National Marine Fisheries Service for green sturgeon spawning (Acipenser medirostris), yet spawning is known to occur at only a few specific locations. This study reveals the range of physical habitat variables selected by adult green sturgeon during their spawning period. We integrated fine-scale fish positions, physical habitat characteristics, discharge, bathymetry, and simulated velocity and depth using a 2-dimensional hydraulic model (FaSTMECH). The objective was to create habitat suitability curves for depth, velocity, and substrate type within three known spawning locations over two years. An overall cumulative habitat suitability score was calculated that averaged the depth, velocity, and substrate scores over all fish, sites, and years. A weighted usable area (WUA) index was calculated throughout the sampling periods for each of the three sites. Cumulative results indicate that the microhabitat characteristics most preferred by green sturgeon in these three spawning locations were velocities between 1.0-1.1 m/s, depths of 8-9 m, and gravel and sand substrate. This study provides guidance for those who may in the future want to increase spawning habitat for green sturgeon within the Sacramento River.

Seasonal variation in plasma nonesterified fatty acids of Lake Sturgeon (Acipenser fulvescens) in the vicinity of hydroelectric facilities

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McKinley, R.S.; Power, G.; Singer, T.D.; Ballantyne, J.S.

1993-01-01

To establish the effects of hydroelectric generation on the health of lake sturgeon (Acipenser fulvescens), seasonal variations in plasma nonesterified fatty acids (NEFAs) upstream and downstream from hydroelectric stations were measured over a 2-y period. Plasma NEFA profiles were also compared up- and downstream of the stations for differences in utilization of individual NEFA species as substrates for lipid oxidation. Significantly higher levels of total plasma NEFA were found in lake sturgeon upstream (2355 ± 395.9 nmole/ml) compared with those downstream (798 ± 133.5 nmole/ml) of the generating stations during the spring. The NEFA profiles for several key fatty acid species differed significantly among seasons up- and downstream of the facilities. In particular, during spring and summer, the levels of oleic acid (18:1n9) were highest upstream of the stations and levels of a polyunsaturated fatty acid, docosahexaenoic acid (22:6n3), were higher below rather than above the stations. The differences in plasma NEFA concentration may be attributed to altered nutritional status due to the varying flow regime located downstream of the hydroelectric stations. 33 refs., 4 figs., 1 tab

Reintroduction of Lake Sturgeon (Acipenser fulvescens) into the St. Regis River, NY: Post-release assessment of habitat use and growth

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Dittman, Dawn E.; Chalupnicki, Marc A.; Johnson, James H.; Snyder, James

2015-01-01

One of the depleted endemic fish species of the Great Lakes, Acipenser fulvescens (Lake Sturgeon), has been the target of extensive conservation efforts. One strategy is reintroduction into historically productive waters. The St. Regis River, NY, represents one such adaptive-management effort, with shared management between New York and the St. Regis Mohawk Tribe. Between 1998 and 2004, a total of 4977 young-of-year Lake Sturgeon were released. Adaptive management requires intermediate progress metrics. During 2004 and 2005, we measured growth, habitat use, and survivorship metrics of the released fish. We captured a total of 95 individuals of all stocked ages. Year-class minimal-survival rates ranged from 0.19–2.1%. The size-at-age and length/biomass relationships were comparable to those reported for juveniles in other Great Lakes waters. These intermediate assessment metrics can provide feedback to resource managers who make restoration-program decisions on a much shorter time-scale than the time-frame in which the ultimate goal of a self-sustaining population can be attained.

Paternity assignment in the polyploid Acipenser dabryanus based on a novel microsatellite marker system.

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Ya Liu

Full Text Available Acipenser dabryanus is listed as a Critical Endangered species in the IUCN Red List and the first class protected animals in China. Fortunately, A. dabryanus specimens are being successfully bred in captivity for conservation. However, for effective ex situ conservation, we should be aware of the genetic diversity and the degree of relatedness of the individuals selected for breeding. In this study, we aimed at the development of novel and reliable microsatellites used for the genetic study of A. dabryanus. A total of 14,321 simple sequence repeats (SSRs were detected by transcriptome sequencing and screening. We selected 20 novel and polymorphic microsatellites (non-dinucleotide with good repeatability from the 100 tested loci for a subsequent genetic and paternity study. A set of captive broodstock (F1 stock, n = 43 and their offspring (F2 stock, n = 96 were used to examine the efficiency of the 20 SSRs for assigning parentage to offspring, with an allocation success of 91.7%. We also found that only a few families predominantly contributed to the progeny produced by the 43 breeders. In addition, mitochondrial DNA data showed that the captive broodstock (F1 individuals had an excellent probability of the same lineage, implying that a high level of inbreeding may have occurred in these individuals. Our research provides useful information on genetic diversity and reproductive pattern of A. dabryanus, and the 20 SSRs developed in this study can be applied to the future breeding program to avoid inbreeding for this stock or other related species of Acipenseriformes.

Sensitivity of lake sturgeon (Acipenser fulvescens) early life stages to 2,3,7,8-tetrachlorodibenzo-P-dioxin and 3,3′,4,4′,5-pentachlorobiphenyl

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Tillitt, Donald E.; Buckler, Justin A.; Nicks, Diane; Candrl, James; Claunch, Rachel; Gale, Robert W.; Puglis, Holly J.; Little, Edward E.; Linbo, Tiffany L.; Baker, Mary

2017-01-01

The aquatic food web of the Great Lakes has been contaminated with polychlorinated biphenyls (PCBs) since the mid-20th century. Threats of PCB exposures to long-lived species of fish, such as lake sturgeon (Acipenser fulvescens), have been uncertain because of a lack of information on the relative sensitivity of the species. The objective of the present study was to evaluate the sensitivity of early–life stage lake sturgeon to 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. Mortality, growth, morphological and tissue pathologies, swimming performance, and activity levels were used as assessment endpoints. Pericardial and yolk sac edema, tubular heart, yolk sac hemorrhaging, and small size were the most commonly observed pathologies in both TCDD and PCB-126 exposures, beginning as early as 4 d postfertilization, with many of these pathologies occurring in a dose-dependent manner. Median lethal doses for PCB-126 and TCDD in lake sturgeon were 5.4 ng/g egg (95% confidence interval, 3.9–7.4 ng/g egg) and 0.61 ng/g egg (0.47–0.82 ng/g egg), respectively. The resulting relative potency factor for PCB-126 (0.11) was greater than the World Health Organization estimate for fish (toxic equivalency factor = 0.005), suggesting that current risk assessments may underestimate PCB toxicity toward lake sturgeon. Swimming activity and endurance were reduced in lake sturgeon survivors from the median lethal doses at 60 d postfertilization. Threshold and median toxicity values indicate that lake sturgeon, like other Acipenser species, are more sensitive to PCB and TCDD than the other genus of sturgeon, Scaphirhynchus, found in North America. Indeed, lake sturgeon populations in the Great Lakes and elsewhere are susceptible to PCB/TCDD-induced developmental toxicity in embryos and reductions in swimming performance.

The effect of thermal shock on morphological characteristics of blood cells in Siberian sturgeon (Acipenser baerii triploids

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Teresa Wlasow

2011-01-01

Full Text Available The aim of the study was to evaluate the effect of thermal shock on morphotic blood elements in Siberian sturgeon Acipenser baerii triploids. The thermal shock (37 °C for 2 min was applied in the 18th min after fertilization. Blood was sampled from parallel cultured ten triploids and ten diploids on day 70 after hatching. Ploidy was assessed with the cytogenetic method and measurements of cellular nuclei. In the blood of triploids, significant dominance of immature red blood cells, erythrocytes with a displaced nucleus, microcytes and erythroplastids were observed. The blood of triploids was also characterized by a reduced number of lymphocytes. The percentage of neutrophil and eosinophil granulocytes was elevated; increased share of neutrophil granulocytes with a 4-, 5- or 6-segmented nucleus and eosinophil granulocytes with a nucleus consisting of three and more segments was observed. Disturbances in the picture of red blood cells can be considered as an expression of intensification of end-stage changes in triploids. The response to these changes in the blood of triploid Siberian sturgeon is an increase in the share of polymorphonuclear PMN, cells counted as microphages. Frequent presence of immature red blood cells in triploid Siberian sturgeon is a process that aims at counterbalancing the loss among these blood cells. It is the first report on morphological changes and proportions among blood cells in triploid Siberian sturgeon.

Behavioral responses of Pacific lamprey to alarm cues

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Porter, Laurie L.; Hayes, Michael C.; Jackson, Aaron D.; Burke, Brian J.; Moser, Mary L.; Wagner, R. Steven

2017-01-01

Pacific lamprey (Entosphenus tridentatus), an anadromous ectoparasite, faces several challenges during adult migration to spawning grounds. Developing methods to address these challenges is critical to the success of ongoing conservation efforts. The challenges are diverse, and include anthropogenic alterations to the ecosystem resulting in loss of habitat, impassable barriers such as dams, climate change impacts, and altered predator fields. We conducted a behavioral study to understand how adult migrating Pacific lamprey respond to potential alarm cues: White Sturgeon (Acipenser transmontanus), human saliva, decayed Pacific lamprey, and river otter (Lontra canadensis). Research has shown that some species of lamprey can be guided to a location using odors and similar cues may be useful as a management tool for Pacific lamprey. Experiments were conducted over 2 nights and measured the number of entries (count) and duration of time spent (occupancy) by adult lamprey in each arm of a two-choice maze. During the first night, no odor was added to test for selection bias between arms. During the second night odor was added to one arm of the maze. Contrary to expectations, lamprey were significantly attracted to the river otter odor in both count and occupancy. No significant differences were found in the response of lamprey to the other three odors. Results from this study indicate that Pacific lamprey do respond to some odors; however, additional tests are necessary to better identify the types of odors and concentrations that elicit a repeatable response.

The relationship between morphological and sexual indices in suitable brood Russian sturgeon Acipenser gueldenstaedtii (Brandt and Ratzeburg, 1833

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Bahram Falahatkar

2014-09-01

Full Text Available Owing to reduction of sturgeon stocks in various water bodies, artificial propagation has become significantly important for stock restoration and appropriate broodstock selection is vital in this process. Selection of suitable broodstocks may influence the quality and quantity of obtained eggs and larva. The present study aimed to examine correlation between some morphometric and reproductive parameters to find suitable brood fish for artificial reproduction in Russian sturgeon, Acipenser gueldenstaedtii. Forty fish free of any external disease symptom and abnormality were selected for the study. Following biometric measurements including weight, total length, abdominal girth, PV (distance between pectoral and pelvic fins, LX (distance between anal and caudal fins, polarization index (PI, gonadosomatic index, absolute fecundity, and fertilization rate, correlations between these morphometric and biological characteristics with emphasis on breeding were calculated. There was higher correlation between weight-absolute fecundity and length-PV in fish responded to artificial breeding, while correlation between age-PV, length-PV and weight-abdominal girth were higher in those fish not responded to artificial breeding. The results suggests that it is quite possible to select suitable Russian sturgeon spawners for artificial propagation based on combination of body weight, LX, PV, age, abdominal girth and total length, however the most useful criteria for the selection seems to be precise measurement of the polarization index.

Establishment and long-term culture of the cell lines derived from gonad tissues of Siberian sturgeon (Acipenser baerii

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Jun Hyung Ryu

2016-06-01

Full Text Available Abstract To culture germline stem cells in vitro, establishment of the cell lines that can be used as the feeder cells is a prerequisite. In this study, we tried to establish gonad-derived cell lines in Siberian sturgeon (Acipenser baerii. Five 1-year-old A. baerii were used as a donor of gonad tissues, and gonad-dissociated cells were cultured in vitro. Subsequently, determination of growth conditions, long-term culture, characterization, and cryopreservation of the cell lines were also conducted. Five gonad-derived cell lines were stably established and cultured continuously over at least the 73th passage and 402 culture days under the media containing 20 % fetal bovine serum at 28 °C. All cell lines consisted of two main cell types based on morphology even if the ratio of the two cell types was different depending on cell lines. Despite long-term culture, all cell lines maintained diploid DNA contents and expression of several genes that are known to express in the A. baerii gonad. After freezing and thawing of the cell lines, post-thaw cell viabilities between 57.6 and 92.9 % depending on cell lines were indentified, suggesting that stable cryopreservation is possible. The results and the cell lines established in this study will contribute to the development of an in vitro system for A. baerii germline stem cell culture.

Biomarker responses in persian sturgeon (Acipenser persicus exposed to benzo-a-pyrene and beta-naphthoflavone

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Karimzadeh Katayoon

2013-01-01

Full Text Available Biotransformation enzymes of xenobiotics (ethoxyresorufin-O-deethylase, cytochrome P4501A1 content and glutathione-S-transferase were investigated in the liver of Persian Sturgeon (Acipenser persicus after a 96-hour exposure to polycyclic aromatic hydrocarbons (PAHs, premutagenic benzo[a]pyrene (BaP and beta-naphthoflavone (BNF. The fish were injected 10 mg/kg wet-body weight in corn oil for 96 hours every days. Ethoxyresorufin-O-deethylase activity (EROD and glutathione s-transferase activity (GST were measured in the fish liver. Cytochrome P4501A1 (CYP1A1 content was estimated by indirect enzyme-linked immunosorbent assay (ELISA. The response appeared as early as 12 hours post exposure. A time-dependent response was observed in the EROD activity, being significantly higher at 48 hours post exposure to 10 mg/kg of BaP. The greatest induction occurred in the fish treated with 10 mg/kg BaP, in which a 32.1- fold increase in EROD activity was observed. Results showed that EROD activity in A. persicus is significantly increased by BaP and BNF treatments. Both chemicals showed higher values of EROD activity compared to the liver CYP1A content. There was a rise in glutathione-S-transferase activity in fish exposed to BNF, but no increase was observed in fish treated with BaP. The results showed that hepatic CYP1A expression in terms of induction of EROD activity might be suited as a biomarker of organic contamination in aquatic environments and led to lower sensitivity of the second phase in the detoxification enzyme.

Functional C1q is present in the skin mucus of Siberian sturgeon (Acipenser baerii).

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Fan, Chunxin; Wang, Jian; Zhang, Xuguang; Song, Jiakun

2015-01-01

The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components. However, the presence of the critical classical complement component C1q, which links the innate and adaptive immune systems of mammalians, has not been explored in a primitive actinopterygian fish. In this study, we report that C1q is present in the skin mucus of the Siberian sturgeon (Acipenser baerii). The skin mucus was able to inhibit the growth of Escherichia coli. The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody. We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC, which had 44.7-51.4% identity with C1qCs in teleosts and tetrapods. A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch. The C1qC transcript was expressed in many tissues as well as in skin. Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria, and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Metabolic changes in droplet vitrified semen of wild endangered Persian sturgeon Acipenser persicus (Borodin, 1997).

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Abed-Elmdoust, Amirreza; Farahmand, Hamid; Mojazi-Amiri, Bagher; Rafiee, Gholamreza; Rahimi, Ruhollah

2017-06-01

Comparative quantitative metabolite profiling can be used for better understanding of cell functions and dysfunctions in particular circumstances such as sperm banking which is an important approach for cryopreservation of endangered species. Cryopreservation techniques have some deleterious effects on spermatozoa which put the obtained results in controversy. Therefore, in the present study, quantitative 1 H NMR (Nuclear Magnetic Resonance) based metabolite profiling was conducted to evaluate metabolite changes related to energetics and some other detected metabolites in vitrified semen of critically endangered wild Acipenser persicus. The semen was diluted with extenders containing 0, 5, 10, and 15 μM of fish antifreeze protein (AFP) type III as a cryoprotectant. Semen-extenders were vitrified and stored for two days. Based on post-thaw motility duration and motility percentage assessments, two treatments with 10 μM and 0 μM of AFP had the highest and the lowest motility percentages respectively and they were objected to 1 H NMR spectroscopy investigations in order to reveal the extremes of the metabolites dynamic range. Univariate (ANOVA) and multivariate (PCA) analysis of the resulting metabolic profiles indicated significant changes (P > 0.05) in metabolites. The level of some metabolites including acetate, adenine, creatine, creatine phosphate, lactate, betaine, sarcosine, β-alanine and trimethylamine N-oxide significantly decreased in vitrified semen while some others such as creatinine, guanidinoacetate, N, N-dimethylglycine, and glycine significantly increased. There were also significant differences between vitrified treatments in levels of creatine, creatine phosphate, creatinine, glucose, guanidinoacetate, lactate, N, N-dimethylglycine, and glycine, suggesting how fish AFP type III can be effective as a cryoprotectant. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of multiple collections on spermatozoa quality of Persian sturgeon, Acipenser persicus: motility, density and seminal plasma composition.

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Aramli, M S; Kalbassi, M R; Gharibi, M R

2015-02-01

In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH-A2, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl(-) ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Effects of temperature and fatigue on the metabolism and swimming capacity of juvenile Chinese sturgeon (Acipenser sinensis).

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Yuan, Xi; Zhou, Yi-Hong; Huang, Ying-Ping; Guo, Wen-Tao; Johnson, David; Jiang, Qing; Jing, Jin-Jie; Tu, Zhi-Ying

2017-10-01

Chinese sturgeon (Acipenser sinensis) is a critically endangered species. A flume-type respirometer, with video, was used to conduct two consecutive stepped velocity tests at 10, 15, 20, and 25 °C. Extent of recovery was measured after the 60-min recovery period between trials, and the recovery ratio for critical swimming speed (U crit ) averaged 91.88% across temperatures. Temperature (T) effects were determined by comparing U crit , oxygen consumption rate (MO 2 ), and tail beat frequency (TBF) for each temperature. Results from the two trials were compared to determine the effect of exercise. The U crit occurring at 15 °C in both trials was significantly higher than that at 10 and 25 °C (p swimming temperature 3.28 BL/s at 15.96 °C (trial 1) and 2.98 BL/s at 15.85 °C (trial 2). In trial 1, MO 2 increased rapidly with U, but then declined sharply as swimming speed approached U crit . In trial 2, MO 2 increased more slowly, but continuously, to U crit . TBF was directly proportional to U and the slope (dTBF/dU) for trial 2 was significantly lower than that for trial 1. The inverse slope (tail beats per body length, TB/BL) is a measure of swimming efficiency and the significant difference in slopes implies that the exercise training provided by trial 1 led to a significant increase in swimming efficiency in trial 2.

A spatial model of white sturgeon rearing habitat in the lower Columbia River, USA

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Hatten, J.R.; Parsley, M.J.

2009-01-01

Concerns over the potential effects of in-water placement of dredged materials prompted us to develop a GIS-based model that characterizes in a spatially explicit manner white sturgeon Acipenser transmontanus rearing habitat in the lower Columbia River, USA. The spatial model was developed using water depth, riverbed slope and roughness, fish positions collected in 2002, and Mahalanobis distance (D2). We created a habitat suitability map by identifying a Mahalanobis distance under which >50% of white sturgeon locations occurred in 2002 (i.e., high-probability habitat). White sturgeon preferred relatively moderate to high water depths, and low to moderate riverbed slope and roughness values. The eigenvectors indicated that riverbed slope and roughness were slightly more important than water depth, but all three variables were important. We estimated the impacts that fill might have on sturgeon habitat by simulating the addition of fill to the thalweg, in 3-m increments, and recomputing Mahalanobis distances. Channel filling simulations revealed that up to 9 m of fill would have little impact on high-probability habitat, but 12 and 15 m of fill resulted in habitat declines of ???12% and ???45%, respectively. This is the first spatially explicit predictive model of white sturgeon rearing habitat in the lower Columbia River, and the first to quantitatively predict the impacts of dredging operations on sturgeon habitat. Future research should consider whether water velocity improves the accuracy and specificity of the model, and to assess its applicability to other areas in the Columbia River.

Preliminary evaluation of the effectiveness of visible implant elastomer and coded wire tags for tagging young-of-the-year Atlantic sturgeon, Acipenser oxyrinchus

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Kapusta Andrzej

2015-12-01

Full Text Available The aim of the study was to determine the retention rates of visible implant elastomer (VIE and coded wire tags (CWT and the impact tagging had on the growth of Atlantic sturgeon, Acipenser oxyrinchus Mitchill, during an eight-week rearing period under laboratory conditions. Two size groups of young-of-the-year (YOY sturgeon were used in the study. The tagging was not found to have a significant impact on the final total length or body weight or the condition coefficient of the sturgeon from either size group. Sturgeon survival in the different groups ranged from 90.6 to 100%. Mortality was not noted until two (CWT and four (VIE weeks following tagging and was probably not linked to tagging. The retention rate for VIE tags implanted in the rostrum in both size groups was 100%, while for tags implanted at the base of the pectoral fin was 93.5%. The retention of CWT in the smaller fish was 90%, and in the larger sturgeon it was 100%. Tagging small sturgeon with CWT and VIE is minimally invasive, and it did not impact the growth or condition of the tagged fish.

Ontogeny of salinity tolerance and evidence for seawater-entry preparation in juvenile green sturgeon, Acipenser medirostris.

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Allen, Peter J; McEnroe, Maryann; Forostyan, Tetyana; Cole, Stephanie; Nicholl, Mary M; Hodge, Brian; Cech, Joseph J

2011-12-01

We measured the ontogeny of salinity tolerance and the preparatory hypo-osmoregulatory physiological changes for seawater entry in green sturgeon (Acipenser medirostris), an anadromous species occurring along the Pacific Coast of North America. Salinity tolerance was measured every 2 weeks starting in 40-day post-hatch (dph) juveniles and was repeated until 100% survival at 34‰ was achieved. Fish were subjected to step increases in salinity (5‰ 12 h(-1)) that culminated in a 72-h exposure to a target salinity, and treatment groups (0, 15, 20, 25, 30, 34‰; and abrupt exposure to 34‰) were adjusted as fish developed. After 100% survival was achieved (134 dph), a second experiment tested two sizes of fish for 28-day seawater (33‰) tolerance, and gill and gastrointestinal tract tissues were sampled. Their salinity tolerance increased and plasma osmolality decreased with increasing size and age, and electron microscopy revealed three types of mitochondria-rich cells: one in fresh water and two in seawater. In addition, fish held on a natural photoperiod in fresh water at 19°C showed peaks in cortisol, thyroid hormones and gill and pyloric ceca Na(+), K(+)-ATPase activities at body sizes associated with seawater tolerance. Therefore, salinity tolerance in green sturgeon increases during ontogeny (e.g., as these juveniles may move down estuaries to the ocean) with increases in body size. Also, physiological and morphological changes associated with seawater readiness increased in freshwater-reared juveniles and peaked at their seawater-tolerant ages and body sizes. Their seawater-ready body size also matched that described for swimming performance decreases, presumably associated with downstream movements. Therefore, juvenile green sturgeon develop structures and physiological changes appropriate for seawater entry while growing in fresh water, indicating that hypo-osmoregulatory changes may proceed by multiple routes in sturgeons.

Exposure-related effects of Zequanox on juvenile lake sturgeon (Acipenser fulvescens) and lake trout (Salvelinus namaycush)

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Luoma, James A.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

2018-01-01

The environmental fate, persistence, and non-target animal impacts of traditional molluscicides for zebra, Dreissena polymorpha, and quagga, D. bugensis, mussel control led to the development of the biomolluscicide Zequanox. Although previous research has demonstrated the specificity of Zequanox, one study indicated sensitivity of salmonids and lake sturgeon, Acipenser fulvescens, following non-label compliant exposures to Zequanox. This study was conducted to evaluate sublethal and lethal impacts of Zequanox exposure on juvenile lake sturgeon and lake trout, Salvelinus namaycush, following applications that were conducted in a manner consistent with the Zequanox product label. Fish were exposed to 50 or 100 mg/L of Zequanox as active ingredient for 8 h and then held for 33 d to evaluate latent impacts. No acute mortality was observed in either species; however, significant latent mortality (P < 0.01, df = 9; 46.2%) was observed in lake trout that were exposed to the highest dose of Zequanox. Statistically significant (P < 0.03, df = 9), but biologically minimal differences were observed in the weight (range 20.17 to 21.49 g) of surviving lake sturgeon at the termination of the 33 d post-exposure observation period. Statistically significant (P < 0.05, df = 9) and biologically considerable differences were observed in the weight (range 6.19 to 9.55 g) of surviving lake trout at the termination of the 33 d post-exposure observation period. Histologic evaluation of lake trout gastrointestinal tracts suggests that the mode of action in lake trout is different from the mode of action that induces zebra and quagga mussel mortality. Further research could determine the sensitivity of other salmonid species to Zequanox and determine if native fish will avoid Zequanox treated water.

Identification of bester hybrid and its parental species (♀ Huso huso Linnaeus, 1758 and ♂ Acipenser ruthenus Linnaeus, 1758 by nuclear markers

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Andreea Dudu

2015-05-01

Full Text Available In Romania, sturgeon farming is gaining advance, different species being raised for commercial purposes and for restocking activities. A correct identification of individuals is imposed since severe ecological damages might occur if non-native species or hybrids are used for restocking. Such identification is required also for commercial reasons, the meat and caviar from different species having different prices. The aim of our study was to analyze two sturgeon species, Huso huso and Acipenser ruthenus and their interspecific hybrid - bester, using nuclear markers, in order to set up a molecular method for their accurate identification. The genetic pattern of the species was inferred from the analysis of nine microsatellite loci (LS19, LS34, LS39, LS54, AoxD234, AnacC11, LS68, Aox45 and Aox27 amplified by multiplex PCR reactions. The genotype data were analyzed with GENETIX v4.05 and STRUCTURE. The FCA analysis grouped the individuals in three distinct clusters corresponding to each of the pure species and to the interspecific hybrids. The admixture analysis performed in STRUCTURE also assigned three groups, confirming the results highlighted by FCA. We can conclude that the selected microsatellite markers allow the unambiguously identification of the bester hybrid and its genitor species from Romanian farms.

Contaminants in Atlantic sturgeon and shortnose sturgeon recovered from the Penobscot and Kennebec rivers, Maine.

Data.gov (United States)

Department of the Interior — In the Gulf of Maine, the shortnose sturgeon (Acipenser brevirostrum) is a federally‐listed endangered species and the Atlantic sturgeon (Acipenser oxyrinchus) is a...

Using drift nets to capture early life stages and monitor spawning of the yangtze river chinese sturgeon (Acipenser sinensis)

Science.gov (United States)

Wei, Q.W.; Kynard, B.; Yang, D.G.; Chen, X.H.; Du, H.; Shen, L.; Zhang, H.

2009-01-01

A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population. ?? 2009 Blackwell Verlag GmbH.

Radionuclide concentrations in white sturgeons from the Hanford Reach of the Columbia River

International Nuclear Information System (INIS)

Dauble, D.D.; Poston, T.M.

1994-01-01

We summarized radionuclide concentrations in white sturgeons Acipenser transmontanus from the Columbia River during a period when several plutonium-production reactors were operating at the Hanford Site in Washington State and compared these values to those measured several years after reactor shutdown. Studies conducted in the Hanford Reach of the Columbia River during 1953-1955 indicated that high concentrations of radionuclides (as total beta) were present in some internal organs on the external surface of white sturgeons. Average concentrations were about 1,480 Bq/kg for liver and kidney and exceeded 2,200 Bq/kg for fins and scutes. The principal radionuclides in the tissues of white sturgeons from the Hanford Reach during 1963-1967, the peak reactor operation interval, were 32 P, 65 Zn, and 51 Cr. Average concentrations of 32 P in muscle ranged from 925 to 2,109 Bq/kg and were typically two to seven times greater than 65 Zn. Average concentrations of radionuclides were usually in the order of gut contents much-gt carcass > muscle. Studies from 1989 to 1990 showed that radionuclide concentrations had decreased dramatically in white sturgeon tissue since the time of reactor operation. Maximum concentrations for artificial radionuclides ( 90 Sr, 60 Co, 137 Cs) in muscle and cartilage of white sturgeons in the Columbia River had declined to less than 4 Bq/kg. Formerly abundant radionuclides, including 32 P, 65 Zn, and 51 Cr, could not be detected in recent tissue samples. Further, radionuclide tissue burden in populations of sturgeons from the Hanford Reach and the upstream or downstream reference locations did not differ significantly. 34 refs., 3 figs., 4 tabs

Kootenai River white sturgeon investigations. Chapter 1: Kootenai River white sturgeon spawning and recruitment evaluation; Annual report, January 1--December 31, 1996

International Nuclear Information System (INIS)

Paragamian, V.L.; Kruse, G.; Wakkinen, V.

1997-09-01

Test flows for Kootenai River white sturgeon Acipenser transmontanus spawning, scheduled for June 1996, were postponed until July. However, an estimated 126% snow pack and unusually heavy precipitation created conditions for sturgeon spawning that were similar to those occurring before construction of Libby Dam. Discharge in the Kootenai River at Bonners Ferry rose to nearly 1,204 m 3 /s (42,500 cfs) during May and water temperature ranged from 5.8 C to 8.4 C (42 F to 47 F). Migration of adult white sturgeon into spawning areas occurred in late May during a rising hydrograph. Discharge and water temperature were rising and had reached approximately 1,077 m 3 /s (38,000 cfs) and 8 C (46 F). Discharge at Bonners Ferry peaked at about 1,397 m 3 /s (49,300 cfs) on June 5. A total of 348 eggs (and one egg shell) were collected with 106,787 h of mat effort during the flow events. The first white sturgeon eggs were collected on June 8 and continued through June 30. Staging of eggs and back-calculating to spawning dates indicated there were at least 18 spawning episodes between June 6 and June 25. Discharge on June 6 was 1,196 m 3 /s (42,200 cfs) and decreased steadily to 850 m 3 /s (30,000 cfs) by June 26. Although sturgeon spawned in the same reach of river that they had during 1994 and 1995, the majority of eggs were found significantly (P = 0.0001) farther upstream than 1994 and 1995 and this in turn may be related to elevation of Kootenay Lake

How Low Can You Go? Determining a Size Threshold for Implantation of a New Acoustic Transmitter in Age-0 White Sturgeon

Energy Technology Data Exchange (ETDEWEB)

Ashton, Neil K.; Liss, Stephanie A.; Walker, Ricardo W.; Brown, Richard S.; Klassen, Cheryl; Backhouse, Stephanie; Bates, Phil; Townsend, Richard L.

2017-01-01

Telemetry studies are often used to investigate sturgeon habitat use and movement patterns; however, existing acoustic transmitters are generally too large to implant into age-0 sturgeon without harming the fish. Recent development of a miniaturized acoustic transmitter (cylindrical, 0.7 g in air, 24.2 mm long, 5.0 mm diameter) with up to 365 d battery life has the potential to advance our understanding of age-0 sturgeon ecology in rivers and lakes. Prior to use in field studies, it is essential to conduct experiments evaluating potential adverse transmitter effects on fish. We tested transmitter retention, fish survival, and growth of a broad size range of age-0 white sturgeon (Acipenser transmontanus; 158–277 mm fork length; 26–126 g; 0.6–2.6% transmitter burden) in an 84 d laboratory study, with an ultimate goal of determining a minimum size threshold of sturgeon that can be implanted with this acoustic transmitter. At 84 d post-implantation, transmitter retention and fish survival were 100%. Specific growth rates were reduced at 7 and 14 d post-implantation, resulting in minimum fork length thresholds of 250 and 171 mm, respectively. Juveniles implanted with transmitters regained their growth potential by 28 d post-implantation and no size differences were detected in comparisons with unmarked control fish. This study demonstrates the ability to implant small age-0 sturgeon with high transmitter retention and fish survival, and only minor growth effects. Use of new miniaturized acoustic transmitters may give researchers a means to address questions about young-of-the-year fish recruitment, ecological patterns, and potentially advance conservation management of sturgeon populations.

Acquisition of glial cells missing 2 enhancers contributes to a diversity of ionocytes in zebrafish.

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Takanori Shono

Full Text Available Glial cells missing 2 (gcm2 encoding a GCM-motif transcription factor is expressed in the parathyroid in amniotes. In contrast, gcm2 is expressed in pharyngeal pouches (a homologous site of the parathyroid, gills, and H(+-ATPase-rich cells (HRCs, a subset of ionocytes on the skin surface of the teleost fish zebrafish. Ionocytes are specialized cells that are involved in osmotic homeostasis in aquatic vertebrates. Here, we showed that gcm2 is essential for the development of HRCs and Na(+-Cl(- co-transporter-rich cells (NCCCs, another subset of ionocytes in zebrafish. We also identified gcm2 enhancer regions that control gcm2 expression in ionocytes of zebrafish. Comparisons of the gcm2 locus with its neighboring regions revealed no conserved elements between zebrafish and tetrapods. Furthermore, We observed gcm2 expression patterns in embryos of the teleost fishes Medaka (Oryzias latipes and fugu (Fugu niphobles, the extant primitive ray-finned fishes Polypterus (Polypterus senegalus and sturgeon (a hybrid of Huso huso × Acipenser ruhenus, and the amphibian Xenopus (Xenopus laevis. Although gcm2-expressing cells were observed on the skin surface of Medaka and fugu, they were not found in Polypterus, sturgeon, or Xenopus. Our results suggest that an acquisition of enhancers for the expression of gcm2 contributes to a diversity of ionocytes in zebrafish during evolution.

Rethinking the influence of hydroelectric development on gene flow in a long-lived fish, the Lake Sturgeon Acipenser fulvescens.

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Craig A McDougall

Full Text Available Many hydroelectric dams have been in place for 50 - >100 years, which for most fish species means that enough generations have passed for fragmentation induced divergence to have accumulated. However, for long-lived species such as Lake Sturgeon, Acipenser fulvescens, it should be possible to discriminate between historical population structuring and contemporary gene flow and improve the broader understanding of anthropogenic influence. On the Winnipeg River, Manitoba, two hypotheses were tested: 1 Measureable quantities of former reservoir dwelling Lake Sturgeon now reside downstream of the Slave Falls Generating Station, and 2 genetically differentiated populations of Lake Sturgeon occur upstream and downstream, a result of historical structuring. Genetic methods based on ten microsatellite markers were employed, and simulations were conducted to provide context. With regards to contemporary upstream to downstream contributions, the inclusion of length-at-age data proved informative. Both pairwise relatedness and Bayesian clustering analysis substantiated that fast-growing outliers, apparently entrained after residing in the upstream reservoir for several years, accounted for ~15% of the Lake Sturgeon 525-750 mm fork length captured downstream. With regards to historical structuring, upstream and downstream populations were found to be differentiated (FST = 0.011, and 0.013-0.014 when fast-growing outliers were excluded, and heterozygosity metrics were higher for downstream versus upstream juveniles. Historical asymmetric (downstream gene flow in the vicinity of the generating station was the most logical explanation for the observed genetic structuring. In this section of the Winnipeg River, construction of a major dam does not appear to have fragmented a previously panmictic Lake Sturgeon population, but alterations to habitat may be influencing upstream to downstream contributions in unexpected ways.

Effects of stocking density on lipid deposition and expression of lipid-related genes in Amur sturgeon (Acipenser schrenckii).

Science.gov (United States)

Ren, Yuanyuan; Wen, Haishen; Li, Yun; Li, Jifang; He, Feng; Ni, Meng

2017-12-01

To investigate the correlation between lipid deposition variation and stocking density in Amur sturgeon (Acipenser schrenckii) and the possible physiological mechanism, fish were conducted in different stocking densities (LSD 5.5 kg/m 3 , MSD 8.0 kg/m 3 , and HSD 11.0 kg/m 3 ) for 70 days and then the growth index, lipid content, lipase activities, and the mRNA expressions of lipid-related genes were examined. Results showed that fish subjected to higher stocking density presented lower final body weights (FBW), specific growth ratio (SGR), and gonad adipose tissue index (GAI) (P density lipoprotein cholesterol (HDL-C) decreased significantly with increasing stocking density, while no significant change was observed for low-density lipoprotein cholesterol (LDL-C). Furthermore, the cDNAs encoding lipoprotein lipase (LPL) and hepatic lipase (HL) were isolated in Amur sturgeon, respectively. The full-length LPL cDNA was composed of 1757 bp with an open reading frame of 501 amino acids, while the complete nucleotide sequences of HL covered 1747 bp encoding 499 amino acids. In the liver, the activities and mRNA levels of LPL were markedly lower in HSD group, which were consistent with the variation tendency of HL. Fish reared in HSD group also presented lower levels of activities and mRNA expression of LPL in the muscle and gonad. Moreover, the expressions of peroxisome proliferator-activated receptor α (PPARα) in both the liver and skeletal muscle were significantly upregulated in HSD group. Overall, the results indicated that high stocking density negatively affects growth performance and lipid deposition of Amur sturgeon to a certain extent. The downregulation of LPL and HL and the upregulation of PPARα may be responsible for the lower lipid distribution of Amur sturgeon in higher stocking density.

Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor.

Science.gov (United States)

Kessel, Steven T; Hondorp, Darryl W; Holbrook, Christopher M; Boase, James C; Chiotti, Justin A; Thomas, Michael V; Wills, Todd C; Roseman, Edward F; Drouin, Richard; Krueger, Charles C

2018-01-01

Population structure, distribution, abundance and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations are an important aspect of the ecology of highly mobile animals, allowing populations to exploit spatially or temporally distributed food and space resources. This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes. Over 6 years (2011-2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 years battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use. Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assigned to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 "contingents" (spatiotemporally segregated subgroups). Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor

Science.gov (United States)

Kessel, Steven T.; Hondorp, Darryl W.; Holbrook, Christopher; Boase, James C.; Chiotti, Justin A.; Thomas, Michael V.; Wills, Todd C.; Roseman, Edward; Drouin, Richard; Krueger, Charles C.

2018-01-01

Population structure, distribution, abundance, and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations is an important aspect of the ecology of highly-mobile animals, allowing populations to exploit spatially- or temporally-distributed food and space resources.This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes.Over six years (2011 – 2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 yr battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use.Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assign to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 “contingents” (spatiotemporally segregated subgroups).Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

The evidence of apelin has the bidirectional effects on feeding regulation in Siberian sturgeon (Acipenser baerii).

Science.gov (United States)

Hao, Jin; Liu, Qing; Zhang, Xin; Wu, Yuanbing; Zhu, Jieyao; Qi, Jinwen; Tang, Ni; Wang, Shuyao; Wang, Hong; Chen, Defang; Li, Zhiqiong

2017-08-01

Apelin is a peptide, mainly produced in the brain, which participates in several physiologic effects. However, knowledge about the mechanism of appetite regulation in teleosts, including the role of apelin is not well understood. The aim of this study is to explore the effect of feeding status on the expression of apelin mRNA in the whole brain and the effects of injection of apelin on food intake in Siberian sturgeon (Acipenser baerii). In this study, we first cloned the apelin cDNA sequence of the Siberian sturgeon. We obtained a 1046-bp cDNA fragment, including a 237-bp open reading frame (ORF) that encoded 78 amino acids. Apelin was widely distributed in 11 tissues related to feeding regulation, with the highest expression in thewhole brain, followed by the spleen and trunk kidney. In addition, we measured the effects of periprandial (preprandial and postprandial) change, fasting and re-feeding on apelin mRNA expression in whole brain. The level of apelin mRNA was significantly decreased 1h after feeding. The results of the fasting experiment showed that the expression of apelin mRNA in the brain was significantly reduced after 1day of fasting but consistently increased throughout the 15-day food deprivation period. When the 15-day fasted fish were re-fed, apelin mRNA expression in the brain was significantly increased as compared to that of the control. These results suggest that apelin may play a bidirectional role in the regulation of food intake in the Siberian sturgeon. In order to further examine the effect of apelin on feeding regulation in Siberian sturgeons, acute and chronic intraperitoneal (i.p.) injection experiments were performed and food intakes were recorded. Results showed that acute i.p. injection of apelin-13 reduced food intake, however, chronic i.p. injection apelin-13 increased the food intake for 7days in Siberian sturgeons. In conclusion, our results show that apelin has a bidirectional effect on feeding regulation in Siberian sturgeons

Predicted effects of future climate warming on thermal habitat suitability for Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) in rivers in Wisconsin, USA

Science.gov (United States)

Lyons, John D.; Stewart, Jana S.

2015-01-01

The Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) may be threatened by future climate warming. The purpose of this study was to identify river reaches in Wisconsin, USA, where they might be vulnerable to warming water temperatures. In Wisconsin, A. fulvescens is known from 2291 km of large-river habitat that has been fragmented into 48 discrete river-lake networks isolated by impassable dams. Although the exact temperature tolerances are uncertain, water temperatures above 28–30°C are potentially less suitable for this coolwater species. Predictions from 13 downscaled global climate models were input to a lotic water temperature model to estimate amounts of potential thermally less-suitable habitat at present and for 2046–2065. Currently, 341 km (14.9%) of the known habitat are estimated to regularly exceed 28°C for an entire day, but only 6 km (0.3%) to exceed 30°C. In 2046–2065, 685–2164 km (29.9–94.5%) are projected to exceed 28°C and 33–1056 km (1.4–46.1%) to exceed 30°C. Most river-lake networks have cooler segments, large tributaries, or lakes that might provide temporary escape from potentially less suitable temperatures, but 12 short networks in the Lower Fox and Middle Wisconsin rivers totaling 93.6 km are projected to have no potential thermal refugia. One possible adaptation to climate change could be to provide fish passage or translocation so that riverine Lake Sturgeon might have access to more thermally suitable habitats.

Is the Ghost of Waste Management's Past Coming Back to Haunt Us In Our Seafood?

Science.gov (United States)

Rochman, C. M.; Tahir, A.; Serrato, S.; Williams, S.; Baxa, D.; Lam, R.; Teh, C.; Miller, J.; Werorilangi, S.; Teh, S.

2016-02-01

Plastic debris is recognized globally as a persistent contaminant, littered across multiple habitats worldwide. Most striking is its occurrence in wildlife. Plastic has been recovered from hundreds of species across multiple trophic levels and in animals we consider seafood. This has led policy-makers to ask about the extent that our seafood is contaminated with plastic debris and associated contaminants. To help address these policy-relevant and emerging scientific questions, we first measured the simple presence of anthropogenic debris in many different species of fish and one species of shellfish sold as seafood at local fish markets in Half Moon Bay, California, USA and Makassar, Sulawesi, Indonesia. We found anthropogenic debris in roughly 25% of all animals purchased, demonstrating that some seafood items are contaminated with plastic debris, including some that we consume whole (e.g., anchovies and oysters). Next, to understand if plastic debris can act as a vector for organic pollutants to move through the food chain and indirectly into the meat of fish at higher trophic levels, we designed a laboratory dietary exposure to measure the bioaccumulation of sorbed PCBs in Asian clams (Corbicula fluminea) and the biomagnifications in white sturgeon (Acipenser transmontanus). Asian clams were exposed for 30 days to separate treatments of microplastic (polyethylene terephthalate, polyethylene, polyvinyl chloride and polystyrene) with and without sorbed PCBs. Next, diets were formulated using purified ingredients and clams from the first exposure and fed to their predators (sturgeon) for 30 days. Chemical analyses, allowing us to understand how chemical contaminants from plastics move through food chains, will be presented. Combined, this work demonstrates the presence of plastic debris in seafood and will help us understand whether plastic acts as a vector for chemicals to transfer through aquatic foodwebs, including our own.

Gender and gonadal maturity stage identification of captive Chinese sturgeon, Acipenser sinensis, using ultrasound imagery and sex steroids.

Science.gov (United States)

Du, Hao; Zhang, Xiaoyan; Leng, Xiaoqian; Zhang, Shuhuan; Luo, Jiang; Liu, Zhigang; Qiao, Xingmei; Kynard, Boyd; Wei, Qiwei

2017-05-01

Long lifespan and late maturation make it difficult to establish gamete maturity and breeding age of captive endangered Chinese sturgeon, Acipenser sinensis. This greatly handicaps timely breeding and future conservation stocking efforts. We used ultrasound imagery and sex steroids to determine the gender and gonadal maturity stage of captive Chinese sturgeon (age, 10-17years old). The echogenicity of the reproductive organs and the respective morphology of the gonads were described and two quantitative parameters p o (proportion of the ovary to the entire reproductive organs) and d (thickness of the reproductive organs) were measured to characterize sex and maturity stage of Chinese sturgeon. Females were accordingly placed fish into several categories: F II (F II - , F II , F II + ), F III (F III , F III + ) and F IV (F IV , F IV + ) and F VI and males as M II , M III , M IV , M V and M VI . The accuracy of gender and maturity stage determination provided by ultrasonographic methods was 72.7% for F II - ovary (n=11) and 76.2% for M II testis (n=42). Accuracy of sex and maturity determination using only serum sex steroid of testosterone (T) and estradiol-17β (E 2 ) was low (58-73%, depending on maturity stage). However, when the two methods were used together, accuracy increased sharply, especially for immature (II stage) females. In summary, of 151 Chinese sturgeon, whose sex and maturity stage were independently confirmed, 88.1% (n=133), 62.9% (n=95), and 96.7% (n=146) were successfully sexed and staged using ultrasound, sex steroids, or both methods, respectively. The results provide reliable non-invasive techniques for determining sex and gonadal maturation of captive Chinese sturgeon. These methods can track individual gonad characteristics over multi-year reproductive cycles, which will assist captive broodstock management, artificial reproduction, and future conservation stocking. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of cortisol and salinity acclimation on Na+/K+/2Cl–- cotransporter gene expression and Na+, K+-ATPase activity in the gill of Persian sturgeon, Acipenser persicus, fry

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Saber Khodabandeh

2009-10-01

Full Text Available Na+, K+-ATPase activity and Na+/K+/2Cl–- cotransporter (NKCC gene expression in the gills of Persian sturgeon, Acipenser persicus, fry (2-3 g, 3.30-8.12 cm total body length in freshwater (control group, diluted Caspian Sea water (5 ppt and after treatment with cortisol in freshwater were studied. Na+, K+-ATPase activity was lower in the 5 ppt-acclimated fish (1.07±0.05 _mol Pi/mg protein/h than in the control fish (1.19±0.05 μmol Pi/mg protein/h but this difference was not significant. nKCC gene expression in the 5 ppt-acclimated fish (1.6±0.07 was significantly higher than in the control fish (0.8±0.00. In the cortisol treated fish, Na+, K+-ATPase activity (1.91±0.05 μmol Pi/mg protein/h and NKCC gene expression (3.2±0.1 were significantly higher than in the control group. our results show that Persian sturgeon fry (2-3 g can tolerate 5 ppt salinity by changing their enzymatic content and activity, and that exogenous cortisol application can increase the osmoregulatory capacity of fry before release into brackish water and can reduce their mortality.

Neomycin damage and regeneration of hair cells in both mechanoreceptor and electroreceptor lateral line organs of the larval Siberian sturgeon (Acipenser baerii).

Science.gov (United States)

Fan, Chunxin; Zou, Sha; Wang, Jian; Zhang, Bo; Song, Jiakun

2016-05-01

The lateral line found in some amphibians and fishes has two distinctive classes of sensory organs: mechanoreceptors (neuromasts) and electroreceptors (ampullary organs). Hair cells in neuromasts can be damaged by aminoglycoside antibiotics and they will regenerate rapidly afterward. Aminoglycoside sensitivity and the capacity for regeneration have not been investigated in ampullary organs. We treated Siberian sturgeon (Acipenser baerii) larvae with neomycin and observed loss and regeneration of sensory hair cells in both organs by labeling with DASPEI and scanning electron microscopy (SEM). The numbers of sensory hair cells in both organs were reduced to the lowest levels at 6 hours posttreatment (hpt). New sensory hair cells began to appear at 12 hpt and were regenerated completely in 7 days. To reveal the possible mechanism for ampullary hair cell regeneration, we analyzed cell proliferation and the expression of neural placodal gene eya1 during regeneration. Both cell proliferation and eya1 expression were concentrated in peripheral mantle cells and both increased to the highest level at 12 hpt, which is consistent with the time course for regeneration of the ampullary hair cells. Furthermore, we used Texas Red-conjugated gentamicin in an uptake assay following pretreatment with a cation channel blocker (amiloride) and found that entry of the antibiotic was suppressed in both organs. Together, our results indicate that ampullary hair cells in Siberian sturgeon larvae can be damaged by neomycin exposure and they can regenerate rapidly. We suggest that the mechanisms for aminoglycoside uptake and hair cell regeneration are conserved for mechanoreceptors and electroreceptors. J. Comp. Neurol. 524:1443-1456, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Emergency Fish Restoration Project; Final Report 2002.

Energy Technology Data Exchange (ETDEWEB)

LeCaire, Richard

2003-03-01

Lake Roosevelt is a 151-mile impoundment created by the construction of Grand Coulee Dam during the early 1940's. The construction of the dam permanently and forever blocked the once abundant anadromous fish runs to the upper Columbia Basin. Since the construction of Grand Coulee Dam in 1943 and Chief Joseph Dam in 1956 this area is known as the blocked area. The blocked area is totally dependant upon resident fish species to provide a subsistence, recreational and sport fishery. The sport fishery of lake Roosevelt is varied but consists mostly of Rainbow trout (Oncorhynchus mykiss), Kokanee salmon (Oncorhynchus nerka), Walleye (Stizostedion vitreum) Small mouth bass (Micropterus dolomieui) and white sturgeon (Acipenser transmontanus). Currently, Bonneville Power Administration funds and administers two trout/kokanee hatcheries on Lake Roosevelt. The Spokane Tribe of Indians operates one hatchery, the Washington Department of Fish and Wildlife the other. In addition to planting fish directly into Lake Roosevelt, these two hatcheries also supply fish to a net pen operation that also plants the lake. The net pen project is administered by Bonneville Power funded personnel but is dependant upon volunteer labor for daily feeding and monitoring operations. This project has demonstrated great success and is endorsed by the Colville Confederated Tribes, the Spokane Tribe of Indians, the Washington Department of Fish and Wildlife, local sportsmen associations, and the Lake Roosevelt Forum. The Lake Roosevelt/Grand Coulee Dam area is widely known and its diverse fishery is targeted by large numbers of anglers annually to catch rainbow trout, kokanee salmon, small mouth bass and walleye. These anglers contribute a great deal to the local economy by fuel, grocery, license, tackle and motel purchases. Because such a large portion of the local economy is dependant upon the Lake Roosevelt fishery and tourism, any unusual operation of the Lake Roosevelt system may have a

Temporal trends of polychlorinated biphenyls, polybrominated diphenyl ethers, and perfluorinated compounds in Chinese sturgeon (Acipenser sinensis) eggs (1984-2008).

Science.gov (United States)

Jianxian, Sun; Hui, Peng; Jianying, Hu

2015-02-03

Because investigation on the temporal trends of persistent halogenated compounds (PHCs) is necessary to predict their future impacts on the environment and human health and evaluate the effectiveness of regulations on their production and usage, it is of concern to investigate annual temporal trends of PHCs in biota samples. This study examined the temporal trends of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorinated compounds (PFCs) in Chinese sturgeon (Acipenser sinensis) eggs over a period of 25 years (1984-2008), and 62 PCBs (19.2-1030 ng/g dw for total PCBs), 16 PBDEs (4.7-572 ng/g dw for total PBDEs), and 14 PFCs (26-46 ng/g dw for total PFCs) were detected. Although a decreasing temporal trend was observed for total PCBs with annual reduction rate of 3.4% (ρ = 0.005), a clear break point was observed around 1991, indicating their continuing emission in the 1980s in China. All major PBDEs showed increasing temporal trends, with annual change rates at 3.5-10.2% over the 25 years, but a sharp decreasing trend was observed after 2006, indicating a rapid response to the banning of PBDE usage in China in 2004. The greatest annual rate of increase was observed for BDE-28 (10.2%) followed by BDE-100 (7.7%), which would be due to metabolism input from higher brominated PBDEs. Significantly increasing temporal trends were observed for all PFCs, and the annual rates of increase were 7.9% and 5.9% for total perfluorinated carboxylic acids and perfluorooctanesulfonate (PFOS), respectively. A peak concentration for PFOS was observed in 1989, which may be related to the import history of PFCs in China. The present study is the first report of systematic temporal trends of PHCs in biota samples from China and shows that regulatory policy is needed to reduce their potential health and ecological risk in China considering the increasing temporal trends of PBDEs and PFCs.

Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA).

Science.gov (United States)

Levesque, Juan C; Hager, Christian; Diaddorio, Eric; Dickey, R Jason

2016-01-01

Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given this conservation and management need, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon incidental encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 39.6% and 60.9%, respectively. Our design entangled 51.6% fewer southern flounder, which corresponded to a 48.9% reduction in total weight; the modified gear entangled slightly larger southern flounder than the control gear. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper (5.1-6.3 m) than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. Most southern flounder (n = 518, 39.7%) were taken at a water depth between 3.76 and 5.0 m. This observation suggests that southern flounder prefer slightly shallower waters than Atlantic sturgeon.

Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fulvescens show highly restricted movement and habitat use over-winter

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Donnette Thayer

2017-04-01

Full Text Available The relationship between species’ size and home range size has been well studied. In practice, home range may provide a good surrogate of broad spatial coverage needed for species conservation, however, many species can show restricted movement during critical life stages, such as breeding and over-wintering. This suggests the existence of either a behavioral or habitat mediated ‘temporal bottleneck,’ where restricted or sedentary movement can make populations more susceptible to harm during specific life stages. Here, we study over-winter movement and habitat use of Lake Sturgeon (Acipenser fulvescens, the largest freshwater fish in North America. We monitored over-winter movement of 86 fish using a hydro-acoustic receiver array in the South Saskatchewan River, Canada. Overall, 20 fish remained within our study system throughout the winter. Lake Sturgeon showed strong aggregation and sedentary movement over-winter, demonstrating a temporal bottleneck. Movement was highly restricted during ice-on periods (ranging from 0.9 km/day in November and April to 0.2 km/day in mid-November to mid-March, with Lake Sturgeon seeking deeper, slower pools. We also show that Lake Sturgeon have strong aggregation behavior, where distance to conspecifics decreased (from 575 to 313 m in preparation for and during ice-on periods. Although the Lake Sturgeon we studied had access to 1100 kilometers of unfragmented riverine habitat, we show that during the over-winter period Lake Sturgeon utilized a single, deep pool (<0.1% of available habitat. The temporal discrepancy between mobile and sedentary behaviors in Lake Sturgeon suggest adaptive management is needed with more localized focus during periods of temporal bottlenecks, even for large-bodied species.

Life history and status of Shortnose Sturgeon (Acipenser brevirostrum LeSueur, 1818)

Science.gov (United States)

Kynard, Boyd; Bolden, Stephania; Kieffer, Micah; Collins, Mark; Brundage, Hal; Hilton, Eric; Litvak, Mark; Kinnison, Michael T.; King, Timothy L.; Peterson, Douglas C.

2016-01-01

Shortnose Sturgeon = SNS (Acipenser brevirostrum) is a small diadromous species with most populations living in large Atlantic coast rivers and estuaries of North America from New Brunswick, Canada, to GA, USA. There are no naturally landlocked populations, so all populations require access to fresh water and salt water to complete a natural life cycle. The species is amphidromous with use of fresh water and salt water (the estuary) varied across the species range, a pattern that may reflect whether freshwater or saltwater habitats provide optimal foraging and growth conditions. Migration is a dominant behavior during life history, beginning when fish are hatchling free embryos (southern SNS) or larvae (northeastern and far northern SNS). Migration continues by juveniles and nonspawning adult life stages on an individual time schedule with fish moving between natal river and estuary to forage or seek refuge, and by spawning adults migrating to and from riverine spawning grounds. Coastal movements by adults throughout the range (but particularly in the Gulf of Maine = GOM and among southern rivers) suggest widespread foraging, refuge use, and widespread colonization of new rivers. Colonization may also be occurring in the Potomac River, MD–VA–DC (midAtlantic region). Genetic studies (mtDNA and nDNA) identified distinct individual river populations of SNS, and recent rangewide nDNA studies identified five distinct evolutionary lineages of SNS in the USA: a northern metapopulation in GOM rivers; the Connecticut River; the Hudson River; a Delaware River–Chesapeake Bay metapopulation; and a large southern metapopulation (SC rivers to Altamaha River, GA). The Saint John River, NB, Canada, in the Bay of Fundy (north of the GOM), is the sixth distinct genetic lineage within SNS. Life history information from telemetry tracking supports the genetic information documenting extensive movement of adults among rivers within the three metapopulations. However

Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

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Jon C Svendsen

Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

REFERENCED TECHNOLOGICAL PERFORMANCES FOR STURGEON FINGERLING BREEDING IN INTENSIVE SYSTEM

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MARILENA TALPES

2008-10-01

Full Text Available Work objective is to present an oversight regarding the modality to rearing the descendents of anadromous sturgeon species, Acipenser stellatus, Acipenser gueldenstaedti and Huso huso, obtained trough artificial reproduction, indicating successively, the production system, its management, alimentation strategy for sturgeon species and technological performances registered by these. Experiments developed during two phases, respectively the post-embryonary one and sapling rearing during of a 168 days period. Registered performances of sturgeon species material were assessed in conformity with specifically biotechnological indicators.

Status of scientific knowledge, recovery progress, and future research directions for the Gulf Sturgeon, Acipenser oxyrinchus desotoi Vladykov, 1955

Science.gov (United States)

Sulak, Kenneth J.; Parauka, F; Slack, W. Todd; Ruth, T; Randall, Michael T.; Luke, K; Mette, M. F; Price, M. E

2016-01-01

The Gulf Sturgeon, Acipenser oxyrinchus desotoi, is an anadromous species of Acipenseridae and native to North America. It currently inhabits and spawns in the upper reaches of seven natal rivers along the northern coast of the Gulf of Mexico from the Suwannee River, Florida, to the Pearl River, Louisiana, during spring to autumn. Next to the Alligator Gar (Atractosteus spatula), the Gulf Sturgeon is currently the largest fish species occurring in U.S. Gulf Coast rivers, attaining a length of 2.35 m and weights exceeding 135 kg, but historically attained a substantially larger size. Historically, the spawning populations existed in additional rivers from which the species has been wholly or nearly extirpated, such as the Mobile and Ochlockonee rivers, and possibly the Rio Grande River. Most Gulf Sturgeon populations were decimated by unrestricted commercial fishing between 1895–1910. Subsequently most populations remained unrecovered or extirpated due to continued harvest until the 1970s–1980s, and the construction of dams blocking access to ancestral upriver spawning grounds. Late 20th Century harvest bans and net bans enacted by the several Gulf Coast states have stabilized several populations and enabled the Suwannee River population to rebound substantially and naturally. Hatchery supplementation has not been necessary in this regard to date. Sturgeon are resilient and adaptable fishes with a geological history of 150 million years. Research undertaken since the 1970s has addressed many aspects of Gulf Sturgeon life history, reproduction, migration, population biology, habitat requirements, and other aspects of species biology. However, many knowledge gaps remain, prominently including the life history of early developmental stages in the first year of life. Natural population recovery is evident for the Suwannee River population, but seems promising as well for at least four other populations. The Pascagoula and Pearl River populations face a challenging

(Acipenser baerii hindgut

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Ebrahim Najdegerami

2017-09-01

Full Text Available Introduction:Poly-β-hydroxybutyrate (PHB is a natural polymer that can be depolymerized by bacterial extracellular enzymes into β-hydroxybutyric acid monomers. Materials and methods: In this study, the effects of PHB and it’s degrading bacteria on the metabolic diversity of anaerobic bacteria in Siberian sturgeon hindgut were investigated in four treatments (Control, 2% PHB, combination of two degrading bacteria, 2% PHB + two bateria for 60 days. The Shanon diversity index, Evenness and Pareto-Lorenz curve was calculated with BiologTM Ecoplates data. Results: The results indicated that using supplemented diets significantly increased Shanon index and evenness then control (P

Gluconeogenesis during starvation and refeeding phase is affected by previous dietary carbohydrates levels and a glucose stimuli during early life in Siberian sturgeon (Acipenser baerii

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Xiaofang Liang

2017-09-01

Full Text Available Gluconeogenesis responses was assessed during a short starvation period and subsequent refeeding in Siberian sturgeon (Acipenser baerii previously fed different dietary carbohydrates levels and experienced to a glucose stimuli during early life. The sturgeon larvae were previously fed either a high glucose diet (G or a low glucose diet (F from the first feeding to yolk absorption (8 to 12 d post-hatching [dph]. Each group of fish was sub-divided into 2 treatments at 13 dph and was fed either a high-carbohydrate diet (H or a low carbohydrate diet (L until 20 wk. In the current study, the fish in 4 groups (GL, FL, GH and FH were experienced to starvation for 21 d following by re-feeding of their corresponding diets for 21 d. Fish were sampled at postprandial 6 and 24 h before starvation (P6h and P24h, starvation 7, 14 and 21 d (S7, S14 and S21 and 1, 7, 14 and 21 d during refeeding (R1, R7, R14 and R21. Plasma samples during refeeding were taken at P6h at each time point. Glycaemia levels, liver and muscle glycogen contents, activities and mRNA levels of hepatic gluconeogenic enzymes were examined. We found that both dietary carbohydrate levels and early glucose stimuli significantly affected the metabolic responses to starvation and refeeding in Siberian sturgeon (P < 0.05. During prolonged starvation, Siberian sturgeon firstly mobilized the liver glycogen and then improved gluconeogenesis when the dietary carbohydrates were abundant, whereas preserved the liver glycogen stores at a stable level and more effectively promoted gluconeogenesis when the dietary carbohydrates are absent to maintain glucose homoeostasis. During refeeding, as most teleostean, Siberian sturgeon failed controlling the activities and mRNA levels of phosphoenolpyruvate carboxykinase cytosolic forms (PEPCK-C, fructose-1,6-bisphosphatase (FBPase, but particularly controlled phosphoenolpyruvate carboxykinase mitochondrial forms (PEPCK-M activities and mRNA expression

Environmental contaminants in shortnose sturgeon from Bears Bluff National Fish Hatchery, Wadmalaw Island, South Carolina

Data.gov (United States)

Department of the Interior — The shortnose sturgeon (Acipenser brevirostrum) is a federally‐listed endangered species. In 2008, eleven shortnose sturgeon, reared at the Bears Bluff National Fish...

The influence of environmental abiotic factors on the qualitative and quantitative structure of ichthyofauna from predeltaic Danube area

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Petronela Georgiana Calin Sandu

2013-05-01

Full Text Available The aim of the paper  is to analyse the influence of environmental factors on the capture and fish communities structure from Danube, between Siret River and Prut River mouth. Fish were collected from April to December 2012 in four fishing areas. During the year, 4910 kg, respectively 7121 fish of 31 species were collected. Cyprinidae, the dominant family, 54.84% in term of number of species, was represented by 17 species (Cyprinus carpio, Carassius gibelio, Barbus barbus, Abramis brama, Abramis sapa, Blicca bjoerkna, Leuciscus idus, Vimba vimba, Aspius aspius, Pelecus cultratus, Chondrostoma nasus, Ctenopharingodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Scardinius erythrophthalmus, Rutilus rutilus, Alburnus alburnus. Other families had the following structure: Percidae (16.13% with 5 species (Sander lucioperca, Zingel zingel, Zingel streber, Perca fluviatilis, Gymnocephalus schraetzer, Acipenseridae (12.90% with 4 species (Huso huso, Acipenser stellatus, Acipenser ruthenus, Acipenser gueldenstaedtii, Clupeidae (6.45% with two species (Alosa immaculata, Alosa tanaica, Siluridae (3.23% with one species (Silurus glanis, Esocidae (3.23% with one species (Esox lucius  and Salmonidae (3.23% with one species also (Salmo labrax. The highest capture was 2977.93 kg (60.65%, during the spring season (April-May, followed by autumn season (September–November, with 992.39 kg (20.21%. The water level and water flow showed high correlation with both number and total catch, respectively.

The genus Hypostomus Lacépède, 1803, and its Surinam representatives (Siluriformes, Loricariidae)

NARCIS (Netherlands)

Boeseman, M.

1968-01-01

CONTENTS Introduction................... 3 The generic name................. 4 The type species of Hypostomus Lacépède.......... 6 The identity of Acipenser plecostomus Linnaeus........ 9 The distribution and habitats of the Surinam species........ 12 The relationship of the Surinam

Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2003-2004 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Rust, Pete; Wakkinen, Virginia (Idaho Department of Fish and Game, Boise, ID)

2005-06-01

The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the various life stages of Kootenai River white sturgeon. Sampling for adult Kootenai River white sturgeon in 2003 began in March and continued through April. Eighty-one adult white sturgeon were captured with 3,576 hours of angling and set-lining effort in the Kootenai River. Discharge from Libby Dam and river stage at Bonners Ferry in 2003 peaked in May and early June. Flows remained above 500 m{sup 3}/s throughout June, decreased rapidly through mid July, and increased back to near 500 m{sup 3}/s after mid July and through mid August. By late August, flows had decreased to below 400 m{sup 3}/s. We monitored the movements of 24 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from March 15, 2003 to August 31, 2003. Some of the fish were radio or sonic tagged in previous years. Twelve adult white sturgeon were moved upstream to the Hemlock Bar reach (rkm 260.0) and released as part of the Set and Jet Program. Transmitters were attached to seven of these fish, and their movements were monitored from the time of release until they moved downstream of Bonners Ferry. Eight additional radio-tagged white sturgeon adults were located in the traditional spawning reach (rkm 228-240) during May and June. Sampling with artificial substrate mats began May 21, 2003 and ended June 30, 2003. We sampled 717 mat d (a mat d is one 24 h set) during white sturgeon spawning. Three white sturgeon eggs were collected near Shortys Island on June 3, 2003, and five eggs were collected from the Hemlock Bar reach on June 5, 2003. Prejuvenile sampling began June 17, 2003 and continued until July 31, 2003. Sampling occurred primarily at Ambush Rock (rkm 244.0) in an attempt to document any recruitment that might have occurred from

Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon

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Weifang Wang

2016-03-01

Full Text Available An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus to elevated dietary selenium (Se based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70, and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet. The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM were raised in indoor tanks provided with flow through freshwater (18–19 °C. There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05. Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks on muscle RNA/DNA ratio (P ≥ 0.05, the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks and higher levels (40.1 and 77.7 mg Se/kg diet of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the

The evolution of Root effect hemoglobins in the absence of intracellular pH protection of the red blood cell: insights from primitive fishes.

Science.gov (United States)

Regan, Matthew D; Brauner, Colin J

2010-06-01

The Root effect, a reduction in blood oxygen (O(2)) carrying capacity at low pH, is used by many fish species to maximize O(2) delivery to the eye and swimbladder. It is believed to have evolved in the basal actinopterygian lineage of fishes, species that lack the intracellular pH (pH(i)) protection mechanism of more derived species' red blood cells (i.e., adrenergically activated Na(+)/H(+) exchangers; betaNHE). These basal actinopterygians may consequently experience a reduction in blood O(2) carrying capacity, and thus O(2) uptake at the gills, during hypoxia- and exercise-induced generalized blood acidoses. We analyzed the hemoglobins (Hbs) of seven species within this group [American paddlefish (Polyodon spathula), white sturgeon (Acipenser transmontanus), spotted gar (Lepisosteus oculatus), alligator gar (Atractosteus spatula), bowfin (Amia calva), mooneye (Hiodon tergisus), and pirarucu (Arapaima gigas)] for their Root effect characteristics so as to test the hypothesis of the Root effect onset pH value being lower than those pH values expected during a generalized acidosis in vivo. Analysis of the haemolysates revealed that, although each of the seven species displayed Root effects (ranging from 7.3 to 40.5% desaturation of Hb with O(2), i.e., Hb O(2) desaturation), the Root effect onset pH values of all species are considerably lower (ranging from pH 5.94 to 7.04) than the maximum blood acidoses that would be expected following hypoxia or exercise (pH(i) 7.15-7.3). Thus, although these primitive fishes possess Hbs with large Root effects and lack any significant red blood cell betaNHE activity, it is unlikely that the possession of a Root effect would impair O(2) uptake at the gills following a generalized acidosis of the blood. As well, it was shown that both maximal Root effect and Root effect onset pH values increased significantly in bowfin over those of the more basal species, toward values of similar magnitude to those of most of the more derived

FORMACION DE UN PLANTEL DE REPRODUCTORES PARA EL DESARROLLO DE LA TECNOLOGIA DE PRODUCCION DE HUEVOS Y JUVENILES DE ESTURION BLANCO (ACIPENSER TRANSMONTANUS) Y DE ESTURION SIBERIANO (ACIPE NSER BAERII) A ESCALA INDUSTRIAL EN CHILE

OpenAIRE

URIBE BARICHIVIC, JUAN CARLOS

2013-01-01

La fuerte demanda internacional por el caviar ha provocado una sobrepesca en las áreas tradicionales de producción de Esturión, haciendo que la viabilidad de estas pesquerías esté en peligro. La sobre explotación, la falta de planes de repoblamiento, la pesca furtiva, la contaminación de los ríos de desove que ha alterado las tasas de reproducción natural, junto a la falta de controles, entre otros factores, han contribuido a una alarmante disminución de los esturiones existentes a nive...

Desk-study on habitat quality for the European Sturgeon in the Dutch Rhine and southern North Sea

NARCIS (Netherlands)

Winter, H.V.; Teal, L.R.; Wolfshaar, van de K.E.; Griffioen, A.B.; Houben, B.; Breve, N.W.P.

2015-01-01

One of the most endangered fish species worldwide is the European sturgeon Acipenser sturio. The River Rhine was home to an important sturgeon population that went locally extinct in the first half of the 20th century. In recent decades, many improvements of the ecological quality of the Rhine have

Molecular Cytogenetics in Artificial Hybrid and Highly Polyploid Sturgeons: An Evolutionary Story Narrated by Repetitive Sequences

Czech Academy of Sciences Publication Activity Database

Symonová, Radka; Flajšhans, M.; Sember, Alexandr; Havelka, M.; Gela, D.; Kořínková, Tereza; Rodina, M.; Rábová, Marie; Ráb, Petr

2013-01-01

Roč. 141, 2-3 (2013), s. 153-162 ISSN 1424-8581 R&D Projects: GA ČR GA523/08/0824; GA ČR(CZ) GPP506/11/P596 Institutional support: RVO:67985904 Keywords : Acipenser * GISH * Hybridization * Macrochromosomes Subject RIV: EG - Zoology Impact factor: 1.905, year: 2013

Hydrology and water resources in Caspian Sea

Science.gov (United States)

Haddadi Moghaddam, Kourosh

2016-10-01

Precipitation is the main driver of the water balance variability of the water over space and time, and changes in precipitation have very important implications for hydrology and water resources. Variations in precipitation over daily, seasonal, annual, and decadal time scales influence hydrological variability over time in a catchment. Flood frequency is affected by changes in the year-to-year variability in precipitation and by changes in short-term rainfall properties. Desiccation of the Caspian Sea is one of the world's most serious ecosystem catastrophes. The Persian Sturgeon (Acipenser persicus) caught under 10 m depth using bottom trawl net by research vessel during winter 2012, summer and winter 2013 and spring 2014 in east, central and west of southern parts of Caspian Sea, then, their diets were investigated. During 136 trawling in the aimed seasons, Persian sturgeon with 1 to 2 years old and 179.67 × 0.2 g (body weight) and 29.97 ± 0.4 cm (Total length) captured. Examination of stomach contents in the sturgeon specimens revealed that the food spectrum was composed of bony fishes (Neogobius sp., Atherina sp. and Clupeonella delicatula), invertebrates belonging to the family Ampharetidae polychaeta worms including (Hypanai sp. and Nereis diversicolor), various crustaceans (Gammarus sp. and Paramysis sp.). Investigation on stomach contents of sturgeon Acipenser persicus caught under 10 m depth in 2012 to 2013 surveys showed that there is significant difference in the consumed food. The most food diversity have been observed in winter 2013, also Polychaeta is the primary consumed food and crustacean is the secondary one (P > 0.05), no new types of food (such as bony fishes or benthics) have been observed on food chain of Acipenser persicus and shows no significant difference (P > 0.05).

Bathymetric and sediment facies maps for China Bend and Marcus Flats, Franklin D. Roosevelt Lake, Washington, 2008 and 2009

Science.gov (United States)

Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.; Barton, Gary J.

2011-01-01

The U.S. Geological Survey (USGS) created bathymetric and sediment facies maps for portions of two reaches of Lake Roosevelt in support of an interdisciplinary study of white sturgeon (Acipenser transmontanus) and their habitat areas within Franklin D. Roosevelt Lake, Washington. In October 2008, scientists from the USGS used a boat-mounted multibeam echo sounder (MBES) to describe bathymetric data to characterize surface relief at China Bend and Marcus Flats, between Northport and Kettle Falls, Washington. In March 2009, an underwater video camera was used to view and record sediment facies that were then characterized by sediment type, grain size, and areas of sand deposition. Smelter slag has been identified as having the characteristics of sand-sized black particles; the two non-invasive surveys attempted to identify areas containing black-colored particulate matter that may be elements and minerals, organic material, or slag. The white sturgeon population in Lake Roosevelt is threatened by the failure of natural recruitment, resulting in a native population that consists primarily of aging fish and that is gradually declining as fish die and are not replaced by nonhatchery reared juvenile fish. These fish spawn and rear in the riverine and upper reservoir reaches where smelter slag is present in the sediment of the river lake bed. Effects of slag on the white sturgeon population in Lake Roosevelt are largely unknown. Two recent studies demonstrated that copper and other metals are mobilized from slag in aqueous environments with concentrations of copper and zinc in bed sediments reaching levels of 10,000 and 30,000 mg/kg due to the presence of smelter slag. Copper was found to be highly toxic to 30-day-old white sturgeon with 96-h LC50 concentrations ranging from 3 to 5 (u or mu)g copper per liter. Older juvenile and adult sturgeons commonly ingest substantial amounts of sediment while foraging. Future study efforts in Lake Roosevelt should include sampling of

Indidivual differences in the behaviour of fishes

OpenAIRE

Budaev, Dr. Sergey

2000-01-01

This is the official printed Russian summary of PhD Thesis, describing a series of studies of the phenotypic organization and ecological significance of individual differences in fish behavior. The following species were studied: guppy Poecilia retuculata, lion-headed cichlid Steatocranus cassuarius, convict cichlid Archocentrus nigrofasciatum, wrasses Symphodus ocellatus, S. tinca, and two species of sturgeons Acipenser stellatus and A. gueldenstaedti. In this Thesis, I developed methods for...

Lake Roosevelt White Sturgeon Recovery Project : Annual Progress Report, January 2003 – March 2004.

Energy Technology Data Exchange (ETDEWEB)

Howell, Matthew D.; McLellan, Jason G. [Washington Department of Fish and Wildlife

2009-07-15

This report summarizes catch data collected from white sturgeon Acipenser transmontanus in Lake Roosevelt during limited setlining and gill netting activities in the fall of 2003, and documents progress toward development of a U.S. white sturgeon conservation aquaculture program for Lake Roosevelt. From 27-30 October, 42 overnight small mesh gill net sets were made between Marcus and Northport, WA for a total catch of 15 juvenile white sturgeon (275-488 mm FL). All sturgeon captured were of Canadian hatchery origin. These fish had been previously released as sub-yearlings into the Canadian portion (Keenleyside Reach) of the Transboundary Reach of the Columbia River during 2002 and 2003. Most sturgeon (n=14) were caught in the most upstream area sampled (Northport) in low velocity eddy areas. Five fish exhibited pectoral fin deformities (curled or stunted). Growth rates were less than for juvenile sturgeon captured in the Keenleyside Reach but condition factor was similar. Condition factor was also similar to that observed in juvenile sturgeon (ages 1-8) captured in the unimpounded Columbia River below Bonneville Dam between 1987-92. From 10-14 November, 28 overnight setline sets were made in the Roosevelt Reach between the confluence of the Spokane River and Marcus Island for a total catch of 17 white sturgeon (94-213 cm FL). Catch was greatest in the most upstream areas sampled, a distribution similar to that observed during a WDFW setline survey in Lake Roosevelt in 1998. The mean W{sub r} index of 110% for fish captured this year was higher than the mean W{sub r} of 91% for fish captured in 1998. Excellent fish condition hindered surgical examination of gonads as lipid deposits made the ventral body wall very thick and difficult to penetrate with available otoscope specula. Acoustic tags (Vemco model V16 coded pingers, 69 kHz, 48-month life expectancy) were internally applied to 15 fish for subsequent telemetry investigations of seasonal and reproductively

Evaluate Potenial Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2002 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Everett, Scott R.; Tuell, Michael A.; Hesse, Jay A. (Nez Perce Tribe, Department of Fisheries Management, Lapwai, ID)

2004-02-01

The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This report presents a summary of results from the 1997-2002 Phase II data collection and represents the end of phase II. From 1997 to 2001 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon. A total of 1,785 white sturgeon were captured and tagged in the Snake River and 77 in the Salmon River. Since 1997, 25.8 percent of the tagged white sturgeon have been recaptured. Relative density of white sturgeon was highest in the free-flowing segment of the Snake River, with reduced densities of fish in Lower Granite Reservoir, and low densities the Salmon River. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir, the free-flowing Snake River and the Salmon River (Chi-Square test, P<0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River has shown an increase of 30 percent since the 1970's. Using the Jolly-Seber model, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,483 fish, with a 95% confidence interval of 1,208-7,477. Total annual mortality rate was estimated to be 0.14 (95% confidence interval of 0.12 to 0.17). A total of 35 white sturgeon were fitted with radio-tags during 1999-2002. The movement of these fish ranged from 53 km (33 miles) downstream to 77 km (48 miles) upstream; however, 38.8 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No

Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 1999 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Tuell, Michael A.; Everett, Scott R. (Nez Perce Tribe, Department of Fisheries Resource Management, Lapwai, ID)

2003-03-01

The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 1999 annual report covers the third year of sampling of this multi-year study. In 1999 white sturgeon were captured, marked and population data were collected in the Snake and Salmon rivers. A total of 33,943 hours of setline effort and 2,112 hours of hook-and-line effort was employed in 1999. A total of 289 white sturgeon were captured and tagged in the Snake River and 29 in the Salmon River. Since 1997, 11.1 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 27 cm to 261 cm and averaged 110 cm. In the Salmon River, white sturgeon ranged in total length from 98 cm to 244 cm and averaged 183.5 cm. Using the Jolly-Seber model, the abundance of white sturgeon < 60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 1,823 fish, with a 95% confidence interval of 1,052-4,221. A total of 15 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 6.4 km (4 miles) downstream to 13.7 km (8.5 miles) upstream; however, 83.6 percent of the detected movement was less than 0.8 kilometers (0.5 miles). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of white sturgeon in Lower Granite Reservoir and the free-flowing Snake River (Chi-Square test, P < 0.05). The proportion of white sturgeon greater than 92 cm (total length) in the free-flowing Snake River

EDITORIAL: Nano-enhanced! Nano-enhanced!

Science.gov (United States)

Demming, Anna

2010-08-01

In the early 19th century, a series of engineering and scientific breakthroughs by Nicolas Léonard Sadi Carnot, James Watt and many others led to the foundations of thermodynamics and a new pedigree of mechanical designs that reset the standards of engineering efficiency. The result was the industrial revolution. In optical- and electronics- based nanotechnology research, a similarly subtle bargain is being made; we cannot alter the fact that systems have a finite response to external excitations, but what we can do is enhance that response. The promising attributes of ZnO have long been recognised; its large band gap and high exciton binding energy lend it to a number of applications from laser diodes, LEDs, optical waveguides and switches, and acousto-optic applications to sun cream. When this material is grown into nanowires and nanorods, the material gains a whole new dimension, as quantum confinement effects come into play. Discovery of the enhanced radiative recombination, which has potential for exploitation in many optical and opto-electronic applications, drove intensive research into investigating these structures and into finding methods to synthesise them with optimised properties. This research revealed further subtleties in the properties of these materials. One example is the work by researchers in the US reporting synthesis procedures that produced a yield—defined as the weight ratio of ZnO nanowires to the original graphite flakes—of 200%, and which also demonstrated, through photoluminescence analysis of nanowires grown on graphite flakes and substrates, that graphite induces oxygen vacancies during annealing, which enhances the deep-level to near-band-edge emission ratio [1]. Other one-dimensional materials that provide field emission enhancements include carbon nanotubes, and work has been performed to find ways of optimising the emission efficiency from these structures, such as through control of the emitter density [2]. One of the

Draft Environmental Assessment for the Combat Support Training Complex, Tyndall Air Force Base, Florida.

Science.gov (United States)

1989-07-25

nwdas Green Seaturtle PK E E 1,19 FISH Acipenser oxyrhynchus &esotoi Gulf Sturgeon SR SSC UR2 17,19 Mustela vison lutensis Florida Mink P - UR2 13...immediately dangerous to life and health (IDLH) with respect to respiratory irritation. This represents the maximum concentration from which one could...Threshold 0.004 mg/m3 ACGIH’ Median effective concentration 1-5 mg/m3 ACGIH Respiratory irritation Permissible exposure limit (PEL) 0.4 mg/m3

Gd-enhanced MR imaging of the herniated lumbar disc: patterns of enhancement

International Nuclear Information System (INIS)

Kwag, Hyon Joo; Choi, Hye Young; Kim, Hyae Young; Kim, Yoo Kyung; Kim, Ah Young; Chung, Eun Chul

1995-01-01

The purpose of this study is to describe the patterns of enhancement of the herniated lumbar disc with Gd-DTPA enhanced MR imaging. Out of 65 patients, 103 lumbar discs diagnosed to be herniated by MR image were retrospectively analyzed. The MR imaging was performed with 1.5 T MR unit, using T1-and T2-weighted sagittal and axial spin echo techniques. Contrast-enhanced T1 weighted sagittal and axial images were performed after intravenous injection of Gadopentetate-dimeglumine(Magnevist, Shering) (0.1 mmol/kg). Contrast enhancement was seen in 66 cases(64%). Thirteen cases of bulging disc were not enhanced. Twenty-eight cases of protruded disc showed intraannular enchantment in 23 cases, peripheral linear and irregular enhancement in each of one case, and nonenhancement in three cases. Fifty-seven cases of extruded disc showed irregular enhancement in 14 cases, peripheral linear enhancement in 12 cases, peripheral ring enhancement in five cases and intraannular enhancement in five cases. All five cases of sequestered disc showed peripheral ring enhancement. Protruded discs show intraannular enhancement frequently and sequestered discs usually show peripheral ring enhancement. Enhanced MR imaging may be helpful to evaluate the type of herniated lumbar disc and relationship among disc material, nerve root and thecal sac

Tip enhancement

CERN Document Server

Kawata, Satoshi

2007-01-01

This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field.·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection

Morphology, chemical contents and physiology of chondrostean fish sperm: a comparative study between Siberian sturgeon (Acipenser baerii) and sterlet (Acipenser ruthenus)

Czech Academy of Sciences Publication Activity Database

Pšenička, M.; Hadi Alavi, S.M.; Číčová, Zdeňka; Gela, D.; Cosson, J.; Nebesářová, Jana; Linhart, O.

2008-01-01

Roč. 24, č. 4 (2008), s. 371-377 ISSN 0175-8659 Grant - others:GA ČR(CZ) GA524/06/0817 Program:GA Institutional research plan: CEZ:AV0Z60220518 Keywords : NORTH-AMERICAN STURGEONS * TRANSMISSION ELECTRON-MICROSCOPY * CELL ULTRASTRUCTURE * SHOVELNOSE STURGEON * LAKE STURGEON * MOTILITY * SPERMATOZOA * PADDLEFISH * SALMON * OSMOLALITY Subject RIV: EC - Immunology Impact factor: 0.638, year: 2008

COMPARISON OF IMAGE ENHANCEMENT METHODS FOR CHROMOSOME KARYOTYPE IMAGE ENHANCEMENT

Directory of Open Access Journals (Sweden)

Dewa Made Sri Arsa

2017-02-01

Full Text Available The chromosome is a set of DNA structure that carry information about our life. The information can be obtained through Karyotyping. The process requires a clear image so the chromosome can be evaluate well. Preprocessing have to be done on chromosome images that is image enhancement. The process starts with image background removing. The image will be cleaned background color. The next step is image enhancement. This paper compares several methods for image enhancement. We evaluate some method in image enhancement like Histogram Equalization (HE, Contrast-limiting Adaptive Histogram Equalization (CLAHE, Histogram Equalization with 3D Block Matching (HE+BM3D, and basic image enhancement, unsharp masking. We examine and discuss the best method for enhancing chromosome image. Therefore, to evaluate the methods, the original image was manipulated by the addition of some noise and blur. Peak Signal-to-noise Ratio (PSNR and Structural Similarity Index (SSIM are used to examine method performance. The output of enhancement method will be compared with result of Professional software for karyotyping analysis named Ikaros MetasystemT M . Based on experimental results, HE+BM3D method gets a stable result on both scenario noised and blur image.

Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging

International Nuclear Information System (INIS)

Fujii, Shinya; Kido, Aki; Baba, Tsukasa; Fujimoto, Koji; Daido, Sayaka; Matsumura, Noriomi; Konishi, Ikuo; Togashi, Kaori

2015-01-01

Highlights: •We have assessed the peritumoral enhancement (PTE), which mimics SEE on DCE. •We evaluated the diagnostic accuracy of SEE for the myometrial invasion and the frequency of PTE. •We assessed the relationship between these enhancements and important pathologic factors. •PTE Type 1 is the main factor causing the overestimation of myometrial invasion using SEE on DCE. •PTE Type 2 correlates the myometrial invasion and may play an important role in the diagnosis of LVSI. -- Abstract: Objectives: To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. Materials and methods: MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. Results: The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1–46.4%, 85.8–88.5%, 69.2–76.5%, and 84.4–87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p < 0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p < 0.05) and depth (p < 0.01). Conclusion: Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the

Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging

Energy Technology Data Exchange (ETDEWEB)

Fujii, Shinya [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, Yonago (Japan); Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Kido, Aki, E-mail: akikido@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Baba, Tsukasa [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Fujimoto, Koji; Daido, Sayaka [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Matsumura, Noriomi; Konishi, Ikuo [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

2015-04-15

Highlights: •We have assessed the peritumoral enhancement (PTE), which mimics SEE on DCE. •We evaluated the diagnostic accuracy of SEE for the myometrial invasion and the frequency of PTE. •We assessed the relationship between these enhancements and important pathologic factors. •PTE Type 1 is the main factor causing the overestimation of myometrial invasion using SEE on DCE. •PTE Type 2 correlates the myometrial invasion and may play an important role in the diagnosis of LVSI. -- Abstract: Objectives: To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. Materials and methods: MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. Results: The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1–46.4%, 85.8–88.5%, 69.2–76.5%, and 84.4–87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p < 0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p < 0.05) and depth (p < 0.01). Conclusion: Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the

Pancultural self-enhancement.

Science.gov (United States)

Sedikides, Constantine; Gaertner, Lowell; Toguchi, Yoshiyasu

2003-01-01

The culture movement challenged the universality of the self-enhancement motive by proposing that the motive is pervasive in individualistic cultures (the West) but absent in collectivistic cultures (the East). The present research posited that Westerners and Easterners use different tactics to achieve the same goal: positive self-regard. Study 1 tested participants from differing cultural backgrounds (the United States vs. Japan), and Study 2 tested participants of differing self-construals (independent vs. interdependent). Americans and independents self-enhanced on individualistic attributes, whereas Japanese and interdependents self-enhanced on collectivistic attributes. Independents regarded individualistic attributes, whereas interdependents regarded collectivistic attributes, as personally important. Attribute importance mediated self-enhancement. Regardless of cultural background or self-construal, people self-enhance on personally important dimensions. Self-enhancement is a universal human motive.

Pracovní plodnost mlíčáků jesetera malého v provozních podmínkách českých chovů

OpenAIRE

SCHACHERLOVÁ, Jiřina

2015-01-01

Currently, fish fertility studies are mainly focused on female fertility. Studies showing fertility of male fish of any kind are missing to a large extent. The main objective of my thesis was to identify what level of fertility is achieved by male sterlet (Acipenser ruthenus) in the conditions of fish farming in the Czech Republic. Male fish from the Vodňany farm where the raised population comes from Russia was compared to male fish from Pohořelice where the raised population comes from Danu...

Enhanced MRI in patients with facial palsy; Study of time-related enhancement

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Masahiro; Kato, Tsutomu; Ushiro, Koichi; Kitajiri, Masanori; Yamashita, Toshio; Kumazawa, Tadami; Tanaka, Yoshimasa (Kansai Medical School, Moriguchi, Osaka (Japan))

1991-03-01

We performed Gd-DTPA-enhanced magnetic resonance imaging (MRI) examinations at several stages in 40 patients with peripheral facial nerve palsy (Bell's palsy and Ramsay-Hunt syndrome). In 38 of the 40 patients, one and more enhanced region could be seen in certain portion of the facial nerve in the temporal bone on the affected side, whereas no enhanced regions were seen on the intact side. Correlations between the timing of the MRI examination and the location of the enhanced regions were analysed. In all 6 patients examined by MRI within 5 days after the onset of facial nerve palsy, enhanced regions were present in the meatal portion. In 3 of the 8 patients (38%) examined by MRI 6 to 10 days after the onset of facial palsy, enhanced areas were seen in both the meatal and labyrinthine portions. In 8 of the 9 patients (89%) tested 11 to 20 days after the onset of palsy, the vertical portion was enhanced. In the 12 patients examined by MRI 21 to 40 days after the onset of facial nerve palsy, the meatal portion was not enhanced while the labyrinthine portion, the horizontal portion and the vertical portion were enhanced in 5 (42%), 8 (67%) and 11 (92%), respectively. Enhancement in the vertical portion was observed in all 5 patients examined more than 41 days after the onset of facial palsy. These results suggest that the central portion of the facial nerve in the temporal bone tends to be enhanced in the early stage of facial nerve palsy, while the peripheral portion is enhanced in the late stage. These changes of Gd-DTPA enhanced regions in the facial nerve may suggest dromic degeneration of the facial nerve in peripheral facial nerve palsy. (author).

Evaluate Potential Means of Rebuilding Sturgeon Populations in the Snake River between Lower Granite and Hells Canyon Dams, 2000 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Everett, Scott R.; Tuell, Michael A. (Nez Perce Tribe, Department of Fishereis Resource Management, Lapwai, ID)

2003-03-01

The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This 2000 annual report covers the fourth year of sampling of this multi-year study. In 2000 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon rivers. The Snake River was sampled between Lower Granite Dam (rkm 174) and the mouth of the Salmon River (rkm 303), and the Salmon River was sampled from its mouth upstream to Hammer Creek (rkm 84). A total of 53,277 hours of setline effort and 630 hours of hook-and-line effort was employed in 2000. A total of 538 white sturgeon were captured and tagged in the Snake River and 25 in the Salmon River. Since 1997, 32.8 percent of the tagged white sturgeon have been recaptured. In the Snake River, white sturgeon ranged in total length from 48 cm to 271 cm and averaged 107 cm. In the Salmon River, white sturgeon ranged in total length from 103 cm to 227 cm and averaged 163 cm. Using the Jolly-Seber open population estimator, the abundance of white sturgeon <60 cm, between Lower Granite Dam and the mouth of the Salmon River, was estimated at 2,725 fish, with a 95% confidence interval of 1,668-5,783. A total of 10 white sturgeon were fitted with radio-tags. The movement of these fish ranged from 54.7 km (34 miles) downstream to 78.8 km (49 miles) upstream; however, 43.6 percent of the detected movement was less than 0.8 km (0.5 mile). Both radio-tagged fish and recaptured white sturgeon in Lower Granite Reservoir appear to move more than fish in the free-flowing segment of the Snake River. No seasonal movement pattern was detected, and no movement pattern was detected for different size fish. Differences were detected in the length frequency distributions of

Excitation enhancement and extraction enhancement with photonic crystals

Science.gov (United States)

Shapira, Ofer; Soljacic, Marin; Zhen, Bo; Chua, Song-Liang; Lee, Jeongwon; Joannopoulos, John

2015-03-03

Disclosed herein is a system for stimulating emission from at least one an emitter, such as a quantum dot or organic molecule, on the surface of a photonic crystal comprising a patterned dielectric substrate. Embodiments of this system include a laser or other source that illuminates the emitter and the photonic crystal, which is characterized by an energy band structure exhibiting a Fano resonance, from a first angle so as to stimulate the emission from the emitter at a second angle. The coupling between the photonic crystal and the emitter may result in spectral and angular enhancement of the emission through excitation and extraction enhancement. These enhancement mechanisms also reduce the emitter's lasing threshold. For instance, these enhancement mechanisms enable lasing of a 100 nm thick layer of diluted organic molecules solution with reduced threshold intensity. This reduction in lasing threshold enables more efficient organic light emitting devices and more sensitive molecular sensing.

Detectability of hepatocellular carcinoma: comparison of Gd-DTPA-enhanced and SPIO-enhanced MR imaging

International Nuclear Information System (INIS)

Kwak, Hyo Sung; Lee, Jeong Min; Kim In Hwan; Kim, Chong Soo; Han, Hyeun Young; Yoon, Kwon ha; Shin, Kyung Sook

2000-01-01

To compare the detectability of hepatocellular carcinoma (HCC) using superparamagnetic iron oxide (SPIO)-enhanced T2-weighted turbo spin echo (TSE), SPIO-enhanced T2-weighted FISP, and dynamic Gd-DTPA-enhanced fast low-angle shot (FLASH) MR images. In order to assess their hepatic lesions, 25 patients (20 men and 5 women) with HCC were enrolled in an MR study in which both gadolinium and Spiro were used. Since the lesions were most conspicuous during the phase of dynamic arterial dominant phase of dynamic gadolinium-enhanced imaging, this was the phase used for analysis. Images were analyzed qualitatively and quantitatively, and to compare the diagnostic value of gadolinium-enhanced imaging with that of SPIO-enhanced imaging for the detection of HCCs, a receiver-operated characteristic curve was obtained. Qualitative analysis revealed a significantly higher percentage of signal loss and a higher liver-lesion contrast-to-noise ratio on SPIO-enhanced FISP imaging than on SPIO-enhanced T2-weighted TSE imaging (p less than 0.05). It also showed that the lesions were most clearly visible on SPIO-enhanced FISP imaging (and significantly so), followed by SPIO-enhanced T2-weighted TSE imaging, and dynamic gadolinium-enhanced imaging. Imaging artifacts were more prominent on SPIO-enhanced T2-weighted TSE than on SPIO-enhanced PISF imaging or dynamic gadolinium-enhanced imaging (p less than 0.05). According to ROC analysis, SPIO-enhanced T2-weighted turbo spin echo (TSE) or SPIO-enhanced FISP imaging achieved higher accuracy than did dynamic gadolinium-enhanced FLASH imaging (p less than 0.05). For the detection of hepatocellular carcinomas, SPIO-enhanced MR imaging is better than gadolinium-enhanced FLASH imaging

Quantitative analysis of enhanced malignant and benign lesions on contrast-enhanced spectral mammography.

Science.gov (United States)

Deng, Chih-Ying; Juan, Yu-Hsiang; Cheung, Yun-Chung; Lin, Yu-Ching; Lo, Yung-Feng; Lin, GiGin; Chen, Shin-Cheh; Ng, Shu-Hang

2018-02-27

To retrospectively analyze the quantitative measurement and kinetic enhancement among pathologically proven benign and malignant lesions using contrast-enhanced spectral mammography (CESM). We investigated the differences in enhancement between 44 benign and 108 malignant breast lesions in CESM, quantifying the extent of enhancements and the relative enhancements between early (between 2-3 min after contrast medium injection) and late (3-6 min) phases. The enhancement was statistically stronger in malignancies compared to benign lesions, with good performance by the receiver operating characteristic curve [0.877, 95% confidence interval (0.813-0.941)]. Using optimal cut-off value at 220.94 according to Youden index, the sensitivity was 75.9%, specificity 88.6%, positive likelihood ratio 6.681, negative likelihood ratio 0.272 and accuracy 82.3%. The relative enhancement patterns of benign and malignant lesions, showing 29.92 vs 73.08% in the elevated pattern, 7.14 vs 92.86% in the steady pattern, 5.71 vs 94.29% in the depressed pattern, and 80.00 vs 20.00% in non-enhanced lesions (p < 0.0001), respectively. Despite variations in the degree of tumour angiogenesis, quantitative analysis of the breast lesions on CESM documented the malignancies had distinctive stronger enhancement and depressed relative enhancement patterns than benign lesions. Advances in knowledge: To our knowledge, this is the first study evaluating the feasibility of quantifying lesion enhancement on CESM. The quantities of enhancement were informative for assessing breast lesions in which the malignancies had stronger enhancement and more relative depressed enhancement than the benign lesions.

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Xu Huixiong; Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu; Lu Mingde

2010-01-01

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

Energy Technology Data Exchange (ETDEWEB)

Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

2010-08-15

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

Energy Technology Data Exchange (ETDEWEB)

Kim, Bohyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Ajou University School of Medicine, Department of Radiology, Suwon (Korea, Republic of); Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

2016-01-15

To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI

International Nuclear Information System (INIS)

Kim, Bohyun; Byun, Jae Ho; Kim, Hyoung Jung; Won, Hyung Jin; Kim, So Yeon; Shin, Yong Moon; Kim, Pyo Nyun

2016-01-01

To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL). On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP. Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP. Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups. (orig.)

EDITORIAL: Enhancing nanolithography Enhancing nanolithography

Science.gov (United States)

Demming, Anna

2012-01-01

Lithography was invented in late 18th century Bavaria by an ambitious young playwright named Alois Senefelder. Senefelder experimented with stone, wax, water and ink in the hope of finding a way of reproducing text so that he might financially gain from a wider distribution of his already successful scripts. His discovery not only facilitated the profitability of his plays, but also provided the world with an affordable printing press that would ultimately democratize the dissemination of art, knowledge and literature. Since Senefelder, experiments in lithography have continued with a range of innovations including the use of electron beams and UV that allow increasingly higher-resolution features [1, 2]. Applications for this have now breached the limits of paper printing into the realms of semiconductor and microelectronic mechanical systems technology. In this issue, researchers demonstrate a technique for fabricating periodic features in poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) [3]. Their method combines field enhancements from silica nanospheres with laser-interference lithography to provide a means of patterning a polymer that has the potential to open the market of low-end, high-volume microelectronics. Laser-interference lithography has already been used successfully in patterning. Researchers in Korea used laser-interference lithography to generate stamps for imprinting a two-dimensional photonic crystal structure into green light emitting diodes (LEDs) [4]. The imprinted patterns comprised depressions 100 nm deep and 180 nm wide with a periodicity of 295 nm. In comparison with unpatterned LEDs, the intensity of photoluminescence was enhanced by a factor of seven in the LEDs that had the photonic crystal structures imprinted in them. The potential of exploiting field enhancements around nanostructures for new technologies has also attracted a great deal of attention. Researchers in the USA and Australia have used the field

A saturation hypothesis to explain both enhanced and impaired learning with enhanced plasticity

Science.gov (United States)

Nguyen-Vu, TD Barbara; Zhao, Grace Q; Lahiri, Subhaneil; Kimpo, Rhea R; Lee, Hanmi; Ganguli, Surya; Shatz, Carla J; Raymond, Jennifer L

2017-01-01

Across many studies, animals with enhanced synaptic plasticity exhibit either enhanced or impaired learning, raising a conceptual puzzle: how enhanced plasticity can yield opposite learning outcomes? Here, we show that the recent history of experience can determine whether mice with enhanced plasticity exhibit enhanced or impaired learning in response to the same training. Mice with enhanced cerebellar LTD, due to double knockout (DKO) of MHCI H2-Kb/H2-Db (KbDb−/−), exhibited oculomotor learning deficits. However, the same mice exhibited enhanced learning after appropriate pre-training. Theoretical analysis revealed that synapses with history-dependent learning rules could recapitulate the data, and suggested that saturation may be a key factor limiting the ability of enhanced plasticity to enhance learning. Optogenetic stimulation designed to saturate LTD produced the same impairment in WT as observed in DKO mice. Overall, our results suggest that the recent history of activity and the threshold for synaptic plasticity conspire to effect divergent learning outcomes. DOI: http://dx.doi.org/10.7554/eLife.20147.001 PMID:28234229

Usefulness of percentage enhancement washout value calculated on unenhanced, contrast-enhanced, and delayed enhanced CT in adrenal masses: adenoma versus metastasis

International Nuclear Information System (INIS)

Sohn, Kyung Myung; Lee, Sung Yong; Lee, Keun Ho

2003-01-01

To determine the usefulness of percentage enhancement washout value calculated on unenhanced, enhanced and delayed enhanced CT scans for the characterization of adrenal masses. Forty adrenal masses less than 5 cm in size were assessed using a protocol consisting of unenhanced CT, enhanced CT 60 seconds after intravenous administration of contrast material, and delayed enhanced CT at 10 minutes. The CT attenuation value of adrenal tumors was estimated on each scan, and percentage enhancement washout value was calculated as follows:[(attenuation value at enhanced CT-attenuation value at delayed CT)/ (attenuation value at enhanced CT-attenuation value at unenhanced CT)x100]. An adrenal mass was considered benign if its percentage enhancement washout value was at the threshold value, set to 60% and 50%, or higher. The accuracy of the procedure was determined by comparing its findings with the final clinical diagnosis. Twenty-nine massess were benign and 11 were malignant. The mean percentage enhancement washout value of the former was significantly higher than that of the latter (66.7% vs. 21.8%; p<0.01). All adenomas except one had a washout value of more than 50%. With a percentage washout threshold of 60%, 35 of 40 lesions were correctly characterized as benign or malignant [sensitivity 82.7% (24/29), specificity 100% (11/11), accuracy 87.5% (35/40)]; with a threshold of 50%, 39 of 40 lesions were correctly characterized [(sensitivity 96.5% (28/29), specificity 100% (11/11), accuracy 97.5% (39/40)]. Percentage enhancement washout values are useful for characterizing an adrenal mass as benign or malignant. For characterization, a threshold value of 50% was more accurate than one of 60%

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.; Theodorou, I. G.; Centeno, A.; Petrov, P. K.; Alford, N. M.; Ryan, M. P.; Xie, F.

2016-01-01

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.

2016-12-28

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Comparative enhancing effects of electret with chemical enhancers on transdermal delivery of meloxicam in vitro

International Nuclear Information System (INIS)

Cui, L L; Hou, X M; Li, G D; Jiang, J; Liang, Y Y; Xin, X

2008-01-01

Electret offers enhancing effect in transdermal drug delivery for altering of the arrangement of lipid molecules in the stratum corneum, forming many transient permeable apertures and enhancing the transdermal drug delivery. In this paper, meloxicam patch formulations were developed to make the comparative study of transdermal drug delivery between electret and chemical enhancers. Patches were made into control, electret, chemical enhancer and electret with chemical enhancer ones, according to the preparation procedure. The electret combined with chemical enhancer patch was designed to probe the incorporation between electret and chemical enhancer in transdermal drug delivery. The meloxicam release from the patch was found to increase in order of blank, chemical enhancer, electret and electret with chemical enhancer patch, in general.

A Monte Carlo Study of dose enhancement according to the enhancement agents

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Hoon; Kim, Chang Soo [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of); Hwang, Chul Hwan [Dept. of Radiation Oncology, Pusan National University Hospital, Busan (Korea, Republic of)

2017-03-15

Dose enhancement effects at megavoltage (MV) X and γ-ray energies, and the effects of different energy levels on incident energy, dose enhancement agents, and concentrations were analyzed using Monte Carlo simulations. Gold, gadolinium, Iodine, and iron oxide (Fe2O3) were compared as dose enhancement agents. For incident energy, 4, 6, 10 and 15 MV X-ray spectra produced by a linear accelerator and a Co60 γ-ray were used. The dose enhancement factor (DEF) was calculated using an ICRU Slab phantom for concentrations of 7, 18, and 30 mg/g. The DEF was higher at higher concentrations of dose enhancement agents and at lower incident energies. The calculated DEF ranged from 1.035 to 1.079, and dose enhancement effects were highest for iron oxide, followed by iodine, gadolinium, and gold. Thus, this study contributes to improving the therapeutic ratio by delivering larger doses of radiation to tumor volume, and provides data to support further in vivo and in vitro studies.

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

International Nuclear Information System (INIS)

Hosoya, T.; Adachi, M.; Sugai, Y.; Yamaguchi, K.; Yamaguchi, K.; Kato, T.

2001-01-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

Energy Technology Data Exchange (ETDEWEB)

Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

2001-04-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Kawai, Yuichi; Suzuki, Kojiro; Itoh, Shigeki; Takada, Akira; Mori, Yoshine; Naganawa, Shinji

2012-01-01

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the “enhanced duct sign”, for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kawai, Yuichi, E-mail: kawai.yuichi@a.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Itoh, Shigeki, E-mail: shigeito@nagoya-1st.jrc.or.jp [Department of Diagnostic Radiology, Japan Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya 453-8511 (Japan); Takada, Akira, E-mail: takadaa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Mori, Yoshine, E-mail: yoshine@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Naganawa, Shinji, E-mail: naganawa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

2012-11-15

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the 'enhanced duct sign', for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Metal-enhanced fluorescence exciplex emission.

Science.gov (United States)

Zhang, Yongxia; Mali, Buddha L; Geddes, Chris D

2012-01-01

In this letter, we report the first observation of metal-enhanced exciplex fluorescence, observed from anthracene in the presence of diethylaniline. Anthracene in the presence of diethylaniline in close proximity to Silver Island Films (SIFs) shows enhanced monomer and exciplex emission as compared to a non-silvered control sample containing no silver nanoparticles. Our findings suggest two complementary methods for the enhancement: (i) surface plasmons can radiate coupled monomer and exciplex fluorescence efficiently, and (ii) enhanced absorption (enhanced electric near-field) further facilitates enhanced emission. Our exciplex studies help us to further understand the complex photophysics of the metal-enhanced fluorescence technology. Copyright © 2011 Elsevier B.V. All rights reserved.

Gd-EOB-DTPA enhanced MRI of the liver: Correlation of relative hepatic enhancement, relative renal enhancement, and liver to kidneys enhancement ratio with serum hepatic enzyme levels and eGFR

Energy Technology Data Exchange (ETDEWEB)

Talakic, Emina; Steiner, Jürgen; Kalmar, Peter; Lutfi, Andre [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Quehenberger, Franz [Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Auenbruggerplatz 2, 8036 Graz (Austria); Reiter, Ursula; Fuchsjäger, Michael [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Schöllnast, Helmut, E-mail: helmut.schoellnast@medunigraz.at [Division of General Radiology, Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz (Austria)

2014-04-15

Objectives: To assess the correlation of relative hepatic enhancement (RHE), relative renal enhancement (RRE) and liver to kidneys enhancement ratio (LKR) with serum hepatic enzyme levels and eGFR in Gd-EOB-DTPA enhanced MRI of the liver and to assess threshold levels for predicting enhancement of the liver parenchyma. Methods: Data of 75 patients who underwent Gd-EOB-DTPA enhanced MRI of the liver were collected. Images were obtained before contrast injection, during the early arterial phase, late arterial phase, venous phase, delayed phase, and hepatobiliary phase which was 20 min after Gd-EOB-DTPA administration. Signal intensity of the liver and the kidneys in all phases was defined using region-of-interest measurements for relative enhancement calculation. Serum hepatic enzyme levels and eGFR were available in all patients. Spearman correlation test was used to test the correlation of RHE, RRE and LKR with serum hepatic enzyme levels and eGFR. Results: In the hepatobiliary phase all serum hepatic enzymes were significantly correlated with RHE; total bilirubin (TBIL) and cholin esterase (CHE) showed strongest correlations. TBIL and CHE were significantly correlated with RRE in the arterial phases. TBIL and CHE were significantly correlated with LKR in the arterial phase and hepatobiliary phase. eGFR showed no correlation. Conclusions: In Gd-EOB-DTPA enhanced MRI, TBIL and CHE levels may predict RHE, RRE and LKR.

Contrast-enhanced ultrasound study of primary hepatic angiosarcoma: A pitfall of non-enhancement

International Nuclear Information System (INIS)

Wang, Liang; Lv, Ke; Chang, Xiao-Yan; Xia, Yu; Yang, Zhi-Ying; Jiang, Yu-Xin; Dai, Qing; Tan, Li; Li, Jian-Chu

2012-01-01

Highlights: ► The contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA) in three patients were retrospectively analyzed. ► PHA appeared similar peripheral enhancement pattern in our series. ► Non-necrotic tumor tissue of PHA unexpectedly demonstrated non-enhancement on CEUS. ► It may be associated with the very low velocity of blood flow in the central region of tumors. ► This interesting finding warrants further investigations, particularly on intratumoral hemodynamics. -- Abstract: Objective: To investigate the contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA). Methods: The sonographic findings and CEUS images of PHA in three patients were retrospectively analyzed. Results: In our study, 3 cases of PHA (2 multiple nodules and 1 solitary mass) showed similar enhancement pattern on CEUS, characterized by remarkable central non-enhancement and peripheral irregular enhancement in the arterial and portal phase, and complete wash-out in the late phase. Furthermore, we unexpectedly found that abundant neoplastic tissues were present in the central area of non-enhancement on pathological evaluation. Based on literature review, we supposed that the unusual finding may be associated with the very low velocity of blood flow in the central region of tumors. Conclusion: CEUS could well depict PHA with some common features, which may provide valuable clues in diagnosis of this rare disease. And non-necrotic tumor tissue of PHA could also demonstrate non-enhancement on CEUS, which warrant further investigations

Gd-DTPA enhanced MRI of the brain infarction: correlation between onset of infarction and enhancing patterns

International Nuclear Information System (INIS)

Joo, An Young; Kim, Myung Soon; Lee, Sung Soo

1994-01-01

To evaluate the correlation between onset of brain infarction and Gd-DTPA enhancing patterns on MRI. We reviewed MRI of 58 lesions in 45 patients with clinically documented brain infarction retrospectively. Axial, coronal and sagittal T1WI (TR/TE 450-520/20), T2WI (TR/TE 2190/90) and Gd-DTPA enhanced T1WI were performed with a 0.5T superconductive MR system. We analyzed Gd-enhancing patterns that were divided into intravascular, meningeal, and parenchymal enhancement. Parenchymal pattern was subdivided into mottled, partial ring like and dense enhancement. Intravascular enhancement was seen at 1-10 days in 30(53%) of 58 infarctions. Meningeal enhancement (13%) was noted at 1-6 days. Parenchymal enhancement (50%) was seen at 2-28 days and subdividing patterns are as follows: The mottled enhancement pattern was seen earlier at 2-8 days and partial ring like or dense enhancement patterns at 5-28 days. After reviewing Gd-enhanced MRI of infarction, the intravascular and meningeal enhancement patterns were earlier than parenchymal enhancement. Among parenchymal patterns, the mottled pattern was seen earlier than partial ring like or dense patterns. In conclusion, Gd-enhancing patterns of brain infarction are useful in estimating the age of infarction including acute infarction

Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography

Energy Technology Data Exchange (ETDEWEB)

Li Tao [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhao Xihai [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Liu Xin [Paul C. Lauterbur Biomedical Imaging Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen 518067 (China); Gao Jianhua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Zhao Shaohong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Li Xin; Zhou Weihua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Cai Zulong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhang Weiguo [Cardiovascular and Neurological Consulting Institute, 6771 San Fernando, Irving, TX 75039 (United States); Yang Li, E-mail: Yangli301@yahoo.com [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China)

2011-10-15

Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis ({>=}50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

International Nuclear Information System (INIS)

Bartolotta, Tommaso Vincenzo; Taibbi, Adele; Galia, Massimo; Lo Re, Giuseppe; La Grutta, Ludovico; Grassi, Roberto; Midiri, Massimo

2007-01-01

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

Energy Technology Data Exchange (ETDEWEB)

Bartolotta, Tommaso Vincenzo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: tv.bartolotta@unipa.it; Taibbi, Adele [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: taibbi_adele@yahoo.it; Galia, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mgalia@yahoo.com; Lo Re, Giuseppe [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: giuseppe.lore12@tin.it; La Grutta, Ludovico [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: lagrutta@mbox.infcom.it; Grassi, Roberto [Institute of Radiology, Second University of Naples, Piazza Miraglia, 80138 Naples (Italy)], E-mail: roberto.grassi@libero.it; Midiri, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mmidiri@hotmail.com

2007-12-15

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma.

In vitro percutaneous absorption enhancement of granisetron by chemical penetration enhancers.

Science.gov (United States)

Zhao, Nanxi; Cun, Dongmei; Li, Wei; Ma, Xu; Sun, Lin; Xi, Honglei; Li, Li; Fang, Liang

2013-04-01

Granisetron (GRN), a potent antiemetic agent, is frequently used to prevent nausea and vomiting induced by cancer cytotoxic chemotherapy and radiation therapy. As part of our efforts to further modify the physicochemical properties of this market drug, with the ultimate goal to formulate a better dosage form for GRN, this work was carried out to improve its permeability in vitro. The permeation behavior of GRN in isopropyl myristate (IPM) was investigated across excised rabbit abdominal skin and the enhancing activities of three novel O-acylmenthol derivatives synthesized in our laboratory as well as five well-known chemical enhancers were evaluated. It was found that the steady-state flux of granisetron free base (GRN-B) was about 26-fold higher than that of granisetron hydrochloride (GRN-H). The novel enhancer, 2-isopropyl-5-methylcyclohexyl heptanoate (M-HEP), was observed to provide the most significant enhancement for the absorption of GRN-B. When incorporated in the donor solution with the optimal enhancer M-HEP, the steady-state flux of GRN-B increased from (196.44 ± 12.03) μg·cm⁻²·h⁻¹ to (1044.95 ± 71.99) μg·cm⁻²·h⁻¹ (P < 0.01). These findings indicated that the application of chemical enhancers was an effective approach to increase the percutaneous absorption of GRN in vitro.

Contrast-enhanced turbo spin-echo(TSE) T1-weighted imaging: improved contrast of enhancing lesions

International Nuclear Information System (INIS)

Choi, Sung Wook; Lee, Ghi Jai; Shim, Jae Chan; Lee, Young Ju; Jeong, Se Hyung; Kim, Ho kyun

1997-01-01

The purpose of this study was to evaluate the effect of contrast improvement of enhancing brain lesions by inherent magnetization transfer effect in turbo spin-echo(TSE)T1-weighted MR imaging. Twenty-six enhancing lesions of 19 patients were included in this study. Using a 1.0T superconductive MR unit, contrast-enhanced SE T1-weighted images(TR=3D600 msec, TE=3D12 msec, NEX=3D2, acquistition time=3D4min 27sec) and contrast-enhanced TSE T1-weighted images(TR=3D600 msec, TE=3D12, acquistition time=3D1min 44sec) were obtained. Signal intensities at enhancing lesions and adjacent white matter were measured in the same regions of both images. Signal-to-noise ratio(SNR) of enhancing lesions and adjacent white matter, and con-trast-to-noise ratio(CNR) and lesion-to-background contrast (LBC) of enhancing lesions were calculated and statistically analysed using the paired t-test. On contrast-enhanced TSE T1-weighted images, SNR of enhancing lesions and adjacent white matter decreased by 18%(p<0.01) and 32%(p<0.01), respectively, compared to contrast-enhanced SE T1-weighted images. CNR and LBC of enhancing lesions increased by 16%(p<0.05) and 66%(p<0.01), respectively. Due to the proposed inherent magnetization transfer effects in TSE imaging, con-trast-enhanced T1-weighted TSE images demonstrated a statistically significant improvement in CNR and LBC, compared to conventional contrast-enhanced T1-weighted SE images, and scan time was much shorter

Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

Energy Technology Data Exchange (ETDEWEB)

Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

1993-03-15

To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding.

Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

International Nuclear Information System (INIS)

Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo

1993-01-01

To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding

Hepatic enhancement on Gd-BOPTA-enhanced MR imaging: comparison between cirrhotic and normal livers

International Nuclear Information System (INIS)

Shin, Sang Soo; Jeong, Yong Yeon; Kang, Heoung Keun; Lim, Hyo Soon; Yoon, Woong; Seo, Jeong Jin; Park, Jin Gyoon

2004-01-01

To compare the enhancement features of hepatic parenchyma between cirrhotic and normal liver, using Gd-BOPTA-enhanced delayed MR imaging. The 60 patients (35 with cirrhotic and 25 with normal liver) included in our study underwent Gd-BOPTA-enhanced MR imaging using a 1.5T system with a phase-array multicoil. In all cases, T1-weighted in-phase and opposed-phase gradient-echo MR imaging was performed before and 60 minutes after intravenous administration of a bolus of Gd-BOPTA. All images were quantitatively analysed by comparing the signal-to-noise ratio (SNR) and signal enhancement (SE) of cirrhotic and normal liver before and after contrast enhancement, and in cirrhotic patients, SNR and SE were also compared in terms of the Child-Pugh classification. For qualitative analysis, the hepatic enhancement patterns of cirrhotic and normal liver were classified as homogeneous or heterogeneous according to the consensual findings of two radiologists. At contrast-enhanced imaging, both cirrhotic (p<0.001) and normal liver (p<0.001) showed substantially increased SNR relative to unenhanced images, and the SNR of cirrhotic liver was significantly lower than that of normal livers at both in-phase (p<0.001) and opposed-phase (p<0.001) imaging. The SE of cirrhotic liver was significantly lower than that of normal liver (in-phase:p=0.002; opposed phase:p=0.011). Both Child-Pugh class A (p<0.001) and B (p<0.001) cirrhotic liver showed a substantial increase in SNR at contrast-enhanced imaging relative to unenhanced imaging and the SNR of Child-Pugh class A was significantly higher than that of Child-Pugh class B at both in-phase (p<0.001) and opposed-phase (p=0.022) imaging. In addition, the SE of class A was significantly higher than that of class B at in-phase imaging (p=0.004). Cirrhotic liver showed heterogeneous enhancement in 20 of 35 patients (57%), whereas normal liver showed homogeneous enhancement in all patients. At Gd-BOPTA-enhanced delayed MR imaging, cirrhotic liver

Novel medical image enhancement algorithms

Science.gov (United States)

Agaian, Sos; McClendon, Stephen A.

2010-01-01

In this paper, we present two novel medical image enhancement algorithms. The first, a global image enhancement algorithm, utilizes an alpha-trimmed mean filter as its backbone to sharpen images. The second algorithm uses a cascaded unsharp masking technique to separate the high frequency components of an image in order for them to be enhanced using a modified adaptive contrast enhancement algorithm. Experimental results from enhancing electron microscopy, radiological, CT scan and MRI scan images, using the MATLAB environment, are then compared to the original images as well as other enhancement methods, such as histogram equalization and two forms of adaptive contrast enhancement. An image processing scheme for electron microscopy images of Purkinje cells will also be implemented and utilized as a comparison tool to evaluate the performance of our algorithm.

Theoretical studies of surface enhanced hyper-Raman spectroscopy: The chemical enhancement mechanism

Science.gov (United States)

Valley, Nicholas; Jensen, Lasse; Autschbach, Jochen; Schatz, George C.

2010-08-01

Hyper-Raman spectra for pyridine and pyridine on the surface of a tetrahedral 20 silver atom cluster are calculated using static hyperpolarizability derivatives obtained from time dependent density functional theory. The stability of the results with respect to choice of exchange-correlation functional and basis set is verified by comparison with experiment and with Raman spectra calculated for the same systems using the same methods. Calculated Raman spectra were found to match well with experiment and previous theoretical calculations. The calculated normal and surface enhanced hyper-Raman spectra closely match experimental results. The chemical enhancement factors for hyper-Raman are generally larger than for Raman (102-104 versus 101-102). Integrated hyper-Raman chemical enhancement factors are presented for a set of substituted pyridines. A two-state model is developed to predict these chemical enhancement factors and this was found to work well for the majority of the molecules considered, providing a rationalization for the difference between hyper-Raman and Raman enhancement factors.

Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas

International Nuclear Information System (INIS)

Fromm, David P.; Sundaramurthy, Arvind; Kinkhabwala, Anika; Schuck, P. James; Kino, Gordon S.; Moerner, W.E.

2006-01-01

Single metallic bowtie nanoantennas provide a controllable environment for surface-enhanced Raman scattering (SERS) of adsorbed molecules. Bowties have experimentally measured electromagnetic enhancements, enabling estimation of chemical enhancement for both the bulk and the few-molecule regime. Strong fluctuations of selected Raman lines imply that a small number of p-mercaptoaniline molecules on a single bowtie show chemical enhancement >10 7 , much larger than previously believed, likely due to charge transfer between the Au surface and the molecule. This chemical sensitivity of SERS has significant implications for ultra-sensitive detection of single molecules

Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

International Nuclear Information System (INIS)

Sardanelli, Francesco; Di Leo, Giovanni; Aliprandi, Alberto; Flor, Nicola; Papini, Giacomo D.E.; Roccatagliata, Luca; Cotticelli, Biagio; Nano, Giovanni; Cornalba, Gianpaolo

2009-01-01

Objectives: This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA). Materials and methods: IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET. Results: With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%). Conclusion: Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.

Plasmonic enhancement of electroluminescence

Science.gov (United States)

Guzatov, D. V.; Gaponenko, S. V.; Demir, H. V.

2018-01-01

Here plasmonic effect specifically on electroluminescence (EL) is studied in terms of radiative and nonradiative decay rates for a dipole near a metal spherical nanoparticle (NP). Contribution from scattering is taken into account and is shown to play a decisive role in EL enhancement owing to pronounced size-dependent radiative decay enhancement and weak size effect on non-radiative counterpart. Unlike photoluminescence where local incident field factor mainly determines the enhancement possibility and level, EL enhancement is only possible by means of quantum yield rise, EL enhancement being feasible only for an intrinsic quantum yield Q0 red-orange range only. Independently of positive effect on quantum yield, metal nanoparticles embedded in an electroluminescent device will improve its efficiency at high currents owing to enhanced overall recombination rate which will diminish manifestation of Auger processes. The latter are believed to be responsible for the known undesirable efficiency droop in semiconductor commercial quantum well based LEDs at higher current. For the same reason plasmonics can diminish quantum dot photodegradation from Auger process induced non-radiative recombination and photoionization thus opening a way to avoid negative Auger effects in emerging colloidal semiconductor LEDs.

Natural Image Enhancement Using a Biogeography Based Optimization Enhanced with Blended Migration Operator

Directory of Open Access Journals (Sweden)

J. Jasper

2014-01-01

Full Text Available This paper addresses a novel and efficient algorithm for solving optimization problem in image processing applications. Image enhancement (IE is one of the complex optimization problems in image processing. The main goal of this paper is to enhance color images such that the eminence of the image is more suitable than the original image from the perceptual viewpoint of human. Traditional methods require prior knowledge of the image to be enhanced, whereas the aim of the proposed biogeography based optimization (BBO enhanced with blended migration operator (BMO algorithm is to maximize the objective function in order to enhance the image contrast by maximizing the parameters like edge intensity, edge information, and entropy. Experimental results are compared with the current state-of-the-art approaches and indicate the superiority of the proposed technique in terms of subjective and objective evaluation.

Mechanisms of Memory Enhancement

Science.gov (United States)

Stern, Sarah A.

2012-01-01

The ongoing quest for memory enhancement is one that grows necessary as the global population increasingly ages. The extraordinary progress that has been made in the past few decades elucidating the underlying mechanisms of how long-term memories are formed has provided insight into how memories might also be enhanced. Capitalizing on this knowledge, it has been postulated that targeting many of the same mechanisms, including CREB activation, AMPA/NMDA receptor trafficking, neuromodulation (e.g. via dopamine, adrenaline, cortisol or acetylcholine) and metabolic processes (e.g. via glucose and insulin) may all lead to the enhancement of memory. These and other mechanisms and/or approaches have been tested via genetic or pharmacological methods in animal models, and several have been investigated in humans as well. In addition, a number of behavioral methods, including exercise and reconsolidation, may also serve to strengthen and enhance memories. By capitalizing on this knowledge and continuing to investigate these promising avenues, memory enhancement may indeed be achieved in the future. PMID:23151999

Rethinking enhancement in sport.

Science.gov (United States)

Miah, Andy

2006-12-01

This article explores the arguments surrounding the use of human enhancement technologies in sport, arguing for a reconceptualization of the doping debate. First, it develops an overview and critique of the legislative structures on enhancement. Subsequently, a conceptual framework for understanding the role of technological effects in sport is advanced. Finally, two case studies (hypoxic chambers and gene transfer) receive specific attention, through which it is argued that human enhancement technologies can enrich the practice of elite sports rather than diminish them. In conclusion, it is argued that elite sports are at a pivotal moment in their history as an increasing range of enhancements makes less relevant the protection of the natural human through anti-doping.

Multiple layered metallic nanostructures for strong surface-enhanced Raman spectroscopy enhancement

International Nuclear Information System (INIS)

Xia, Ming; Xie, Ya-Hong; Qiao Kuan; Cheng Zhiyuan

2016-01-01

We report a systematic study on a practical way of patterning metallic nanostructures to achieve high surface-enhanced Raman spectroscopy (SERS) enhancement factors (EFs) and high hot-spot density. By simply superimposing a 1-layer Au nanotriangle array on another to form a multilayer nanotriangle array, the SERS signal can be enhanced by 2 orders of magnitude compared with a 1-layer nanotriangle array. The drastic increases in the SERS EF and the hot spot density of the multilayer Au nanotriangle array are due to the increase in the number of gaps formed between Au nanotriangles and the decrease of the gap width. (author)

Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Takano, Koichi, E-mail: k-takano@fukuoka-u.ac.jp; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

2017-01-15

Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

International Nuclear Information System (INIS)

Takano, Koichi; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

2017-01-01

Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

Heat transfer enhancement

International Nuclear Information System (INIS)

Hasatani, Masanobu; Itaya, Yoshinori

1985-01-01

In order to develop energy-saving techniques and new energy techniques, and also most advanced techniques by making industrial equipment with high performance, heat transfer performance frequently becomes an important problem. In addition, the improvement of conventional heat transfer techniques and the device of new heat transfer techniques are often required. It is most proper that chemical engineers engage in the research and development for enhancing heat transfer. The research and development for enhancing heat transfer are important to heighten heat exchange efficiency or to cool equipment for preventing overheat in high temperature heat transfer system. In this paper, the techniques of enhancing radiative heat transfer and the improvement of radiative heat transfer characteristics are reported. Radiative heat transfer is proportional to fourth power of absolute temperature, and it does not require any heat transfer medium, but efficient heat-radiation converters are necessary. As the techniques of enhancing radiative heat transfer, the increase of emission and absorption areas, the installation of emissive structures and the improvement of radiative characteristics are discussed. (Kako, I.)

Motif signatures of transcribed enhancers

KAUST Repository

Kleftogiannis, Dimitrios

2017-09-14

In mammalian cells, transcribed enhancers (TrEn) play important roles in the initiation of gene expression and maintenance of gene expression levels in spatiotemporal manner. One of the most challenging questions in biology today is how the genomic characteristics of enhancers relate to enhancer activities. This is particularly critical, as several recent studies have linked enhancer sequence motifs to specific functional roles. To date, only a limited number of enhancer sequence characteristics have been investigated, leaving space for exploring the enhancers genomic code in a more systematic way. To address this problem, we developed a novel computational method, TELS, aimed at identifying predictive cell type/tissue specific motif signatures. We used TELS to compile a comprehensive catalog of motif signatures for all known TrEn identified by the FANTOM5 consortium across 112 human primary cells and tissues. Our results confirm that distinct cell type/tissue specific motif signatures characterize TrEn. These signatures allow discriminating successfully a) TrEn from random controls, proxy of non-enhancer activity, and b) cell type/tissue specific TrEn from enhancers expressed and transcribed in different cell types/tissues. TELS codes and datasets are publicly available at http://www.cbrc.kaust.edu.sa/TELS.

Quantum mechanical limit to plasmonic enhancement as observed by surface-enhanced Raman scattering.

Science.gov (United States)

Zhu, Wenqi; Crozier, Kenneth B

2014-10-14

Plasmonic nanostructures enable light to be concentrated into nanoscale 'hotspots', wherein the intensity of light can be enhanced by orders of magnitude. This plasmonic enhancement significantly boosts the efficiency of nanoscale light-matter interactions, enabling unique linear and nonlinear optical applications. Large enhancements are often observed within narrow gaps or at sharp tips, as predicted by the classical electromagnetic theory. Only recently has it become appreciated that quantum mechanical effects could emerge as the feature size approaches atomic length-scale. Here we experimentally demonstrate, through observations of surface-enhanced Raman scattering, that the emergence of electron tunnelling at optical frequencies limits the maximum achievable plasmonic enhancement. Such quantum mechanical effects are revealed for metallic nanostructures with gap-widths in the single-digit angstrom range by correlating each structure with its optical properties. This work furthers our understanding of quantum mechanical effects in plasmonic systems and could enable future applications of quantum plasmonics.

Speech enhancement

CERN Document Server

Benesty, Jacob; Chen, Jingdong

2006-01-01

We live in a noisy world! In all applications (telecommunications, hands-free communications, recording, human-machine interfaces, etc.) that require at least one microphone, the signal of interest is usually contaminated by noise and reverberation. As a result, the microphone signal has to be ""cleaned"" with digital signal processing tools before it is played out, transmitted, or stored.This book is about speech enhancement. Different well-known and state-of-the-art methods for noise reduction, with one or multiple microphones, are discussed. By speech enhancement, we mean not only noise red

Dural enhancement with primary calvarial lesions.

Science.gov (United States)

Arana, E; Martí-Bonmatí, L; Ricart, V; Pérez-Ebrí, M

2004-11-01

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

Dural enhancement with primary calvarial lesions

Energy Technology Data Exchange (ETDEWEB)

Arana, E. [Clinica Quiron, Department of Radiology, Valencia (Spain); Marti-Bonmati, L. [Clinica Quiron, Department of Radiology, Valencia (Spain); Hospital Universitario Dr. Peset, Department of Radiology, Valencia (Spain); Ricart, V. [Hospital de la Ribera, Department of Radiology, Valencia (Spain); Perez-Ebri, M. [Hospital Universitario Dr. Peset, Department of Pathology, Valencia (Spain)

2004-11-01

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign (''dural tail'') on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms. (orig.)

Delayed enhanced MRI in intraparenchymal tumors

International Nuclear Information System (INIS)

Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

1991-01-01

Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

The perils of moral enhancement

Directory of Open Access Journals (Sweden)

Dobrijević Aleksandar

2012-01-01

Full Text Available The idea of biotechnological enhancement of people for non-medical purposes is not unambiguous. A gap that may arise between the “cognitive” and so-called “moral” enhancement points precisely to this fact. This article shows that, contrary to the intentions of its supporters, the idea according to which moral enhancement has precedence over cognitive enhancement is essentially just a new form of undermining human freedom. [Projekat Ministarstva nauke Republike Srbije, br. 41004

Enhanced Input in LCTL Pedagogy

Directory of Open Access Journals (Sweden)

Marilyn S. Manley

2009-08-01

Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

Enhanced Input in LCTL Pedagogy

Directory of Open Access Journals (Sweden)

Marilyn S. Manley

2010-08-01

Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

Clinical significance of nerve root enhancement in contrast-enhanced MR imaging of the postoperative lumbar spine

International Nuclear Information System (INIS)

Lee, Yeon Soo; Lee, Eun Ja; Kang, Si Won; Choi, Eun Seok; Song, Chang June; Kim, Jong Chul

2001-01-01

To determine the significance of nerve root contrast enhancement in patients with residual or recurrent symptomatic postoperative lumbar spine. Eighty-eight patients with 116 postoperative lumbar disc lesions causing radiating back pain underwent enhanced MR imaging. Intradural nerve root enhancement was quantified by pixel measurement, and affected nerve roots were compared before and after contrast administration. Extradural nerve root enhancement was assessed visually, and nerve root enhancement and clinical symptoms were correlated. Associated lesions such as recurrent disc herniation, scar tissue, nerve root thickening and nerve root displacement were also evaluated. Of 26 cases (22.4%) involving intradural nerve root enhancement, 22 (84.6%) showed significant clinical symptoms (p=0.002). and of 59 (50.9%) demonstrating extradural enhancement, clinical symptoms showed significant correlation in 47 (79.7%) (p=0.001). Nerve root enhancement, including eleven cases where this was both intra-and extradural, showed highly significant association with clinical symptoms in 74 of the 116 cases (63.8%) (p=0.000). Among 33 cases (28.4%) of recurrent disc herniation, nerve root enhancement was observed in 28 (84.8%) and in 24 of these 28 (85.7%), significant correlation with clinical symptoms was observed (p=0.000). Where epidural fibrosis was present, correlation between nerve root enhancement and clinical symptoms was not significant (p>0.05). Nerve root thickening and displaced nerve root were, however, significantly associated with symptoms (87.2% and 88.6%, respectively). In patients with postoperative lumbar spine, the association between nerve root enhancement revealed by MRI and clinical symptoms was highly significant

Meningeal enhancement on MRI after craniotomy

International Nuclear Information System (INIS)

Nomura, Motohiro; Hasegawa, Mitsuhiro; Yamashima, Tetsumori; Yamashita, Junkoh; Suzuki, Masayuki

1991-01-01

Gd-DPTA-enhanced MR images in 94 patients who had undergone craniotomy were studied, with particular attention paid to the meningeal enhancement. Such enhancement was noted in 26 of the 94 (27.6%) in the portion surrounding the craniotomy site. Meningeal enhancement, presumably of the subdural neomembrane, was apparent as a third line of a high signal intensity on T 1 -weighted MR images. The outer two high-intensity lines were derived from fat in the subcutaneous tissues of the scalp and fat in the bone marrow of the calvaria. We designated this characteristic enhancement as a 'triple white line'. Of the 26 patients with meningeal enhancement, 22 cases (23.4%) showed such a 'triple white line', 11 cases (11.7%) showed falx enhancement, and 12 cases (12.8%) showed tentorial enhancement. The intervals between surgery and the appearance of the meningeal enhancement ranged from 4 days to 88 weeks. A small amount of bleeding into the dura-arachnoid interface induced by surgery might result in the subdural neomembrane, as has previously been reported. This neomembrane might be enhanced by the leakage of Gd-DTPA through the proliferating capillaries. As meningeal enhancement occurs in approximately a third of the cases following craniotomy, much care should be taken in the differential diagnosis of the infection, inflammation, and metastasis or dissemination of malignant brain tumors. (author)

Multispectral histogram normalization contrast enhancement

Science.gov (United States)

Soha, J. M.; Schwartz, A. A.

1979-01-01

A multispectral histogram normalization or decorrelation enhancement which achieves effective color composites by removing interband correlation is described. The enhancement procedure employs either linear or nonlinear transformations to equalize principal component variances. An additional rotation to any set of orthogonal coordinates is thus possible, while full histogram utilization is maintained by avoiding the reintroduction of correlation. For the three-dimensional case, the enhancement procedure may be implemented with a lookup table. An application of the enhancement to Landsat multispectral scanning imagery is presented.

DENdb: database of integrated human enhancers

KAUST Repository

Ashoor, Haitham

2015-09-05

Enhancers are cis-acting DNA regulatory regions that play a key role in distal control of transcriptional activities. Identification of enhancers, coupled with a comprehensive functional analysis of their properties, could improve our understanding of complex gene transcription mechanisms and gene regulation processes in general. We developed DENdb, a centralized on-line repository of predicted enhancers derived from multiple human cell-lines. DENdb integrates enhancers predicted by five different methods generating an enriched catalogue of putative enhancers for each of the analysed cell-lines. DENdb provides information about the overlap of enhancers with DNase I hypersensitive regions, ChIP-seq regions of a number of transcription factors and transcription factor binding motifs, means to explore enhancer interactions with DNA using several chromatin interaction assays and enhancer neighbouring genes. DENdb is designed as a relational database that facilitates fast and efficient searching, browsing and visualization of information.

DENdb: database of integrated human enhancers

KAUST Repository

Ashoor, Haitham; Kleftogiannis, Dimitrios A.; Radovanovic, Aleksandar; Bajic, Vladimir B.

2015-01-01

Enhancers are cis-acting DNA regulatory regions that play a key role in distal control of transcriptional activities. Identification of enhancers, coupled with a comprehensive functional analysis of their properties, could improve our understanding of complex gene transcription mechanisms and gene regulation processes in general. We developed DENdb, a centralized on-line repository of predicted enhancers derived from multiple human cell-lines. DENdb integrates enhancers predicted by five different methods generating an enriched catalogue of putative enhancers for each of the analysed cell-lines. DENdb provides information about the overlap of enhancers with DNase I hypersensitive regions, ChIP-seq regions of a number of transcription factors and transcription factor binding motifs, means to explore enhancer interactions with DNA using several chromatin interaction assays and enhancer neighbouring genes. DENdb is designed as a relational database that facilitates fast and efficient searching, browsing and visualization of information.

Personal Identity in Enhancement

Directory of Open Access Journals (Sweden)

Jana Podroužková

2015-09-01

Full Text Available The aim of this paper is to introduce the concept of human enhancement, its methods and its relation to personal identity. Also several approaches to personal identity will be described. Transhumanism is a special think tank supporting human enhancement through modern technologies and some of its representatives claim, that even great changes to human organisms will not affect their personal identity. I will briefly describe the most important means of human enhancment and consider the problem of personal identity for each of them separately.

Surface-enhanced Raman spectroscopy based on conical holed enhancing substrates

International Nuclear Information System (INIS)

Chen, Yao; Chen, Zeng-Ping; Zuo, Qi; Shi, Cai-Xia; Yu, Ru-Qin

2015-01-01

In this contribution, surface-enhanced Raman spectroscopy (SERS) based on conical holed glass substrates deposited with silver colloids was reported for the first time. It combines the advantages of both dry SERS assays based on plane films deposited with silver colloids and wet SERS assays utilizing cuvettes or capillary tubes. Compared with plane glass substrates deposited with silver colloids, the conical holed glass substrates deposited with silver colloids exhibited five-to ten-folds of increase in the rate of signal enhancement, due to the internal multiple reflections of both the excitation laser beam and the Raman scattering photons within conical holes. The application of conical holed glass substrates could also yield significantly stronger and more reproducible SERS signals than SERS assays utilizing capillary tubes to sample the mixture of silver colloids and the solution of the analyte of interest. The conical holed glass substrates in combination with the multiplicative effects model for surface-enhanced Raman spectroscopy (MEM SERS ) achieved quite sensitive and precise quantification of 6-mercaptopurine in complex plasma samples with an average relative prediction error of about 4% and a limit of detection of about 0.02 μM using a portable i-Raman 785H spectrometer. It is reasonable to expect that SERS technique based on conical holed enhancing substrates in combination with MEM SERS model can be developed and extended to other application areas such as drug detection, environmental monitoring, and clinic analysis, etc. - Highlights: • A novel conical holed SERS enhancing substrate was designed and manufactured. • The optimal conical holed glass substrates can produce stronger SERS signal. • The novel substrates can overcome the shortcomings of both dry and wet methods. • The novel substrates coupled with MEM SERS can realize quantitative SERS assays

Non-enhanced CT versus contrast-enhanced CT in integrated PET/CT studies for nodal staging of rectal cancer

International Nuclear Information System (INIS)

Tateishi, Ukihide; Maeda, Tetsuo; Morimoto, Tsuyoshi; Miyake, Mototaka; Arai, Yasuaki; Kim, E.E.

2007-01-01

The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer. Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([ 18 F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities. Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001). Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer. (orig.)

Self-enhancement: Conceptualization and Assessment

Directory of Open Access Journals (Sweden)

Joachim I. Krueger

2017-11-01

Full Text Available Self-enhancement bias is conventionally construed as an unwarranted social comparison in social psychology and a misperception of social reality in personality psychology. Researchers in both fields rely heavily on discrepancy scores to represent self-enhancement and fail to distinguish between a general tendency or bias to self-enhance and a self-enhancement error, or 'false' perception of own excellence. We critically review prominent discrepancy measures and then propose a decision-theoretic alternative that [a] mitigates confounds between self-positivity and self-superiority, [b] separates error from bias, and [c] discourages reliance on measures that reify self-enhancement as a stable personality trait. To evaluate our hypotheses, we re-analyze data collected in our laboratory and perform a series of simulation studies. We share these materials with interested researchers.

Enhancement of HHG yield

International Nuclear Information System (INIS)

Serrat, C.; Biegert, J.

2011-01-01

A static electric field periodically distributed in space controls and enhances the yield in high harmonic generation. The method is relatively simple to implement and allows tuning from the extreme-ultraviolet to soft X-ray. The radiation yield is selectively enhanced due to symmetry breaking induced by a static electric field on the interaction between the driving laser and the medium. The enhanced spectral region is tuned by varying the periodicity of the static electric field. Simulations predict an increase of more than two orders of magnitude for harmonics in the water window spectral range.

Assessing Impacts of Navigation Dredging on Atlantic Sturgeon (Acipenser oxyrinchus)

Science.gov (United States)

2014-11-01

are known to be opportunistic benthivores, feeding primarily on mollusks, polychaete worms, amphipods, isopods, shrimps and small bottom-dwelling...fishes and insect larvae (Smith 1985, Dadswell 2006). Shallow water shoals located adjacent to both sides of the Federal navigation channel, provide a...and J. Hoeman (1982). Distribution and abundance of the Dungeness crab and Crangon shrimp , and dredging-related mortality of invertebrates and fish

Fertility of a spontaneous hexaploid male Siberian sturgeon, Acipenser baerii

Czech Academy of Sciences Publication Activity Database

Havelka, M.; Hulák, M.; Ráb, Petr; Rábová, Marie; Lieckfeldt, D.; Ludwig, A.; Rodina, M.; Gela, D.; Pšenička, M.; Bytyutskyy, D.; Flajšhans, M.

2014-01-01

Roč. 15, č. 5 (2014) ISSN 1471-2156 Grant - others:GA MŠk(CZ) EE2.3.30.0049; GA MŠk(CZ) ED2.1.00/01.0024; GA ČR(CZ) GA523/08/0824 Program:GA Institutional support: RVO:67985904 Keywords : Acipenseridae * polyploidy determination * sperm quality Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.397, year: 2014

Resolution enhancement techniques in microscopy

Science.gov (United States)

Cremer, Christoph; Masters, Barry R.

2013-05-01

We survey the history of resolution enhancement techniques in microscopy and their impact on current research in biomedicine. Often these techniques are labeled superresolution, or enhanced resolution microscopy, or light-optical nanoscopy. First, we introduce the development of diffraction theory in its relation to enhanced resolution; then we explore the foundations of resolution as expounded by the astronomers and the physicists and describe the conditions for which they apply. Then we elucidate Ernst Abbe's theory of optical formation in the microscope, and its experimental verification and dissemination to the world wide microscope communities. Second, we describe and compare the early techniques that can enhance the resolution of the microscope. Third, we present the historical development of various techniques that substantially enhance the optical resolution of the light microscope. These enhanced resolution techniques in their modern form constitute an active area of research with seminal applications in biology and medicine. Our historical survey of the field of resolution enhancement uncovers many examples of reinvention, rediscovery, and independent invention and development of similar proposals, concepts, techniques, and instruments. Attribution of credit is therefore confounded by the fact that for understandable reasons authors stress the achievements from their own research groups and sometimes obfuscate their contributions and the prior art of others. In some cases, attribution of credit is also made more complex by the fact that long term developments are difficult to allocate to a specific individual because of the many mutual connections often existing between sometimes fiercely competing, sometimes strongly collaborating groups. Since applications in biology and medicine have been a major driving force in the development of resolution enhancing approaches, we focus on the contribution of enhanced resolution to these fields.

Distinguishing enhancing from nonenhancing renal masses with dual-source dual-energy CT: iodine quantification versus standard enhancement measurements.

Science.gov (United States)

Ascenti, Giorgio; Mileto, Achille; Krauss, Bernhard; Gaeta, Michele; Blandino, Alfredo; Scribano, Emanuele; Settineri, Nicola; Mazziotti, Silvio

2013-08-01

To compare the diagnostic accuracy of iodine quantification and standard enhancement measurements in distinguishing enhancing from nonenhancing renal masses. The Institutional Review Board approved this retrospective study conducted from data found in institutional patient databases and archives. Seventy-two renal masses were characterised as enhancing or nonenhancing using standard enhancement measurements (in HU) and iodine quantification (in mg/ml). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of standard enhancement measurements and iodine quantification were calculated from χ (2) tests of contingency with histopathology or imaging follow-up as the reference standard. Difference in accuracy was assessed by means of McNemar analysis. Sensitivity, specificity, PPV, NPV and diagnostic accuracy for standard enhancement measurements and iodine quantification were 77.7 %, 100 %, 100 %, 81.8 %, 89 % and 100 %, 94.4 %, 94.7, 100 % and 97 %, respectively. The McNemar analysis showed that the accuracy of iodine quantification was significantly better (P < 0.001) than that of standard enhancement measurements. Compared with standard enhancement measurements, whole-tumour iodine quantification is more accurate in distinguishing enhancing from nonenhancing renal masses. • Enhancement of renal lesions is important when differentiating benign from malignant tumours. • Dual-energy CT offers measurement of iodine uptake rather than mere enhancement values. • Whole-tumour iodine quantification seems more accurate than standard CT enhancement measurements.

Open-ring enhancement sign in diagnosing demyelinating pseudotumor

International Nuclear Information System (INIS)

Fang Liting; Wang Zhiping; Wang Linyou

2010-01-01

Objective: To describe open-ring enhancement sign on MRI of demyelinating pseudotumor. Methods: Contrast-enhanced MRI of histologically confirmed demyelinating pseudotumors (14 patients) and astrocytomas (21) was reviewed. Results: Of the 14 cases of demyelinating pseudotumor, open-ring enhancement pattern was observed in 6; closed ring enhancement in 2; nodular enhancement in 3; patchy enhancement in 1; slight enhancement in 1; and no enhancement in 1. Of the 21 cases of astrocytoma, there was complete ring or lace-like enhancement in 13, no contrast enhancement in 6, patchy enhancement in 2, and none with open-ring enhancement pattern. Conclusion: Open-ring enhancement is a valuable sign in differential diagnosis between demyelinating pseudotumor and astrocytoma. (authors)

Enhancement and knowledge

Directory of Open Access Journals (Sweden)

Cinzia Talamo

2012-04-01

Full Text Available Many issues related to enhancement strategies emerge nowadays both from the scenario offered by public real estates and from the current processes of conveyance of public assets to local authorities. On one hand it is still difficult, from a strategic point of view, to approach in the medium-long term the chronic problems of the public estates due to deterioration, obsolescence and organizational inadequacy. On the other hand there is the risk that inadequate levels of knowledge lead on one side to a prevalence of the binomial enhancement-alienation and on the other side to a lack of full comprehension of the actual potentialities of the existing assets. In this direction it is possible to analyze the topic of enhancement through, among many, the key of knowledge during the lifecycle of a building.

Defining Human Enhancement

DEFF Research Database (Denmark)

Nordberg, Ana

2017-01-01

-matter definitions are vital legal tools to determine what is currently regulated in established fields of law and whether there is room for a new legal field – Enhancement Law. This paper provides a reflection on the relevance of establishing a legal definition of human enhancement and to what extent different...... legal fields and jurisdictions may warrant different understandings of such concept. It reviews a number of different and often divergent concepts and taxonomies of human enhancement and concludes with the proposal and analysis of a definition: Use of technological means with the intention to improve......Emerging technologies open the prospect of extraordinary interventions on the human body. These may go beyond what is strictly necessary to sustain health and well-being. While responding to social and ethical challenges of such advances, the Law simultaneously faces the challenge of reflecting...

Contrast enhanced CT-scans are not comparable to non-enhanced scans in emphysema quantification

International Nuclear Information System (INIS)

Heussel, C.P.; Kappes, J.; Hantusch, R.; Hartlieb, S.; Weinheimer, O.; Kauczor, H.-U.; Eberhardt, R.

2010-01-01

Systemic, interventional and surgical treatments have gone new ways in treatment of emphysema. For longitudinal therapy monitoring and as end-points for clinical trials, quantification of the disease is necessary. Sensitive, easy to measure, as well as stable and reproducible parameters have to be characterized. One parameter that might affect emphysema quantification is IV contrast enhancement, which might also be indicated. Whether or not the contrast enhanced scan is also suited for emphysema quantification or an additional scan is necessary, a retrospective analysis of 12 adult patients undergoing clinically indicated both, a non-enhanced and enhanced thin section MSCT within a week (median 0 days, range 0-4 days) was done. The in-house YACTA software was used for automatic quantification of lung and emphysema volume, emphysema index, mean lung density, and 5th, 10th, 15th percentile. After IV contrast administration, the median CT derived lung volume decreased mild by 1.1%, while median emphysema volume decreased by relevant 11%. This results in a decrease of median emphysema index by 9%. The median lung density (15th percentile) increased after contrast application by 18 HU (9 HU). CT quantification delivers emphysema values that are clearly affected by IV contrast application. The detected changes after contrast application show the results of higher density in the lung parenchyma. Therefore the amount of quantified emphysema is reduced and the lung density increased after contrast enhancement. In longitudinal analyses, non-enhanced scans should be the reference, while enhanced scans cannot be used.

Enhanced superconductivity of fullerenes

Energy Technology Data Exchange (ETDEWEB)

Washington, II, Aaron L.; Teprovich, Joseph A.; Zidan, Ragaiy

2017-06-20

Methods for enhancing characteristics of superconductive fullerenes and devices incorporating the fullerenes are disclosed. Enhancements can include increase in the critical transition temperature at a constant magnetic field; the existence of a superconducting hysteresis over a changing magnetic field; a decrease in the stabilizing magnetic field required for the onset of superconductivity; and/or an increase in the stability of superconductivity over a large magnetic field. The enhancements can be brought about by transmitting electromagnetic radiation to the superconductive fullerene such that the electromagnetic radiation impinges on the fullerene with an energy that is greater than the band gap of the fullerene.

Infrared image enhancement with learned features

Science.gov (United States)

Fan, Zunlin; Bi, Duyan; Ding, Wenshan

2017-11-01

Due to the variation of imaging environment and limitations of infrared imaging sensors, infrared images usually have some drawbacks: low contrast, few details and indistinct edges. Hence, to promote the applications of infrared imaging technology, it is essential to improve the qualities of infrared images. To enhance image details and edges adaptively, we propose an infrared image enhancement method under the proposed image enhancement scheme. On the one hand, on the assumption of high-quality image taking more evident structure singularities than low-quality images, we propose an image enhancement scheme that depends on the extractions of structure features. On the other hand, different from the current image enhancement algorithms based on deep learning networks that try to train and build the end-to-end mappings on improving image quality, we analyze the significance of first layer in Stacked Sparse Denoising Auto-encoder and propose a novel feature extraction for the proposed image enhancement scheme. Experiment results prove that the novel feature extraction is free from some artifacts on the edges such as blocking artifacts, ;gradient reversal;, and pseudo contours. Compared with other enhancement methods, the proposed method achieves the best performance in infrared image enhancement.

Metaheuristic applications to speech enhancement

CERN Document Server

Kunche, Prajna

2016-01-01

This book serves as a basic reference for those interested in the application of metaheuristics to speech enhancement. The major goal of the book is to explain the basic concepts of optimization methods and their use in heuristic optimization in speech enhancement to scientists, practicing engineers, and academic researchers in speech processing. The authors discuss why it has been a challenging problem for researchers to develop new enhancement algorithms that aid in the quality and intelligibility of degraded speech. They present powerful optimization methods to speech enhancement that can help to solve the noise reduction problems. Readers will be able to understand the fundamentals of speech processing as well as the optimization techniques, how the speech enhancement algorithms are implemented by utilizing optimization methods, and will be given the tools to develop new algorithms. The authors also provide a comprehensive literature survey regarding the topic.

Resolution Enhancement of Multilook Imagery

Energy Technology Data Exchange (ETDEWEB)

Galbraith, Amy E. [Univ. of Arizona, Tucson, AZ (United States)

2004-07-01

This dissertation studies the feasibility of enhancing the spatial resolution of multi-look remotely-sensed imagery using an iterative resolution enhancement algorithm known as Projection Onto Convex Sets (POCS). A multi-angle satellite image modeling tool is implemented, and simulated multi-look imagery is formed to test the resolution enhancement algorithm. Experiments are done to determine the optimal con guration and number of multi-angle low-resolution images needed for a quantitative improvement in the spatial resolution of the high-resolution estimate. The important topic of aliasing is examined in the context of the POCS resolution enhancement algorithm performance. In addition, the extension of the method to multispectral sensor images is discussed and an example is shown using multispectral confocal fluorescence imaging microscope data. Finally, the remote sensing issues of atmospheric path radiance and directional reflectance variations are explored to determine their effect on the resolution enhancement performance.

When is diminishment a form of enhancement? Rethinking the enhancement debate in biomedical ethics

Directory of Open Access Journals (Sweden)

Brian D. Earp

2014-02-01

Full Text Available The enhancement debate in neuroscience and biomedical ethics tends to focus on the augmentation of certain capacities or functions: memory, learning, attention, and the like. Typically, the point of contention is whether these augmentative enhancements are permissible for individuals with no particular ‘medical’ disadvantage along any of the dimensions of interest. Less frequently addressed in the literature, however, is the fact that sometimes the diminishment of a capacity or function, under the right set of circumstances, could plausibly contribute to an individual’s overall well-being: more is not always better, and sometimes less is more. Such cases may be especially likely, we suggest, when trade-offs in our modern environment have shifted since the environment of evolutionary adaptation. In this article, we introduce the notion of diminishment as enhancement and go on to defend a welfarist conception of enhancement. We show how this conception resolves a number of definitional ambiguities in the enhancement literature, and we suggest that it can provide a useful framework for thinking about the use of emerging neurotechnologies to promote human flourishing.

The cerebral intravascular enhancement sign is not specific: a contrast-enhanced MRI study

Energy Technology Data Exchange (ETDEWEB)

Bakshi, R.; Kinkel, W.R.; Bates, V.E.; Mechtler, L.L.; Kinkel, P.R. [Lucy Dent Imaging Center, University at Buffalo, NY (United States)

1999-02-01

The intravascular enhancement (IVE) sign, also known as the ``arterial enhancement sign``, is an abnormal finding in the brain on contrast-enhanced MRI studies. IVE has been described in arterial cerebrovascular disorders, most commonly in acute or subacute arterial ischemic infarcts. However, the specificity of this sign has not been established. We describe four patients with disorders other than arterial strokes in whom gadolinium-enhanced high-field (1.5 T) MRI suggested IVE. The conditions were herpes simplex viral encephalitis, idiopathic cerebellitis, pneumococcal meningitis, and superior sagittal sinus thrombosis with venous infarction. IVE in these cases may be due to multiple factors, including arterial, venous, perivascular, and leptomeningeal or sulcal contrast medium accumulation. Our observations suggest that arterial ischemia, previously described as the cardinal cause of IVE, probably does not explain all instances, and urge caution in interpreting this sign as a specific MRI manifestation of acute arterial infarction or ischemia. (orig.) With 4 figs., 1 tab., 44 refs.

Cavity-enhanced spectroscopies

CERN Document Server

van Zee, Roger

2003-01-01

""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

Multivariable analysis of clinical influence factors on liver enhancement of Gd-EOB-DTPA-enhanced 3T MRI

International Nuclear Information System (INIS)

Verloh, N.; Haimerl, M.; Stroszczynski, C.; Fellner, C.; Wiggermann, P.; Zeman, F.; Teufel, A.; Lang, S.

2015-01-01

The purpose of this study was to identify clinical factors influencing Gd-EOB-DTPA liver uptake in patients with healthy liver parenchyma. A total of 124 patients underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 minutes after contrast injection. The relative enhancement (RE) between plain and contrast-enhanced signal intensity was calculated. Simple and multiple linear regression analyses were performed to evaluate clinical factors influencing the relative enhancement. Patients were subdivided into three groups according to their relative liver enhancement (HRE, RE ≥ 100 %; MRE, 100 % > RE > 50 %; NRE, RE ≤ 50 %) and were analyzed according to the relevant risk factors. Simple regression analyses revealed patient age, transaminases (AST, ALT, GGT), liver, spleen and delta-liver volume (the difference between the volumetrically measured liver volume and the estimated liver volume based on body weight) as significant factors influencing relative enhancement. In the multiple analysis the transaminase AST, spleen and delta liver volume remained significant factors influencing relative enhancement. Delta liver volume showed a significant difference between all analyzed groups. Liver enhancement in the hepatobiliary phase depends on a variety of factors. Body weight-adapted administration of Gd-EOB-DTPA may lead to inadequate liver enhancement after 20 minutes especially when the actual liver volume differs from the expected volume.

Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

DEFF Research Database (Denmark)

Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

2017-01-01

Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

Resonant enhancement in leptogenesis

Science.gov (United States)

Dev, P. S. B.; Garny, M.; Klaric, J.; Millington, P.; Teresi, D.

2018-02-01

Vanilla leptogenesis within the type I seesaw framework requires the mass scale of the right-handed neutrinos to be above 109 GeV. This lower bound can be avoided if at least two of the sterile states are almost mass degenerate, which leads to an enhancement of the decay asymmetry. Leptogenesis models that can be tested in current and upcoming experiments often rely on this resonant enhancement, and a systematic and consistent description is therefore necessary for phenomenological applications. In this paper, we give an overview of different methods that have been used to study the saturation of the resonant enhancement when the mass difference becomes comparable to the characteristic width of the Majorana neutrinos. In this limit, coherent flavor transitions start to play a decisive role, and off-diagonal correlations in flavor space have to be taken into account. We compare various formalisms that have been used to describe the resonant regime and discuss under which circumstances the resonant enhancement can be captured by simplified expressions for the CP asymmetry. Finally, we briefly review some of the phenomenological aspects of resonant leptogenesis.

Human freedom and enhancement.

Science.gov (United States)

Heilinger, Jan-Christoph; Crone, Katja

2014-02-01

Ideas about freedom and related concepts like autonomy and self-determination play a prominent role in the moral debate about human enhancement interventions. However, there is not a single understanding of freedom available, and arguments referring to freedom are simultaneously used to argue both for and against enhancement interventions. This gives rise to misunderstandings and polemical arguments. The paper attempts to disentangle the different distinguishable concepts, classifies them and shows how they relate to one another in order to allow for a more structured and clearer debate. It concludes in identifying the individual underpinnings and the social conditions of choice and decision-making as particularly salient dimensions of freedom in the ethical debate about human enhancement.

Geothermal Permeability Enhancement - Final Report

Energy Technology Data Exchange (ETDEWEB)

Joe Beall; Mark Walters

2009-06-30

The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

Enhancement of retronasal odors by taste.

Science.gov (United States)

Green, Barry G; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

2012-01-01

Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste ("sweet," "sour," "salty," and "bitter") and odor ("other") intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste-odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of "cherry" and "vanilla" flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. © The Author 2011. Published by Oxford University Press. All rights reserved.

Clinical evaluation of contrast-enhanced digital mammography and contrast enhanced tomosynthesis--Comparison to contrast-enhanced breast MRI.

Science.gov (United States)

Chou, Chen-Pin; Lewin, John M; Chiang, Chia-Ling; Hung, Bao-Hui; Yang, Tsung-Lung; Huang, Jer-Shyung; Liao, Jia-Bin; Pan, Huay-Ben

2015-12-01

To compare the diagnostic accuracy of contrast-enhanced digital mammography (CEDM) and contrast-enhanced tomosynthesis (CET) to dynamic contrast enhanced breast MRI (DCE-MRI) using a multireader-multicase study. Institutional review board approval and informed consents were obtained. Total 185 patients (mean age 51.3) with BI-RADS 4 or 5 lesions were evaluated before biopsy with mammography, tomosynthesis, CEDM, CET and DCE-MRI. Mediolateral-oblique and cranio-caudal views of the target breast CEDM and CET were acquired at 2 and 4 min after contrast agent injection. A mediolateral-oblique view of the non-target breast was taken at 6 min. Each lesion was scored with forced BI-RADS categories by three readers. Each reader interpreted lesions in the following order: mammography, tomosynthesis, CEDM, CET, and DCE-MRI during a single reading session. Histology showed 81 cancers and 144 benign lesions in the study. Of the 81 malignant lesions, 44% (36/81) were invasive and 56% (45/81) were non-invasive. Areas under the ROC curve, averaged for the 3 readers, were as follows: 0.897 for DCE-MRI, 0.892 for CET, 0.878 for CEDM, 0.784 for tomosynthesis and 0.740 for mammography. Significant differences in AUC were found between the group of contrast enhanced modalities (CEDM, CET, DCE-MRI) and the unenhanced modalities (all p0.05). CET and CEDM may be considered as an alternative modality to MRI for following up women with abnormal mammography. All three contrast modalities were superior in accuracy to conventional digital mammography with or without tomosynthesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Demand for Enhanced Annuities

OpenAIRE

Schuhmacher, Petra

2008-01-01

In enhanced annuities, the annuity payment depends on one's state of health at some contracted date while in "standard annuities", it does not. The focus of this paper is on an annuity market where "standard" and enhanced annuities areoffered simultaneously. When all insured know equally well on their future health status either enhanced annuities drive standard annuities out of the market or vice versa. Both annuity types can exist simultaneously when the insured know varying exactly on thei...

The Misfortunes of Moral Enhancement.

Science.gov (United States)

Azevedo, Marco Antonio

2016-10-01

In Unfit for the Future, Ingmar Persson and Julian Savulescu present a sophisticated argument in defense of the imperative of moral enhancement. They claim that without moral enhancement, the future of humanity is seriously compromised. The possibility of ultimate harm, caused by a dreadful terrorist attack or by a final unpreventable escalation of the present environmental crisis aggravated by the availability of cognitive enhancement, makes moral enhancement a top priority. It may be considered optimistic to think that our present moral capabilities can be successfully improved by means of moral education, moral persuasion, and fear of punishment. So, without moral enhancement, drastic restrictions on human freedom would become the only alternative to prevent those dramatic potential outcomes. In this article, I will try to show that we still have reason to be less pessimistic and that Persson & Savulescu's arguments are fortunately unconvincing. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced MRI in patients with facial palsy

International Nuclear Information System (INIS)

Yanagida, Masahiro; Kato, Tsutomu; Ushiro, Koichi; Kitajiri, Masanori; Yamashita, Toshio; Kumazawa, Tadami; Tanaka, Yoshimasa

1991-01-01

We performed Gd-DTPA-enhanced magnetic resonance imaging (MRI) examinations at several stages in 40 patients with peripheral facial nerve palsy (Bell's palsy and Ramsay-Hunt syndrome). In 38 of the 40 patients, one and more enhanced region could be seen in certain portion of the facial nerve in the temporal bone on the affected side, whereas no enhanced regions were seen on the intact side. Correlations between the timing of the MRI examination and the location of the enhanced regions were analysed. In all 6 patients examined by MRI within 5 days after the onset of facial nerve palsy, enhanced regions were present in the meatal portion. In 3 of the 8 patients (38%) examined by MRI 6 to 10 days after the onset of facial palsy, enhanced areas were seen in both the meatal and labyrinthine portions. In 8 of the 9 patients (89%) tested 11 to 20 days after the onset of palsy, the vertical portion was enhanced. In the 12 patients examined by MRI 21 to 40 days after the onset of facial nerve palsy, the meatal portion was not enhanced while the labyrinthine portion, the horizontal portion and the vertical portion were enhanced in 5 (42%), 8 (67%) and 11 (92%), respectively. Enhancement in the vertical portion was observed in all 5 patients examined more than 41 days after the onset of facial palsy. These results suggest that the central portion of the facial nerve in the temporal bone tends to be enhanced in the early stage of facial nerve palsy, while the peripheral portion is enhanced in the late stage. These changes of Gd-DTPA enhanced regions in the facial nerve may suggest dromic degeneration of the facial nerve in peripheral facial nerve palsy. (author)

Enhanced localized fluorescence in plasmonic nanoantennae

DEFF Research Database (Denmark)

Bakker, R.M.; Yuan, H.-K.; Liu, Z.

2008-01-01

in fluorescence that reaches 100 times enhancement. Near-field excitation shows enhanced fluorescence from a single nanoantenna localized in a subwavelength area of similar to 0.15 mu m(2). The polarization of enhanced emission is along the main antenna axis. These observed experimental results are important...

Does technology really enhance nurse education?

Science.gov (United States)

Goodchild, Tim

2018-07-01

Technology has clearly impacted upon our working lives, and the purpose of this paper is to offer a critical insight into the ubiquitous presence of technology in nurse education. This paper argues that technology enhanced learning is predicated on the promise of potential and purported transformation of teaching and learning. It suggests that there is a lack of critical engagement in the academic field of technology enhanced learning, and adds a critical voice to some of the emerging arguments in this area. There is also a lack of systematic evidence supporting the enhancement offered by technology, and yet the technology enhanced project continues to persist. The discourse surrounding technology enhanced learning has become so dominant, so pervasive, that those of us within it can no longer see alternatives. But there are alternatives, and this paper argues that we need to challenge the dominance of technology enhanced learning, and become aware of its contingent nature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

Energy Technology Data Exchange (ETDEWEB)

Rasselet, Benjamin [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Larbi, Ahmed; Viala, Pierre [Medical Imaging Department, Nimes University Hospital, 4 rue du Professeur Robert Debré, 30029 Nîmes (France); Molinari, Nicolas [Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Tetreau, Raphael [Medical Imaging Department, Montpellier Cancer Institute (ICM), 208 Avenue des Apothicaires, 34298 Montpellier Cedex 5 (France); Faruch-Bilfeld, Marie [Medical Imaging Department, Toulouse University Hospital, Place du Docteur Baylac, 31059 Toulouse Cedex 9 (France); Taourel, Patrice [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Cyteval, Catherine, E-mail: c-cyteval@chu-montpellier.fr [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France)

2017-01-15

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

International Nuclear Information System (INIS)

Rasselet, Benjamin; Larbi, Ahmed; Viala, Pierre; Molinari, Nicolas; Tetreau, Raphael; Faruch-Bilfeld, Marie; Taourel, Patrice; Cyteval, Catherine

2017-01-01

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Metal plasmon enhanced europium complex luminescence

International Nuclear Information System (INIS)

Liu Feng; Aldea, Gabriela; Nunzi, Jean-Michel

2010-01-01

The plasmon enhanced luminescence of a rare-earth complex Tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato) europium (Eu(fod) 3 ) was investigated. A polyvinyl alcohol (PVA) thin film was successfully adopted as a spacer to separate the Eu complex from the silver island film (SIF), and five-fold enhancement of the radiative decay rate of the Eu complex on SIF was demonstrated based on the luminescence intensity and lifetime measurement. Investigation of the distance dependent luminescence indicates that 7 nm is an optimal distance for SIF enhanced Eu luminescence. Plasmon enhanced rare-earth luminescence based on an organic film spacer would find potential applications in plasmon enhanced organic light emitting diode (OLED) devices.

Molecular selectivity of graphene-enhanced Raman scattering.

Science.gov (United States)

Huang, Shengxi; Ling, Xi; Liang, Liangbo; Song, Yi; Fang, Wenjing; Zhang, Jin; Kong, Jing; Meunier, Vincent; Dresselhaus, Mildred S

2015-05-13

Graphene-enhanced Raman scattering (GERS) is a recently discovered Raman enhancement phenomenon that uses graphene as the substrate for Raman enhancement and can produce clean and reproducible Raman signals of molecules with increased signal intensity. Compared to conventional Raman enhancement techniques, such as surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS), in which the Raman enhancement is essentially due to the electromagnetic mechanism, GERS mainly relies on a chemical mechanism and therefore shows unique molecular selectivity. In this paper, we report graphene-enhanced Raman scattering of a variety of different molecules with different molecular properties. We report a strong molecular selectivity for the GERS effect with enhancement factors varying by as much as 2 orders of magnitude for different molecules. Selection rules are discussed with reference to two main features of the molecule, namely its molecular energy levels and molecular structures. In particular, the enhancement factor involving molecular energy levels requires the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies to be within a suitable range with respect to graphene's Fermi level, and this enhancement effect can be explained by the time-dependent perturbation theory of Raman scattering. The enhancement factor involving the choice of molecular structures indicates that molecular symmetry and substituents similar to that of the graphene structure are found to be favorable for GERS enhancement. The effectiveness of these factors can be explained by group theory and the charge-transfer interaction between molecules and graphene. Both factors, involving the molecular energy levels and structural symmetry of the molecules, suggest that a remarkable GERS enhancement requires strong molecule-graphene coupling and thus effective charge transfer between the molecules and graphene. These conclusions are further

Optimizing laser crater enhanced Raman spectroscopy.

Science.gov (United States)

Lednev, V N; Sdvizhenskii, P A; Grishin, M Ya; Filichkina, V A; Shchegolikhin, A N; Pershin, S M

2018-03-20

Raman signal enhancement by laser crater production was systematically studied for 785 nm continuous wave laser pumping. Laser craters were produced in L-aspartic acid powder by a nanosecond pulsed solid state neodymium-doped yttrium aluminum garnet laser (532 nm, 8 ns, 1 mJ/pulse), while Raman spectra were then acquired by using a commercial spectrometer with 785 nm laser beam pumping. The Raman signal enhancement effect was studied in terms of the number of ablating pulses used, the lens-to-sample distance, and the crater-center-laser-spot offset. The influence of the experiment parameters on Raman signal enhancement was studied for different powder materials. Maximum Raman signal enhancement reached 11 fold for loose powders but decreased twice for pressed tablets. Raman signal enhancement was demonstrated for several diverse powder materials like gypsum or ammonium nitrate with better results achieved for the samples tending to give narrow and deep craters upon the laser ablation stage. Alternative ways of cavity production (steel needle tapping and hole drilling) were compared with the laser cratering technique in terms of Raman signal enhancement. Drilling was found to give the poorest enhancement of the Raman signal, while both laser ablation and steel needle tapping provided comparable results. Here, we have demonstrated for the first time, to the best of our knowledge, that a Raman signal can be enhanced 10 fold with the aid of simple cavity production by steel needle tapping in rough highly reflective materials. Though laser crater enhancement Raman spectroscopy requires an additional pulsed laser, this technique is more appropriate for automatization compared to the needle tapping approach.

Gadolinium-DTPA enhanced MRI of the brain

International Nuclear Information System (INIS)

Hosten, N.; Felix, R.

1994-01-01

The text reviews MRI findings in a variety of cerebral diseases. Advantages of Gadolinium-DTPA (Gd-DTPA) enhanced MRI over plain MRI and enhanced CT are discussed. Enhanced MRI is far superior to enhanced CT in the detection of meningeal tumor spread, meningeal inflammation, inflammatory lesions of the optic nerve, brain lesions in multiple sclerosis and infarction. Enhanced MRI is today the most sensitive diagnostic tool in hypophaseal adenomas. Also enhancement of gliomas is detected by MRI with higher sensitivity than by CT. Use Gd-DTPA allow to separate of vital tumor tissue from necrosis and edema, improve delineation of tumor extension and improve detection of lesions localized in gray matter

Patterns of uterine enhancement with helical CT

Energy Technology Data Exchange (ETDEWEB)

Kaur, H.; Loyer, E.M.; Charnsangavej, C. [Department of Diagnostic Radiology, Box 57, The University of Texas, M.D. Anderson Cancer Center, 1515 Holcombe Blvd. Houston, TX 77030 (United States); Minami, M. [Department of Radiology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113 (Japan)

1998-10-01

Objective: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. Methods: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. Results: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. Conclusion: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT

Patterns of uterine enhancement with helical CT

International Nuclear Information System (INIS)

Kaur, H.; Loyer, E.M.; Charnsangavej, C.; Minami, M.

1998-01-01

Objective: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. Methods: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. Results: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. Conclusion: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT

Contrast enhanced CT of spinal cord angioma

International Nuclear Information System (INIS)

Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

1982-01-01

Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

Enhanced Raman scattering in porous silicon grating.

Science.gov (United States)

Wang, Jiajia; Jia, Zhenhong; Lv, Changwu

2018-03-19

The enhancement of Raman signal on monocrystalline silicon gratings with varying groove depths and on porous silicon grating were studied for a highly sensitive surface enhanced Raman scattering (SERS) response. In the experiment conducted, porous silicon gratings were fabricated. Silver nanoparticles (Ag NPs) were then deposited on the porous silicon grating to enhance the Raman signal of the detective objects. Results show that the enhancement of Raman signal on silicon grating improved when groove depth increased. The enhanced performance of Raman signal on porous silicon grating was also further improved. The Rhodamine SERS response based on Ag NPs/ porous silicon grating substrates was enhanced relative to the SERS response on Ag NPs/ porous silicon substrates. Ag NPs / porous silicon grating SERS substrate system achieved a highly sensitive SERS response due to the coupling of various Raman enhancement factors.

Speech enhancement theory and practice

CERN Document Server

Loizou, Philipos C

2013-01-01

With the proliferation of mobile devices and hearing devices, including hearing aids and cochlear implants, there is a growing and pressing need to design algorithms that can improve speech intelligibility without sacrificing quality. Responding to this need, Speech Enhancement: Theory and Practice, Second Edition introduces readers to the basic problems of speech enhancement and the various algorithms proposed to solve these problems. Updated and expanded, this second edition of the bestselling textbook broadens its scope to include evaluation measures and enhancement algorithms aimed at impr

Public opinions about human enhancement can enhance the expert-only debate. A review study

NARCIS (Netherlands)

Dijkstra, Anne M.; Schuijff, Mirjam

2016-01-01

Human enhancement, the non-medical use of biomedical technologies to improve the human body or performance beyond their ‘natural’ limitations, is a growing trend. At the same time, the use of these technologies has societal consequences. In societal debates about human enhancement, however, it is

Towards a Moderate Stance on Human Enhancement

Directory of Open Access Journals (Sweden)

Nikil Mukerji

2014-05-01

Full Text Available In this essay, we argue against radical ethical views about human enhancement that either dismiss or endorse it tout court. Instead, we advocate the moderate stance that issues of enhancement should be examined with an open mind and on a case-by-case basis. To make this view plausible, we offer three reasons. The first lies in the fact that it is difficult to delineate enhancement conceptually, which makes it hard to argue for general ethical conclusions about it. The second is that an appropriate view of the edifice of moral theory suggests that tenable moral judgements about human enhancement are the result of a careful consideration of the pros and cons that attach to the use of a specific enhancement technology. Lastly, we show that important normative factors in the enhancement debate can be used both in arguments for and in arguments against enhancement. The bottom line of our discussion is that we should treat issues of human enhancement like we do any other ethical issue, viz. by weighing up the reasons pro and con.

An enhanced fractal image denoising algorithm

International Nuclear Information System (INIS)

Lu Jian; Ye Zhongxing; Zou Yuru; Ye Ruisong

2008-01-01

In recent years, there has been a significant development in image denoising using fractal-based method. This paper presents an enhanced fractal predictive denoising algorithm for denoising the images corrupted by an additive white Gaussian noise (AWGN) by using quadratic gray-level function. Meanwhile, a quantization method for the fractal gray-level coefficients of the quadratic function is proposed to strictly guarantee the contractivity requirement of the enhanced fractal coding, and in terms of the quality of the fractal representation measured by PSNR, the enhanced fractal image coding using quadratic gray-level function generally performs better than the standard fractal coding using linear gray-level function. Based on this enhanced fractal coding, the enhanced fractal image denoising is implemented by estimating the fractal gray-level coefficients of the quadratic function of the noiseless image from its noisy observation. Experimental results show that, compared with other standard fractal-based image denoising schemes using linear gray-level function, the enhanced fractal denoising algorithm can improve the quality of the restored image efficiently

Moderate eugenics and human enhancement.

Science.gov (United States)

Selgelid, Michael J

2014-02-01

Though the reputation of eugenics has been tarnished by history, eugenics per se is not necessarily a bad thing. Many advocate a liberal new eugenics--where individuals are free to choose whether or not to employ genetic technologies for reproductive purposes. Though genetic interventions aimed at the prevention of severe genetic disorders may be morally and socially acceptable, reproductive liberty in the context of enhancement may conflict with equality. Enhancement could also have adverse effects on utility. The enhancement debate requires a shift in focus. What the equality and/or utility costs of enhancement will be is an empirical question. Rather than philosophical speculation, more social science research is needed to address it. Philosophers, meanwhile, should address head-on the question of how to strike a balance between liberty, equality, and utility in cases of conflict (in the context of genetics).

Chronological evaluation of liver enhancement in patients with chronic liver disease at Gd-EOB-DTPA-enhanced 3-T MR imaging. Does liver function correlate with enhancement?

International Nuclear Information System (INIS)

Nakamura, Shinichi; Utsunomiya, Daisuke; Namimoto, Tomohiro; Yamashita, Yasuyuki; Awai, Kazuo; Nakaura, Takeshi; Morita, Kosuke

2012-01-01

The purpose of this study was to investigate the chronological relationship between scan delay and liver enhancement for the hepatobiliary phase on Gd-EOB-DTPA-enhanced MRI and evaluate the effects of liver function on liver enhancement. Hepatobiliary-phase images were retrospectively evaluated in 125 patients with chronic liver disease. Hepatobiliary phase images were obtained at 5, 10, 15, and 20 min after injection. We calculated relative liver enhancement (RLE) at t min after injection by dividing the signal intensity (SI) of the liver at t min by precontrast SI. We compared RLE values at 5, 10, 15, and 20 min and evaluated the detectability of focal hepatic lesions. We analyzed the effect of liver function on RLE with the generalized linear model. There was not significant difference in RLE and lesion detectability at 15 and 20 min. RLE in the Child-Pugh C group was significantly lower than in the Child-Pugh A and B groups. The serum albumin level and prothrombin time were significantly correlated with the liver enhancement. A delay time of 15 min for the hepatobiliary phase was thought to be adequate in patients with mild liver dysfunction. The serum albumin level and prothrombin time would be predictive of liver enhancement in the hepatobiliary phase. (author)

Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced Ecg-gated multidetector-row computed tomography

International Nuclear Information System (INIS)

Ko, S.M.; Seo, J.B.; Hong, M.K.; Do, K.H.; Lee, S.H.; Lee, J.S.; Song, J.W.; Park, S.J.; Park, S.W.; Lim, T.H.

2006-01-01

Aim: To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). METHODS: Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. RESULTS: Subendocardial (n=9) or transmural (n=6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n=6); (2) transmural late enhancement (n=1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n=2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. CONCLUSION: Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction

Gd-EOB-DTPA-enhanced magnetic resonance imaging features of hepatic hemangioma compared with enhanced computed tomography

OpenAIRE

Tateyama, Akihiro; Fukukura, Yoshihiko; Takumi, Koji; Shindo, Toshikazu; Kumagae, Yuichi; Kamimura, Kiyohisa; Nakajo, Masayuki

2012-01-01

AIM: To clarify features of hepatic hemangiomas on gadolinium-ethoxybenzyl-diethylenetriaminpentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared with enhanced computed tomography (CT).

Enhanced recovery from surgery in the UK: an audit of the enhanced recovery partnership programme 2009-2012.

Science.gov (United States)

Simpson, J C; Moonesinghe, S R; Grocott, M P W; Kuper, M; McMeeking, A; Oliver, C M; Galsworthy, M J; Mythen, M G

2015-10-01

The UK Department of Health Enhanced Recovery Partnership Programme collected data on 24 513 surgical patients in the UK from 2009-2012. Enhanced Recovery is an approach to major elective surgery aimed at minimizing perioperative stress for the patient. Previous studies have shown Enhanced Recovery to be associated with reduced hospital length of stay and perioperative morbidity. In this national clinical audit, National Health Service hospitals in the UK were invited to submit patient-level data. The data regarding length of stay and compliance with each element of Enhanced Recovery protocols for colorectal, orthopaedic, urological and gynaecological surgery patients were analysed. The relationship between Enhanced Recovery protocol compliance and length of stay was measured. From 16 267 patients from 61 hospital trusts, three out of four surgical specialties showed Enhanced Recovery, compliance being weakly associated with shorter length of stay (correlation coefficients -0.18, -0.14, -0.25 in colorectal, orthopaedics and gynaecology respectively). At a cut-off of 80% compliance, good compliance was associated with two, one and three day reductions in median length of stay respectively in colorectal, orthopaedic and urological surgeries, with no saving in gynaecology. This study is the largest assessment of the relationship between Enhanced Recovery protocol compliance and outcome in four surgical specialties. The data suggest that higher compliance with an Enhanced Recovery protocol has a weak association with shorter length of stay. This suggests that changes in process, resulting from highly protocolised pathways, may be as important in reducing perioperative length of stay as any individual element of Enhanced Recovery protocols in isolation. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Enhance Video Film using Retnix method

Science.gov (United States)

Awad, Rasha; Al-Zuky, Ali A.; Al-Saleh, Anwar H.; Mohamad, Haidar J.

2018-05-01

An enhancement technique used to improve the studied video quality. Algorithms like mean and standard deviation are used as a criterion within this paper, and it applied for each video clip that divided into 80 images. The studied filming environment has different light intensity (315, 566, and 644Lux). This different environment gives similar reality to the outdoor filming. The outputs of the suggested algorithm are compared with the results before applying it. This method is applied into two ways: first, it is applied for the full video clip to get the enhanced film; second, it is applied for every individual image to get the enhanced image then compiler them to get the enhanced film. This paper shows that the enhancement technique gives good quality video film depending on a statistical method, and it is recommended to use it in different application.

Speech enhancement on smartphone voice recording

International Nuclear Information System (INIS)

Atmaja, Bagus Tris; Farid, Mifta Nur; Arifianto, Dhany

2016-01-01

Speech enhancement is challenging task in audio signal processing to enhance the quality of targeted speech signal while suppress other noises. In the beginning, the speech enhancement algorithm growth rapidly from spectral subtraction, Wiener filtering, spectral amplitude MMSE estimator to Non-negative Matrix Factorization (NMF). Smartphone as revolutionary device now is being used in all aspect of life including journalism; personally and professionally. Although many smartphones have two microphones (main and rear) the only main microphone is widely used for voice recording. This is why the NMF algorithm widely used for this purpose of speech enhancement. This paper evaluate speech enhancement on smartphone voice recording by using some algorithms mentioned previously. We also extend the NMF algorithm to Kulback-Leibler NMF with supervised separation. The last algorithm shows improved result compared to others by spectrogram and PESQ score evaluation. (paper)

Source memory enhancement for emotional words.

Science.gov (United States)

Doerksen, S; Shimamura, A P

2001-03-01

The influence of emotional stimuli on source memory was investigated by using emotionally valenced words. The words were colored blue or yellow (Experiment 1) or surrounded by a blue or yellow frame (Experiment 2). Participants were asked to associate the words with the colors. In both experiments, emotionally valenced words elicited enhanced free recall compared with nonvalenced words; however, recognition memory was not affected. Source memory for the associated color was also enhanced for emotional words, suggesting that even memory for contextual information is benefited by emotional stimuli. This effect was not due to the ease of semantic clustering of emotional words because semantically related words were not associated with enhanced source memory, despite enhanced recall (Experiment 3). It is suggested that enhancement resulted from facilitated arousal or attention, which may act to increase organization processes important for source memory.

IDENTIFICATION OF ANIMAL ADHESIVES USING DNA AMPLIFICATION

DEFF Research Database (Denmark)

Eriksen, Anne Marie; Kristensen, Hans Viborg; Bøllingtoft, Peder

2014-01-01

The aim of this study was to examine whether DNA was degraded in the manufacturing of animal glue. To test this, two different types of sturgeon glue (Acipenser sp.) were manufactured using historic recipes. One glue was boiled for a substantial amount of time and the other was kept under 75°C. DNA...... of the glue and in 18 out of 24 samples collected of the canvas. In four out of the five cases where it was not possible amplify DNA, the sample belongs to the smallest size of the canvas investigated. As shown in this study it is possible to get DNA out of boiled animal glue and glue applied onto canvas...

Concentrations of elements in fish fillets, fish muscle plugs, and crayfish from the 2007 Missouri Department of Conservation General Contaminant Monitoring Program

Science.gov (United States)

May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

2009-01-01

This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in fish fillets, fish muscle plugs, and crayfish. Fillets of channel catfish (Ictalurus punctatus), bass (Micropterus salmoides, Micropterus dolomieu, Morone chrysops), walleye (Sander vitreus), common carp (Cyprinus carpio), lake sturgeon (Acipenser fulvescens), northern hog sucker (Hypentelium nigricans), and rainbow trout (Oncorhynchus mykiss) were collected from 21 sites as part of the Department's Fish Contaminant Monitoring Program. Long-pincered crayfish (Orconectes longidigitus) were collected from one site to assess trophic transfer of metals to fish. Fish muscle plugs were collected from smallmouth bass (Micropterus dolomieu) at two different locations from one site.

Biocatalyst Enhancement

Science.gov (United States)

The increasing availability of enzyme collections has assisted attempts by pharmaceutical producers to adopt green chemistry approaches to manufacturing. A joint effort between an enzyme producer and a pharmaceutical manufacturer has been enhanced over the past three years by ena...

Comparative analysis of different methods for image enhancement

Institute of Scientific and Technical Information of China (English)

吴笑峰; 胡仕刚; 赵瑾; 李志明; 李劲; 唐志军; 席在芳

2014-01-01

Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively, it can improve image visual effect. The objective of this work is to implement the image enhancement to gray scale images using different techniques. After the fundamental methods of image enhancement processing are demonstrated, image enhancement algorithms based on space and frequency domains are systematically investigated and compared. The advantage and defect of the above-mentioned algorithms are analyzed. The algorithms of wavelet based image enhancement are also deduced and generalized. Wavelet transform modulus maxima (WTMM) is a method for detecting the fractal dimension of a signal, it is well used for image enhancement. The image techniques are compared by using the mean (μ), standard deviation (s), mean square error (MSE) and PSNR (peak signal to noise ratio). A group of experimental results demonstrate that the image enhancement algorithm based on wavelet transform is effective for image de-noising and enhancement. Wavelet transform modulus maxima method is one of the best methods for image enhancement.

Breast dynamic contrast enhanced MRI: fibrocystic changes presenting as a non-mass enhancement mimicking malignancy

Directory of Open Access Journals (Sweden)

Milosevic Zorica C.

2017-06-01

Full Text Available We aimed to analyse the morphokinetic features of breast fibrocystic changes (nonproliferative lesions, proliferative lesions without atypia and proliferative lesions with atypia presenting as a non-mass enhancement (NMEin dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI examination.

Recent Progress on Plasmon-Enhanced Fluorescence

Directory of Open Access Journals (Sweden)

Dong Jun

2015-12-01

Full Text Available The optically generated collective electron density waves on metal–dielectric boundaries known as surface plasmons have been of great scientific interest since their discovery. Being electromagnetic waves on gold or silver nanoparticle’s surface, localised surface plasmons (LSP can strongly enhance the electromagnetic field. These strong electromagnetic fields near the metal surfaces have been used in various applications like surface enhanced spectroscopy (SES, plasmonic lithography, plasmonic trapping of particles, and plasmonic catalysis. Resonant coupling of LSPs to fluorophore can strongly enhance the emission intensity, the angular distribution, and the polarisation of the emitted radiation and even the speed of radiative decay, which is so-called plasmon enhanced fluorescence (PEF. As a result, more and more reports on surface-enhanced fluorescence have appeared, such as SPASER-s, plasmon assisted lasing, single molecule fluorescence measurements, surface plasmoncoupled emission (SPCE in biological sensing, optical orbit designs etc. In this review, we focus on recent advanced reports on plasmon-enhanced fluorescence (PEF. First, the mechanism of PEF and early results of enhanced fluorescence observed by metal nanostructure will be introduced. Then, the enhanced substrates, including periodical and nonperiodical nanostructure, will be discussed and the most important factor of the spacer between molecule and surface and wavelength dependence on PEF is demonstrated. Finally, the recent progress of tipenhanced fluorescence and PEF from the rare-earth doped up-conversion (UC and down-conversion (DC nanoparticles (NPs are also commented upon. This review provides an introduction to fundamentals of PEF, illustrates the current progress in the design of metallic nanostructures for efficient fluorescence signal amplification that utilises propagating and localised surface plasmons.

ICRF enhanced potentials

International Nuclear Information System (INIS)

Nelson, B.A.

1987-01-01

Ion-confining potentials in the Phaedrus tandem mirror are shown to be enhanced over Boltzmann-relations predicted values by radio-frequency (rf) waves in the ion cyclotron range of frequencies (ICRF). The ICRF enhanced potential is larger in the end cell with a lower passing density. Peak potential values decrease with increasing ion endloss current (or central cell density) for a constant rf capacitor bank voltage, and increase with increasing rf-capacitor bank voltage, for a constant ion endloss value (or central cell density). In fully axisymmetric operation, a potential peak is produced in an end cell by the central-cell rf, (with-out end-cell rf) and is found only in the end cell nearer the central-cell antenna. ICRF enhanced potentials are explained as an equilibrium between the electron-collisional filling-in rate and the electron pumping out rate provided by axial time-varying electric fields. Thermal barrier-like potential structures were found in the transition regions between the central cell and end cells, in the fully axisymmetric Phaedrus. Central-cell ICRF trapping effects combined with end-cell μΔ B forces create and pump the barrier potential wells

Identification of activated enhancers and linked transcription factors in breast, prostate, and kidney tumors by tracing enhancer networks using epigenetic traits.

Science.gov (United States)

Rhie, Suhn Kyong; Guo, Yu; Tak, Yu Gyoung; Yao, Lijing; Shen, Hui; Coetzee, Gerhard A; Laird, Peter W; Farnham, Peggy J

2016-01-01

Although technological advances now allow increased tumor profiling, a detailed understanding of the mechanisms leading to the development of different cancers remains elusive. Our approach toward understanding the molecular events that lead to cancer is to characterize changes in transcriptional regulatory networks between normal and tumor tissue. Because enhancer activity is thought to be critical in regulating cell fate decisions, we have focused our studies on distal regulatory elements and transcription factors that bind to these elements. Using DNA methylation data, we identified more than 25,000 enhancers that are differentially activated in breast, prostate, and kidney tumor tissues, as compared to normal tissues. We then developed an analytical approach called Tracing Enhancer Networks using Epigenetic Traits that correlates DNA methylation levels at enhancers with gene expression to identify more than 800,000 genome-wide links from enhancers to genes and from genes to enhancers. We found more than 1200 transcription factors to be involved in these tumor-specific enhancer networks. We further characterized several transcription factors linked to a large number of enhancers in each tumor type, including GATA3 in non-basal breast tumors, HOXC6 and DLX1 in prostate tumors, and ZNF395 in kidney tumors. We showed that HOXC6 and DLX1 are associated with different clusters of prostate tumor-specific enhancers and confer distinct transcriptomic changes upon knockdown in C42B prostate cancer cells. We also discovered de novo motifs enriched in enhancers linked to ZNF395 in kidney tumors. Our studies characterized tumor-specific enhancers and revealed key transcription factors involved in enhancer networks for specific tumor types and subgroups. Our findings, which include a large set of identified enhancers and transcription factors linked to those enhancers in breast, prostate, and kidney cancers, will facilitate understanding of enhancer networks and mechanisms

Overhauser-enhanced MR imaging (OMRI)

DEFF Research Database (Denmark)

Golman, K; Leunbach, I; Ardenkjaer-Larsen, JH

1998-01-01

Purpose. To evaluate a new single-electron contrast agent for Overhauser-enhanced MR imaging. The contrast agents that are currently available give enhancement factors that are too low to make the technique a valid option for routine clinical use. Material and Methods. MR images were generated di...

Spectroscopic enhancement in nanoparticles embedded glasses

Energy Technology Data Exchange (ETDEWEB)

Sahar, M. R., E-mail: mrahim057@gmail.com; Ghoshal, S. K., E-mail: mrahim057@gmail.com [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

2014-09-25

This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

MRI enhancement of the facial nerve with Gd-DTPA, 2; Investigation of enhanced nerve portions in patients with facial palsy

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Masahiro [Kansai Medical School, Moriguchi, Osaka (Japan)

1993-08-01

We performed enhanced MRI using Gd-DTPA in 84 patients with facial palsy. After assessing enhancement of the normal facial nerve, we examined enhancement in patients with Bell's palsy and Ramsay Hunt syndrome. In 95% of patients with Bell's palsy, enhancement was obtained in the distal IAC and labyrinthine portions. In 72%, enhancement was significant from the distal IAC portion through the vertical portion. In some of the patients who underwent enhanced MRI twice, increased signal intensity was observed in distal portions such as the vertical portion. In many cases of Ramsay Hunt syndrome, enhancement was seen extensively in the IAC portion through the vertical portion. In the subjects with internal auditory symptoms such as vertigo and tinnitus, enhancement of the IAC portion was seen not only in the facial nerve but also in the vestibular and the cochlear nerves. These results suggest that the vascular permeability of lesions in Bell's palsy may be increased from the distal IAC portion to the vertical portion. Judging from the present findings with Ramsay Hunt syndrome, symptoms related to the enhanced portions suggest that accompanying internal auditory symptoms occur due to inflammation of the IAC portions of cochlear and vestibular nerves. (author).

A simulation study of enhancement duration in three-dimensional contrast-enhanced MR angiography

International Nuclear Information System (INIS)

Ohkubo, Masaki; Ohgoshi, Yukio; Inoue, Tomoko; Naito, Kenichi; Suzuki, Kiyotaka

2001-01-01

In our study on three-dimensional (3D) contrast-enhanced MR angiography we performed a computer simulation to investigate quantitative vessel visibility. In the simulation, we evaluated the relative loss of signal intensity in a vessel due to shortened duration of contrast-enhancement. The mid-point of enhancement-duration was assumed to be at the point in which the data in the center of k-space (k y axis) was acquired. Signal intensity of a vessel decreased as the enhancement-duration was shortened and the diameter of the vessel was decreased. When the duration was shortened 40%, the signal intensity of a vessel in which the diameter was more than 2 pixels was preserved by approximately 70% or more. This suggests that the vessel visibility is high. When the duration was shortened 20%, the signal intensity of a vessel in which the diameter was less than 2 pixels decreased to less than approximately 40% or less. The simulation was confirmed by using 3D MR angiography with a tube phantom filled with Gd-DTPA to simulate a vessel model. At anytime during data acquisition, we could set the phantom on the region being scanned or take it out by using the ''pause'' function of the MR scanner. This made it possible to change the enhancement-duration to match the simulation. Results of the phantom study were comparable to those of the simulation, suggesting that the simulation was valid. Our results and simple techniques for both the simulation and the phantom study using the ''pause'' function, were considered useful in the study of 3D MR angiography. (author)

Gd-DTPA-enhanced MR imaging in meningitis

International Nuclear Information System (INIS)

Han, M.H.; Chang, K.H.; Roh, J.K.; Kim, I.O.; Han, M.C.; Kim, C.W.

1988-01-01

Gd-DPTA-enhanced MR imaging was performed in 16 patients with meningitis (seven tuberculous, four bacterial, three fungal, and two viral) on a 2.0-T unit. Hemorrhagic infarcts of basal ganglia and localized enhancement of thickened dura adjacent were demonstrated on T1-weighted images in three patients with tuberculous meningitis and four with bacterial meningitis, respectively, that were not seen on CT. Enhanced T1-weighted images readily differentiated leptomeningeal enhancement from vessels in two cases with CT of equivocal meningeal enhancement. Nonenhanced T2-weighted images were most sensitive for demonstrating ischemia/infarct and edema. Otherwise, MR images generally matched CT scans

Post Fukushima safety enhancements in Indian PHWRS

International Nuclear Information System (INIS)

Ramasomayajulu, M.; Khot, Pankaj; Chauhan, Ashok

2016-01-01

Fukushima event was reviewed in Nuclear Power Corporation of India (NPCIL) and based on these reviews, safety enhancements were identified for Indian PHWRs. Safety enhancements such as additional emergency power sources, enhanced onsite water inventories, external water injection arrangements (Hook up points), measures related to hydrogen management, containment venting provision, seismic trip, mobile pumps, onsite emergency support Centre. These safety enhancements were reviewed by the regulatory body (Atomic Energy Regulatory Board, AERB) and were approved for implementation. Most of these are either implemented or in the advance stage of implementation. The paper elaborates above safety enhancements implemented post Fukushima accident; and preparedness to use these provisions. (author)

Evaluation of residual hepatocellular carcinoma after transcatheter arterial chemoembolization: Comparison between contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography

International Nuclear Information System (INIS)

Kim, Seung Hoon; Lim, Hyo Keun; Lee, Won Jae

2001-01-01

To evaluate the effectiveness of contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography (PDUS) in assessing the therapeutic effect of transcatheter arterial chemoembolization (TACE) in hepatocellular carcinomas (HCCs). The follow-up contrast-enhanced helical CT and contrast-enhanced PDUS were performed for twenty-nine nodular HCCs from twelve patients previously treated with TACE. We defined the residual HCCs as intratumoral enhancing area on contrast-enhanced helical CT and color signal on contrast-enhanced PDUS. The interval between two examinations was less than 2 weeks (mean, 9 days). Two radiologists evaluated two examinations by consensus, and the results of these two examination were compared with the findings of other examinations including CT, angiography, and/or pathology to calculate the sensitivity, specificity and accuracy of two examinations. Of the 29 HCCs, 20 had residual HCCs whereas no residual HCCs in 9 HCCs on pathologic examination and/or follow-up radiologic study. The sensitivity, sensitivity and accuracy of contrast-enhanced helical CT were 65 (13/20), 89 (8/9), and 72% (21/29) while those of contrast-enhanced PDUS were 100 (20/20), 89 (8/9) and 97% (28/29), respectively. A microbubble contrast-enhanced PDUS was more effective in the detection of residual tumor in HCCs following TACE than contrast-enhanced helical CT.

Heat transfer enhancement on nucleate boiling

International Nuclear Information System (INIS)

Zhuang, M.; Guibai, L.

1990-01-01

This paper reports on enhancement of nucleate boiling heat transfer with additives that was investigated experimentally. More than fifteen kinds of additives were chosen and tested. Eight kinds of effective additives which can enhance nucleate boiling heat transfer were selected. Experimental results showed that boiling heat transfer coefficient of water was increased by 1 to 5 times and that of R-113 was increased by 1 to 4 times when trace amount additives were put in the two boiling liquids. There exist optimum concentrations for the additives, respectively, which can enhance nucleate boiling heat transfer rate best. In order to analyze the mechanism of the enhancement of boiling heat transfer with additives, the surface tension and the bubble departure diameter were measured. The nucleation sites were investigated by use of high-speed photograph. Experimental results showed that nucleation sites increase with additive amount increasing and get maximum. Increasing nucleation sites is one of the most important reason why nucleate boiling heat transfer can be enhanced with additives

Adaptive multiscale processing for contrast enhancement

Science.gov (United States)

Laine, Andrew F.; Song, Shuwu; Fan, Jian; Huda, Walter; Honeyman, Janice C.; Steinbach, Barbara G.

1993-07-01

This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms within a continuum of scale space and used to enhance features of importance to mammography. Choosing analyzing functions that are well localized in both space and frequency, results in a powerful methodology for image analysis. We describe methods of contrast enhancement based on two overcomplete (redundant) multiscale representations: (1) Dyadic wavelet transform (2) (phi) -transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by non-linear, logarithmic and constant scale-space weight functions. Multiscale edges identified within distinct levels of transform space provide a local support for enhancement throughout each decomposition. We demonstrate that features extracted from wavelet spaces can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.

Gabor filter based fingerprint image enhancement

Science.gov (United States)

Wang, Jin-Xiang

2013-03-01

Fingerprint recognition technology has become the most reliable biometric technology due to its uniqueness and invariance, which has been most convenient and most reliable technique for personal authentication. The development of Automated Fingerprint Identification System is an urgent need for modern information security. Meanwhile, fingerprint preprocessing algorithm of fingerprint recognition technology has played an important part in Automatic Fingerprint Identification System. This article introduces the general steps in the fingerprint recognition technology, namely the image input, preprocessing, feature recognition, and fingerprint image enhancement. As the key to fingerprint identification technology, fingerprint image enhancement affects the accuracy of the system. It focuses on the characteristics of the fingerprint image, Gabor filters algorithm for fingerprint image enhancement, the theoretical basis of Gabor filters, and demonstration of the filter. The enhancement algorithm for fingerprint image is in the windows XP platform with matlab.65 as a development tool for the demonstration. The result shows that the Gabor filter is effective in fingerprint image enhancement technology.

Enhanced Gain in Photonic Crystal Amplifiers

DEFF Research Database (Denmark)

Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

2012-01-01

We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission....... These results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

Memory enhancing drugs and Alzheimer's disease: enhancing the self or preventing the loss of it?

NARCIS (Netherlands)

Dekkers, W.J.M.; Olde Rikkert, M.G.M.

2007-01-01

In this paper we analyse some ethical and philosophical questions related to the development of memory enhancing drugs (MEDs) and anti-dementia drugs. The world of memory enhancement is coloured by utopian thinking and by the desire for quicker, sharper, and more reliable memories. Dementia is

Tumoural portal vein thrombosis. Enhancement with MnDPDP

International Nuclear Information System (INIS)

Marti-Bonmati, L.; Lonjedo, E.; Mathieu, D.; Coffin, C.; Poyatos, C.; Anglade, M.C.

1997-01-01

Purpose: Intrahepatic thrombus is usually associated with either cirrhosis or hepatocellular carcinoma (HCC). Most HCCs enhance after the administration of MnDPDP (Teslascan). Our objective was to analyze the enhancement characteristics of tumour portal vein thrombi. Material and Methods: Thrombi affecting the main or segmental portal veins (17 cases) and the suprahepatic inferior vena cava (1 case) were retrospectively selected from a series of 128 patients studied with MR imaging before and after the administration of MnDPDP. Enhancement was assessed qualitatively and quantitatively. Results: All tumour thrombi enhanced after MnDPDP administration. The enhancement was more conspicuous in the GRE images. On the quantitative evaluation, the portal thrombus enhancement was greater for GRE images than SE images. Portal thrombi enhanced more than the liver and the HCCs. There was a significant difference between the enhancement of the HCCs and the thrombi with both MR imaging techniques. (orig./AJ)

Neurostimulation for Memory Enhancement in Epilepsy.

Science.gov (United States)

Meisenhelter, Stephen; Jobst, Barbara C

2018-04-19

Memory is one of the top concerns of epilepsy patients, but there are no known treatments to directly alleviate the memory deficits associated with epilepsy. Neurostimulation may provide new therapeutic tools to enhance memory in epilepsy patients. Here, we critically review recent investigations of memory enhancement using transcranial electrical stimulation (tES), transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), chronic intracranial stimulation, and acute intracranial stimulation. Existing literature suggests that transcranial direct current stimulation (tDCS) produces a small enhancement in memory in neuropsychological patients, but transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) have not been found to have an effect on memory. Most studies of transcranial magnetic stimulation (TMS) have found that TMS has no positive effect on memory. Vagus nerve stimulation can acutely enhance memory, while chronic therapy does not appear to alter memory performance. We found that there is the most evidence for significant memory enhancement using intracranial stimulation techniques, especially chronic stimulation of the fornix and task-responsive stimulation of the lateral temporal lobe. Presently, there are no existing therapeutic options for directly treating epilepy-related memory deficits. While neurostimulation technologies for memory enhancement are largely still in the experimental phase, neurostimulation appears promising as a future technique for treating epilepsy-related memory deficits.

Contrast Enhanced US in the Abdomen

International Nuclear Information System (INIS)

Chung, Yong Eun; Kim, Ki Whang

2012-01-01

Contrast enhanced ultrasound, which was introduced in 1996, has been widely used in Europe and Eastern Asia. Ultrasound contrast agent can be classified as first generation and second generation, depending on the gas within the microbubble. With the first generation contrast agent, the high MI technique was used, and only intermittent scanning was possible due to destruction of the microbubble during scanning. Use of the second generation contrast agent with the low MI technique makes continuous scanning possible. Contrast enhanced US can be used in detection and differentiation of focal liver lesions. It is also helpful for monitoring of radiofrequency ablation and for targeting of US guided biopsy. Currently, because morphologic criteria alone may not reflect the response of the tumor to treatment, new criteria are needed for treatment evaluation after administration of anti-angiogenic agents. Contrast enhanced US could provide quantitative markers for evaluation of the response to treatment via use of dynamic contrast enhanced US. Due to cost-effectiveness, contrast enhanced US is not yet widely used in Korea; however, considering recent issues regarding contrast agent related adverse reaction, such as contrast induced nephropathy and nephrogenic systemic fibrosis, and radiation exposure, contrast enhanced US might be more widely used in Korea, as an alternative imaging modality in the future.

Chemical Penetration Enhancers for Transdermal Drug Delivery ...

African Journals Online (AJOL)

for transdermal administration. The permeation of drug through skin can be enhanced by both chemical penetration enhancement and physical methods. In this review, we have discussed the chemical penetration enhancement technology for transdermal drug delivery as well as the probable mechanisms of action.

Radiographic enhancement and analysis system

International Nuclear Information System (INIS)

Schlosser, M.S.

1981-01-01

Radiographic image enhancement and analysis techniques are discussed as they apply to nondestructive inspection. A system is described which has been developed to enhance and quantitatively evaluate radiographic images using digital computer techniques. Some examples of typical applications are also presented as an introduction to this new inspection technique. (author)

Enhancement of blurred image portions

NARCIS (Netherlands)

2008-01-01

This invention relates to a method for image enhancement, comprising a first step ( 41 ) of distinguishing blurred and non-blurred image portions of an input image, and a second step ( 42 ) of enhancing at least one of said blurred image portions of said input image to produce an output image. Said

Antenna-assisted enhanced transmission through subwavelength nanoholes

DEFF Research Database (Denmark)

Xiao, Sanshui; Peng, Liang; Mortensen, Asger

2010-01-01

By structural engineering of sub-wavelength apertures, we numerically demonstrate that transmission through apertures can be significantly enhanced. Based on equivalent circuit theory analysis, structured apertures are obtained with a 1900-fold transmission enhancement factor. We show that the en......By structural engineering of sub-wavelength apertures, we numerically demonstrate that transmission through apertures can be significantly enhanced. Based on equivalent circuit theory analysis, structured apertures are obtained with a 1900-fold transmission enhancement factor. We show...

Comparative polymorphism of sterlet fertilizers (Acipenser Ruthenus for microsatellite DNA markers

Directory of Open Access Journals (Sweden)

Ольга Олексіївна Малишева

2015-11-01

Full Text Available Based on microsatellite DNA markers in three (LG-19, LS-68 and LS-39 it is examined intraspecific genetic structure of sterlet fertilizers. As a result of this work it was found that this group of fish is in a balanced state in terms of the genetic polymorphism. On the basis of certain individual differences in allelic variants have been selected and combined the parental pairs for alternative genotypes. The results of the research allow optimize further work on the reproduction of sturgeon under artificial cultivation

Chlorella biomass as feed supplement for freshwater fish: sterlet, Acipenser ruthenus

Czech Academy of Sciences Publication Activity Database

Sergejevova, Magda; Masojídek, Jiří

2012-01-01

Roč. 44, č. 1 (2012), s. 157-159 ISSN 1355-557X R&D Projects: GA ČR GA521/09/0656; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : carotenoid * colouration * lutein Subject RIV: EE - Microbiology, Virology Impact factor: 1.422, year: 2012

MRI enhancement of the facial nerve with Gd-DTPA, 2; Investigation of enhanced nerve portions in patients with facial palsy

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Masahiro (Kansai Medical School, Moriguchi, Osaka (Japan))

1993-08-01

We performed enhanced MRI using Gd-DTPA in 84 patients with facial palsy. After assessing enhancement of the normal facial nerve, we examined enhancement in patients with Bell's palsy and Ramsay Hunt syndrome. In 95% of patients with Bell's palsy, enhancement was obtained in the distal IAC and labyrinthine portions. In 72%, enhancement was significant from the distal IAC portion through the vertical portion. In some of the patients who underwent enhanced MRI twice, increased signal intensity was observed in distal portions such as the vertical portion. In many cases of Ramsay Hunt syndrome, enhancement was seen extensively in the IAC portion through the vertical portion. In the subjects with internal auditory symptoms such as vertigo and tinnitus, enhancement of the IAC portion was seen not only in the facial nerve but also in the vestibular and the cochlear nerves. These results suggest that the vascular permeability of lesions in Bell's palsy may be increased from the distal IAC portion to the vertical portion. Judging from the present findings with Ramsay Hunt syndrome, symptoms related to the enhanced portions suggest that accompanying internal auditory symptoms occur due to inflammation of the IAC portions of cochlear and vestibular nerves. (author).

Enhanced sludge washing evaluation plan

Energy Technology Data Exchange (ETDEWEB)

Jensen, R.D.

1994-09-01

The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices.

Enhanced sludge washing evaluation plan

International Nuclear Information System (INIS)

Jensen, R.D.

1994-09-01

The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices

Human Enhancement and the Story of Job.

Science.gov (United States)

Agar, Nicholas; McDonald, Johnny

2017-07-01

This article explores some implications of the concept of transformative change for the debate about human enhancement. A transformative change is understood to be one that significantly alters the value an individual places on his or her experiences or achievements. The clearest examples of transformative change come from science fiction, but the concept can be illuminatingly applied to the enhancement debate. We argue that it helps to expose a threat from too much enhancement to many of the things that make human lives valuable. Among the things threated by enhancement are our relationships with other human beings. The potential to lose these relationships provides a compelling reason for almost all humans to reject too much enhancement.

Enhanced Recovery in Thoracic Surgery: A Review

Directory of Open Access Journals (Sweden)

Vesna D. Dinic

2018-02-01

Full Text Available The main goal of enhanced recovery program after thoracic surgery is to minimize stress response, reduce postoperative pulmonary complications, and improve patient outcome, which will in addition decrease hospital stay and reduce hospital costs. As minimally invasive technique, video-assisted thoracoscopic surgery represents an important element of enhanced recovery program in thoracic surgery. Anesthetic management during preoperative, intraoperative and postoperative period is essential for the enhanced recovery. In the era of enhanced recovery protocols, non-intubated thoracoscopic procedures present a step forward. This article focuses on the key elements of the enhanced recovery program in thoracic surgery. Having reviewed recent literature, the authors highlight potential procedures and techniques that might be incorporated into the program.

Enhancing operational safety

Energy Technology Data Exchange (ETDEWEB)

Wiebe, J S

1997-09-01

The presentation briefly considers the following aspects concerning enhancing operational safety of NPP: licensed control room supervision, reactivity changes, personnel access to control room, simulator training.

Comparison of Oral Contrast-Enhanced Transabdominal Ultrasound Imaging With Transverse Contrast-Enhanced Computed Tomography in Preoperative Tumor Staging of Advanced Gastric Carcinoma.

Science.gov (United States)

He, Xuemei; Sun, Jing; Huang, Xiaoling; Zeng, Chun; Ge, Yinggang; Zhang, Jun; Wu, Jingxian

2017-12-01

This study assessed the diagnostic performance of transabdominal oral contrast-enhanced ultrasound (US) imaging for preoperative tumor staging of advanced gastric carcinoma by comparing it with transverse contrast-enhanced computed tomography (CT). This retrospective study included 42 patients with advanced gastric cancer who underwent laparoscopy, radical surgery, or palliative surgery because of serious complications and had a body mass index of less than 25 kg/m 2 . A cereal-based oral contrast agent was used for transabdominal oral contrast-enhanced US. Retrospective analyses were conducted using preoperative tumor staging data acquired by either transabdominal oral contrast-enhanced US or transverse contrast-enhanced CT. Both contrast-enhanced US and contrast-enhanced CT examinations were reviewed by 2 experienced radiologists independently for preoperative tumor staging according to the seventh edition of the TNM classification. The accuracy, sensitivity, and specificity were calculated by comparing the results of contrast-enhanced US and contrast-enhanced CT with pathologic findings. The overall accuracies of the imaging modalities were compared by the McNemar test. No significant difference was noted in the overall accuracy of transabdominal oral contrast-enhanced US (86% [36 of 42]) and transverse contrast-enhanced CT (83% [35 of 42] P > .999). For stage T2 to T4 gastric cancer, the accuracies of transabdominal oral contrast-enhanced US were 88%, 86%, and 98%, respectively, and those of transverse contrast-enhanced CT were 93%, 83%, and 90%. The overall accuracy of transabdominal oral contrast-enhanced US was comparable with that of transverse contrast-enhanced CT for preoperative tumor staging of advanced gastric cancer. © 2017 by the American Institute of Ultrasound in Medicine.

Surfactant enhanced non-classical extraction

International Nuclear Information System (INIS)

Szymanowski, J.

2000-01-01

Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilisation abilities are also discussed. (author)

Surfactant enhanced non-classical extraction

International Nuclear Information System (INIS)

Szymanowski, J.

1999-01-01

Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilization abilities are also discussed. (author)

Histopathologic diversity of gastric cancers: Relationship between enhancement pattern on dynamic contrast-enhanced CT and histological type.

Science.gov (United States)

Tsurumaru, Daisuke; Miyasaka, Mitsutoshi; Muraki, Toshio; Nishie, Akihiro; Asayama, Yoshiki; Oki, Eiji; Oda, Yoshinao; Honda, Hiroshi

2017-12-01

To evaluate the diagnostic value of contrast-enhanced computed tomography gastrography (CE-CTG) to predict the histological type of gastric cancer. We analyzed 47 consecutive patients with resectable advanced gastric cancer preoperatively evaluated by multiphasic dynamic contrast-enhanced CT. Two radiologists independently reviewed the CT images and they determined the peak enhancement phase, and then measured the CT attenuation value of the gastric lesion for each phase. The histological types of gastric cancers were assigned to three groups as differentiated-type, undifferentiated-type, and mixed-type. We compared the peak enhancement phase of the three types and compared the CT attenuation values in each phase. The peak enhancement was significantly different between the three types of gastric cancers for both readers (reader 1, p=0.001; reader 2, p=0.009); most of the undifferentiated types had peak enhancement in the delayed phase. The CT attenuation values of undifferentiated type were significantly higher than those of differentiated or mixed type in the delayed phase according to both readers (reader 1, p=0.002; reader 2, p=0.004). CE-CTG could provide helpful information in diagnosing the histological type of gastric cancers preoperatively. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancing Rotational Diffusion Using Oscillatory Shear

KAUST Repository

Leahy, Brian D.; Cheng, Xiang; Ong, Desmond C.; Liddell-Watson, Chekesha; Cohen, Itai

2013-01-01

Taylor dispersion - shear-induced enhancement of translational diffusion - is an important phenomenon with applications ranging from pharmacology to geology. Through experiments and simulations, we show that rotational diffusion is also enhanced

Analyzing Security-Enhanced Linux Policy Specifications

National Research Council Canada - National Science Library

Archer, Myla

2003-01-01

NSA's Security-Enhanced (SE) Linux enhances Linux by providing a specification language for security policies and a Flask-like architecture with a security server for enforcing policies defined in the language...

Novel routes to electromagnetic enhancement and its characterisation in surface- and tip-enhanced Raman scattering.

Science.gov (United States)

Dawson, P; Frey, D; Kalathingal, V; Mehfuz, R; Mitra, J

2017-12-04

Quantitative understanding of the electromagnetic component in enhanced Raman spectroscopy is often difficult to achieve on account of the complex substrate structures utilised. We therefore turn to two structurally simple systems amenable to detailed modelling. The first is tip-enhanced Raman scattering under electron scanning tunnelling microscopy control (STM-TERS) where, appealing to understanding developed in the context of photon emission from STM, it is argued that the localised surface plasmon modes driving the Raman enhancement exist in the visible and near-infrared regime only by virtue of significant modification to the optical properties of the tip and sample metals (gold here). This is due to the strong dc field-induced (∼10 9 V m -1 ) non-linear corrections to the dielectric function of gold via the third order susceptibility term in the polarisation. Also, sub-5 nm spatial resolution is shown in the modelling. Secondly, we suggest a novel deployment of hybrid plasmonic waveguide modes in surface enhanced Raman scattering (HPWG-SERS). This delivers strong confinement of electromagnetic energy in a ∼10 nm oxide 'gap' between a high-index dielectric material of nanoscale width (a GaAs nanorod and a 100 nm Si slab are considered here) and a metal, yielding a monotonic variation in the Raman enhancement factor as a function of wavelength with no long-wavelength cut-off, both features that contrast with STM-TERS.

Novelty enhances visual perception.

Directory of Open Access Journals (Sweden)

Judith Schomaker

Full Text Available The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

Novelty enhances visual perception.

Science.gov (United States)

Schomaker, Judith; Meeter, Martijn

2012-01-01

The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

Cortical enhancement in chronic subdural hematoma

International Nuclear Information System (INIS)

Taguchi, Yoshio; Sato, Jun; Makita, Tadatoshi; Hayashi, Shigetoshi; Nakamura, Norio.

1981-01-01

In the CT findings of chronic subdural hematoma, brain enhancement adjacent to a subdural hematoma was seen occasionally after the injection of a contrast material. The authors called this finding ''cortical enhancement'', and 35 cases of chronic subdural hematoma were studied concerning cortical enhancement in relation to age, clinical signs and symptoms, hematoma density, and volume of the hematoma. Eight cases out of the 35 were subjected to measurements of the regional cerebral blood flow preoperatively by the method of the carotid injection of Xe-133. Cortical enhancement was apt to be seen in the cases which revealed intracranial hypertension or disturbance of consciousness, in isodensity or mixed-density hematomas, and in huge subdural hematomas. There was no specific correlation with age distribution. The pathogenesis of cortical enhancement seemed to be the result of cerebral compression with an increase in the contrast material per unit of volume and a prolonged venous outflow from the hemisphere, but no characteristic feature was detected in the average regional cerebral blood flow in our cases. (author)

7 CFR 457.172 - Coverage Enhancement Option.

Science.gov (United States)

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Coverage Enhancement Option. 457.172 Section 457.172..., DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.172 Coverage Enhancement Option. The Coverage Enhancement Option for the 2009 and succeeding crop years are as follows: FCIC policies: United...

A Methodology for Measuring the Physiological Strain of Enhanced Soldiers: The 1998 Soldier Combat System Enhancement Study

National Research Council Canada - National Science Library

Amos, Denys

1998-01-01

... or enhanced capabilities conducting routine operations in the tropics. Core temperature, mean skin temperature and heart rate are appropriate measures for evaluating the physiological burden of soldier combat system enhancements...

Sequential contrast-enhanced MR imaging of the penis.

Science.gov (United States)

Kaneko, K; De Mouy, E H; Lee, B E

1994-04-01

To determine the enhancement patterns of the penis at magnetic resonance (MR) imaging. Sequential contrast material-enhanced MR images of the penis in a flaccid state were obtained in 16 volunteers (12 with normal penile function and four with erectile dysfunction). Subjects with normal erectile function showed gradual and centrifugal enhancement of the corpora cavernosa, while those with erectile dysfunction showed poor enhancement with abnormal progression. Sequential contrast-enhanced MR imaging provides additional morphologic information for the evaluation of erectile dysfunction.

Enhancing and Customizing Laboratory Information Systems to Improve/Enhance Pathologist Workflow.

Science.gov (United States)

Hartman, Douglas J

2015-06-01

Optimizing pathologist workflow can be difficult because it is affected by many variables. Surgical pathologists must complete many tasks that culminate in a final pathology report. Several software systems can be used to enhance/improve pathologist workflow. These include voice recognition software, pre-sign-out quality assurance, image utilization, and computerized provider order entry. Recent changes in the diagnostic coding and the more prominent role of centralized electronic health records represent potential areas for increased ways to enhance/improve the workflow for surgical pathologists. Additional unforeseen changes to the pathologist workflow may accompany the introduction of whole-slide imaging technology to the routine diagnostic work. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

International Nuclear Information System (INIS)

Kim, Tae Yun; Kim, Sung Hun; Kang, Bong Joo; Kim, Hyeon Sook; Cha, Eun Suk; Kim, Ji Youn; Song, Byung Joo

2013-01-01

Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Yun [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Sung Hun, E-mail: rad-ksh@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kang, Bong Joo [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Hyeon Sook [Department of Radiology, St. Paul Hospital, The Catholic University of Korea (Korea, Republic of); Cha, Eun Suk [Department of Radiology, Ewha Womans University, School of Medicine, Mokdong Hospital (Korea, Republic of); Kim, Ji Youn [Department of Radiology, Yeouido St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Song, Byung Joo [Department of Surgery, Seoul St. Mary' s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of)

2013-12-01

Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

Enhancement of Retronasal Odors by Taste

OpenAIRE

Green, Barry G.; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

2011-01-01

Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste (“sweet,” “sour,” “salty,” and “bitter”) and odor (“ot...

Coherent enhancement of resonance-mediated multiphoton absorption

International Nuclear Information System (INIS)

Zhang, Shian; Zhang, Hui; Jia, Tianqing; Wang, Zugeng; Sun, Zhenrong

2010-01-01

In this paper, we theoretically investigate the coherent enhancement of resonance-mediated (2+2) four-photon absorption. It is found that by shaping the spectral phase with a π phase step, the resonance-mediated (2+2) four-photon transition probability can be enhanced. Furthermore, the coherent enhancement dependences on the detuning between the two two-photon absorptions, laser spectral bandwidth and laser centre frequency are explicitly discussed and analysed. We believe these theoretical results may play an important role in enhancing more complex resonance-mediated multiphoton absorption processes.

New enhancements to SCALE for criticality safety analysis

International Nuclear Information System (INIS)

Hollenbach, D.F.; Bowman, S.M.; Petrie, L.M.; Parks, C.V.

1995-01-01

As the speed, available memory, and reliability of computer hardware increases and the cost decreases, the complexity and usability of computer software will increase, taking advantage of the new hardware capabilities. Computer programs today must be more flexible and user friendly than those of the past. Within available resources, the SCALE staff at Oak Ridge National Laboratory (ORNL) is committed to upgrading its computer codes to keep pace with the current level of technology. This paper examines recent additions and enhancements to the criticality safety analysis sections of the SCALE code package. These recent additions and enhancements made to SCALE can be divided into nine categories: (1) new analytical computer codes, (2) new cross-section libraries, (3) new criticality search sequences, (4) enhanced graphical capabilities, (5) additional KENO enhancements, (6) enhanced resonance processing capabilities, (7) enhanced material information processing capabilities, (8) portability of the SCALE code package, and (9) other minor enhancements, modifications, and corrections to SCALE. Each of these additions and enhancements to the criticality safety analysis capabilities of the SCALE code system are discussed below

Assessment of arterial hypervascularity of hepatocellular carcinoma: comparison of contrast-enhanced US and gadoxetate disodium-enhanced MR imaging

International Nuclear Information System (INIS)

Sugimoto, Katsutoshi; Moriyasu, Fuminori; Taira, Junichi; Imai, Yasuharu; Shiraishi, Junji; Saito, Kazuhiro; Saguchi, Toru

2012-01-01

To compare contrast-enhanced (CE) ultrasound with gadoxetate disodium-enhanced magnetic resonance (MR) imaging in the assessment of arterial hypervascularity of hepatocellular carcinoma (HCC) and dysplastic nodule (DN), with CT during hepatic arteriography (CTHA) as the reference standard. This study included 54 consecutively diagnosed patients, with 57 histologically confirmed HCCs and 3 DNs (high-grade). All patients underwent CE ultrasound, gadoxetate disodium-enhanced MR imaging and CTHA. Two trained diagnostic radiologists interpreted the CTHA images and rated the degree of intratumoral arterial vascularity by consensus using a five-point confidence scale as the reference standard. In the observer study, the degrees of vascularity on CE ultrasound and gadoxetate disodium-enhanced MR images were qualitatively analysed by four independent readers using a five-point confidence scale. Diagnostic accuracy was analysed by receiver-operating characteristic (ROC) analysis. The diagnostic accuracies of the average area under the ROC curve (AUC) were significantly greater with CE ultrasound (average AUC: 0.94; 95% confidence interval [CI]: 0.88-1.00) than with gadoxetate disodium-enhanced MR imaging (average AUC 0.84, 95% CI 0.74-0.93, P = 0.0014). Contrast-enhanced ultrasound yields a significantly higher AUC value than gadoxetate disodium-enhanced MR imaging in the assessment of arterial hypervascularity of HCC and DN. Key Points circle Arterial hypervascularity is an important feature determining treatment options in hepatocellular carcinoma. circle It can be assessed by contrast-enhanced (CE) ultrasound or magnetic resonance (MR) imaging. circle CE ultrasound was more accurate than Gd-EOB-DTPA MRI in assessing intratumoral vascularity. circle Hypovascular hepatic nodules should be further investigated using CE ultrasound. (orig.)

The status of penile enhancement procedures.

Science.gov (United States)

Vardi, Yoram; Gruenwald, Ilan

2009-11-01

Most men who request surgical penile enhancement have a normal-sized and fully functional penis but visualize their penises as small (psychological dysmorphism). This fact by itself leads to controversy regarding the true indications for penile enhancement procedures in men without micropenis. One of the typical aspects of penile enhancement is the lack of true methodological evaluation of the more commonly performed procedures. Even recently, only few solid scientific studies are available which can shed some light on results and outcome of these controversial procedures. Although some additional data has emerged during the past year, there is still no consensus in regard to indications and surgical techniques used for penile augmentation or penile girth enhancement. There is further need for more studies to provide a better overview of the value and worthiness of these procedures.

Enhanced Microgrid Dynamic Performance Using a Modulated Power Filter Based on Enhanced Bacterial Foraging Optimization

Directory of Open Access Journals (Sweden)

Ahmed M. Othman

2017-06-01

Full Text Available This paper presents a design of microgrid (MG with enhanced dynamic performance. Distributed energy resources (DER are widely used in MGs to match the various load types and profiles. DERs include solar PV cells, wind energy sources, fuel cells, batteries, micro gas-engines and storage elements. MG will include AC/DC circuits, developed power electronics devices, inverters and power electronic controllers. A novel modulated power filters (MPF device will be applied in MG design. Enhanced bacterial foraging optimization (EBFO will be proposed to optimize and set the MPF parameters to enhance and tune the MG dynamic response. Recent dynamic control is applied to minimize the harmonic reference content. EBFO will adapt the gains of MPF dynamic control. The present research achieves an enhancement of MG dynamic performance, in addition to ensuring improvements in the power factor, bus voltage profile and power quality. MG operation will be evaluated by the dynamic response to be fine-tuned by MPF based on EBFO. Digital simulations have validated the results to show the effectiveness and efficient improvement by the proposed strategy.

Carbon dioxide efficiency of terrestrial enhanced weathering.

Science.gov (United States)

Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

2014-05-06

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

Contrast-enhanced MR angiography in Leriche's syndrome

International Nuclear Information System (INIS)

Link, J.; Steffens, J.C.; Brossmann, J.; Heller, M.; Loose, R.

1998-01-01

Purpose: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. Material and methods: Leriche's syndrome was seen in 7 patients via DSA. In [dition, contrast-enhanced MR angiography was performed (T R 7.8 ms/T E 2.1 ms, flip angle 30 , slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500x438 mm, matrix 224x512). Results: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In [dition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. Conclusion: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients. (orig.) [de

Textual Enhancement of Input: Issues and Possibilities

Science.gov (United States)

Han, ZhaoHong; Park, Eun Sung; Combs, Charles

2008-01-01

The input enhancement hypothesis proposed by Sharwood Smith (1991, 1993) has stimulated considerable research over the last 15 years. This article reviews the research on textual enhancement of input (TE), an area where the majority of input enhancement studies have aggregated. Methodological idiosyncrasies are the norm of this body of research.…

Technology Enhanced Learning

NARCIS (Netherlands)

Klemke, Roland; Specht, Marcus

2013-01-01

Klemke, R., & Specht, M. (2013, 26-27 September). Technology Enhanced Learning. Presentation at the fourth international conference on eLearning (eLearning 2013), Belgrade, Serbia. http://econference.metropolitan.ac.rs/

Complete suppression of boron transient-enhanced diffusion and oxidation-enhanced diffusion in silicon using localized substitutional carbon incorporation

Science.gov (United States)

Carroll, M. S.; Chang, C.-L.; Sturm, J. C.; Büyüklimanli, T.

1998-12-01

In this letter, we show the ability, through introduction of a thin Si1-x-yGexCy layer, to eliminate the enhancement of enhanced boron diffusion in silicon due to an oxidizing surface or ion implant damage. This reduction of diffusion is accomplished through a low-temperature-grown thin epitaxial Si1-x-yGexCy layer which completely filters out excess interstitials introduced by oxidation or ion implant damage. We also quantify the oxidation-enhanced diffusion (OED) and transient-enhanced diffusion (TED) dependence on substitutional carbon level, and further report both the observation of carbon TED and OED, and its dependence on carbon levels.

Contrast enhanced MRI findings of ductal carcinoma in situ

International Nuclear Information System (INIS)

Kang, Bong Joo; Cha, Eun Suk; Kim, Hyeon Sook; Suh, Young Jin; Choi, Hyun Joo

2006-01-01

The purpose of this study is to describe characteristic contrast enhanced MR mammographic findings of ductal carcinoma in situ (DCIS) and also DCIS with microinvasion. From January 2000 to July 2005, 32 women with 33 lesions affected by DCIS or DCIS with microinvasion underwent contrast enhanced MRI, and they were then retrospectively evaluated. All the patients had previously undergone mammography and ultrasonography. All the findings of mammography, ultrasonography (US), and MRI were analyzed by using an ACR BI-RADS lexicon. All 33 cases were enhanced on the enhanced MR images. A smooth margined homogeneous enhanced mass was seen in the two (2/33) cases, and nonmass enhancement was seen in 31 (31/33) cases. Among the non-mass enhancement, focal enhancement (7/31), ductal enhancement (5/31), segmental enhancement (9/31), and regional enhancement (10/31) were observed. On the kinetic study, a wash-out pattern (10/33), a plateau pattern (20/33), and a persistent pattern (3/33) were demonstrated. No significant differences were noted between the pure and microinvasive DCIS. There is no significant difference between pure and microinvasive DCIS. However, contrast enhanced MR images can demonstrate occult foci, multifocal lesion and the tumor extent of DCIS on mammogram or ultrasonogram

Enhanced

Directory of Open Access Journals (Sweden)

Martin I. Bayala

2014-06-01

Full Text Available Land Surface Temperature (LST is a key parameter in the energy balance model. However, the spatial resolution of the retrieved LST from sensors with high temporal resolution is not accurate enough to be used in local-scale studies. To explore the LST–Normalised Difference Vegetation Index relationship potential and obtain thermal images with high spatial resolution, six enhanced image sharpening techniques were assessed: the disaggregation procedure for radiometric surface temperatures (TsHARP, the Dry Edge Quadratic Function, the Difference of Edges (Ts∗DL and three models supported by the relationship of surface temperature and water stress of vegetation (Normalised Difference Water Index, Normalised Difference Infrared Index and Soil wetness index. Energy Balance Station data and in situ measurements were used to validate the enhanced LST images over a mixed agricultural landscape in the sub-humid Pampean Region of Argentina (PRA, during 2006–2010. Landsat Thematic Mapper (TM and Moderate Resolution Imaging Spectroradiometer (EOS-MODIS thermal datasets were assessed for different spatial resolutions (e.g., 960, 720 and 240 m and the performances were compared with global and local TsHARP procedures. Results suggest that the Ts∗DL technique is the most adequate for simulating LST to high spatial resolution over the heterogeneous landscape of a sub-humid region, showing an average root mean square error of less than 1 K.

Landscape encodings enhance optimization.

Directory of Open Access Journals (Sweden)

Konstantin Klemm

Full Text Available Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state.

Landscape Encodings Enhance Optimization

Science.gov (United States)

Klemm, Konstantin; Mehta, Anita; Stadler, Peter F.

2012-01-01

Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states) of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state. PMID:22496860

Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

International Nuclear Information System (INIS)

Kim, Hyun Su; Kim, Seong Hyun; Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil; Park, Cheol Keun

2015-01-01

Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm 2 were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP images

Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Su [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kim, Seong Hyun, E-mail: kshyun@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Park, Cheol Keun [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710 (Korea, Republic of)

2015-04-15

Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm{sup 2} were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP

Contrast-enhanced harmonic endoscopic ultrasound

DEFF Research Database (Denmark)

Săftoiu, A; Dietrich, C F; Vilmann, P

2012-01-01

Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

Moral enhancement requires multiple virtues.

Science.gov (United States)

Hughes, James J

2015-01-01

Some of the debates around the concept of moral enhancement have focused on whether the improvement of a single trait, such as empathy or intelligence, would be a good in general, or in all circumstances. All virtue theories, however, both secular and religious, have articulated multiple virtues that temper and inform one another in the development of a mature moral character. The project of moral enhancement requires a reengagement with virtue ethics and contemporary moral psychology to develop an empirically grounded model of the virtues and a fuller model of character development. Each of these virtues may be manipulable with electronic, psychopharmaceutical, and genetic interventions. A set of interdependent virtues is proposed, along with some of the research pointing to ways such virtues could be enhanced.

Hermetic compartments leak-tightness enhancement

International Nuclear Information System (INIS)

Murani, J.

2000-01-01

In connection with the enhancement of the nuclear safety of the Jaslovske Bohunice V-1 NPP actions for the increase of the leak tightness are performed. The reconstruction has been done in the following directions: hermetic compartments leak tightness enhancement; air lock installation; installation of air lock in SP 4 vent system; integrated leakage rate test to hermetic compartments with leak detection. After 'major' leaks on the hermetic boundary components had been eliminated, since 1994 works on a higher qualitative level began. The essence of the works consists in the detection and identification of leaks in the structural component of the hermetic boundary during the planned refueling outages. The results of the Small Reconstruction and gradual enhancement of leak tightness are presented

Ring-enhancement pattern on contrast-enhanced CT predicts adenosquamous carcinoma of the pancreas: a matched case-control study.

Science.gov (United States)

Imaoka, Hiroshi; Shimizu, Yasuhiro; Mizuno, Nobumasa; Hara, Kazuo; Hijioka, Susumu; Tajika, Masahiro; Tanaka, Tsutomu; Ishihara, Makoto; Ogura, Takeshi; Obayashi, Tomohiko; Shinagawa, Akihide; Sakaguchi, Masafumi; Yamaura, Hidekazu; Kato, Mina; Niwa, Yasumasa; Yamao, Kenji

2014-01-01

Adenosquamous carcinoma of the pancreas (ASC) is a rare malignant neoplasm of the pancreas, exhibiting both glandular and squamous differentiation. However, little is known about its imaging features. This study examined the imaging features of pancreatic ASC. We evaluated images of contrast-enhanced computed tomography (CT) and endoscopic ultrasonography (EUS). As controls, solid pancreatic neoplasms matched in a 2:1 ratio to ASC cases for age, sex and tumor location were also evaluated. Twenty-three ASC cases were examined, and 46 solid pancreatic neoplasms (43 pancreatic ductal adenocarcinomas, two pancreatic neuroendocrine tumors and one acinar cell carcinoma) were matched as controls. Univariate analysis demonstrated significant differences in the outline and vascularity of tumors on contrast-enhanced CT in the ASC and control groups (P outline, cystic changes, and the ring-enhancement pattern on contrast-enhanced CT were seen to have significant predictive powers by stepwise forward logistic regression analysis (P = 0.044, P = 0.010, and P = 0.001, respectively). Of the three, the ring-enhancement pattern was the most useful, and its predictive diagnostic sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of ASC were 65.2%, 89.6%, 75.0% and 84.3%, respectively. These results demonstrate that presence of the ring-enhancement pattern on contrast-enhanced CT is the most useful predictive factor for ASC. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.

CT findings of pancreatic carcinoma. Evaluation with the combined method of early enhancement CT and high dose enhancement CT

International Nuclear Information System (INIS)

Itoh, Shigeki; Endo, Tokiko; Isomura, Takayuki; Ishigaki, Takeo; Ikeda, Mitsuru; Senda, Kouhei.

1995-01-01

Computed tomographic (CT) findings of pancreatic ductal adenocarcinoma were studied with the combined method of early enhancement CT and high dose enhancement CT in 72 carcinomas. Common Findings were change in pancreatic contour, abnormal attenuation in a tumor and dilatation of the main pancreatic duct. The incidence of abnormal attenuation and dilatation of the main pancreatic duct and bile duct was constant regardless of tumor size. The finding of hypoattenuation at early enhancement CT was most useful for demonstrating a carcinoma. However, this finding was negative in ten cases, five of which showed inhomogenous hyperattenuation at high dose enhancement CT. The detection of change in pancreatic contour and dilatation of the main pancreatic duct was most frequent at high dose enhancement CT. The finding of change in pancreatic contour and/or abnormal attenuation in a tumor could be detected in 47 cases at plain CT, 66 at early enhancement CT and 65 at high dose enhancement CT. Since the four cases in which neither finding was detected by any CT method showed dilatated main pancreatic duct, there was no case without abnormal CT findings. This combined CT method will be a reliable diagnostic technique in the imaging of pancreatic carcinoma. (author)

A novel approach to surveying sturgeon using side-scan sonar and occupancy modeling

Science.gov (United States)

Flowers, H. Jared; Hightower, Joseph E.

2013-01-01

Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling-important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to developmethods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater-freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data.We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

Progress and challenges in bioinformatics approaches for enhancer identification

KAUST Repository

Kleftogiannis, Dimitrios A.

2017-02-03

Enhancers are cis-acting DNA elements that play critical roles in distal regulation of gene expression. Identifying enhancers is an important step for understanding distinct gene expression programs that may reflect normal and pathogenic cellular conditions. Experimental identification of enhancers is constrained by the set of conditions used in the experiment. This requires multiple experiments to identify enhancers, as they can be active under specific cellular conditions but not in different cell types/tissues or cellular states. This has opened prospects for computational prediction methods that can be used for high-throughput identification of putative enhancers to complement experimental approaches. Potential functions and properties of predicted enhancers have been catalogued and summarized in several enhancer-oriented databases. Because the current methods for the computational prediction of enhancers produce significantly different enhancer predictions, it will be beneficial for the research community to have an overview of the strategies and solutions developed in this field. In this review, we focus on the identification and analysis of enhancers by bioinformatics approaches. First, we describe a general framework for computational identification of enhancers, present relevant data types and discuss possible computational solutions. Next, we cover over 30 existing computational enhancer identification methods that were developed since 2000. Our review highlights advantages, limitations and potentials, while suggesting pragmatic guidelines for development of more efficient computational enhancer prediction methods. Finally, we discuss challenges and open problems of this topic, which require further consideration.

Progress and challenges in bioinformatics approaches for enhancer identification

KAUST Repository

Kleftogiannis, Dimitrios A.; Kalnis, Panos; Bajic, Vladimir B.

2017-01-01

Enhancers are cis-acting DNA elements that play critical roles in distal regulation of gene expression. Identifying enhancers is an important step for understanding distinct gene expression programs that may reflect normal and pathogenic cellular conditions. Experimental identification of enhancers is constrained by the set of conditions used in the experiment. This requires multiple experiments to identify enhancers, as they can be active under specific cellular conditions but not in different cell types/tissues or cellular states. This has opened prospects for computational prediction methods that can be used for high-throughput identification of putative enhancers to complement experimental approaches. Potential functions and properties of predicted enhancers have been catalogued and summarized in several enhancer-oriented databases. Because the current methods for the computational prediction of enhancers produce significantly different enhancer predictions, it will be beneficial for the research community to have an overview of the strategies and solutions developed in this field. In this review, we focus on the identification and analysis of enhancers by bioinformatics approaches. First, we describe a general framework for computational identification of enhancers, present relevant data types and discuss possible computational solutions. Next, we cover over 30 existing computational enhancer identification methods that were developed since 2000. Our review highlights advantages, limitations and potentials, while suggesting pragmatic guidelines for development of more efficient computational enhancer prediction methods. Finally, we discuss challenges and open problems of this topic, which require further consideration.

Placebo can enhance creativity.

Directory of Open Access Journals (Sweden)

Liron Rozenkrantz

Full Text Available The placebo effect is usually studied in clinical settings for decreasing negative symptoms such as pain, depression and anxiety. There is interest in exploring the placebo effect also outside the clinic, for enhancing positive aspects of performance or cognition. Several studies indicate that placebo can enhance cognitive abilities including memory, implicit learning and general knowledge. Here, we ask whether placebo can enhance creativity, an important aspect of human cognition.Subjects were randomly assigned to a control group who smelled and rated an odorant (n = 45, and a placebo group who were treated identically but were also told that the odorant increases creativity and reduces inhibitions (n = 45. Subjects completed a recently developed automated test for creativity, the creative foraging game (CFG, and a randomly chosen subset (n = 57 also completed two manual standardized creativity tests, the alternate uses test (AUT and the Torrance test (TTCT. In all three tests, participants were asked to create as many original solutions and were scored for originality, flexibility and fluency.The placebo group showed higher originality than the control group both in the CFG (p<0.04, effect size = 0.5 and in the AUT (p<0.05, effect size = 0.4, but not in the Torrance test. The placebo group also found more shapes outside of the standard categories found by a set of 100 CFG players in a previous study, a feature termed out-of-the-boxness (p<0.01, effect size = 0.6.The findings indicate that placebo can enhance the originality aspect of creativity. This strengthens the view that placebo can be used not only to reduce negative clinical symptoms, but also to enhance positive aspects of cognition. Furthermore, we find that the impact of placebo on creativity can be tested by CFG, which can quantify multiple aspects of creative search without need for manual coding. This approach opens the way to explore the behavioral and neural mechanisms by which

On the chemical enhancement in SERS

Science.gov (United States)

Jensen, Lasse

2012-12-01

In Surface-enhanced Raman scattering (SERS), the Raman signal of a molecule adsorbed on a metal surface is enhanced by many orders of magnitude. This provides a "finger-print" of molecules which can be used in ultrasensitive sensing devises. Here we present a time-dependent density functional theory (TDDFT) study of the molecule-surface chemical coupling in SERS. A systematic study of the chemical enhancement (CHEM) of meta-and para-substituted pyridines interacting with a small silver cluster (Ag20) is presented. We find that the magnitude of chemical enhancement is governed to a large extent by the energy difference between the highest occupied energy level (HOMO) of the metal and the lowest unoccupied energy level (LUMO) of the molecule. A two-state approximation shows that the enhancement scales roughly as (ωX/ω¯e)4, where accent="true">ω¯e is an average excitation energy between the HOMO of the metal and the LUMO of the molecule and wX the HOMO-LUMO gap of the free molecule. Furthermore, we demonstrate that it is possible to control the CHEM enhancement by switching a dithienylethene photoswitch from its closed form to its open form. The open form of the photoswitch is found to be the strongest Raman scatterer when adsorbed on the surface whereas the opposite is found for the free molecule. This trend is explained using the simple two-state approximation.

Non Pharmacological Cognitive Enhancers - Current Perspectives.

Science.gov (United States)

Sachdeva, Ankur; Kumar, Kuldip; Anand, Kuljeet Singh

2015-07-01

Cognition refers to the mental processes involved in thinking, knowing, remembering, judging, and problem solving. Cognitive dysfunctions are an integral part of neuropsychiatric disorders as well as in healthy ageing. Cognitive Enhancers are molecules that help improve aspects of cognition like memory, intelligence, motivation, attention and concentration. Recently, Non Pharmacological Cognitive Enhancers have gained popularity as effective and safe alternative to various established drugs. Many of these Non Pharmacological Cognitive Enhancers seem to be more efficacious compared to currently available Pharmacological Cognitive Enhancers. This review describes and summarizes evidence on various Non Pharmacological Cognitive Enhancers such as physical exercise, sleep, meditation and yoga, spirituality, nutrients, computer training, brain stimulation, and music. We also discuss their role in ageing and different neuro-psychiatric disorders, and current status of Cochrane database recommendations. We searched the Pubmed database for the articles and reviews having the terms 'non pharmacological and cognitive' in the title, published from 2000 till 2014. A total of 11 results displayed, out of which 10 were relevant to the review. These were selected and reviewed. Appropriate cross-references within the articles along with Cochrane reviews were also considered and studied.

TALE-mediated modulation of transcriptional enhancers in vivo.

Science.gov (United States)

Crocker, Justin; Stern, David L

2013-08-01

We tested whether transcription activator-like effectors (TALEs) could mediate repression and activation of endogenous enhancers in the Drosophila genome. TALE repressors (TALERs) targeting each of the five even-skipped (eve) stripe enhancers generated repression specifically of the focal stripes. TALE activators (TALEAs) targeting the eve promoter or enhancers caused increased expression primarily in cells normally activated by the promoter or targeted enhancer, respectively. This effect supports the view that repression acts in a dominant fashion on transcriptional activators and that the activity state of an enhancer influences TALE binding or the ability of the VP16 domain to enhance transcription. In these assays, the Hairy repression domain did not exhibit previously described long-range transcriptional repression activity. The phenotypic effects of TALER and TALEA expression in larvae and adults are consistent with the observed modulations of eve expression. TALEs thus provide a novel tool for detection and functional modulation of transcriptional enhancers in their native genomic context.

Tissue-specific RNA expression marks distant-acting developmental enhancers.

Directory of Open Access Journals (Sweden)

Han Wu

2014-09-01

Full Text Available Short non-coding transcripts can be transcribed from distant-acting transcriptional enhancer loci, but the prevalence of such enhancer RNAs (eRNAs within the transcriptome, and the association of eRNA expression with tissue-specific enhancer activity in vivo remain poorly understood. Here, we investigated the expression dynamics of tissue-specific non-coding RNAs in embryonic mouse tissues via deep RNA sequencing. Overall, approximately 80% of validated in vivo enhancers show tissue-specific RNA expression that correlates with tissue-specific enhancer activity. Globally, we identified thousands of tissue-specifically transcribed non-coding regions (TSTRs displaying various genomic hallmarks of bona fide enhancers. In transgenic mouse reporter assays, over half of tested TSTRs functioned as enhancers with reproducible activity in the predicted tissue. Together, our results demonstrate that tissue-specific eRNA expression is a common feature of in vivo enhancers, as well as a major source of extragenic transcription, and that eRNA expression signatures can be used to predict tissue-specific enhancers independent of known epigenomic enhancer marks.

Production-enhancement partnerships: Successful business arrangements

International Nuclear Information System (INIS)

Coble, L.E.; Weitzel, K.R.; Attai, L.F.; Gray, K.A.

1996-01-01

Production-enhancement projects are creating changes in business relationships between oil and gas and service companies. The most successful projects are building partnerships. Service companies are being asked to share the risk while supplying services to enhance well performance. Risk sharing creates common project objectives and requires the service company's involvement in initial project planning, job design, and reservoir understanding. Service-work compensation is based on well- or field-performance improvement resulting from the treatment(s). This paper presents an integrated approach to the selection and prioritization of well candidates for production-enhancement jobs or treatments. Processes are illustrated, and data requirements and techniques necessary to select well candidates that provide the highest return on investment are discussed. Field examples demonstrate the techniques, critical factors, and appropriate software used by geoscience and field-operations teams to maximize benefits from production-enhancement projects

Innovative Solution to Video Enhancement

Science.gov (United States)

2001-01-01

Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.

Overhauser-enhanced MR imaging (OMRI)

International Nuclear Information System (INIS)

Golman, K.; Leunbach, I.; Ardenkjaer-Larsen, J.H.; Wistrand, L.G.; Petersson, J.S.; Ehnholm, G.J.; Jaervi, A.; Vahasalo, S.

1998-01-01

Purpose: To evaluate a new single-electron contrast agent for Overhauser-enhanced MR imaging. The contrast agents that are currently available give enhancement factors that are too low to make the technique a valid option for routine clinical use. Material and Methods: MR images were generated directly following the injection of the substance into rats. The MR scanner was operated at a main magnetic field of 0.01 T and equipped with a separate rf-transmitter tuned to the electron paramagnetic resonance frequency of the contrast agent. Results: As expected, the images generated show a high level of enhancement in areas where the contrast agent was present, and a maximum enhancement of 60 times the normal proton signal was obtained in the vascular area. The signal-to-noise ratios in the images were superior to those previously attained. Conclusion: The new contrast agent makes it possible to generate MR images with both morphological and functional information at 0.01 T. The signal-to-noise ratios found in the generated images were of the same order as, or better than, those obtained with the standard clinical routine. (orig.)

Identification of Enhancers In Human: Advances In Computational Studies

KAUST Repository

Kleftogiannis, Dimitrios A.

2016-03-24

Roughly ~50% of the human genome, contains noncoding sequences serving as regulatory elements responsible for the diverse gene expression of the cells in the body. One very well studied category of regulatory elements is the category of enhancers. Enhancers increase the transcriptional output in cells through chromatin remodeling or recruitment of complexes of binding proteins. Identification of enhancer using computational techniques is an interesting area of research and up to now several approaches have been proposed. However, the current state-of-the-art methods face limitations since the function of enhancers is clarified, but their mechanism of function is not well understood. This PhD thesis presents a bioinformatics/computer science study that focuses on the problem of identifying enhancers in different human cells using computational techniques. The dissertation is decomposed into four main tasks that we present in different chapters. First, since many of the enhancer’s functions are not well understood, we study the basic biological models by which enhancers trigger transcriptional functions and we survey comprehensively over 30 bioinformatics approaches for identifying enhancers. Next, we elaborate more on the availability of enhancer data as produced by different enhancer identification methods and experimental procedures. In particular, we analyze advantages and disadvantages of existing solutions and we report obstacles that require further consideration. To mitigate these problems we developed the Database of Integrated Human Enhancers (DENdb), a centralized online repository that archives enhancer data from 16 ENCODE cell-lines. The integrated enhancer data are also combined with many other experimental data that can be used to interpret the enhancers content and generate a novel enhancer annotation that complements the existing integrative annotation proposed by the ENCODE consortium. Next, we propose the first deep-learning computational

Transcriptional Dysregulation of MYC Reveals Common Enhancer-Docking Mechanism

Directory of Open Access Journals (Sweden)

Jurian Schuijers

2018-04-01

Full Text Available Summary: Transcriptional dysregulation of the MYC oncogene is among the most frequent events in aggressive tumor cells, and this is generally accomplished by acquisition of a super-enhancer somewhere within the 2.8 Mb TAD where MYC resides. We find that these diverse cancer-specific super-enhancers, differing in size and location, interact with the MYC gene through a common and conserved CTCF binding site located 2 kb upstream of the MYC promoter. Genetic perturbation of this enhancer-docking site in tumor cells reduces CTCF binding, super-enhancer interaction, MYC gene expression, and cell proliferation. CTCF binding is highly sensitive to DNA methylation, and this enhancer-docking site, which is hypomethylated in diverse cancers, can be inactivated through epigenetic editing with dCas9-DNMT. Similar enhancer-docking sites occur at other genes, including genes with prominent roles in multiple cancers, suggesting a mechanism by which tumor cell oncogenes can generally hijack enhancers. These results provide insights into mechanisms that allow a single target gene to be regulated by diverse enhancer elements in different cell types. : Schuijers et al. show that a conserved CTCF site at the promoter of the MYC oncogene plays an important role in enhancer-promoter looping with tumor-specific super-enhancers. Perturbation of this site provides a potential therapeutic vulnerability. Keywords: gene regulation, super-enhancers, chromosome structure, enhancer docking

Acoustic Purcell Effect for Enhanced Emission

KAUST Repository

Landi, Maryam

2018-03-13

We observe that our experimentally measured emission power enhancement of a speaker inside a previously proposed metacavity agrees with our numerically calculated enhancement of the density of states (DOS) of the source-cavity system. We interpret the agreement by formulating a relation between the emitted sound power and the acoustic DOS. The formulation is an analog to Fermi’s golden rule in quantum emission. The formulation complements the radiation impedance theory in traditional acoustics for describing sound emission. Our study bridges the gap between acoustic DOS and the acoustic Purcell effect for sound emission enhancement.

Acoustic Purcell Effect for Enhanced Emission

KAUST Repository

Landi, Maryam; Zhao, Jiajun; Prather, Wayne E.; Wu, Ying; Zhang, Likun

2018-01-01

We observe that our experimentally measured emission power enhancement of a speaker inside a previously proposed metacavity agrees with our numerically calculated enhancement of the density of states (DOS) of the source-cavity system. We interpret the agreement by formulating a relation between the emitted sound power and the acoustic DOS. The formulation is an analog to Fermi’s golden rule in quantum emission. The formulation complements the radiation impedance theory in traditional acoustics for describing sound emission. Our study bridges the gap between acoustic DOS and the acoustic Purcell effect for sound emission enhancement.

Application of silver nanoparticles in the detection of SYBR Green I by surface enhanced Raman and surface-enhanced fluorescence

Science.gov (United States)

Guo, Wei; Wu, Jian; Wang, Chunyan; Zhang, Tian; Chen, Tao

2018-05-01

Silver nanomaterials have remarkable application in biomedical detection due to their unique surface plasmon resonance (SPR) characteristics. It can be used for surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). Current research elaborates a technique for improvement of SYBR Green I detection obtained from surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF) by silver nanoparticles with the average size about 70 nm. Primarily, SYBR Green I is an important fluorescent dye used in polymerase chain reaction (PCR). It is found that both Raman and fluorescence can be used for detection of this dye. Furthermore, the enhanced efficiency of the Raman and fluorescence by SERS and SEF is observed in this study, the enhancement factor for Raman signals is 3.2 × 103, and the fluorescence intensity bincreased two times by SEF. The quantitative detection of SYBR Green I by SERS and SEF can be achieved. The present work can be used to improve the detection of SYBR Green I by SERS and SEF. It would also be employed for high-sensitive detection of other materials in the future.

Enhancing Brief Cognitive Behavioral Therapy with Motivational Enhancement Techniques in Cocaine Users

Science.gov (United States)

McKee, Sherry A.; Carroll, Kathleen M.; Sinha, Rajita; Robinson, Jane E.; Nich, Charla; Cavallo, Dana; O’Malley, Stephanie

2008-01-01

Background We investigated the impact of enhancing brief cognitive behavioral therapy with motivational interviewing techniques for cocaine abuse or dependence, using a focused intervention paradigm. Methods Participants (n=74) who met current criteria for cocaine abuse or dependence were randomized to 3-session cognitive behavioral therapy (CBT) or 3-session enhanced CBT (MET + CBT), which included an initial session of motivational enhancement therapy (MET). Outcome measures included treatment retention, process measures (e.g., commitment to abstinence, satisfaction with treatment), and cocaine use. Results Participants who received the MET+CBT intervention attended more drug treatment sessions following the study interventions, reported significantly greater desire for abstinence and expectation of success, and they expected greater difficulty in maintaining abstinence compared to the CBT condition. There were no differences across treatment conditions on cocaine use. Conclusions These findings offer mixed support for the addition of MET as an adjunctive approach to CBT for cocaine users. In addition, the study provides evidence for the feasibility of using short-term studies to test the effects of specific treatment components or refinements on measures of therapy process and outcome. PMID:17573205

ChIP-seq Identification of Weakly Conserved Heart Enhancers

Energy Technology Data Exchange (ETDEWEB)

Blow, Matthew J.; McCulley, David J.; Li, Zirong; Zhang, Tao; Akiyama, Jennifer A.; Holt, Amy; Plajzer-Frick, Ingrid; Shoukry, Malak; Wright, Crystal; Chen, Feng; Afzal, Veena; Bristow, James; Ren, Bing; Black, Brian L.; Rubin, Edward M.; Visel, Axel; Pennacchio, Len A.

2010-07-01

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of heart enhancers. Here we used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over three thousand candidate heart enhancers genome-wide. Compared to other tissues studied at this time-point, most candidate heart enhancers are less deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary constraint of embryonic enhancers can vary depending on tissue type.

Bose enhancement and the ridge

Energy Technology Data Exchange (ETDEWEB)

Altinoluk, Tolga [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Armesto, Néstor, E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Kovner, Alex [Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269-3046 (United States); Lublinsky, Michael [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

2015-12-17

We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

Luminescence enhancement in irradiated polyethylene

International Nuclear Information System (INIS)

Charlesby, A.; Owen, G.P.

1976-01-01

Results are presented for the luminescence decay in polyethylene following irradiation at liquid nitrogen temperature and its enhancement on application of an electric field. It is found that both the luminescence enhancement and its subsequent decay may be described by a model involving electron tunnelling from a monoenergetic trap distribution to the parent positive ion. The possible nature of the trap is briefly discussed. (author)

Enhancement of lymphocyte proliferation by mouse glandular kallikrein.

Science.gov (United States)

Hu, Z Q; Murakami, K; Ikigai, H; Shimamura, T

1992-03-01

Mouse glandular kallikrein (mGK) strongly enhanced the spontaneous and mitogen-induced proliferation of lymphocytes. Both blast formation and 3H-TdR incorporation were dose-dependently enhanced at the same time many cells were killed. The enhancing activity was independent of EGF, because EGF-binding proteins (mGK-9 in mGK-6,9 mixture and mGK-13), renal kallikrein (mGK-6) and human kallikrein all displayed the same enhancement. A serine proteinase inhibitor, diisopropyl fluorophosphate, could block the enhancement by mGK. The new function suggests that mGK is important in the immune system as a regulatory molecule.

Plasticity enhancement mechanisms in refractory metals and intermetallics

International Nuclear Information System (INIS)

Gibala, R.; Chang, H.; Czarnik, C.M.; Edwards, K.M.; Misra, A.

1993-01-01

Plasticity enhancement associated with surface films and precipitates or dispersoids in bcc refractory metals is operative in ordered intermetallic compounds. Some results are given for NiAl and MoSi 2 -based materials. The monotonic and cyclic plasticity of NiAl at room temperature can be enhanced by surface films. Ductile second phases also enhance the plasticity of NiAl. MoSi 2 exhibits similar effects of surface films and dispersoids, but primarily at elevated temperatures. The plasticity enhancement is associated with enhanced dislocation generation from constrained deformation at the film-substrate or precipitate/dispersoid-matrix interface of the composite systems

MR findings of chondroblastoma with emphasis on enhancement pattern

International Nuclear Information System (INIS)

Oh, Kyung Joong; Go, Sung Hye; Lee, Gyung Kyu; Kim, Jung Eun; Choi, Jung A; Park, Chang Min; Choi, Seung Hong; Kang, Heung Sik; Ahn, Jung Mo; Kim, Sung Moon

2003-01-01

To analyze the MR findings of chondroblastoma and peritumoral bone marrow, focussing on the enhancement pattern. Enhanced MR images obtained from 23 patients with pathologically proven chondroblastoma were retrospectively reviewed by three radiologists. The enhancement pattern was classified as one of three types: homogeneous, heterogeneous, or peripheral rim, while peritumoral bone marrow enhancement was assigned one of four grades. Correlation between the enhancement pattern and T2 signal intensity of a tumor was analyzed by fisher's exact test. The enhancement pattern was homogeneous in ten cases, heterogeneous in six, and involved the peripheral rim in seven. In 11 cases, peritumoral bone marrow enhancement was observed. Among the ten instances of homogeneous enhancement the signal intensity seen at T2W1 was homogeneously iso or low in six cases, homogeneously high in two, and heterogeneous in two. Among the seven cases in which three was peripheral rim enhancement, the signal intensity observed at T2W1 was homogeneously high in three, fluid-fluid level in three, and homogeneously iso or low in one. At MR imaging, chondroblastoma shows variable signal intensities and enhancement patterns. The peripheral rim enhancement observed at T2W1 correlated with homogeneously high signal intensity or fluid-fluid levels

MR findings of chondroblastoma with emphasis on enhancement pattern

Energy Technology Data Exchange (ETDEWEB)

Oh, Kyung Joong; Go, Sung Hye; Lee, Gyung Kyu; Kim, Jung Eun; Choi, Jung A; Park, Chang Min; Choi, Seung Hong; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of); Ahn, Jung Mo [Samsung Medical Center, Seoul (Korea, Republic of); Kim, Sung Moon [Asan Medical Center, Seoul (Korea, Republic of)

2003-03-01

To analyze the MR findings of chondroblastoma and peritumoral bone marrow, focussing on the enhancement pattern. Enhanced MR images obtained from 23 patients with pathologically proven chondroblastoma were retrospectively reviewed by three radiologists. The enhancement pattern was classified as one of three types: homogeneous, heterogeneous, or peripheral rim, while peritumoral bone marrow enhancement was assigned one of four grades. Correlation between the enhancement pattern and T2 signal intensity of a tumor was analyzed by fisher's exact test. The enhancement pattern was homogeneous in ten cases, heterogeneous in six, and involved the peripheral rim in seven. In 11 cases, peritumoral bone marrow enhancement was observed. Among the ten instances of homogeneous enhancement the signal intensity seen at T2W1 was homogeneously iso or low in six cases, homogeneously high in two, and heterogeneous in two. Among the seven cases in which three was peripheral rim enhancement, the signal intensity observed at T2W1 was homogeneously high in three, fluid-fluid level in three, and homogeneously iso or low in one. At MR imaging, chondroblastoma shows variable signal intensities and enhancement patterns. The peripheral rim enhancement observed at T2W1 correlated with homogeneously high signal intensity or fluid-fluid levels.

Characteristics of hypertrophic cardiomyopathy on delayed contrast-enhanced MRI

International Nuclear Information System (INIS)

Yan Chaowu; Zhao Shihua; Li Hua; Jiang Shiliang; Lu Minjie; Zhang Yan; Wei Yunqing; Ling Jian; Fang Wei

2010-01-01

Objective: To analyze the characteristics of hypertrophic cardiomyopathy (HCM) on delayed contrast-enhanced cardiac magnetic resonance imaging (CMRI). Methods: All patients underwent delayed contrast-enhanced CMRI. The left ventricle was divided into 9 segments to assess the location, extent and function of the hypertrophic segments. The t test was applied for the statistics. Results: Of 154 patients, delayed enhancement of' hypertrophic segment was found in 95 cases and non-delayed enhancement in 59 cases. The thickness and number of hypertrophic segment in patients with delayed enhancement were larger than those with non-delayed enhancement [(24.8±5.5) mm vs (20.4± 3.8) mm, t=3.82, P<0.05; (3.3±1.9) vs (2.4±1.7), t=2.26, P<0.05], and the age was younger [(46.0±15.2) years vs (55.0±11.9) years, t=-3.67, P<0.05]. The diffuse enhancement was found in 62 patients, and confluent enhancement in 33 patients. Confluent enhancement was found in all 14 patients after the alcohol ablation procedure. Conclusion: The age, thickness and number of hypertrophic segments in patients with delayed enhancement are different from those with non-delayed enhancement. (authors)

Exposure-related effects of Pseudomonas fluorescens, strain CL145A, on coldwater, coolwater, and warmwater fish

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Denise A. Mayer,

2015-01-01

The exposure-related effects of a commercially prepared spray-dried powder (SDP) formulation of Pseudomonas fluorescens, strain CL145A, were evaluated on coldwater, coolwater, and warmwater fish endemic to the Great Lakes and Upper Mississippi River Basins. Nine species of young-of-the-year fish were exposed to SDP for 24 hours by using continuous-flow, serial-dilution exposure systems at temperatures of 12 degrees Celsius (°C; 2 species; Oncorhynchus mykiss [rainbow trout] and Salvelinus fontinalis [brook trout]), 17 °C (3 species; Perca flavescens [yellow perch], Sander vitreus [walleye], and Acipenser fulvescens [lake sturgeon]), or 22 °C (4 species; Micropterus salmoides [largemouth bass], Micropterus dolomieu [smallmouth bass], Lepomis macrochirus [bluegill sunfish], and Ictalurus punctatus [channel catfish]).

Placebo can enhance creativity.

Science.gov (United States)

Rozenkrantz, Liron; Mayo, Avraham E; Ilan, Tomer; Hart, Yuval; Noy, Lior; Alon, Uri

2017-01-01

The placebo effect is usually studied in clinical settings for decreasing negative symptoms such as pain, depression and anxiety. There is interest in exploring the placebo effect also outside the clinic, for enhancing positive aspects of performance or cognition. Several studies indicate that placebo can enhance cognitive abilities including memory, implicit learning and general knowledge. Here, we ask whether placebo can enhance creativity, an important aspect of human cognition. Subjects were randomly assigned to a control group who smelled and rated an odorant (n = 45), and a placebo group who were treated identically but were also told that the odorant increases creativity and reduces inhibitions (n = 45). Subjects completed a recently developed automated test for creativity, the creative foraging game (CFG), and a randomly chosen subset (n = 57) also completed two manual standardized creativity tests, the alternate uses test (AUT) and the Torrance test (TTCT). In all three tests, participants were asked to create as many original solutions and were scored for originality, flexibility and fluency. The placebo group showed higher originality than the control group both in the CFG (pcreativity. This strengthens the view that placebo can be used not only to reduce negative clinical symptoms, but also to enhance positive aspects of cognition. Furthermore, we find that the impact of placebo on creativity can be tested by CFG, which can quantify multiple aspects of creative search without need for manual coding. This approach opens the way to explore the behavioral and neural mechanisms by which placebo might amplify creativity.

Surface-enhanced Raman spectroscopy: nonlocal limitations

DEFF Research Database (Denmark)

Toscano, Giuseppe; Raza, Søren; Xiao, Sanshui

2012-01-01

for our understanding of surface-enhanced Raman spectroscopy (SERS). The intrinsic length scale of the electron gas serves to smear out assumed field singularities, leaving the SERS enhancement factor finite, even for geometries with infinitely sharp features. For silver nanogroove structures, mimicked...

Sickle erythrocytes enhance phenylephrine and histamine ...

African Journals Online (AJOL)

Sickle erythrocytes enhance phenylephrine and histamine contractions of isolated rabbit carotid arteries. ... enhancement of histamine contractions, compared with phenylephrine (in AS and SS), suggests a possible role for histamine in the increased vascular tone and vaso-occlusive crisis in sickle cell disease.

Enhancement of Cellulose Degradation by Cattle Saliva

Science.gov (United States)

Seki, Yasutaka; Kikuchi, Yukiko; Kimura, Yoshihiro; Yoshimoto, Ryo; Takahashi, Masatoshi; Aburai, Kenichi; Kanai, Yoshihiro; Ruike, Tatsushi; Iwabata, Kazuki; Sugawara, Fumio; Sakai, Hideki; Abe, Masahiko; Sakaguchi, Kengo

2015-01-01

Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale. PMID:26402242

Dissemination of radiological information using enhanced podcasts.

Science.gov (United States)

Thapa, Mahesh M; Richardson, Michael L

2010-03-01

Podcasts and vodcasts (video podcasts) have become popular means of sharing educational information via the Internet. In this article, we introduce another method, an enhanced podcast, which allows images to be displayed with the audio. Bookmarks and URLs may also be imbedded within the presentation. This article describes a step-by-step tutorial for recording and distributing an enhanced podcast using the Macintosh operating system. Enhanced podcasts can also be created on the Windows platform using other software. An example of an enhanced podcast and a demonstration video of all the steps described in this article are available online at web.mac.com/mthapa. An enhanced podcast is an effective method of delivering radiological information via the Internet. Viewing images while simultaneously listening to audio content allows the user to have a richer experience than with a simple podcast. Incorporation of bookmarks and URLs within the presentation will make learning more efficient and interactive. The use of still images rather than video clips equates to a much smaller file size for an enhanced podcast compared to a vodcast, allowing quicker upload and download times.

Localized basal meningeal enhancement in tuberculous meningitis

Energy Technology Data Exchange (ETDEWEB)

Theron, Salomine; Andronikou, Savvas; Grobbelaar, Marie; Steyn, Freda; Mapukata, Ayanda; Plessis, Jaco du [University of Stellenbosch, Department of Radiology, Tygerberg Hospital, P.O. BOX 19063, Tygerberg (South Africa)

2006-11-15

Focal basal meningeal enhancement may produce a confusing CT picture in children with suspected tuberculous meningitis (TBM). To demonstrate the incidence, distribution and appearance of localized basal meningeal enhancement in children with TBM. CT scans of patients with definite (culture proven) and probable (CSF suggestive) TBM were retrospectively evaluated by two observers. Localized basal enhancement was documented as involving: unilateral cistern of the lateral fossa (CLF), unilateral sylvian fissure, unilateral CLF and sylvian fissure in combination, unilateral CLF and sylvian fissure with ipsi- or contralateral ambient cistern and isolated quadrigeminal plate cistern. The study included 130 patients with TBM (aged 2 months to 13 years 9 months). Focal basal enhancement was seen in 11 patients (8.5%). The sylvian fissure was involved most commonly, followed by the lateral fossa cistern. The ambient cistern was involved in three patients and the quadrigeminal plate cistern in one. Focal areas of enhancement corresponded to the areas of infarction in every patient. Focal basal meningeal enhancement is common (8.5%) in paediatric TBM. This must be kept in mind when evaluating CT scans in children presenting with focal neurological findings, seizures or meningism in communities where TBM is endemic. (orig.)

Localized basal meningeal enhancement in tuberculous meningitis

International Nuclear Information System (INIS)

Theron, Salomine; Andronikou, Savvas; Grobbelaar, Marie; Steyn, Freda; Mapukata, Ayanda; Plessis, Jaco du

2006-01-01

Focal basal meningeal enhancement may produce a confusing CT picture in children with suspected tuberculous meningitis (TBM). To demonstrate the incidence, distribution and appearance of localized basal meningeal enhancement in children with TBM. CT scans of patients with definite (culture proven) and probable (CSF suggestive) TBM were retrospectively evaluated by two observers. Localized basal enhancement was documented as involving: unilateral cistern of the lateral fossa (CLF), unilateral sylvian fissure, unilateral CLF and sylvian fissure in combination, unilateral CLF and sylvian fissure with ipsi- or contralateral ambient cistern and isolated quadrigeminal plate cistern. The study included 130 patients with TBM (aged 2 months to 13 years 9 months). Focal basal enhancement was seen in 11 patients (8.5%). The sylvian fissure was involved most commonly, followed by the lateral fossa cistern. The ambient cistern was involved in three patients and the quadrigeminal plate cistern in one. Focal areas of enhancement corresponded to the areas of infarction in every patient. Focal basal meningeal enhancement is common (8.5%) in paediatric TBM. This must be kept in mind when evaluating CT scans in children presenting with focal neurological findings, seizures or meningism in communities where TBM is endemic. (orig.)

Incidentally Detected Enhancing Breast Lesions on Chest Computed Tomography

International Nuclear Information System (INIS)

Lin, Wen Chiung; Hsu, Hsian He; Yu, Jyh Cherng; Hsu, Giu Cheng; Yu, Cheng Ping; Chang, Tsun Hou; Huang, Guo Shu; Li, Chao Shiang

2011-01-01

To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fi broglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-significant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. Routine contrast-enhanced chest CT can reveal sufficient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy

LSD enhances suggestibility in healthy volunteers.

Science.gov (United States)

Carhart-Harris, R L; Kaelen, M; Whalley, M G; Bolstridge, M; Feilding, A; Nutt, D J

2015-02-01

Lysergic acid diethylamide (LSD) has a history of use as a psychotherapeutic aid in the treatment of mood disorders and addiction, and it was also explored as an enhancer of mind control. The present study sought to test the effect of LSD on suggestibility in a modern research study. Ten healthy volunteers were administered with intravenous (i.v.) LSD (40-80 μg) in a within-subject placebo-controlled design. Suggestibility and cued mental imagery were assessed using the Creative Imagination Scale (CIS) and a mental imagery test (MIT). CIS and MIT items were split into two versions (A and B), balanced for 'efficacy' (i.e. A ≈ B) and counterbalanced across conditions (i.e. 50 % completed version 'A' under LSD). The MIT and CIS were issued 110 and 140 min, respectively, post-infusion, corresponding with the peak drug effects. Volunteers gave significantly higher ratings for the CIS (p = 0.018), but not the MIT (p = 0.11), after LSD than placebo. The magnitude of suggestibility enhancement under LSD was positively correlated with trait conscientiousness measured at baseline (p = 0.0005). These results imply that the influence of suggestion is enhanced by LSD. Enhanced suggestibility under LSD may have implications for its use as an adjunct to psychotherapy, where suggestibility plays a major role. That cued imagery was unaffected by LSD implies that suggestions must be of a sufficient duration and level of detail to be enhanced by the drug. The results also imply that individuals with high trait conscientiousness are especially sensitive to the suggestibility-enhancing effects of LSD.

Biomedical enhancements as justice.

Science.gov (United States)

Nam, Jeesoo

2015-02-01

Biomedical enhancements, the applications of medical technology to make better those who are neither ill nor deficient, have made great strides in the past few decades. Using Amartya Sen's capability approach as my framework, I argue in this article that far from being simply permissible, we have a prima facie moral obligation to use these new developments for the end goal of promoting social justice. In terms of both range and magnitude, the use of biomedical enhancements will mark a radical advance in how we compensate the most disadvantaged members of society. © 2013 John Wiley & Sons Ltd.

Hyperintense hepatocellular carcinoma on gadolinium-enhanced hepatic MRI

International Nuclear Information System (INIS)

Yoshikawa, Jun; Matsui, Osamu; Kadoya, Masumi; Gabata, Toshifumi; Arai, Kazunori; Takashima, Tsutomu

1992-01-01

We reported a phenomenon in which some hepatocellular carcinomas (HHCs) visualized as hypointense on plain T1 weighted MR images became hyperintense on gadolinium-DTPA (Gd-DTPA) (0.06∼0.23 mmol/kg) enhanced delayed images. Gd-DTPA enhanced images (using a super conducting magnet operating at 1.5T) of 44 HCCs were studied in comparison with contrast enhanced CT using 30∼80g of iodine. Six of 44 HCCs (14%) which were visualized as hypointense on plain T1 weighted image became hyperintense on delayed Gd-DTPA enhanced images. Although these were visualized as low intensity areas on both plain and enhanced CT, the contrast between HCC and the surrounding liver was small on post contrast CT. These findings were thought to be due to a stronger enhancement effect of Gd-DTPA than that of iodine. (author)

Bose enhancement and the ridge

Directory of Open Access Journals (Sweden)

Tolga Altinoluk

2015-12-01

Full Text Available We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

Recommender Systems in Technology Enhanced Learning

NARCIS (Netherlands)

Manouselis, Nikos; Drachsler, Hendrik; Verbert, Katrien; Santos, Olga

2010-01-01

Manouselis, N., Drachsler, H., Verbert, K., & Santos, C. S. (Eds.) (2010). Recommender System in Technology Enhanced Learning. Elsevier Procedia Computer Science: Volume 1, Issue 2. Proceedings of the 1st Workshop on Recommender Systems for Technology Enhanced Learning (RecSysTEL). September, 29-30,

23 CFR 710.511 - Transportation enhancements.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Transportation enhancements. 710.511 Section 710.511 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT RIGHT-OF-WAY AND REAL ESTATE Property Acquisition Alternatives § 710.511 Transportation enhancements. (a...

Enhancing Rotational Diffusion Using Oscillatory Shear

KAUST Repository

Leahy, Brian D.

2013-05-29

Taylor dispersion - shear-induced enhancement of translational diffusion - is an important phenomenon with applications ranging from pharmacology to geology. Through experiments and simulations, we show that rotational diffusion is also enhanced for anisotropic particles in oscillatory shear. This enhancement arises from variations in the particle\\'s rotation (Jeffery orbit) and depends on the strain amplitude, rate, and particle aspect ratio in a manner that is distinct from the translational diffusion. This separate tunability of translational and rotational diffusion opens the door to new techniques for controlling positions and orientations of suspended anisotropic colloids. © 2013 American Physical Society.

Mammographic feature enhancement by multiscale analysis

International Nuclear Information System (INIS)

Laine, A.F.; Schuler, S.; Fan, J.; Huda, W.

1994-01-01

This paper introduces a novel approach for accomplishing mammographic feature analysis by overcomplete multiresolution representations. The authors show that efficient representations may be identified within a continuum of scale-space and used to enhance features of importance to mammography. Methods of contrast enhancement are described based on three overcomplete multiscale representations: (1) the dyadic wavelet transform (separable), (2) the var-phi-transform (nonseparable, nonorthogonal), and (3) the hexagonal wavelet transform (nonseparable). Multiscale edges identified within distinct levels of transform space provide local support for image enhancement. Mammograms are reconstructed from wavelet coefficients modified at one or more levels by local and global nonlinear operators. In each case, edges and gain parameters are identified adaptively by a measure of energy within each level of scale-space. The authors show quantitatively that transform coefficients, modified by adaptive nonlinear operators, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. The results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. The authors demonstrate that features extracted from multiresolution representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology, they can improve chances of early detection while requiring less time to evaluate mammograms for most patients

Effect of various enhancers on transdermal penetration of indomethacin and urea, and relationship between penetration parameters and enhancement factors.

Science.gov (United States)

Ogiso, T; Iwaki, M; Paku, T

1995-04-01

The enhancing capacity of various chemicals, which are widely recognized as enhancers, for the transdermal penetration into full-thickness rat skin of a model lipophilic drug [indomethacin (IND)] and a hydrophilic permeant (urea) was estimated by an in vitro technique. In addition, the fluidity of the stratum corneum lipids, the partitioning of IND into skin, the lipid (ceramides) extraction from the stratum corneum by enhancers, and the IND solubility in enhancer vehicle were measured and related to the enhancing capacity. In vitro permeation experiments with hairless rat skin unequivocally revealed that the enhancers varied in abilities to enhance the fluxes of both agents. Laurocapram, isopropylmyristate (IPM), sodium oleate, and cineol increased fluxes of both agents to a great extent, but N-methyl-2-pyrrolidone (NMP), N,N-diethyl-m-tolamide (DEET), and oleyl oleate were less effective acclerants. Many enhancers increased the fluidity of the lipids [with a threshold of approximately 0.6-0.8 ns at 37 degrees C in the rotational correlation time (tau c)], the skin partitioning of IND, the extraction of ceramides from the cornified cells, and the thermodynamic activity of IND in vehicle (calculated from the solubility) to varying extents. A good correlation was observed between the increase in the fluidity of stratum corneum lipids and the partitioning of IND into skin, between the increase in the fluidity and the flux or the decrease in lag time for IND, between the removal of ceramides and the skin partitioning of IND, and between the removal of ceramides and the flux of urea (p < 0.05 in all cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced Use Leasing

National Research Council Canada - National Science Library

Vann-Olejasz, Sandra

2002-01-01

.... The term 'enhanced' was added as part of a 2001 amendment from Section 2812 of R.R. 5408, the Floyd D. Spence National Defense Authorization Act for Fiscal Year 2001 and enacted into Public Law 106-398...

Gadolinium-enhanced MRI for evaluation of peripheral nerve neuropathy

International Nuclear Information System (INIS)

Hayakawa, Katsuhiko; Kobayashi, Shigeru; Suzuki, Katsuji; Yamada, Mitsuko; Kojima, Motohiro.

1995-01-01

We carried out enhanced MRI for the carpal tunnel syndrome, cubital tunnel syndrome, tarsal tunnel syndrome and anterior interosseous nerve palsy that is entrapment neuropathy. The affected nerve was enhanced in entrapment point. Carpal tunnel syndrome: The enhancement of affected nerve was apparent in 41 of 52 cases (79%). Cubital tunnel syndrome: The enhancement of affected nerve was apparent in 4 of 5 cases (80%). Tarsal tunnel syndrome: The enhancement of affected nerve was apparent in 1 of 1 case. Anterior interosseous nerve palsy: The enhancement of affected nerve was apparent in 3 of 4 cases (75%). The affected nerve was strongly enhanced by Gd-DTPA, indicating the blood-nerve barrier in the affected nerve to be broken and intraneural edema to be produced, e.i., the ability of Gd-DTPA to selectively contrast-enhance a pathologic focus within the peripheral nerve is perhaps its most important clinical applications. (author)

Gadolinium-enhanced MRI for evaluation of peripheral nerve neuropathy

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Katsuhiko [Aikoh Orthopaedic Hospital, Nagoya (Japan); Kobayashi, Shigeru; Suzuki, Katsuji; Yamada, Mitsuko; Kojima, Motohiro

1995-11-01

We carried out enhanced MRI for the carpal tunnel syndrome, cubital tunnel syndrome, tarsal tunnel syndrome and anterior interosseous nerve palsy that is entrapment neuropathy. The affected nerve was enhanced in entrapment point. Carpal tunnel syndrome: The enhancement of affected nerve was apparent in 41 of 52 cases (79%). Cubital tunnel syndrome: The enhancement of affected nerve was apparent in 4 of 5 cases (80%). Tarsal tunnel syndrome: The enhancement of affected nerve was apparent in 1 of 1 case. Anterior interosseous nerve palsy: The enhancement of affected nerve was apparent in 3 of 4 cases (75%). The affected nerve was strongly enhanced by Gd-DTPA, indicating the blood-nerve barrier in the affected nerve to be broken and intraneural edema to be produced, e.i., the ability of Gd-DTPA to selectively contrast-enhance a pathologic focus within the peripheral nerve is perhaps its most important clinical applications. (author).

Quantitative evaluation of enhancement patterns in focal solid liver lesions with Gd-EOB-DTPA-enhanced MRI.

Directory of Open Access Journals (Sweden)

Michael Haimerl

Full Text Available PURPOSE: The objective was to investigate the dynamic enhancement patterns in focal solid liver lesions after the administration of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA by means of dynamic magnetic resonance imaging (MRI including hepatobiliary phase (HP images 20 min after Gd-EOB-DTPA administration. MATERIALS AND METHODS: Non-enhanced T1/T2-weighted as well as dynamic magnetic resonance (MR images during the arterial phase (AP, the portal venous phase (PVP, the late phase (LP, and the HP (20 min were obtained from 83 patients (54 male, 29 female, mean age 62.01 years with focal solid liver lesions. MRI was conducted by means of a 1.5-T system for 63 patients with malignant liver lesions (HCCs: n = 34, metastases: n = 29 and for 20 patients with benign liver lesions (FNH lesions: n = 14, hemangiomas: n = 3, adenomas: n = 3. For quantitative analysis, signal-to-noise ratios (SNR, contrast enhancement ratios (CER, lesion-to-liver contrast ratios (LLC, and signal intensity (SI ratios were measured. RESULTS: The SNR of liver parenchyma significantly increased in each dynamic phase after Gd-EOB-DTPA administration compared to the SNR of non-enhanced images (p<0.001. The CER of HCCs and metastases significantly decreased between LP and HP images (p = 0.0011, p<0.0001. However, FNH lesions did not show any significant difference, whereas an increased CER was found in hemangiomas. The mean LLCs of FNH lesions were significantly higher than those of HCCs and metastases. The LLC values of hemangiomas remained negative during the entire time course, whereas the LLC of adenomas indicated hyperintensity from the AP to the LP. Furthermore, adenomas showed hypointensity in HP images. CONCLUSION: Gd-EOB-DTPA-enhanced MRI may help diagnose focal solid liver lesions by evaluating their enhancement patterns.

Research on Wavelet-Based Algorithm for Image Contrast Enhancement

Institute of Scientific and Technical Information of China (English)

Wu Ying-qian; Du Pei-jun; Shi Peng-fei

2004-01-01

A novel wavelet-based algorithm for image enhancement is proposed in the paper. On the basis of multiscale analysis, the proposed algorithm solves efficiently the problem of noise over-enhancement, which commonly occurs in the traditional methods for contrast enhancement. The decomposed coefficients at same scales are processed by a nonlinear method, and the coefficients at different scales are enhanced in different degree. During the procedure, the method takes full advantage of the properties of Human visual system so as to achieve better performance. The simulations demonstrate that these characters of the proposed approach enable it to fully enhance the content in images, to efficiently alleviate the enhancement of noise and to achieve much better enhancement effect than the traditional approaches.

Genetic enhancement in sport: just another form of doping?

Science.gov (United States)

Mehlman, Maxwell J

2012-12-01

Patented genetic technologies such as the ACTN3 genetic test are adding a new dimension to the types of performance enhancement available to elite athletes. Organized sports organizations and governments are seeking to prevent athletes' use of biomedical enhancements. This paper discusses how these interdiction efforts will affect the use and availability of genetic technologies that can enhance athletic performance. The paper provides a working definition of enhancement, and in light of that definition and the concerns of the sports community, reviews genetic enhancement as a result of varied technologies, including, genetic testing to identify innate athletic ability, performance-enhancing drugs developed with genetic science and technology, pharmacogenetics, enhancement through reproductive technologies, somatic gene transfer, and germ line gene transfer.

Patterns of contrast enhancement in the brain and meninges.

Science.gov (United States)

Smirniotopoulos, James G; Murphy, Frances M; Rushing, Elizabeth J; Rees, John H; Schroeder, Jason W

2007-01-01

Contrast material enhancement for cross-sectional imaging has been used since the mid 1970s for computed tomography and the mid 1980s for magnetic resonance imaging. Knowledge of the patterns and mechanisms of contrast enhancement facilitate radiologic differential diagnosis. Brain and spinal cord enhancement is related to both intravascular and extravascular contrast material. Extraaxial enhancing lesions include primary neoplasms (meningioma), granulomatous disease (sarcoid), and metastases (which often manifest as mass lesions). Linear pachymeningeal (dura-arachnoid) enhancement occurs after surgery and with spontaneous intracranial hypotension. Leptomeningeal (pia-arachnoid) enhancement is present in meningitis and meningoencephalitis. Superficial gyral enhancement is seen after reperfusion in cerebral ischemia, during the healing phase of cerebral infarction, and with encephalitis. Nodular subcortical lesions are typical for hematogenous dissemination and may be neoplastic (metastases) or infectious (septic emboli). Deeper lesions may form rings or affect the ventricular margins. Ring enhancement that is smooth and thin is typical of an organizing abscess, whereas thick irregular rings suggest a necrotic neoplasm. Some low-grade neoplasms are "fluid-secreting," and they may form heterogeneously enhancing lesions with an incomplete ring sign as well as the classic "cyst-with-nodule" morphology. Demyelinating lesions, including both classic multiple sclerosis and tumefactive demyelination, may also create an open ring or incomplete ring sign. Thick and irregular periventricular enhancement is typical for primary central nervous system lymphoma. Thin enhancement of the ventricular margin occurs with infectious ependymitis. Understanding the classic patterns of lesion enhancement--and the radiologic-pathologic mechanisms that produce them--can improve image assessment and differential diagnosis.

Enhanced Cooperation under the Lisbon Treaty

NARCIS (Netherlands)

Groenendijk, Nico

2011-01-01

Enhanced cooperation is often regarded as being a way out of EU decision-making deadlock and as a major possibility of proceeding with European integration in selected areas. Although the mechanism has been in place since the Treaty of Amsterdam, enhanced cooperation has only recently become a

Enhancement of colposcopic image by sulphosalicylic acid.

Directory of Open Access Journals (Sweden)

Khilnani P

1993-01-01

Full Text Available Acetic acid is used conventionally for enhancement of the colposcopic image. We used sulphosalicylic acid instead of acetic acid in 50 normal cases. The normal appearance was enhanced in all cases. The image was also enhanced in 70% cases of cervical intraepithelial neoplasia and 90% cases of cervical condyloma accuminata. The image was not inferior to that with acetic acid in any of the cases.

Patentability of methods of human enhancement

DEFF Research Database (Denmark)

Nordberg, Ana

2015-01-01

This article explores how to apply patentability rules to human enhancement, particularly focusing on Article 53(c) of the European Patent Convention (EPC). The global size and value of the cosmetic and wellness market and industry allow for the prediction of considerable market potential for hum...... future evolution and the corresponding public policy choices. This article seeks to provide prospective patentees with guidance and awareness concerning the patentability of methods for human enhancement.......This article explores how to apply patentability rules to human enhancement, particularly focusing on Article 53(c) of the European Patent Convention (EPC). The global size and value of the cosmetic and wellness market and industry allow for the prediction of considerable market potential for human...... enhancement. Patents will be instrumental for companies to protect investment in innovation and tap into this potentially valuable market. The European patent system contains, in Article 53(c) EPC, an exception from patentability for methods for treatment and diagnostic methods. Such rule was created...

Enhancer Evolution across 20 Mammalian Species

Science.gov (United States)

Villar, Diego; Berthelot, Camille; Aldridge, Sarah; Rayner, Tim F.; Lukk, Margus; Pignatelli, Miguel; Park, Thomas J.; Deaville, Robert; Erichsen, Jonathan T.; Jasinska, Anna J.; Turner, James M.A.; Bertelsen, Mads F.; Murchison, Elizabeth P.; Flicek, Paul; Odom, Duncan T.

2015-01-01

Summary The mammalian radiation has corresponded with rapid changes in noncoding regions of the genome, but we lack a comprehensive understanding of regulatory evolution in mammals. Here, we track the evolution of promoters and enhancers active in liver across 20 mammalian species from six diverse orders by profiling genomic enrichment of H3K27 acetylation and H3K4 trimethylation. We report that rapid evolution of enhancers is a universal feature of mammalian genomes. Most of the recently evolved enhancers arise from ancestral DNA exaptation, rather than lineage-specific expansions of repeat elements. In contrast, almost all liver promoters are partially or fully conserved across these species. Our data further reveal that recently evolved enhancers can be associated with genes under positive selection, demonstrating the power of this approach for annotating regulatory adaptations in genomic sequences. These results provide important insight into the functional genetics underpinning mammalian regulatory evolution. PMID:25635462

Distributive justice and cognitive enhancement in lower, normal intelligence.

Science.gov (United States)

Dunlop, Mikael; Savulescu, Julian

2014-01-01

There exists a significant disparity within society between individuals in terms of intelligence. While intelligence varies naturally throughout society, the extent to which this impacts on the life opportunities it affords to each individual is greatly undervalued. Intelligence appears to have a prominent effect over a broad range of social and economic life outcomes. Many key determinants of well-being correlate highly with the results of IQ tests, and other measures of intelligence, and an IQ of 75 is generally accepted as the most important threshold in modern life. The ability to enhance our cognitive capacities offers an exciting opportunity to correct disabling natural variation and inequality in intelligence. Pharmaceutical cognitive enhancers, such as modafinil and methylphenidate, have been shown to have the capacity to enhance cognition in normal, healthy individuals. Perhaps of most relevance is the presence of an 'inverted U effect' for most pharmaceutical cognitive enhancers, whereby the degree of enhancement increases as intelligence levels deviate further below the mean. Although enhancement, including cognitive enhancement, has been much debated recently, we argue that there are egalitarian reasons to enhance individuals with low but normal intelligence. Under egalitarianism, cognitive enhancement has the potential to reduce opportunity inequality and contribute to relative income and welfare equality in the lower, normal intelligence subgroup. Cognitive enhancement use is justifiable under prioritarianism through various means of distribution; selective access to the lower, normal intelligence subgroup, universal access, or paradoxically through access primarily to the average and above average intelligence subgroups. Similarly, an aggregate increase in social well-being is achieved through similar means of distribution under utilitarianism. In addition, the use of cognitive enhancement within the lower, normal intelligence subgroup negates, or at

Enhanced thermophysical properties via PAO superstructure

Science.gov (United States)

Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

2017-01-01

For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

Enhanced thermophysical properties via PAO superstructure.

Science.gov (United States)

Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

2017-12-01

For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

Evaluation of meningeal enhancement with Gd-DTPA

International Nuclear Information System (INIS)

Phillips, M.; Ryals, T.J.; Yuh, W.T.C.; Kambho, S.

1989-01-01

Forty-three consecutive patients (16 with tumor, 11 with inflammation, 16 postoperative) with abnormal meningeal enhancement were studied. Positive pathology was obtained in 75% of tumors and 100% of inflammatory conditions. Pial enhancement was demonstrated in seven of 11 patients with inflammation, four of 16 with tumor, and two of 16 postoperative patients. Diffuse meningeal enhancement was most commonly present with neoplastic and inflammatory etiologies. Localized enhancement predominated in the postoperative population, unless complicated by a subdural hematoma. A nodular appearance was present in two patients with tumor. In conclusion, Gd-DTPA MR imaging is sensitive to but not specific of meningeal pathology. MR imaging is better in inflammatory than in neoplastic conditions

Systems and methods for enhancing optical information

Science.gov (United States)

DeVore, Peter Thomas Setsuda; Chou, Jason T.

2018-01-02

An Optical Information Transfer Enhancer System includes a first system for producing an information bearing first optical wave that is impressed with a first information having a first information strength wherein the first optical wave has a first shape. A second system produces a second optical wave. An information strength enhancer module receives the first and said second optical waves and impresses the first optical wave upon the second optical wave via cross-phase modulation (XPM) to produce an information-strength-enhanced second optical wave having a second information strength that is greater than the first information strength of the first optical wave. Following a center-wavelength changer by an Optical Information Transfer Enhancer System improves its performance.

DEEP: a general computational framework for predicting enhancers

KAUST Repository

Kleftogiannis, Dimitrios A.

2014-11-05

Transcription regulation in multicellular eukaryotes is orchestrated by a number of DNA functional elements located at gene regulatory regions. Some regulatory regions (e.g. enhancers) are located far away from the gene they affect. Identification of distal regulatory elements is a challenge for the bioinformatics research. Although existing methodologies increased the number of computationally predicted enhancers, performance inconsistency of computational models across different cell-lines, class imbalance within the learning sets and ad hoc rules for selecting enhancer candidates for supervised learning, are some key questions that require further examination. In this study we developed DEEP, a novel ensemble prediction framework. DEEP integrates three components with diverse characteristics that streamline the analysis of enhancer\\'s properties in a great variety of cellular conditions. In our method we train many individual classification models that we combine to classify DNA regions as enhancers or non-enhancers. DEEP uses features derived from histone modification marks or attributes coming from sequence characteristics. Experimental results indicate that DEEP performs better than four state-of-the-art methods on the ENCODE data. We report the first computational enhancer prediction results on FANTOM5 data where DEEP achieves 90.2% accuracy and 90% geometric mean (GM) of specificity and sensitivity across 36 different tissues. We further present results derived using in vivo-derived enhancer data from VISTA database. DEEP-VISTA, when tested on an independent test set, achieved GM of 80.1% and accuracy of 89.64%. DEEP framework is publicly available at http://cbrc.kaust.edu.sa/deep/.

Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

Science.gov (United States)

Chamis, Christos C.

2009-01-01

Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

Evolution of transcriptional enhancers and animal diversity

Science.gov (United States)

Rubinstein, Marcelo; de Souza, Flávio S. J.

2013-01-01

Deciphering the genetic bases that drive animal diversity is one of the major challenges of modern biology. Although four decades ago it was proposed that animal evolution was mainly driven by changes in cis-regulatory DNA elements controlling gene expression rather than in protein-coding sequences, only now are powerful bioinformatics and experimental approaches available to accelerate studies into how the evolution of transcriptional enhancers contributes to novel forms and functions. In the introduction to this Theme Issue, we start by defining the general properties of transcriptional enhancers, such as modularity and the coexistence of tight sequence conservation with transcription factor-binding site shuffling as different mechanisms that maintain the enhancer grammar over evolutionary time. We discuss past and current methods used to identify cell-type-specific enhancers and provide examples of how enhancers originate de novo, change and are lost in particular lineages. We then focus in the central part of this Theme Issue on analysing examples of how the molecular evolution of enhancers may change form and function. Throughout this introduction, we present the main findings of the articles, reviews and perspectives contributed to this Theme Issue that together illustrate some of the great advances and current frontiers in the field. PMID:24218630

Performance-Enhancing Drugs: Know the Risks

Science.gov (United States)

... edge by taking muscle-building supplements or other performance-enhancing drugs? Learn how these drugs work and how they can affect your health. By ... to testosterone and estradiol in both men and women. Andro is available legally ... use as a performance-enhancing drug is illegal in the United States. ...

Sonar Image Enhancements for Improved Detection of Sea Mines

DEFF Research Database (Denmark)

Jespersen, Karl; Sørensen, Helge Bjarup Dissing; Zerr, Benoit

1999-01-01

In this paper, five methods for enhancing sonar images prior to automatic detection of sea mines are investigated. Two of the methods have previously been published in connection with detection systems and serve as reference. The three new enhancement approaches are variance stabilizing log...... transform, nonlinear filtering, and pixel averaging for speckle reduction. The effect of the enhancement step is tested by using the full prcessing chain i.e. enhancement, detection and thresholding to determine the number of detections and false alarms. Substituting different enhancement algorithms...... in the processing chain gives a precise measure of the performance of the enhancement stage. The test is performed using a sonar image database with images ranging from very simple to very complex. The result of the comparison indicates that the new enhancement approaches improve the detection performance....

Visual Contrast Enhancement Algorithm Based on Histogram Equalization

Science.gov (United States)

Ting, Chih-Chung; Wu, Bing-Fei; Chung, Meng-Liang; Chiu, Chung-Cheng; Wu, Ya-Ching

2015-01-01

Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE) because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA) based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods. PMID:26184219

Visual Contrast Enhancement Algorithm Based on Histogram Equalization

Directory of Open Access Journals (Sweden)

Chih-Chung Ting

2015-07-01

Full Text Available Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods.

Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T.

2001-01-01

AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T

2001-11-01

AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

Raman enhancement on ultra-clean graphene quantum dots produced by quasi-equilibrium plasma-enhanced chemical vapor deposition.

Science.gov (United States)

Liu, Donghua; Chen, Xiaosong; Hu, Yibin; Sun, Tai; Song, Zhibo; Zheng, Yujie; Cao, Yongbin; Cai, Zhi; Cao, Min; Peng, Lan; Huang, Yuli; Du, Lei; Yang, Wuli; Chen, Gang; Wei, Dapeng; Wee, Andrew Thye Shen; Wei, Dacheng

2018-01-15

Graphene is regarded as a potential surface-enhanced Raman spectroscopy (SERS) substrate. However, the application of graphene quantum dots (GQDs) has had limited success due to material quality. Here, we develop a quasi-equilibrium plasma-enhanced chemical vapor deposition method to produce high-quality ultra-clean GQDs with sizes down to 2 nm directly on SiO 2 /Si, which are used as SERS substrates. The enhancement factor, which depends on the GQD size, is higher than conventional graphene sheets with sensitivity down to 1 × 10 -9  mol L -1 rhodamine. This is attributed to the high-quality GQDs with atomically clean surfaces and large number of edges, as well as the enhanced charge transfer between molecules and GQDs with appropriate diameters due to the existence of Van Hove singularities in the electronic density of states. This work demonstrates a sensitive SERS substrate, and is valuable for applications of GQDs in graphene-based photonics and optoelectronics.

Enhancer evolution across 20 mammalian species

DEFF Research Database (Denmark)

Villar, Diego; Berthelot, Camille; Aldridge, Sarah

2015-01-01

The mammalian radiation has corresponded with rapid changes in noncoding regions of the genome, but we lack a comprehensive understanding of regulatory evolution in mammals. Here, we track the evolution of promoters and enhancers active in liver across 20 mammalian species from six diverse orders...... by profiling genomic enrichment of H3K27 acetylation and H3K4 trimethylation. We report that rapid evolution of enhancers is a universal feature of mammalian genomes. Most of the recently evolved enhancers arise from ancestral DNA exaptation, rather than lineage-specific expansions of repeat elements....... These results provide important insight into the functional genetics underpinning mammalian regulatory evolution....

Low Vision Enhancement System

Science.gov (United States)

1995-01-01

NASA's Technology Transfer Office at Stennis Space Center worked with the Johns Hopkins Wilmer Eye Institute in Baltimore, Md., to incorporate NASA software originally developed by NASA to process satellite images into the Low Vision Enhancement System (LVES). The LVES, referred to as 'ELVIS' by its users, is a portable image processing system that could make it possible to improve a person's vision by enhancing and altering images to compensate for impaired eyesight. The system consists of two orientation cameras, a zoom camera, and a video projection system. The headset and hand-held control weigh about two pounds each. Pictured is Jacob Webb, the first Mississippian to use the LVES.

Learner Ownership of Technology-Enhanced Learning

Science.gov (United States)

Dommett, Eleanor J.

2018-01-01

Purpose: This paper aims to examine the different ways in which learners may have ownership over technology-enhanced learning by reflecting on technical, legal and psychological ownership. Design/methodology/approach: The paper uses a variety of examples of technology-enhanced learning ranging from open-source software to cloud storage to discuss…

Field enhancement induced laser ablation

DEFF Research Database (Denmark)

Fiutowski, Jacek; Maibohm, Christian; Kjelstrup-Hansen, Jakob

Sub-diffraction spatially resolved, quantitative mapping of strongly localized field intensity enhancement on gold nanostructures via laser ablation of polymer thin films is reported. Illumination using a femtosecond laser scanning microscope excites surface plasmons in the nanostructures....... The accompanying field enhancement substantially lowers the ablation threshold of the polymer film and thus creates local ablation spots and corresponding topographic modifications of the polymer film. Such modifications are quantified straightforwardly via scanning electron and atomic force microscopy. Thickness...

Enhanced OpenModelica Python Interface

OpenAIRE

Bajracharya, Sudeep

2016-01-01

OMPython is a Python library for OpenModelica, which provides a Python interface to OpenModelica. This thesis significantly improves OMPython by an enhanced, more powerful and easier to use API. It presents how a user can use the Python interface to simulate and access Modelica models using Python objects. The enhanced OMPython includes the list of functions that have been implemented such as getXXXNames(), getXXXValues(), setXXXValues(), getXXXOptions(), setXXXOptions(), and simulate(), etc....

Retinex enhancement of infrared images.

Science.gov (United States)

Li, Ying; He, Renjie; Xu, Guizhi; Hou, Changzhi; Sun, Yunyan; Guo, Lei; Rao, Liyun; Yan, Weili

2008-01-01

With the ability of imaging the temperature distribution of body, infrared imaging is promising in diagnostication and prognostication of diseases. However the poor quality of the raw original infrared images prevented applications and one of the essential problems is the low contrast appearance of the imagined object. In this paper, the image enhancement technique based on the Retinex theory is studied, which is a process that automatically retrieve the visual realism to images. The algorithms, including Frackle-McCann algorithm, McCann99 algorithm, single-scale Retinex algorithm, multi-scale Retinex algorithm and multi-scale Retinex algorithm with color restoration, are experienced to the enhancement of infrared images. The entropy measurements along with the visual inspection were compared and results shown the algorithms based on Retinex theory have the ability in enhancing the infrared image. Out of the algorithms compared, MSRCR demonstrated the best performance.

Safety enhancement in NPP Bohunice

International Nuclear Information System (INIS)

Lipar, M.; Mihalik, M.

1997-01-01

The upgrading and safety enhancement of both the Bohunice V-1 and V-2 reactors is described in detail. The total estimated cost of the gradual reconstruction of these two units during 1996 to 1999 is 180 mil. US dollars. For the 1995 to 1997 period, the actions common for both units include a quality assurance programme, a personnel training programme, installation of a multifunction simulator, implementation of symptom-oriented operation procedures, installation of diagnostic systems, of a site security system, and of a teledosimetric system. At present, the main maintenance tasks are: to carry out major repair of units, to remedy service interruptions, to enhance equipment service availability, to enhance the technical level of corrective actions at equipment. Investment into maintenance level upgrade has grown from 7.5 mil. Slovak crowns in 1994 to estimated 32 mil. in 2000. The partners of international cooperation are mentioned. (M.D.)

Contrast enhancement CT by iopamidol

International Nuclear Information System (INIS)

Mori, Masaki; Makita, Nobue; Yanai, Kyoko

1984-01-01

In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

Gd enhanced MRI in sensorineural hearing loss

International Nuclear Information System (INIS)

Takenaka, Mika; Tono, Tetsuya; Toyama, Katsuhiro; Kano, Kiyo; Morimitsu, Tamotsu

1996-01-01

The enhanced MRI hearing findings of the inner ear in 124 patients with sensorineural hearing loss were evaluated. MR images were obtained before and after the intravenous administration of gadolinium (0.1 mmol/kg). In three out of seventy-nine patients with unilateral healing loss, cochlear and/or the vestibular enhancement was noted on the symptomatic side. The positive cases included those with Ramsay-Hunt syndrome, mumps and so-called sudden deafness. Forty-five patients with bilateral hearing loss showed no enhancement within the inner ear. Although positive gadolinium enhancement of the inner ear may detect inflammatory lesions due to a viral infection, its incidence in sensorineural hearing loss, including cases of sudden deafness. seems to be extremely rare. (author)

Recent advances in functional assays of transcriptional enhancers.

Science.gov (United States)

Babbitt, Courtney C; Markstein, Michele; Gray, Jesse M

2015-09-01

In this special edition of Genomics, we present reviews of the current state of the field in identifying and functionally understanding transcriptional enhancers in cells and developing tissues. Typically several enhancers coordinate the expression of an individual target gene, each controlling that gene's expression in specific cell types at specific times. Until recently, identifying each gene's enhancers had been challenging because enhancers do not occupy prescribed locations relative to their target genes. Recently there have been powerful advances in DNA sequencing and other technologies that make it possible to identify the majority of enhancers in virtually any cell type of interest. The reviews in this edition of Genomics highlight some of these new and powerful approaches. Copyright © 2015 Elsevier Inc. All rights reserved.

Indulging anxiety: human enhancement from a Protestant perspective.

Science.gov (United States)

Hanson, Mark J

1999-08-01

At the heart of any ethics of human enhancement must be some normative assumptions about human nature. The purpose of this essay is to draw on themes from a Protestant theological anthropology to provide a basis for understanding and evaluating the tension between maintaining our humanity and enhancing it. Drawing primarily on the work of theologian Reinhold Niebuhr, I interpret enhancement as proceeding from the anxiety that characterizes human experience at the juncture of freedom and finiteness. Religious and moral dimensions of human sinfulness are considered in relation to cultural values that motivate human enhancement generally. I employ these dimensions in a series of benchmarks to suggest a background of theological, anthropological, and moral considerations against which enhancement is not to be condemmed but rather critically evaluated.

Surfactant-enhanced flushing enhances colloid transport and alters macroporosity in diesel-contaminated soil.

Science.gov (United States)

Guan, Zhuo; Tang, Xiang-Yu; Nishimura, Taku; Katou, Hidetaka; Liu, Hui-Yun; Qing, Jing

2018-02-01

Soil contamination by diesel has been often reported as a result of accidental spillage, leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates (LAS, an anionic surfactant) was conducted for intact columns (15cm in diameter and 12cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes (representing the diesel) varied with the depth of the topsoil in the range of 14%-96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores (30-250μm in diameter) was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores. Copyright © 2017. Published by Elsevier B.V.

Self-Enhancing Illusions among Chinese Schoolchildren.

Science.gov (United States)

Falbo, Toni; And Others

1997-01-01

Demonstrates that East Asian children (EAC) do engage in some forms of self-enhancing illusions. Responses from 4,000 elementary school students reveal EACs see themselves as possessing more positive attributes than others. Variations in self-enhancing illusions were found for age, gender, and region of residence. Results are discussed in terms of…

Carbon dioxide efficiency of terrestrial enhanced weathering

OpenAIRE

Moosdorf, Nils; Renforth, Philip; Hartmann, Jens

2014-01-01

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimi...

Discovery of stimulation-responsive immune enhancers with CRISPR activation

Science.gov (United States)

Simeonov, Dimitre R.; Gowen, Benjamin G.; Boontanrart, Mandy; Roth, Theodore L.; Gagnon, John D.; Mumbach, Maxwell R.; Satpathy, Ansuman T.; Lee, Youjin; Bray, Nicolas L.; Chan, Alice Y.; Lituiev, Dmytro S.; Nguyen, Michelle L.; Gate, Rachel E.; Subramaniam, Meena; Li, Zhongmei; Woo, Jonathan M.; Mitros, Therese; Ray, Graham J.; Curie, Gemma L.; Naddaf, Nicki; Chu, Julia S.; Ma, Hong; Boyer, Eric; van Gool, Frederic; Huang, Hailiang; Liu, Ruize; Tobin, Victoria R.; Schumann, Kathrin; Daly, Mark J.; Farh, Kyle K.; Ansel, K. Mark; Ye, Chun J.; Greenleaf, William J.; Anderson, Mark S.; Bluestone, Jeffrey A.; Chang, Howard Y.; Corn, Jacob E.; Marson, Alexander

2017-09-01

The majority of genetic variants associated with common human diseases map to enhancers, non-coding elements that shape cell-type-specific transcriptional programs and responses to extracellular cues. Systematic mapping of functional enhancers and their biological contexts is required to understand the mechanisms by which variation in non-coding genetic sequences contributes to disease. Functional enhancers can be mapped by genomic sequence disruption, but this approach is limited to the subset of enhancers that are necessary in the particular cellular context being studied. We hypothesized that recruitment of a strong transcriptional activator to an enhancer would be sufficient to drive target gene expression, even if that enhancer was not currently active in the assayed cells. Here we describe a discovery platform that can identify stimulus-responsive enhancers for a target gene independent of stimulus exposure. We used tiled CRISPR activation (CRISPRa) to synthetically recruit a transcriptional activator to sites across large genomic regions (more than 100 kilobases) surrounding two key autoimmunity risk loci, CD69 and IL2RA. We identified several CRISPRa-responsive elements with chromatin features of stimulus-responsive enhancers, including an IL2RA enhancer that harbours an autoimmunity risk variant. Using engineered mouse models, we found that sequence perturbation of the disease-associated Il2ra enhancer did not entirely block Il2ra expression, but rather delayed the timing of gene activation in response to specific extracellular signals. Enhancer deletion skewed polarization of naive T cells towards a pro-inflammatory T helper (TH17) cell state and away from a regulatory T cell state. This integrated approach identifies functional enhancers and reveals how non-coding variation associated with human immune dysfunction alters context-specific gene programs.

Discovery of stimulation-responsive immune enhancers with CRISPR activation

Science.gov (United States)

Simeonov, Dimitre R.; Gowen, Benjamin G.; Boontanrart, Mandy; Roth, Theodore L.; Gagnon, John D.; Mumbach, Maxwell R.; Satpathy, Ansuman T.; Lee, Youjin; Bray, Nicolas L.; Chan, Alice Y.; Lituiev, Dmytro S.; Nguyen, Michelle L.; Gate, Rachel E.; Subramaniam, Meena; Li, Zhongmei; Woo, Jonathan M.; Mitros, Therese; Ray, Graham J.; Curie, Gemma L.; Naddaf, Nicki; Chu, Julia S.; Ma, Hong; Boyer, Eric; Van Gool, Frederic; Huang, Hailiang; Liu, Ruize; Tobin, Victoria R.; Schumann, Kathrin; Daly, Mark J.; Farh, Kyle K; Ansel, K. Mark; Ye, Chun J.; Greenleaf, William J.; Anderson, Mark S.; Bluestone, Jeffrey A.; Chang, Howard Y.; Corn, Jacob E.; Marson, Alexander

2017-01-01

The majority of genetic variants associated with common human diseases map to enhancers, non-coding elements that shape cell-type-specific transcriptional programs and responses to extracellular cues1–3. Systematic mapping of functional enhancers and their biological contexts is required to understand the mechanisms by which variation in non-coding genetic sequences contributes to disease. Functional enhancers can be mapped by genomic sequence disruption4–6, but this approach is limited to the subset of enhancers that are necessary in the particular cellular context being studied. We hypothesized that recruitment of a strong transcriptional activator to an enhancer would be sufficient to drive target gene expression, even if that enhancer was not currently active in the assayed cells. Here we describe a discovery platform that can identify stimulus-responsive enhancers for a target gene independent of stimulus exposure. We used tiled CRISPR activation (CRISPRa)7 to synthetically recruit a transcriptional activator to sites across large genomic regions (more than 100 kilobases) surrounding two key autoimmunity risk loci, CD69 and IL2RA. We identified several CRISPRa-responsive elements with chromatin features of stimulus-responsive enhancers, including an IL2RA enhancer that harbours an autoimmunity risk variant. Using engineered mouse models, we found that sequence perturbation of the disease-associated Il2ra enhancer did not entirely block Il2ra expression, but rather delayed the timing of gene activation in response to specific extracellular signals. Enhancer deletion skewed polarization of naive T cells towards a pro-inflammatory T helper (TH17) cell state and away from a regulatory T cell state. This integrated approach identifies functional enhancers and reveals how non-coding variation associated with human immune dysfunction alters context-specific gene programs. PMID:28854172

A Framework for Reproducible Latent Fingerprint Enhancements.

Science.gov (United States)

Carasso, Alfred S

2014-01-01

Photoshop processing of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology.

Focal brachial enhancement deficit: a normal anatomic variant?

Energy Technology Data Exchange (ETDEWEB)

Beckmann, Nicholas [Memorial Hermann, Department of Diagnostic and Interventional Imaging, Houston, TX (United States); The University of Texas Health Science Center at Houston, Department of Diagnostic and Interventional Imaging, McGovern Medical School, Houston, TX (United States); Saverino, Benjamin [Missouri PC, Radiology Specialists of St. Joseph, St. Joseph, MO (United States); Cai, Chunyan [The University of Texas Health Science Center at Houston, Department of Internal Medicine, McGovern Medical School, Houston, TX (United States); The University of Texas Health Science Center at Houston, Biostatistics/Epidemiology/Research/Design Core, Center for Clinical and Translational Sciences, Houston, TX (United States)

2016-10-15

To identify the incidence of brachialis enhancement deficits (BEDs) on contrast-enhanced elbow MRIs and determine if there is an association between the presence of BEDs and presenting symptoms, other imaging findings, or patient positioning. Elbow MRIs from 138 patients (64 males, mean age 45.3 years) were reviewed. The presence, size, and degree of enhancement of BEDs as well as degree of elbow flexion, relative degree of forearm rotation, and additional finding of pathology on the MRI were recorded. BEDs were found in 54 % (75/138) of contrast-enhanced elbow MRIs. No statistically significant difference was seen between age, gender, presenting symptoms and the presence of BEDs. The BEDs varied considerably in size and degree of diminished enhancement compared to adjacent muscle. There was a very significant correlation between degree of elbow flexion and presence of BEDs (p < 0.0001) and a significant inverse correlation between cross-sectional size of BEDs and degree of flexion (p < 0.01). There was no significant correlation between BED enhancement difference and degree of flexion and no significant correlation between degree of forearm rotation and cross-sectional area or enhancement difference of the BEDs. No correlation was found between the presence of BEDs and other pathology present on the MRI. BEDs are a common, likely asymptomatic phenomenon seen on post contrast elbow MRIs. The etiology of BEDs is uncertain, but they may represent a vascular phenomenon related to elbow flexion causing diminished enhancement related to brachialis compression. (orig.)

Ring enhancement in recurrent gliomas

International Nuclear Information System (INIS)

Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

1981-01-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas. (author)

Ring enhancement in recurrent gliomas

Energy Technology Data Exchange (ETDEWEB)

Ogashiwa, M; Takeuchi, K; Akai, K [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

1981-08-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas.

Production enhancement partnerships -- successful business arrangements

International Nuclear Information System (INIS)

Coble, L.; Weitzel, K.; Attai, L.; Gray, K.

1995-01-01

Production enhancement projects are creating changes in business relationships between oil and gas and service companies. The most successful projects are building partnerships. Service companies are being asked to share the risk while supplying services to enhance well performance. Risk sharing creates common project objectives and requires the service company's involvement in initial project planning, job design, and reservoir understanding. Service work compensation is based on well or field performance improvement as a result of the treatment(s). This paper presents an integrated approach to the selection and prioritization of well candidates for production enhancement jobs or treatments. Special emphasis is placed on reservoir understanding using field reviews and/or extensive reservoir description studies to provide the essential information for well candidate selection and the best return on investment. Processes are illustrated and discussion gives the data requirements and techniques used to select and prioritize well candidates. Field examples demonstrate the techniques, critical factors, and appropriate software used by geoscience and field operations teams to maximize benefits from production enhancement projects

Limits to human enhancement: nature, disease, therapy or betterment?

Science.gov (United States)

Hofmann, Bjørn

2017-10-10

New technologies facilitate the enhancement of a wide range of human dispositions, capacities, or abilities. While it is argued that we need to set limits to human enhancement, it is unclear where we should find resources to set such limits. Traditional routes for setting limits, such as referring to nature, the therapy-enhancement distinction, and the health-disease distinction, turn out to have some shortcomings. However, upon closer scrutiny the concept of enhancement is based on vague conceptions of what is to be enhanced. Explaining why it is better to become older, stronger, and more intelligent presupposes a clear conception of goodness, which is seldom provided. In particular, the qualitative better is frequently confused with the quantitative more. We may therefore not need "external" measures for setting its limits - they are available in the concept of enhancement itself. While there may be shortcomings in traditional sources of limit setting to human enhancement, such as nature, therapy, and disease, such approaches may not be necessary. The specification-of-betterment problem inherent in the conception of human enhancement itself provides means to restrict its unwarranted proliferation. We only need to demand clear, sustainable, obtainable goals for enhancement that are based on evidence, and not on lofty speculations, hypes, analogies, or weak associations. Human enhancements that specify what will become better, and provide adequate evidence, are good and should be pursued. Others should not be accepted.

Medically-enhanced normality

DEFF Research Database (Denmark)

Møldrup, Claus; Traulsen, Janine Morgall; Almarsdóttir, Anna Birna

2003-01-01

Objective: To consider public perspectives on the use of medicines for non-medical purposes, a usage called medically-enhanced normality (MEN). Method: Examples from the literature were combined with empirical data derived from two Danish research projects: a Delphi internet study and a Telebus...

Enhanced Engine Control for Emergency Operation

Science.gov (United States)

Litt, Jonathan S.

2012-01-01

C-MAPSS40k engine simulation has been developed and is available to the public. The authenticity of the engine performance and controller enabled the development of realistic enhanced control modes through controller modification alone. Use of enhanced control modes improved stability and control of an impaired aircraft. - Fast Response is useful for manual manipulation of the throttles - Use of Fast Response improved stability as part of a yaw rate feedback system. - Use of Overthrust shortened takeoff distance, but was generally useful in flight, too. Initial lack of pilot familiarity resulted in discomfort, especially with yaw rate feedback, but that was the only drawback, overall the pilot found the enhanced modes very helpful.

Giant Magnetic Field Enhancement in Hybridized MIM Structures

KAUST Repository

Alrasheed, Salma

2017-10-23

We propose numerically an approach to narrow the plasmon linewidth and enhance the magnetic near field intensity at a magnetic hot spot in a hybridized metal-insulatormetal (MIM) structure. First we insert in part of the dielectric layer of the MIM, at its center, another dielectric material of a high refractive index (HRI). This results in an increase in the magnetic near field enhancement of the magnetic plasmon (MP) resonance by 82% compared with the MIM without the HRI material. We then couple this enhanced MP resonance to a propagating surface plasmon polariton (SPP) to achieve a further enhancement of 438%. The strong coupling between the MP and the SPP is demonstrated by the large anti-crossing in the reflection spectra. The resulting maximum magnetic field enhancement at the gap is ~ |H / Hi|² = 3555.

Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

Science.gov (United States)

John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

2016-10-25

A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

Enhanced Publications: Data Models and Information Systems

Directory of Open Access Journals (Sweden)

Alessia Bardi

2014-04-01

Full Text Available “Enhanced publications” are commonly intended as digital publications that consist of a mandatory narrative part (the description of the research conducted plus related “parts”, such as datasets, other publications, images, tables, workflows, devices. The state-of-the-art on information systems for enhanced publications has today reached the point where some kind of common understanding is required, in order to provide the methodology and language for scientists to compare, analyse, or simply discuss the multitude of solutions in the field. In this paper, we thoroughly examined the literature with a two-fold aim: firstly, introducing the terminology required to describe and compare structural and semantic features of existing enhanced publication data models; secondly, proposing a classification of enhanced publication information systems based on their main functional goals.

Possible edge effect in enhanced network

Energy Technology Data Exchange (ETDEWEB)

Jones, H P; Brown, D R [National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center

1977-05-01

K-line observations of enhanced network taken with the NASA/SPO Multichannel Spectrometer on 28 September 1975 in support of OSO-8 are discussed. The data show a correlation between core brightness and asymmetry for spatial scans which cross enhanced network boundaries. The implications of this result concerning mass flow in and near supergranule boundaries are discussed.

Man-machine enhancements to existing FFTF control panels

International Nuclear Information System (INIS)

Miller, E.M.

1984-01-01

FFTF Project enhanced existing control panels with tape and labels to mitigate operator problems and to incorporate the guidance of NUREG-0700. The enhancements grouped displays and controls into meaningful units and labelled controls and displays to facilitate their identification and efficient use. The enhancements were inexpensive and well received by the facility's operations staff

Enhanced attention amplifies face adaptation.

Science.gov (United States)

Rhodes, Gillian; Jeffery, Linda; Evangelista, Emma; Ewing, Louise; Peters, Marianne; Taylor, Libby

2011-08-15

Perceptual adaptation not only produces striking perceptual aftereffects, but also enhances coding efficiency and discrimination by calibrating coding mechanisms to prevailing inputs. Attention to simple stimuli increases adaptation, potentially enhancing its functional benefits. Here we show that attention also increases adaptation to faces. In Experiment 1, face identity aftereffects increased when attention to adapting faces was increased using a change detection task. In Experiment 2, figural (distortion) face aftereffects increased when attention was increased using a snap game (detecting immediate repeats) during adaptation. Both were large effects. Contributions of low-level adaptation were reduced using free viewing (both experiments) and a size change between adapt and test faces (Experiment 2). We suggest that attention may enhance adaptation throughout the entire cortical visual pathway, with functional benefits well beyond the immediate advantages of selective processing of potentially important stimuli. These results highlight the potential to facilitate adaptive updating of face-coding mechanisms by strategic deployment of attentional resources. Copyright © 2011 Elsevier Ltd. All rights reserved.

Gd-DTPA-enhanced MR imaging in facial nerve paralysis

International Nuclear Information System (INIS)

Tien, R.D.; Dillon, W.P.

1989-01-01

GD-DTPA-enhanced MR imaging was used to evaluate 11 patients with facial nerve paralysis (five acute idiopathic facial palsy (Bell palsy), three chronic recurrent facial palsy, one acute facial palsy after local radiation therapy, one chronic facial dyskinesia, and one facial neuroma). In eight of 11 patients, there was marked enhancement of the infratemporal facial nerve from the labyrinthine segment to the stylomastoid foramen. Two patients had additional contrast enhancement in the internal auditory canal segment. In one patient, enhancement persisted (but to a lesser degree) 8 weeks after symptoms had resolved. In one patient, no enhancement was seen 15 months after resolution of Bell palsy. The facial neuroma was seen as a focal nodular enhancement in the mastoid segment of the facial nerve

DEEP: a general computational framework for predicting enhancers

KAUST Repository

Kleftogiannis, Dimitrios A.; Kalnis, Panos; Bajic, Vladimir B.

2014-01-01

Transcription regulation in multicellular eukaryotes is orchestrated by a number of DNA functional elements located at gene regulatory regions. Some regulatory regions (e.g. enhancers) are located far away from the gene they affect. Identification of distal regulatory elements is a challenge for the bioinformatics research. Although existing methodologies increased the number of computationally predicted enhancers, performance inconsistency of computational models across different cell-lines, class imbalance within the learning sets and ad hoc rules for selecting enhancer candidates for supervised learning, are some key questions that require further examination. In this study we developed DEEP, a novel ensemble prediction framework. DEEP integrates three components with diverse characteristics that streamline the analysis of enhancer's properties in a great variety of cellular conditions. In our method we train many individual classification models that we combine to classify DNA regions as enhancers or non-enhancers. DEEP uses features derived from histone modification marks or attributes coming from sequence characteristics. Experimental results indicate that DEEP performs better than four state-of-the-art methods on the ENCODE data. We report the first computational enhancer prediction results on FANTOM5 data where DEEP achieves 90.2% accuracy and 90% geometric mean (GM) of specificity and sensitivity across 36 different tissues. We further present results derived using in vivo-derived enhancer data from VISTA database. DEEP-VISTA, when tested on an independent test set, achieved GM of 80.1% and accuracy of 89.64%. DEEP framework is publicly available at http://cbrc.kaust.edu.sa/deep/.

Transcriptional Dysregulation of MYC Reveals Common Enhancer-Docking Mechanism.

Science.gov (United States)

Schuijers, Jurian; Manteiga, John Colonnese; Weintraub, Abraham Selby; Day, Daniel Sindt; Zamudio, Alicia Viridiana; Hnisz, Denes; Lee, Tong Ihn; Young, Richard Allen

2018-04-10

Transcriptional dysregulation of the MYC oncogene is among the most frequent events in aggressive tumor cells, and this is generally accomplished by acquisition of a super-enhancer somewhere within the 2.8 Mb TAD where MYC resides. We find that these diverse cancer-specific super-enhancers, differing in size and location, interact with the MYC gene through a common and conserved CTCF binding site located 2 kb upstream of the MYC promoter. Genetic perturbation of this enhancer-docking site in tumor cells reduces CTCF binding, super-enhancer interaction, MYC gene expression, and cell proliferation. CTCF binding is highly sensitive to DNA methylation, and this enhancer-docking site, which is hypomethylated in diverse cancers, can be inactivated through epigenetic editing with dCas9-DNMT. Similar enhancer-docking sites occur at other genes, including genes with prominent roles in multiple cancers, suggesting a mechanism by which tumor cell oncogenes can generally hijack enhancers. These results provide insights into mechanisms that allow a single target gene to be regulated by diverse enhancer elements in different cell types. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Giant photoluminescence enhancement in tungsten-diselenide–gold plasmonic hybrid structures

KAUST Repository

Wang, Zhuo

2016-05-06

Impressive properties arise from the atomically thin nature of transition metal dichalcogenide two-dimensional materials. However, being atomically thin limits their optical absorption or emission. Hence, enhancing their photoluminescence by plasmonic nanostructures is critical for integrating these materials in optoelectronic and photonic devices. Typical photoluminescence enhancement from transition metal dichalcogenides is 100-fold, with recent enhancement of 1,000-fold achieved by simultaneously enhancing absorption, emission and directionality of the system. By suspending WSe2 flakes onto sub-20-nm-wide trenches in gold substrate, we report a giant photoluminescence enhancement of ~20,000-fold. It is attributed to an enhanced absorption of the pump laser due to the lateral gap plasmons confined in the trenches and the enhanced Purcell factor by the plasmonic nanostructure. This work demonstrates the feasibility of giant photoluminescence enhancement in WSe2 with judiciously designed plasmonic nanostructures and paves a way towards the implementation of plasmon-enhanced transition metal dichalcogenide photodetectors, sensors and emitters.

Giant photoluminescence enhancement in tungsten-diselenide–gold plasmonic hybrid structures

KAUST Repository

Wang, Zhuo; Dong, Zhaogang; Gu, Yinghong; Chang, Yung-Huang; Zhang, Lei; Li, Lain-Jong; Zhao, Weijie; Eda, Goki; Zhang, Wenjing; Grinblat, Gustavo; Maier, Stefan A.; Yang, Joel K. W.; Qiu, Cheng-Wei; Wee, Andrew T. S.

2016-01-01

Impressive properties arise from the atomically thin nature of transition metal dichalcogenide two-dimensional materials. However, being atomically thin limits their optical absorption or emission. Hence, enhancing their photoluminescence by plasmonic nanostructures is critical for integrating these materials in optoelectronic and photonic devices. Typical photoluminescence enhancement from transition metal dichalcogenides is 100-fold, with recent enhancement of 1,000-fold achieved by simultaneously enhancing absorption, emission and directionality of the system. By suspending WSe2 flakes onto sub-20-nm-wide trenches in gold substrate, we report a giant photoluminescence enhancement of ~20,000-fold. It is attributed to an enhanced absorption of the pump laser due to the lateral gap plasmons confined in the trenches and the enhanced Purcell factor by the plasmonic nanostructure. This work demonstrates the feasibility of giant photoluminescence enhancement in WSe2 with judiciously designed plasmonic nanostructures and paves a way towards the implementation of plasmon-enhanced transition metal dichalcogenide photodetectors, sensors and emitters.

Contrast Enhancement Algorithm Based on Gap Adjustment for Histogram Equalization

Science.gov (United States)

Chiu, Chung-Cheng; Ting, Chih-Chung

2016-01-01

Image enhancement methods have been widely used to improve the visual effects of images. Owing to its simplicity and effectiveness histogram equalization (HE) is one of the methods used for enhancing image contrast. However, HE may result in over-enhancement and feature loss problems that lead to unnatural look and loss of details in the processed images. Researchers have proposed various HE-based methods to solve the over-enhancement problem; however, they have largely ignored the feature loss problem. Therefore, a contrast enhancement algorithm based on gap adjustment for histogram equalization (CegaHE) is proposed. It refers to a visual contrast enhancement algorithm based on histogram equalization (VCEA), which generates visually pleasing enhanced images, and improves the enhancement effects of VCEA. CegaHE adjusts the gaps between two gray values based on the adjustment equation, which takes the properties of human visual perception into consideration, to solve the over-enhancement problem. Besides, it also alleviates the feature loss problem and further enhances the textures in the dark regions of the images to improve the quality of the processed images for human visual perception. Experimental results demonstrate that CegaHE is a reliable method for contrast enhancement and that it significantly outperforms VCEA and other methods. PMID:27338412

Contrast Enhancement Algorithm Based on Gap Adjustment for Histogram Equalization

Directory of Open Access Journals (Sweden)

Chung-Cheng Chiu

2016-06-01

Full Text Available Image enhancement methods have been widely used to improve the visual effects of images. Owing to its simplicity and effectiveness histogram equalization (HE is one of the methods used for enhancing image contrast. However, HE may result in over-enhancement and feature loss problems that lead to unnatural look and loss of details in the processed images. Researchers have proposed various HE-based methods to solve the over-enhancement problem; however, they have largely ignored the feature loss problem. Therefore, a contrast enhancement algorithm based on gap adjustment for histogram equalization (CegaHE is proposed. It refers to a visual contrast enhancement algorithm based on histogram equalization (VCEA, which generates visually pleasing enhanced images, and improves the enhancement effects of VCEA. CegaHE adjusts the gaps between two gray values based on the adjustment equation, which takes the properties of human visual perception into consideration, to solve the over-enhancement problem. Besides, it also alleviates the feature loss problem and further enhances the textures in the dark regions of the images to improve the quality of the processed images for human visual perception. Experimental results demonstrate that CegaHE is a reliable method for contrast enhancement and that it significantly outperforms VCEA and other methods.

Contrast-enhanced power Doppler US of hepatocellular carcinomas: Quantitative analysis

International Nuclear Information System (INIS)

Kim, Ah Young; Choi, Byung Ihn; Kim, Tae Kyoung; Lee, Kyoung Ho; Han, Joon Koo

1999-01-01

To determine peak time and duration of contrast enhancement of nodular hepatocellular carcinoma (HCC) on contrast-enhancement power Doppler ultrasound (US) with Levovist by quantitative analysis. Twenty eight patients with nodular HCC were prospectively evaluated with power Doppler US by one examiner. Serial images were obtained before and after injection of 300 mg/mL US contrast agent (SH U 508 A, Levovist, Schering) with the injection rate of 0.2 mL/sec. Power Doppler signals on obtained digital images were quantified using 'Ultrasound Imaging Tool Version 1.0' (Seoul, Korea). The grade, peak time and duration of contrast enhancement of the tumors were analyzed. For nodular HCCs, mean peak enhancement time was 60 seconds after injection of Levovist (mean enhanced area 41.6 ± 28.6 %). These tumoral enhancement decreased from 90 seconds and returned to near baseline state at 5 minutes after injection of Levovist. Maximum enhanced areas (%) were variable at a range of 8-98.5% and mean maximum enhanced area was 46.4 ± 28.6%. On contrast-enhanced power Doppler US with Levovist, nodular HCCs showed peak contrast enhancement (41.6± 28.6) at 60 seconds after injection of contrast agent. This tumoral enhancement nearly disappeared at 5 minutes after injection of contrast agent.

Effectiveness of resource-enhancing family-oriented intervention.

Science.gov (United States)

Häggman-Laitila, Arja; Tanninen, Hanna-Mari; Pietilä, Anna-Maija

2010-09-01

The purpose of the study was to assess the effectiveness of a resource-enhancing family-oriented intervention. There is very little empirical knowledge of how nurses working in a home context develop relationships with families, what methods they use to enhance families' resources and how such relationships affect the families' health outcomes. The study was designed as a descriptive service evaluation. A total of 129 family members from 30 families with small children participated in the study. Data were collected with family care plans and client reports in 2004-2005. Data were analysed by qualitative content analysis and by descriptive statistical methods. Resource-enhancing discussions were carried out in all family meetings. Other methods were video guidance, creation of a family tree and parents' role map, network collaboration, observation and parent-child group activity. The families needed support mostly in parents' health and well-being, coping with parenthood, upbringing and child care, parents' relationships, social relations and children's health and growth. The families had an average of five support needs at the beginning of the intervention and 1·8 needs at the completion. The families set on average 3·6 and achieved 4·5 goals during the family nursing process. The resource-enhancing family nursing can be used for supporting parenthood, the raising of and caring for the children, strengthening of social support networks, decreasing the need for support from the authorities and enhancing the parents' resources to manage the duties related to their work and studies. The study resulted in empirically based concepts that can be used in the future to construct instruments to evaluate the effectiveness of resource-enhancing family nursing from the perspective of families and family health. The findings add to our professional understanding of resource-enhancing family nursing. © 2010 Blackwell Publishing Ltd.

Enormous enhancement of ZnO nanorod photoluminescence

International Nuclear Information System (INIS)

Wang, Y.H.; Duan, W.J.; Wu, Z.L.; Zheng, D.; Zhou, X.W.; Zhou, B.Y.; Dai, L.J.; Wang, Y.S.

2012-01-01

ZnO nanorod arrays were grown on quartz slices in the aqueous solution of zinc acetate and hexamethylenetetramine at 90 °C. Then ZnO:Mg shells were epitaxially grown on the nanorods to form core/shell structures in the aqueous solution of zinc acetate, magnesium acetate and hexamethylenetetramine at the same temperature. Effects of the shells and UV laser beam irradiation on the crystal structure and photoluminescence properties of ZnO nanorods were studied. ZnO:Mg shells suppress the green emission and enhance the UV emission intensity of the nanorods by 38 times. Enhancement of the UV emission depends on the Mg content in the shells. Short time UV laser beam irradiation could improve ZnO nanorod emission efficiently. The UV emission intensity of ZnO nanorods is enhanced by 71 times by capping and subsequent UV laser beam irradiation. - Highlights: ► ZnO nanorod arrays were grown on quartz slices in solution at 90 °C. ► The nanorods were capped by ZnO:Mg layers to form core/shell structures. ► ZnO:MgO shells suppress the green emission and enhance the UV emission intensity by 38 times. ► The enhancement depends on the Mg content in the shells. ► Exposing the nanorods to 325 laser beam improves the UV emission efficiently. ► Capping and 325 nm laser beam irradiation could enhance the nanorod UV emission intensity by 71 times.

Complementary surface charge for enhanced capacitive deionization

NARCIS (Netherlands)

Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

2016-01-01

Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI

Abnormal contrast enhancement after the removal of meningioma

Energy Technology Data Exchange (ETDEWEB)

Soutsu, M; Hashimoto, T; Yamaguchi, Y; Sekino, H; Nakamura, N [Jikei Univ., Tokyo (Japan). School of Medicine

1980-12-01

Since the introduction of Computerized Tomography (CT) in August, 1976, we have had experience with 20 patients with meningioma. In 10 patients out of the 20, the tumors were removed totally and examined by contrast-enhanced CT pre- and postoperatively. In spite of the total removal of the tumor, however, 5 patients showed an unexpected abnormal enhancement at the operated site after the infusion of a contrast material. These changes were relatively intense, so it was suspected that there were residual tumors. Comparing these 5 cases with the remaining 5 that had no postoperative enhancement, the former cases were shown by operative and angiographical findings to have more adhesion and connecting vessels between tumor and cortex. Since such a postoperative abnormal enhancement is seen along the corticotomy or retracted area after operations for and aneurysm or another lesion, damaged brain tissue was though to be the probable reason for this enhancement. Moreover, the circulatory change caused by cutting the connecting vessels between tumor and cortex was considered to be another reason for the enhancement. This mechanism was also considered to be one reason for the post-meningioma syndrome by El-Banhawy. These postoperative enhancements decreased in density and became obscure within 4 or 8 weeks. Any reappearance of such changes after that period should be examined, carefully to determine whether or not it marks a recurrent tumor.

Characterizations of Nanofluid Heat Transfer Enhancements

Science.gov (United States)

2013-09-06

nanoparticles are thought to play important roles. Dispersed nanoparticles and associated nanoparticle Brownian movements are purported to cause the enhancements...Dispersed nanoparticles and associated nanoparticle Brownian movements are purported to cause the enhancements by mixing mechanisms whereas aggregated...Engineering Data, 1994. 39(1): p. 186-190. 30. Einstein, A., Investigations on the theory of the brownian movement . 1915, E. P. Dutton and Company

Hopping Conductivity Enhanced by Microwave Radiation

International Nuclear Information System (INIS)

Ovadyahu, Z

2012-01-01

Hopping conductivity is enhanced when exposed to microwave (MW) fields. Data taken on several Anderson-localized systems and granular-aluminium are presented to illustrate the generality of the phenomenon. It is suggested that the effect is due to a field-enhanced hopping, which is the ac version of a non-ohmic effect familiar from studies in the dc transport regime.

Enhanced Time Out: An Improved Communication Process.

Science.gov (United States)

Nelson, Patricia E

2017-06-01

An enhanced time out is an improved communication process initiated to prevent such surgical errors as wrong-site, wrong-procedure, or wrong-patient surgery. The enhanced time out at my facility mandates participation from all members of the surgical team and requires designated members to respond to specified time out elements on the surgical safety checklist. The enhanced time out incorporated at my facility expands upon the safety measures from the World Health Organization's surgical safety checklist and ensures that all personnel involved in a surgical intervention perform a final check of relevant information. Initiating the enhanced time out at my facility was intended to improve communication and teamwork among surgical team members and provide a highly reliable safety process to prevent wrong-site, wrong-procedure, and wrong-patient surgery. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

BIR 2014 - Bibliometric-enhanced Information Retrieval

DEFF Research Database (Denmark)

This first “Bibliometric-enhanced Information Retrieval” (BIR 2014) workshop1 aims to engage with the IR community about possible links to bibliometrics and scholarly communication. Bibliometric techniques are not yet widely used to enhance retrieval processes in digital libraries, although...... analysis of co-authorship network, can improve retrieval services for specific communities, as well as for large, cross-domain collections. This workshop aims to raise awareness of the missing link between information retrieval (IR) and bibliometrics / scientometrics and to create a common ground...... for the incorporation of bibliometric-enhanced services into retrieval at the digital library interface. Our interests include information retrieval, information seeking, science modelling, network analysis, and digital libraries. The goal is to apply insights from bibliometrics, scientometrics, and informetrics...

Surface enhanced raman spectroscopy on chip

DEFF Research Database (Denmark)

Hübner, Jörg; Anhøj, Thomas Aarøe; Zauner, Dan

2007-01-01

In this paper we report low resolution surface enhanced Raman spectra (SERS) conducted with a chip based spectrometer. The flat field spectrometer presented here is fabricated in SU-8 on silicon, showing a resolution of around 3 nm and a free spectral range of around 100 nm. The output facet...... is projected onto a CCD element and visualized by a computer. To enhance the otherwise rather weak Raman signal, a nanosurface is prepared and a sample solutions is impregnated on this surface. The surface enhanced Raman signal is picked up using a Raman probe and coupled into the spectrometer via an optical...... fiber. The obtained spectra show that chip based spectrometer together with the SERS active surface can be used as Raman sensor....

Enhanced photocatalytic disinfection of indoor air

Energy Technology Data Exchange (ETDEWEB)

Vohra, Amit; Goswami, D.Y.; Deshpande, D.A.; Block, S.S. [Solar Energy and Energy Conversion Laboratory, Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

2006-04-18

A silver ion doped TiO{sub 2} based photocatalyst, with improved destruction of airborne microbes, has been developed. The performance of the silver ion doped photocatalyst is demonstrated using a catalyst coated filter in a recirculating air experimental facility. Bacillus cereus, Staphylococcus aureus, Escherichia coli, Aspergillus niger, and MS2 Bacteriophage have been used as indexes to demonstrate the high disinfection efficiency of the enhanced photocatalysis process. The microbial destruction performance of the enhanced photocatalyst is found to be an order of magnitude higher than that of a conventional TiO{sub 2} photocatalyst. The process of enhanced photocatalysis can thus be used effectively against high concentrations of airborne microorganisms, making it an attractive option as a defense against bio-terrorism. (author)

Enhanced Graphene Photodetector with Fractal Metasurface

DEFF Research Database (Denmark)

Fang, Jieran; Wang, Di; DeVault, Clayton T

2017-01-01

Graphene has been demonstrated to be a promising photodetection material because of its ultrabroadband optical absorption, compatibility with CMOS technology, and dynamic tunability in optical and electrical properties. However, being a single atomic layer thick, graphene has intrinsically small...... optical absorption, which hinders its incorporation with modern photodetecting systems. In this work, we propose a gold snowflake-like fractal metasurface design to realize broadband and polarization-insensitive plasmonic enhancement in graphene photodetector. We experimentally obtain an enhanced...... photovoltage from the fractal metasurface that is an order of magnitude greater than that generated at a plain gold-graphene edge and such an enhancement in the photovoltage sustains over the entire visible spectrum. We also observed a relatively constant photoresponse with respect to polarization angles...

Adaptations respiratoires et circulatoires de l'esturgeon sibérien à une hypoxie environnementale

Directory of Open Access Journals (Sweden)

MAXIME V.

1998-07-01

Full Text Available Les adaptations respiratoires, acido-basiques et quelques effets circulatoires ont été étudiés chez l'esturgeon sibérien Acipenser baeri lors d'une hypoxie progressive ou d'un choc hypoxique, et du retour en normoxie. Au cours d'une hypoxie progressive, ce poisson est capable, en hyperventilant, de maintenir constante sa consommation d'oxygène jusqu'à une valeur critique de pression partielle d'oxygène dans l'eau située entre 20 et 40 mmHg. Le retour en normoxie est caractérisé par le paiement d'une dette d'oxygène, indiquant qu'un recours au métabolisme anaérobie a été nécessaire durant l'hypoxie. L'hypoxie progressive provoque initialement une alcalose ventilatoire associée ensuite à une acidose métabolique. Le choc hypoxique induit un état de stress comme en témoignent les valeurs élevées des taux plasmatiques de catécholamines. L'hyperventilation initiale est suivie d'une importante dépression ventilatoire. L'hypertension observée dans un premier temps, bien que modérée, représente un effet d'une augmentation du taux de catécholamines plasmatiques. Cet effet est ensuite atténué par une bradycardie d'origine vraisemblablement vagale, concomitante de l'hypoventilation. Les conséquences sur l'équilibre acido-basique, bien qu'amplifiées, sont comparables à celles d'une hypoxie progressive. Cependant, la libération très importante de lactate dans le sang lors du retour en normoxie n'entraîne qu'une faible diminution de pH du fait d'une augmentation concomitante du taux de sodium plasmatique. Ainsi l'esturgeon Acipenser baeri, bien que considéré comme un poisson archaïque, a développé les mêmes réponses adaptatives à l'hypoxie que les téléostéens.

Music Enhances Learning.

Science.gov (United States)

Campabello, Nicolette; De Carlo, Mary Jane; O'Neil, Jean; Vacek, Mary Jill

An action research project implemented musical strategies to affect and enhance student recall and memory. The target population was three suburban elementary schools near a major midwestern city: (1) a kindergarten classroom contained 32-38 students; (2) a second grade classroom contained 23 students and five Individualized Education Program…

Enhanced processive cellulases

Science.gov (United States)

Adney, William S.; Beckham, Gregg T.; Jarvis, Eric; Himmel, Michael E.; Decker, Stephen R.; Linger, Jeffrey G.; Podkaminer, Kara; Baker, John O.; Taylor, II, Larry; Xu, Qi; Singh, Arjun

2017-06-20

Nucleic acid sequences encoding chimeric polypeptides that exhibit enhanced cellulase activities are disclosed herein. These nucleic acids may be expressed in hosts such as fungi, which in turn may be cultured to produce chimeric polypeptides. Also disclosed are chimeric polypeptides and their use in the degradation of cellulosic materials.

Dual-Energy Contrast-Enhanced Spectral Mammography: Enhancement Analysis on BI-RADS 4 Non-Mass Microcalcifications in Screened Women.

Directory of Open Access Journals (Sweden)

Yun-Chung Cheung

Full Text Available Mammography screening is a cost-efficient modality with high sensitivity for detecting impalpable cancer with microcalcifications, and results in reduced mortality rates. However, the probability of finding microcalcifications without associated cancerous masses varies. We retrospectively evaluated the diagnosis and cancer probability of the non-mass screened microcalcifications by dual-energy contrast-enhanced spectral mammography (DE-CESM.With ethical approval from our hospital, we enrolled the cases of DE-CESM for analysis under the following inclusion criteria: (1 referrals due to screened BI-RADS 4 microcalcifications; (2 having DE-CESM prior to stereotactic biopsy; (3 no associated mass found by sonography and physical examination; and (4 pathology-based diagnosis using stereotactic vacuum-assisted breast biopsy. We analyzed the added value of post-contrast enhancement on DE-CESM.A total of 94 biopsed lesions were available for analysis in our 87 women, yielding 27 cancers [19 ductal carcinoma in situ (DCIS, and 8 invasive ductal carcinoma (IDC], 32 pre-malignant and 35 benign lesions. Of these 94 lesions, 33 showed associated enhancement in DE-CESM while the other 61 did not. All 8 IDC (100% and 16 of 19 DCIS (84.21% showed enhancement, but the other 3 DCIS (15.79% did not. Overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 88.89%, 86.56%, 72.72%, 95.08% and 87.24%, respectively. The performances of DE-CESM on both amorphous and pleomorphic microcalcifications were satisfactory (AUC 0.8 and 0.92, respectively. The pleomorphous microcalcifications with enhancement showed higher positive predictive value (90.00% vs 46.15%, p = 0.013 and higher cancer probability than the amorphous microcalcifications (46.3% VS 15.1%. The Odds Ratio was 4.85 (95% CI: 1.84-12.82.DE-CESM might provide added value in assessing the non-mass screened breast microcalcification, with enhancement favorable to the

Dual-Energy Contrast-Enhanced Spectral Mammography: Enhancement Analysis on BI-RADS 4 Non-Mass Microcalcifications in Screened Women.

Science.gov (United States)

Cheung, Yun-Chung; Juan, Yu-Hsiang; Lin, Yu-Ching; Lo, Yung-Feng; Tsai, Hsiu-Pei; Ueng, Shir-Hwa; Chen, Shin-Cheh

2016-01-01

Mammography screening is a cost-efficient modality with high sensitivity for detecting impalpable cancer with microcalcifications, and results in reduced mortality rates. However, the probability of finding microcalcifications without associated cancerous masses varies. We retrospectively evaluated the diagnosis and cancer probability of the non-mass screened microcalcifications by dual-energy contrast-enhanced spectral mammography (DE-CESM). With ethical approval from our hospital, we enrolled the cases of DE-CESM for analysis under the following inclusion criteria: (1) referrals due to screened BI-RADS 4 microcalcifications; (2) having DE-CESM prior to stereotactic biopsy; (3) no associated mass found by sonography and physical examination; and (4) pathology-based diagnosis using stereotactic vacuum-assisted breast biopsy. We analyzed the added value of post-contrast enhancement on DE-CESM. A total of 94 biopsed lesions were available for analysis in our 87 women, yielding 27 cancers [19 ductal carcinoma in situ (DCIS), and 8 invasive ductal carcinoma (IDC)], 32 pre-malignant and 35 benign lesions. Of these 94 lesions, 33 showed associated enhancement in DE-CESM while the other 61 did not. All 8 IDC (100%) and 16 of 19 DCIS (84.21%) showed enhancement, but the other 3 DCIS (15.79%) did not. Overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 88.89%, 86.56%, 72.72%, 95.08% and 87.24%, respectively. The performances of DE-CESM on both amorphous and pleomorphic microcalcifications were satisfactory (AUC 0.8 and 0.92, respectively). The pleomorphous microcalcifications with enhancement showed higher positive predictive value (90.00% vs 46.15%, p = 0.013) and higher cancer probability than the amorphous microcalcifications (46.3% VS 15.1%). The Odds Ratio was 4.85 (95% CI: 1.84-12.82). DE-CESM might provide added value in assessing the non-mass screened breast microcalcification, with enhancement favorable to the

Evaluation of the intraspinal enhancement for medulloblastoma on MR imaging

International Nuclear Information System (INIS)

Kim, Hwa Young; Kim, In One; Kim, Woo Sun; Cheon, Jung Eun; Yeon, Kyung Mo

2004-01-01

The purpose of this study was to analyze the enhancement pattern of the spinal cord for patients with medulloblastoma, and to correlate the enhancement pattern with cerebrospinal fluid (CSF) tumor seeding. We retrospectively reviewed 84 MR images, including the initial and follow-up studies after chemotherapy or radiation therapy, of 25 patients with medulloblastoma who were aged from 2 to 13 years. We analyzed the spinal leptomeningeal enhancement pattern on the MR images. The leptomeningeal enhancement patterns were categorized into three types: Type, I, fine or discontinuous linear enhancement, and type II, continuous linear or nodular enhancement, and type III, intradural mass formation. We correlated the enhancement pattern on MRI with the results of CSF cytology at the initial and follow-up examinations after treatment. Of total 25 patients, type I enhancement was observed for 14 patients. Twelve patients were negative on the initial CSF cytology and 2 patients were positive. On the follow-up MR studies, 14 patients showed no change or only a slight decrease of enhancement, and all were negative on the follow-up CSF cytology. Type II enhancement patterns were observed in seven patients, and all of them were positive on the initial CSF cytology. On follow-up MR study, one patient revealed an increased enhancement with the positive result on the follow-up CSF cytology, and six patients had decreased enhancement on the follow-up MR studies with negative conversion on the follow-up CSF cytology. Type III enhancement patterns were observed in four patients and all of them were positive on the initial CSF cytology. All four patients with tradural mass formations revealed progression of the lesions on follow-up MR studies, and all of them were positive on the follow-up CSF cytology. Type II and III enhancement patterns always represented CSF seeding and a type I enhancement pattern had a low probability of metastasis

Early development and growth of sterlet (Acipenser ruthenus) in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Rybnikár, J.; Prokeš, Miroslav; Mareš, J.; Cileček, M.

2011-01-01

Roč. 59, č. 5 (2011), s. 217-225 ISSN 1211-8516 R&D Projects: GA MZe QH71305 Institutional research plan: CEZ:AV0Z60930519 Keywords : early ontogeny * specific growth rate * length-weight relationship * factor of weight condition Subject RIV: GL - Fishing http://www.mendelu.cz/dok_server/slozka.pl?id=51329;download=82072

Mechanisms of enhanced lung injury during sepsis

DEFF Research Database (Denmark)

Czermak, B J; Breckwoldt, M; Ravage, Z B

1999-01-01

. Enhanced lung injury was associated with increased accumulation of neutrophils in lung, enhanced production of CXC chemokines (but not tumor necrosis factor-alpha) in bronchoalveolar lavage fluids, and increased expression of lung vascular intercellular adhesion molecule-1 (ICAM-1). Complement depletion...

Nanoparticles for cells proliferation enhancement

International Nuclear Information System (INIS)

Popa, V.; Braniste, F.; Tiginyanu, I.M.; Lisii, C.; Nacu, V.

2013-01-01

The potential of semiconductor nanoparticles as stimulator for avian mesenchyme stem cells proliferation enhancement is demonstrated. The effect is related to nanoparticles polarization due to external ultrasound field resulting in local electrical stimulation. Our preliminary results demonstrates that the number of cells have been increased by 23 % ±2%) in cell cultures under the action of external ultrasound stimulation. Morphological analysis and viability shows no differences between the control group and the group studied. These results suggest the possibility for tissue regeneration enhancement by remote stimulation of implanted semiconductor nanoparticles. (authors)

Enhanced muscle glucose metabolism after exercise

DEFF Research Database (Denmark)

Richter, Erik; Garetto, L P; Goodman, M N

1984-01-01

Studies in the rat suggest that after voluntary exercise there are two phases of glycogen repletion in skeletal muscle (preceding study). In phase I glucose utilization and glycogen synthesis are enhanced both in the presence and absence of insulin, whereas in phase II only the increase in the pr......Studies in the rat suggest that after voluntary exercise there are two phases of glycogen repletion in skeletal muscle (preceding study). In phase I glucose utilization and glycogen synthesis are enhanced both in the presence and absence of insulin, whereas in phase II only the increase...... in the stimulated leg closely mimicked that observed previously after voluntary exercise on a treadmill. With no insulin added to the perfusate, glucose incorporation into glycogen was markedly enhanced in muscles that were glycogen depleted as were the uptake of 2-deoxyglucose and 3-O-methylglucose. Likewise......, the stimulation of these processes by insulin was enhanced and continued to be so 2 h later when the muscles of the stimulated leg had substantially repleted their glycogen stores. The results suggest that the increases in insulin-mediated glucose utilization and glycogen synthesis in muscle after exercise...

Design of New Antibacterial Enhancers Based on AcrB’s Structure and the Evaluation of Their Antibacterial Enhancement Activity

Directory of Open Access Journals (Sweden)

Yi Song

2016-11-01

Full Text Available Previously, artesunate (AS and dihydroartemisinine 7 (DHA7 were found to have antibacterial enhancement activity against Escherichia coli via inhibition of the efflux pump AcrB. However, they were only effective against E. coli standard strains. This study aimed to develop effective antibacterial enhancers based on the previous work. Our results demonstrate that 86 new antibacterial enhancers were designed via 3D-SAR and molecular docking. Among them, DHA27 had the best antibacterial enhancement activity. It could potentiate the antibacterial effects of ampicillin against not only E. coli standard strain but also clinical strains, and of β-lactam antibiotics, not non-β-lactamantibiotics. DHA27 could increase the accumulation of daunomycin and nile red within E. coli ATCC 35218, but did not increase the bacterial membrane permeability. DHA27 reduced acrB’s mRNA expression of E. coli ATCC 35218 in a dose-dependent manner, and its antibacterial enhancement activity is related to the degree of acrB mRNA expression in E. coli clinical strains. The polypeptides from AcrB were obtained via molecular docking assay; the pre-incubated polypeptides could inhibit the activity of DHA27. Importantly, DHA27 had no cytotoxicity on cell proliferation. In conclusion, among newly designed antibacterial enhancers, DHA27 had favorable physical and pharmacological properties with no significant cytotoxicity at effective concentrations, and might serve as a potential efflux pump inhibitor in the future.

Enhanced transbuccal salmon calcitonin (sCT) delivery: effect of chemical enhancers and electrical assistance on in vitro sCT buccal permeation.

Science.gov (United States)

Oh, Dong-Ho; Chun, Kyeung-Hwa; Jeon, Sang-Ok; Kang, Jeong-Won; Lee, Sangkil

2011-10-01

This study investigates the combined effect of absorption enhancers and electrical assistance on transbuccal salmon calcitonin (sCT) delivery, using fresh swine buccal tissue. We placed 200 IU (40 μg/mL) of each sCT formulation--containing various concentrations of ethanol, N-acetyl-L-cysteine (NAC), and sodium deoxyglycocholate (SDGC)--onto the donor part of a Franz diffusion cell. Then, 0.5 mA/cm(2) of fixed anodal current was applied alone or combined with chemical enhancers. The amount of permeated sCT was analyzed using an ELISA kit, and biophysical changes of the buccal mucosa were investigated using FT-IR spectroscopy, and hematoxylin-eosin staining methods were used to evaluate histological alteration of the buccal tissues. The flux (J(s)) of sCT increased with the addition of absorption enhancer groups, but it was significantly enhanced by the application of anodal iontophoresis (ITP). FT-IR study revealed that all groups caused an increase in lipid fluidity but only the groups containing SDGC showed statistically significant difference. Although the histological data of SDGC groups showed a possibility for tissue damage, the present enhancing methods appear to be safe. In conclusion, the combination of absorption enhancers and electrical assistance is a potential strategy for the enhancement of transbuccal sCT delivery. Copyright © 2011 Elsevier B.V. All rights reserved.

Optogenetic Stimulation of Prefrontal Glutamatergic Neurons Enhances Recognition Memory.

Science.gov (United States)

Benn, Abigail; Barker, Gareth R I; Stuart, Sarah A; Roloff, Eva V L; Teschemacher, Anja G; Warburton, E Clea; Robinson, Emma S J

2016-05-04

Finding effective cognitive enhancers is a major health challenge; however, modulating glutamatergic neurotransmission has the potential to enhance performance in recognition memory tasks. Previous studies using glutamate receptor antagonists have revealed that the medial prefrontal cortex (mPFC) plays a central role in associative recognition memory. The present study investigates short-term recognition memory using optogenetics to target glutamatergic neurons within the rodent mPFC specifically. Selective stimulation of glutamatergic neurons during the online maintenance of information enhanced associative recognition memory in normal animals. This cognitive enhancing effect was replicated by local infusions of the AMPAkine CX516, but not CX546, which differ in their effects on EPSPs. This suggests that enhancing the amplitude, but not the duration, of excitatory synaptic currents improves memory performance. Increasing glutamate release through infusions of the mGluR7 presynaptic receptor antagonist MMPIP had no effect on performance. These results provide new mechanistic information that could guide the targeting of future cognitive enhancers. Our work suggests that improved associative-recognition memory can be achieved by enhancing endogenous glutamatergic neuronal activity selectively using an optogenetic approach. We build on these observations to recapitulate this effect using drug treatments that enhance the amplitude of EPSPs; however, drugs that alter the duration of the EPSP or increase glutamate release lack efficacy. This suggests that both neural and temporal specificity are needed to achieve cognitive enhancement. Copyright © 2016 Benn et al.

Contrast enhancement pattern in MR imaging of acute cerebral infarction

International Nuclear Information System (INIS)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon

1994-01-01

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days

Contrast enhancement pattern in MR imaging of acute cerebral infarction

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon [Inje University College of Medicine, Pusan (Korea, Republic of)

1994-08-15

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days.

The Sommerfeld enhancement for dark matter with an excited state

International Nuclear Information System (INIS)

Slatyer, Tracy R.

2010-01-01

We present an analysis of the Sommerfeld enhancement to dark matter annihilation in the presence of an excited state, where the interaction inducing the enhancement is purely off-diagonal, such as in models of exciting or inelastic dark matter. We derive a simple and accurate semi-analytic approximation for the s-wave enhancement, which is valid provided the mass splitting between the ground and excited states is not too large, and discuss the cutoff of the enhancement for large mass splittings. We reproduce previously derived results in the appropriate limits, and demonstrate excellent agreement with numerical calculations of the enhancement. We show that the presence of an excited state leads to generically larger values of the Sommerfeld enhancement, larger resonances, and shifting of the resonances to lower mediator masses. Furthermore, in the presence of a mass splitting the enhancement is no longer a monotonic function of velocity: the enhancement where the kinetic energy is close to that required to excite the higher state can be up to twice as large as the enhancement at zero velocity

High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

International Nuclear Information System (INIS)

Kallmes, D.F.; Gray, L.; Glass, J.P.

1998-01-01

We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. (orig.)

Humility pills: building an ethics of cognitive enhancement.

Science.gov (United States)

Goodman, Rob

2014-06-01

The use of cognition-enhancing drugs (CEDs) appears to be increasingly common in both academic and workplace settings. But many universities and businesses have not yet engaged with the ethical challenges raised by CED use. This paper considers criticisms of CED use with a particular focus on the Accomplishment Argument: an influential set of claims holding that enhanced work is less dignified, valuable, or authentic, and that cognitive enhancement damages our characters. While the Accomplishment Argument assumes a view of authorship based on individual credit-taking, an impersonal or collaborative view is just as possible. This paper considers the benefits of this view-including humility, a value often claimed by critics of enhancement-and argues that such a view is consistent with open CED use. It proposes an ethics of cognitive enhancement based on toleration, transparency, and humility, and it discusses how institutions and individuals can build a culture of open cognitive enhancement. © The Author 2014. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analysis of normal tongue by dynamic enhanced MRI

International Nuclear Information System (INIS)

Ariyoshi, Yasunori; Shimahara, Masashi

2003-01-01

We qualitatively evaluated dynamic enhanced MR images of normal tongues of 26 patients without oral malignancy, inflammatory diseases or systemic diseases. The selected slices were not affected by apparent artifacts including motion and susceptibility, and the tongue shape was delineated as symmetrical on coronal images, which were obtained using a T1 weighted spin echo pulse sequence (repetition time/echo time (TR/TE)=200/20). Slices at the incisor and molar levels were evaluated. Structures that could be identified on each pre-contrast image could also be identified on the post-contrast dynamic enhanced image. However, identification of the intrinsic tongue musculature was impossible on the images that were composed of symmetrical, relatively high signal areas surrounded by a low signal area. Both areas were gradually but apparently enhanced. The sublingual space was easily identified at the molar level, as it was rapidly enhanced and symmetrically delineated on each image, however, it was difficult to determine at the incisor level. Further, the lingual septum could also be identified in almost all images at the molar level, and showed no enhancement pattern, whereas, the mucosal surface of the dorsum tongue was rapidly enhanced, and identified on each image. (author)

Efficacy of liver parenchymal enhancement and liver volume to standard liver volume ratio on Gd-EOB-DTPA-enhanced MRI for estimation of liver function

Energy Technology Data Exchange (ETDEWEB)

Yoneyama, Tomohide; Fukukura, Yoshihiko; Kamimura, Kiyohisa; Takumi, Koji; Umanodan, Aya; Nakajo, Masayuki [Kagoshima University Graduate School of Medical and Dental Sciences, Department of Radiology, Kagoshima City (Japan); Ueno, Shinichi [Kagoshima University Graduate School of Medical and Dental Sciences, Department of Surgical Oncology and Digestive Surgery, Kagoshima City (Japan)

2014-04-15

We aimed to develop and assess the efficacy of a liver function index that combines liver enhancement and liver volume to standard liver volume (LV/SLV) ratio on gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI. In all, 111 patients underwent a Gd-EOB-DTPA-enhanced MRI, including T1 mapping, before and 20 min after Gd-EOB-DTPA administration. We calculated the following Gd-EOB-DTPA-enhanced MRI-based liver function indices: relative enhancement of the liver, corrected enhancement of the liver-to-spleen ratio, LSC{sub N}20, increase rate of the liver-to-muscle ratio, reduction rate of T1 relaxation time of the liver, ΔR1 of the liver and K{sub Hep}; the indices were multiplied by the LV/SLV ratio. We calculated the correlations between an indocyanine green (ICG) clearance and the Gd-EOB-DTPA-enhanced MRI-based liver function indices multiplied by the LV/SLV ratio, by using Pearson correlation analysis. There were significant correlations between all Gd-EOB-DTPA-enhanced MRI-based liver function indices and ICG clearance (r = -0.354 to -0.574, P < 0.001). All Gd-EOB-DTPA-enhanced MRI-based liver function indices multiplied by the LV/SLV ratio (r = -0.394 to -0.700, P < 0.001) were more strongly correlated with the ICG clearance than those without multiplication by the LV/SLV ratio. Gd-EOB-DTPA-enhanced MRI-based liver function indices that combine liver enhancement and the LV/SLV ratio may more reliably estimate liver function. (orig.)

Gene doping: a review of performance-enhancing genetics.

Science.gov (United States)

Gaffney, Gary R; Parisotto, Robin

2007-08-01

Unethical athletes and their mentors have long arrogated scientific and medical advances to enhance athletic performance, thus gaining a dishonest competitive advantage. Building on advances in genetics, a new threat arises from athletes using gene therapy techniques in the same manner that some abused performance-enhancing drugs were used. Gene doping, as this is known, may produce spectacular physiologic alterations to dramatically enhance athletic abilities or physical appearance. Furthermore, gene doping may present pernicious problems for the regulatory agencies and investigatory laboratories that are entrusted to keep sporting events fair and ethical. Performance-enhanced genetics will likewise present unique challenges to physicians in many spheres of their practice.

Effect of surface density silver nanoplate films toward surface-enhanced Raman scattering enhancement for bisphenol A detection

Science.gov (United States)

Bakar, N. A.; Salleh, M. M.; Umar, A. A.; Shapter, J. G.

2018-03-01

This paper reports a study on surface-enhanced Raman scattering (SERS) phenomenon of triangular silver nanoplate (NP) films towards bisphenol A (BPA) detection. The NP films were prepared using self-assembly technique with four different immersion times; 1 hour, 2 hours, 5 hours, and 8 hours. The SERS measurement was studied by observing the changes in Raman spectra of BPA after BPA absorbed on the NP films. It was found that the Raman intensity of BPA peaks was enhanced by using the prepared SERS substrates. This is clearly indicated that these SERS silver substrates are suitable to sense industrial chemical and potentially used as SERS detector. However, the rate of SERS enhancement is depended on the distribution of NP on the substrate surface.

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

DEFF Research Database (Denmark)

Saftoiu, Adrian; Vilmann, Peter; Bhutani, Manoop S

2016-01-01

contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery......Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest...... of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification...

Policy implications of technologies for cognitive enhancement

Energy Technology Data Exchange (ETDEWEB)

Sarewitz, Daniel R. (Arizona State University, Tempe, AZ); Karas, Thomas H.

2007-02-01

The Advanced Concepts Group at Sandia National Laboratory and the Consortium for Science, Policy and Outcomes at Arizona State University convened a workshop in May 2006 to explore the potential policy implications of technologies that might enhance human cognitive abilities. The group's deliberations sought to identify core values and concerns raised by the prospect of cognitive enhancement. The workshop focused on the policy implications of various prospective cognitive enhancements and on the technologies/nanotechnology, biotechnology, information technology, and cognitive science--that enable them. The prospect of rapidly emerging technological capabilities to enhance human cognition makes urgent a daunting array of questions, tensions, ambitions, and concerns. The workshop elicited dilemmas and concerns in ten overlapping areas: science and democracy; equity and justice; freedom and control; intergenerational issues; ethics and competition; individual and community rights; speed and deliberations; ethical uncertainty; humanness; and sociocultural risk. We identified four different perspectives to encompass the diverse issues related to emergence of cognitive enhancement technologies: (1) Laissez-faire--emphasizes freedom of individuals to seek and employ enhancement technologies based on their own judgment; (2) Managed technological optimism--believes that while these technologies promise great benefits, such benefits cannot emerge without an active government role; (3) Managed technological skepticism--views that the quality of life arises more out of society's institutions than its technologies; and (4) Human Essentialism--starts with the notion of a human essence (whether God-given or evolutionary in origin) that should not be modified. While the perspectives differ significantly about both human nature and the role of government, each encompasses a belief in the value of transparency and reliable information that can allow public discussion and

Enhanced living environments from models to technologies

CERN Document Server

Dobre, Ciprian; Ganchev, Ivan; Garcia, Nuno; Goleva, Rossitza Ivanova

2017-01-01

Enhanced living environments employ information and communications technologies to support true ambient assisted living for people with disabilities. This book provides an overview of today's architectures, techniques, protocols, components, and cloud-based solutions related to ambient assisted living and enhanced living environments.

Leadership Enhancement of Rural Women. | Patwardhan | Gender ...

African Journals Online (AJOL)

The study aimed at developing a training program for enhancement of women leadership and executing and evaluating its effect. The Enhancement of Women Leadership Program (EWLP) was developed, which consists of five broad dimensions as Nurturing Intelligence, Self Development, Developing Leadership Skills, ...

Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

Science.gov (United States)

John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

2017-12-26

A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacyl-ethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings.

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

International Nuclear Information System (INIS)

Charles M. Boyer II; Ronald J. MacDonald P.G.

2001-01-01

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger-Holditch Reservoir Technologies (H-RT) has joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden and Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners have provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We have continued to enhance and streamline our software, and we are testing the final stages of our new Microsoft(trademark) Access/Excel based software. We are continuing to process this well data and are identifying potential candidate wells that can be used in Phase 2 to validate the new methodologies. In addition, preparation of the final technical report is underway

Enhanced metro MSTP and its applications

Science.gov (United States)

Li, Guangcheng; Qiao, Yang

2005-02-01

With the large-scale application of metro MSTP in recent two years, a lot of problems have emerged inevitably. Some more advanced technologies or mechanisms are needed to deal with the application problems of current version MSTP. RPR and MPLS become new focus of enhanced MSTP"s features and the combination of them will boost maturity and further development of enhanced metro MSTP. The MSTP embedded with RPR and MPLS not only find a solution for perfect transport of TDM service, but also improve the support ability for data traffic and bandwidth utilization. With the help of enhanced MSTP, it"s easy for network carriers to provide a reliable, cost-effective, flexible and competitive transport infrastructure delivering various advanced services. RPR firstly solves the conflict between the transport efficiency and QoS of packet service via some mechanisms such as dual counter-rotating ringlet, statistical multiplexing, bandwidth sharing, topology discovery, fairness control etc. Secondly, RPR guarantees the QoS of subscriber by strict service classification and priority. Thirdly, RPR can provide the carrier-class protection within 50ms. On the other hand, MPLS can solve the lack of VLAN ID by LSP labeling and in addition it offers VPN service for different customers then enhances the SLA. Most of all, MPLS provide cross-networking ability, end-to-end service configuration and QoS guarantee, traffic engineering and network optimization. Enhanced MSTP will be applied in convergence or access layer of metro network first. It could have the function of RPR and MPLS at the same time, the reconciliation sub-layer should adopts GFP or LAPS encapsulation, the mapping granularity can be based on VC-12/VC3/VC4-Xc/v and the LCAS should be supported when the transmission channels are configured by virtual concatenation. Enhanced MSTP can be used to build either a single ring network or multi-ring network for improving the ability and quality of Ethernet transportation and

Results of ENHANCED Implantable Cardioverter Defibrillator Programming to Reduce Therapies and Improve Quality of Life (from the ENHANCED-ICD Study)

DEFF Research Database (Denmark)

Mastenbroek, Mirjam H.; Pedersen, Susanne S.; van der Tweel, Ingeborg

2016-01-01

-reported outcomes. The "ENHANCED Implantable Cardioverter Defibrillator programming to reduce therapies and improve quality of life" study (ENHANCED-ICD study) was a prospective, safety-monitoring study enrolling 60 primary and secondary prevention patients at the University Medical Center Utrecht. Patients...... programming strategy, unnecessary ICD therapy was prevented in 10% of ENHANCED-ICD patients during a median follow-up period of 1.3 years. With respect to patient-reported outcomes, levels of distress were highest and perceived health status lowest at the time of implantation, which both gradually improved...... during follow-up. In conclusion, the ENHANCED-ICD study demonstrates that programming a NID 60/80 for VT/VF detection is safe for ICD patients and does not negatively impact their quality of life....

Gadolinium-enhanced MR imaging in evaluation of cholesteatoma

International Nuclear Information System (INIS)

Sugihara, M.; Sugimura, K.; Ishida, T.; Fujino, A.; Miyakuni, Y.

1990-01-01

It was sometimes difficult to differentiate cholesteatoma from accompanied granuloma, cholesterol granuloma, or mastoiditis on high-resolution CT. This study was designed to assess the reliability with which cholesteatoma can be differentiated from those accompanied lesions by gadolinium-enhanced MR imaging. Eight patients suspected to have cholesteatoma were evaluated with GD-DTPA-enhanced MR imaging with a 1.5-T MR imaging GE Signa unit. axial pre- and postcontrast T1-weighted (TR/TE, 600/20) and T2-weighted (TR/TE, 2,000/70) images were studied. MR imaging findings were compared with histologic findings (13 lesions), which included cholesteatoma (n = 6), granuloma (n = 4), cholesterol granuloma (n = 2), and mastoiditis (n = 1). Cholesteatoma had an intermediate to high signal intensity (SI) similar to that of granuloma on both T1- and T2-weighted images. Cholesterol granulomas showed high SI on both T1- and T2-weighted images. Mastoiditis demonstrated marked high SI on T2-weighted images. Cholesterol granuloma and mastoiditis can be distinguished from cholesteatoma or granuloma on both T1- and T2-weighted images. On Gd-DTPA-enhanced images, there was marked enhancement of all granulomas. However, no cholesteatoma enhancement was seen in all six lesions. Gd-DTPA-enhanced images were able to distinguish cholesteatoma from granuloma and to estimate the exact extent of cholesteatoma. Gd-DTPA-enhanced MR imaging is valuable in the evaluation and management of cholesteatoma

Field enhancement in plasmonic nanostructures

Science.gov (United States)

Piltan, Shiva; Sievenpiper, Dan

2018-05-01

Efficient generation of charge carriers from a metallic surface is a critical challenge in a wide variety of applications including vacuum microelectronics and photo-electrochemical devices. Replacing semiconductors with vacuum/gas as the medium of electron transport offers superior speed, power, and robustness to radiation and temperature. We propose a metallic resonant surface combining optical and electrical excitations of electrons and significantly reducing powers required using plasmon-induced enhancement of confined electric field. The properties of the device are modeled using the exact solution of the time-dependent Schrödinger equation at the barrier. Measurement results exhibit strong agreement with an analytical solution, and allow us to extract the field enhancement factor at the surface. Significant photocurrents are observed using combination of {{W}} {{{c}}{{m}}}-2 optical power and 10 V DC excitation on the surface. The model suggests optical field enhancement of 3 orders of magnitude at the metal interface due to plasmonic resonance. This simple planar structure provides valuable evidence on the electron emission mechanisms involved and it can be used for implementation of semiconductor compatible vacuum devices.