In vitro sterilization technique on embryo of black Toraja rice

Science.gov (United States)

Haring, F.; Riadi, M.; Rafiuddin; Sjahril, R.; Muchlis, A. R.

2018-05-01

Toraja black rice has a high anthocyanin content, a water-soluble pigments, with antioxidant activity. Toraja black rice has a variety of seeds colour in one panicles such as full black (the outside and inside the rice), medium black (the outside and slightly inside rice) and a little black (only the outside of rice). Embryo culture in vitro is one way to grow plants in sterile conditions. The presence of contamination and the death of the embryo require in vitro embryo culture. The sterilization technique is a very important first step to eliminate contamination and the death of embryos. This research aims to determine the right material composition for sterilization of black rice’s embryo. The experiment was done by growing black rice on half strength MS media with the treatment of three method of sterilization, i.e.: S1 (70% alcohol for 5 minutes, 3% and 2% Chlorox each for 10 minutes,), S2 (70% alcohol for 3 minutes, 2% Clorox for 10 minutes) and S3 (70% alcohol for 3 minutes and 1% Clorox for 15 minutes). The materials used are rice seedlings that have been cut in two and opened the pericarp of paddy grain, leaving a piece of rice that has a complete embryo. The best sterilization for Toraja black rice embryo culture was using the S3 composition. Best germination was seen on the seeds with full and medium black color.

Organochlorine pesticide, polychlorinated biphenyl, trace element and metal residues in bird eggs from Salton Sea, California, 2004

Science.gov (United States)

Henny, Charles J.; Anderson, T.W.; Crayon, J.J.

2008-01-01

The Salton Sea is a highly eutrophic, hypersaline terminal lake that receives inflows primarily from agricultural drainages in the Imperial and Coachella valleys. Impending reductions in water inflow at Salton Sea may concentrate existing contaminants which have been a concern for many years, and result in higher exposure to birds. Thus, waterbird eggs were collected and analyzed in 2004 and compared with residue concentrations from earlier years; these data provide a base for future comparisons. Eggs from four waterbird species (black-crowned night-heron [Nycticorax nycticorax], great egret [Ardea alba], black-necked stilt [Himantopus mexicanus], and American avocet [Recurvirostra Americana]) were collected. Eggs were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), metals, and trace elements, with current results compared to those reported for eggs collected from the same species and others during 1985a??1993. The two contaminants of primary concern were p,pa??-DDE (DDE) and selenium. DDE concentrations in night-heron and great egret eggs collected from the northwest corner of Salton Sea (Whitewater River delta) decreased 91 and 95%, respectively, by 2004, with a concomitant increase in eggshell thickness for both species. Decreases in bird egg DDE levels paralleled those in tissues of tilapia (Oreochromis mossambicus ?? O. urolepis), an important prey species for herons and egrets. Despite most nests of night-herons and great egrets failing in 2004 due to predation, predicted reproductive effects based on DDE concentrations in eggs were low or negligible for these species. The 2004 DDE findings were in dramatic contrast to those in the past decade, and included an 81% decrease in black-necked stilt eggs, although concentrations were lower historically than those reported in night-herons and egrets. Selenium concentrations in black-necked stilt eggs from the southeast corner of Salton Sea (Davis Road) were similar in 1993 and 2004, with 4

Spatial and temporal trends of contaminants in eggs of wading birds from San Francisco Bay, California

Science.gov (United States)

Hothem, R.L.; Roster, D.L.; King, K.A.; Keldsen, T.J.; Marois, Katherine C.; Wainwright, S.E.

1995-01-01

Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time, At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.

The foraging behaviour of herons and egrets on the Magela Creek flood plain, Northern Territory

International Nuclear Information System (INIS)

Recher, H.F.; Holmes, R.T.

1982-03-01

Five species of diurnal herons are common on the Magela Creek flood plain and forage along the edges of natural and artifical waterbodies both inside and outside the Ranger Uranium Project Area. The species of heron differ in the kinds and sizes of prey they take, their foraging location, degree of sociality and foraging behaviour. Because it takes relatively large fish, the Great Egret, E. alba, is most likely to be affected by any contamination of the aquatic environment by heavy metals or radionuclides. The Nankeen Night Heron, Nycticorax caledonicus is also abundant on the flood plain and probably feeds on large fish and frogs. The other herons take smaller or immature prey or hunt mostly in terrestrial habitats and are therefore less likely to be affected by contamination of the aquatic environment

Chlorinated hydrocarbons and biomarkers of exposure in wading birds and fish of the Lower Rio Grande Valley, Texas

Science.gov (United States)

Wainwright, S.E.; Mora, M.A.; Sericano, J.L.; Thomas, P.

2001-01-01

During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with

14. The Herons (Ardeidae)

Science.gov (United States)

Kushlan, J.A.; Hancock, J.A.

2005-01-01

Herons and their close relatives, the egrets and bitterns, comprise sixty species in total and are found all over the world except in polar regions, and are a strikingly beautiful part of the wetlands they inhabit. They are particularly abundant and popular in South West USA, especially Florida. Herons are a diverse group, easily recognized by their long legs, necks and bills. Many species are notable for their sociality as they feed, roost, and nest together in single or mixed species assemblages. The authors have extensive experience of research and observation of these birds and this book provides an up to date comprehensive review of the herons of the world. Covering their biology, distribution, description, systematics, breeding, feeding, and conservation, James Hancock and James Kushlan have distilled their lifetimes' research on the heron into one volume. This volume is complemented by beautiful color paintings especially painted for the book, color photographs, and distribution maps.

Role of communally nesting ardeid birds in the epidemiology of West Nile virus revisited.

Science.gov (United States)

Reisen, William K; Wheeler, Sarah; Armijos, M Veronica; Fang, Ying; Garcia, Sandra; Kelley, Kara; Wright, Stan

2009-06-01

Although herons and egrets in the family Ardeidae frequently have been associated with viruses in the Japanese encephalitis virus serocomplex, communal nesting colonies do not appear to be a focus of early season and rapid amplification of West Nile virus (WNV) in California. Evidence for repeated WNV infection was found by testing living and dead nestlings collected under trees with mixed species ardeid colonies nesting above in an oak grove near the University of California arboretum in Davis and in a Eucalyptus grove at a rural farmstead. However, mosquito infection rates at both nesting sites were low and positive pools did not occur earlier than at comparison sites within the City of Davis or at the Yolo Bypass wetlands managed for rice production and waterfowl habitat. Black-crowned night herons (Nycticorax nycticorax) were the most abundant and frequently infected ardeid species, indicating that WNV may be an important cause of mortality among nestlings of this species.

Radiocesium dynamics in herons inhabiting a contaminated reservoir system

International Nuclear Information System (INIS)

Dombey, A.H.; Paine, D.; McFarlane, R.W.

1977-01-01

The little blue heron (Florida caerulea) and the green heron (Butorides virescens) nest at a radionuclide-contaminated reservoir on the Savannah River Plant near Aiken, South Carolina. Green herons distributed their nests singly along the periphery of the reservoir but fed their nestlings exclusively upon amphibians collected from adjacent uncontaminated Carolina bays. Radiocesium burdens in green heron nestlings did not exceed 5 pCi/g wet wt. and 12 regurgitated food pellets averaged 0.2 pCi/g. Twelve pairs of little blue herons established a heronry upon a small island and fed their nestlings fish and amphibians foraged from within the differentially radionuclide-contaminated reservoir system. Nestlings within the same nest did not exhibit significant differences in body burdens, and the maximum radiocesium burden determined was 27.4 pCi/g wet wt. Substantial differences were found between nestlings from different nests however. The radiocesium level of 43 regurgitated food pellets had a high correlation with observed levels in the nestlings, and variation in food contamination is believed to be the major contributor in the observed variation in the nestlings. The variable contamination of primary prey species was correlated with the differentially contaminated foraging sites and indicates that adult little blue herons tended to spatially partition the available foraging areas. (author)

Heron Island, Australia

Science.gov (United States)

2002-01-01

Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

ADAPTIVE CHARACTERISTICS OF HERONS PLUMAGE FOR THEIR WAY OF LIFE

Directory of Open Access Journals (Sweden)

Koshelev V. A.

2011-12-01

Full Text Available Feather cover of each bird species reflects spectra of species, age, sex and environmental attributes defined the phylogeny of taxa, habitat and life patterns. In turn, many ecological phenomena in the birds’ life patterns are directly dependent on the state of plumage (e.g., time of breeding, seasonal migration, roost flights. For the first time the quantitative characterization of six heron species' plumage were done as well as the description of powder down feathers. The adaptive features of feathers and various types of heron’s plumages were discussed.The structure of contour feathers of herons is related to the peculiarities of species life pattern. All the species have a relatively small number of contour feathers, despite their large body size. According to this index the herons are more similar to typical wading birds (gulls, sandpipers than for waterfowl. The total number of heron feathers slightly increase in winter, because they are migratory species. Structure of contour feathers of herons corresponds to that of other waterbirds. The rod is not bent, the feathers are large, and the mounting angle to the surface of the body is little. The cores of abdominal feather fracts reduce heat transfer and can be regarded as an adaptation factor to aquatic environment.Buoyancy is provided by heron’s feathers insignificantly, in contrast to the typical waterfowl species. Significant subcutaneous fat stores are typical for herons in spring, autumn and winter, increased buoyancy and being the energy reserves provide thermoregulation in cold environment. Our data indicate weak adaptation of herons’ plumage to aquatic environments, but also confirm its insulating properties, which is prove the herons semi-aquatic rather than aquatic life patterns.Due to color of plumage some three groups of herons were considered: white, mottled and camouflaged. Coloration of second and third group performs a protective function. We didn’t found a clear

Waterbirds (other than Laridae nesting in the middle section of Laguna Cuyutlán, Colima, México

Directory of Open Access Journals (Sweden)

Eric Mellink

2008-03-01

Full Text Available Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the nesting of 15 species of non-Laridae waterbirds: Neotropic Cormorant (Phalacrocorax brasilianus, Tricolored Egret (Egretta tricolor, Snowy Egret (Egretta thula, Little Blue Heron (Egretta caerulea, Great Egret (Ardea alba, Cattle Egret (Bubulcus ibis, Black-crowned Nightheron (Nycticorax nycticorax, Yellow-crowned Night-heron (Nyctanassa violacea, Green Heron (Butorides virescens, Roseate Spoonbill (Platalea ajaja, White Ibis (Eudocimus albus, Black-bellied Whistling-duck (Dendrocygna autumnalis, Clapper Rail (Rallus longirostris, Snowy Plover (Charadrius alexandrinus, and Black-necked Stilt (Himantopus mexicanus. These add to six species of Laridae known to nest in that area: Laughing Gulls (Larus atricilla, Royal Terns (Thalasseus maximus, Gull-billed Terns (Gelochelidon nilotica, Forster’s Terns (S. forsteri, Least Terns (Sternula antillarum, and Black Skimmer (Rynchops niger, and to at least 57 species using it during the non-breeding season. With such bird assemblages, Laguna Cuyutlán is an important site for waterbirds, which should be given conservation status. Rev. Biol. Trop. 56 (1: 391-397. Epub 2008 March 31.Durante la prospección de la parte media de la Laguna Cuyutlán, una gran laguna costera en Colima, México, entre 2003 y 2006, documentamos la anidación de 15 especies de aves acuáticas que no pertenecer a la familia Laridae: Phalacrocorax brasilianus, Egretta tricolor, Egretta thula, Egretta caerulea, Ardea alba, Bubulcus ibis, Nycticorax nycticorax, Nyctanassa violacea, Butorides virescens, Platalea ajaja, Eudocimus albus, Dendrocygna autumnalis, Rallus longirostris

Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida

Science.gov (United States)

Smith, J.P.

1997-01-01

Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor. N = 68; APB = 97.3%). For Little Blue Herons (E. caerulerr. N = 57), grass shrimp (Palaemoneles paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure contin-ued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for

Foggy days and dry nights determine crown-level water balance in a seasonal tropical Montane cloud forest.

Science.gov (United States)

Gotsch, Sybil G; Asbjornsen, Heidi; Holwerda, Friso; Goldsmith, Gregory R; Weintraub, Alexis E; Dawson, Todd E

2014-01-01

The ecophysiology of tropical montane cloud forest (TMCF) trees is influenced by crown-level microclimate factors including regular mist/fog water inputs, and large variations in evaporative demand, which in turn can significantly impact water balance. We investigated the effect of such microclimatic factors on canopy ecophysiology and branch-level water balance in the dry season of a seasonal TMCF in Veracruz, Mexico, by quantifying both water inputs (via foliar uptake, FU) and outputs (day- and night-time transpiration, NT). Measurements of sap flow, stomatal conductance, leaf water potential and pressure-volume relations were obtained in Quercus lanceifolia, a canopy-dominant tree species. Our results indicate that FU occurred 34% of the time and led to the recovery of 9% (24 ± 9.1 L) of all the dry-season water transpired from individual branches. Capacity for FU was independently verified for seven additional common tree species. NT accounted for approximately 17% (46 L) of dry-season water loss. There was a strong correlation between FU and the duration of leaf wetness events (fog and/or rain), as well as between NT and the night-time vapour pressure deficit. Our results show the clear importance of fog and NT for the canopy water relations of Q. lanceifolia. © 2013 John Wiley & Sons Ltd.

Response of different genotypes of wheat, rice and black beans to anther, embryo and other tissue cultures

International Nuclear Information System (INIS)

Franco, E.; Amador, D.; Calderon, J.; Alvarez, G.; Alvarado, J.; Ramazzini, H.; Ramos, S.; Acuna, G.; Zuniga, B.

1996-01-01

The objective of the basic studies we have been conducting in our laboratory is to establish callus induction and in vitro plant regeneration protocols starting with several tissues of Guatemalan varieties of wheat (Triticum aesticum L.), rice (Oryza sativa L.) and especially black bean (Phaseolus vulgaris L.) in order to obtain disease resistance, earliness, and dwarf plants. Wheat anthers and immature embryos of varieties Patzun, Comalapa, Chocoyo, and Xequijel cultured in N 6 , Potato II, and MS basal media supplemented with auxin and cytokinin gave the best responses in callus induction and plant regeneration. Anthers and mature embryos of indica rice varieties Precozicta and Virginai, when cultured in MS, B 5 , N 6 , and Potato II basal media with different hormonal combinations gave a good response in callus induction. However, a satisfactory response in plant regeneration was not obtained. With black beans, when hypocotyls and mature embryos of black bean varieties Quinack Che and Parramos were cultured in MS basal medium supplemented with different concentrations of NAA and kinetin, more than 60% callus induction was produced. When Quinack Che calli were transferred to MS basal medium supplemented with 1 mg/l NAA plus 0.5 mg/l BAP, green points of regeneration were visible in these calli. (author). 34 refs, 28 tabs

Scriptaid and 5-aza-2'deoxycytidine enhanced expression of pluripotent genes and in vitro developmental competence in interspecies Black-footed cat cloned embryos

Science.gov (United States)

Gómez, M. C.; Biancardi, M.N.; Jenkins, J.A.; Dumas, C.; Galiguis, J.; Wang, G.; Earle Pope, C.

2012-01-01

Somatic cell nuclear transfer offers the possibility of preserving endangered species including the black-footed cat, which is threatened with extinction. The effectiveness and efficiency of somatic cell nuclear transfer (SCNT) depends on a variety of factors, but 'inappropriate epigenetic reprogramming of the transplanted nucleus is the primary cause of the developmental failure of cloned embryos. Abnormal epigenetic events such as DNA methylation and histone modifications during SCNT perturb the expression of imprinted and pluripotent-related genes that, consequently, may result in foetal and neonatal abnormalities. We have demonstrated that pregnancies can be established after transfer of black-footed cat cloned embryos into domestic cat recipients, but none of the implanted embryos developed to term and the foetal failure has been associated to aberrant reprogramming in cloned embryos. There is growing evidence that modifying the epigenetic pattern of the chromatin template of both donor cells and reconstructed embryos with a combination of inhibitors of histone deacetylases and DNA methyltransferases results in enhanced gene reactivation and improved in vitro and in vivo developmental competence. Epigenetic modifications of the chromatin template of black-footed cat donor cells and reconstructed embryos with epigenetic-modifying compounds enhanced in vitro development, and regulated the expression of pluripotent genes, but these epigenetic modifications did not improve in vivo developmental competence.

Colony Development and Density-Dependent Processes in Breeding Grey Herons

Directory of Open Access Journals (Sweden)

Takeshi Shirai

2013-01-01

Full Text Available The density-dependent processes that limit the colony size of colonially breeding birds such as herons and egrets remain unclear, because it is difficult to monitor colonies from the first year of their establishment, and the most previous studies have considered mixed-species colonies. In the present study, single-species colonies of the Grey Heron (Ardea cinerea were observed from the first year of their establishment for 16 years in suburban Tokyo. Colony size increased after establishment, illustrating a saturation curve. The breeding duration (days from nest building to fledging by a pair increased, but the number of fledglings per nest decreased, with colony size. The reproductive season in each year began earlier, and there was greater variation in the timing of individual breeding when the colony size was larger. The prolonged duration until nestling feeding by early breeders of the colony suggests that herons at the beginning of the new breeding season exist in an unsteady state with one another, likely owing to interactions with immigrant individuals. Such density-dependent interference may affect reproductive success and limit the colony size of Grey Herons.

'HERON' as a dark matter detector?

International Nuclear Information System (INIS)

Adams, J.S.; Bandler, S.R.; Brouer, S.M.; Enss, C.; Lanou, R.E.; Maris, H.J.; More, T.; Seidel, G.M.

1996-01-01

''HERON'', which is the acronym for '' Helium: Roton detection of Neutrinos'', is a project whose principal goal is a next generation detector of solar neutrinos from the p-p and 7 Be branches. It will utilize superfluid helium as the target material and employ event energy transport out of the target by phonon and roton processes unique to helium. Many of the challenges presented for dark matter detection are very similar to those for low energy solar neutrinos. We present new results from our feasibility studies for HERON which indicate an asymmetry in the roton emission distribution from stopping particles and the ability to detect simultaneously the ultraviolet fluorescence photons also emitted. These features are potentially valuable for solar neutrino detection and the question is explored as to whether or not the same helium technique could be valuable for WIMP dark matter detection

When the dragon wore the crown putting starlight back into myth

CERN Document Server

Cerow, Don

2013-01-01

When our ancestors gazed upon the skies thousands of years ago they looked up into the center of Creation and saw a mighty Dragon, a great celestial serpent with wings circling ceaselessly above them, night after night, century after century. When the Dragon Wore the Crown is a ground breaking book that covers a period of over six thousand years, focusing on what astrologers would call the Ages of Gemini, Taurus and Aries and taking us through the period of classical astronomy with the Greeks and Romans (approx. 7000 BC-200 AD).When the Dragon Wore the Crown opens and closes with the Chinese m

Night shift work and incident diabetes among U.S. black women

Science.gov (United States)

Vimalananda, Varsha G.; Palmer, Julie R.; Gerlovin, Hanna; Wise, Lauren A.; Rosenzweig, James L.; Rosenberg, Lynn; Narváez, Edward A. Ruiz

2015-01-01

Aims To assess shift work in relation to incident type 2 diabetes among African American women. Methods In the Black Women's Health Study (BWHS), an ongoing prospective cohort study, we followed 28,041 participants for incident diabetes during 2005-2013. They answered questions in 2005 about having worked the night shift. We estimated hazard ratios (HR) and 95% confidence intervals (CI) for incident diabetes using Cox proportional hazards models. The basic multivariable model included age, time period, family history of diabetes, education, and neighborhood SES. In further models, we controlled for lifestyle factors and body mass index (BMI). Results Over the 8 years of follow-up, there were 1,786 incident diabetes cases. Relative to never having worked the night shift, HRs (95% CI) of diabetes were 1.17 (1.04, 1.31) for 1-2 years of night shift work, 1.23 (1.06, 1.41) for 3-9 years, and 1.42 (1.19, 1.70) for ≥ 10 years (P-trend shift work and type 2 diabetes remained after multivariable adjustment (P-trend = 0.02). The association did not vary by obesity status, but was stronger in women aged shift work were associated with an increased risk of type 2 diabetes. The association was only partially explained by lifestyle factors and BMI. A better understanding of the mechanisms by which shift work may affect risk of diabetes is needed in view of the high prevalence of shift work among U.S. workers. PMID:25586362

Reproduction in eastern screech-owls fed selenium

Science.gov (United States)

Wiemeyer, Stanley N.; Hoffman, D.J.

1996-01-01

Raptors are occasionally exposed to excessive selenium from contaminated prey, but the effects of this exposure on reproduction are unknown. Therefore, we fed captive eastern screech-owls (Otus asio) diets containing 0, 4.4, or 13.2 ppm (wet wt) added selenium in the form of seleno-DL-methionine. Adult mass at sacrifice and reproductive success of birds receiving 13.2 ppm selenium were depressed (P biochemistries indicative of oxidative stress were affected (P < 0.05) in 5-day-old nestlings from parents fed 4.4 ppm selenium and included a 19% increase in glutathione peroxidase activity, a 43% increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), and a 17% increase in lipid peroxidation. Based on reproductive effects relative to dietary exposure, sensitivity of eastern screech-owls to selenium was similar to that of black-crowned night-herons (Nycticorax nycticorax) but less than that of mallards (Anas platyrhynchos).

The heron that laid the golden egg: metals and metalloids in ibis, darter, cormorant, heron, and egret eggs from the Vaal River catchment, South Africa.

Science.gov (United States)

van der Schyff, V; Pieters, R; Bouwman, H

2016-06-01

Metal pollution issues are afforded the highest priority in developing countries. Only one previous study has addressed metals in African bird eggs. We determined the concentration of metals and metalloids in bird eggs from four sites in the Vaal River catchment (VRC) of South Africa to provide data on the current situation. We analysed 16 pools of 77 heron, ibis, darter, egret, and cormorant eggs for 18 metals and metalloids using ICP-MS. We found high concentrations of gold (Au), uranium (U), thallium (Tl), and platinum (Pt) in Grey Heron eggs from Baberspan. Great white egrets from Bloemhof Dam had high concentrations of mercury (Hg). Multivariate analyses revealed strong associations between Au and U, and between palladium (Pd) and Pt. The toxic reference value (TRV) for Hg was exceeded in seven pools. Selenium exceeded its TRV in one pool; in the same pool, copper (Cu) reached its TRV. Compared with other studies, VRC bird eggs had high concentrations of contaminants. Based on these high concentrations, human health might be at risk as Grey Herons and humans share similar food and are therefore exposed to the same contaminants.

Inscribed polygons and Heron polynomials

International Nuclear Information System (INIS)

Varfolomeev, V V

2003-01-01

Heron's well-known formula expressing the area of a triangle in terms of the lengths of its sides is generalized in the following sense to polygons inscribed in a circle: it is proved that the area is an algebraic function of the lengths of the edges of the polygon. Similar results are proved for the diagonals and the radius of the circumscribed circle. The resulting algebraic equations are studied and elementary geometric applications of the algebraic results obtained are presented

Great Blue Herons in Puget Sound

Science.gov (United States)

2007-06-01

consolidation of the breeding population into relatively few, large reproductive centers. With the breeding population centralized, these colonies become...During nesting and reproduction , heron eggs and young fall prey to forest- associated raptors and other predators, further linking the complexity of...nests up to a meter wide and one-half meter deep. An adequate supply of nest material is also important; both deciduous and conifer twigs are utilized

Definitions of night eating in adolescent girls

NARCIS (Netherlands)

Striegel-Moore, RH; Thompson, D; Franko, DL; Barton, B; Affenito, S; Schreiber, GB; Daniels, [No Value

Objective: To describe the prevalence of night eating in a community cohort of black and white girls, using different definitions of night eating as described in the literature. Research Methods and Procedures: Three-day food diaries collected as part of the National Growth and Health Study were

Diel coral reef acidification driven by porewater advection in permeable sands, Heron Island, Great Barrier Reef

DEFF Research Database (Denmark)

Santos, Isaac R.; Glud, Ronnie N.; Maher, Damien

2011-01-01

Little is known about how biogeochemical processes in permeable sediments affect the pH of coastal waters. We demonstrate that seawater recirculation in permeable sands can play a major role in proton (H+) cycling in a coral reef lagoon. The diel pH range (up to 0.75 units) in the Heron Island...... lagoon was the broadest ever reported for reef waters, and the night‐time pH (7.69) was comparable to worst‐case scenario predictions for seawater pH in 2100. The net contribution of coarse carbonate sands to the whole system H+ fluxes was only 9% during the day, but approached 100% at night when small...... scale (i.e., flow and topography‐induced pressure gradients) and large scale (i.e., tidal pumping as traced by radon) seawater recirculation processes were synergistic. Reef lagoon sands were a net sink for H+, and the sink strength was a function of porewater flushing rate. Our observations suggest...

Metal Concentrations, Foraging Distances, and Fledging Success of Great Blue Herons Nesting Along the Hanford Reach of the Columbia River

Energy Technology Data Exchange (ETDEWEB)

Tiller, Brett L.; Marco, Jeffrey D.; Rickard, William H.

2005-05-01

Excrement sample and livers of juvenile great blue herons were collected at nests at three widely separated colonies along the Hanford Reach of the Columbia River to test the validity of using excrement samples as indicators of metal concentrations in tissues of juvenile herons fed food collected by parent birds within a few kilometers of nests. There was no positive relation noted between metal concentrations in excrement and liver samples taken from the same nests. Statistically significant differences in metal concentrations were noted in excrement samples collected among the different heron colonies. Arsenic, Cd, Cr, and Pb concentrations (dry wt.) were higher in excrement than in liver samples but the opposite was noted for Cu, Hg, and Zn. Mercury concentrations in heron liver samples were biomagnified to a greater extent than Cd and Cr. Fledging success and eggshell thickness measurements were used as indicators of population health. These values were equivalent to or better than those noted for heron colonies elsewhere in the United States.

Effects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos in vivo

Energy Technology Data Exchange (ETDEWEB)

Choi, V.W.Y.; Wong, M.Y.P. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Cheng, S.H. [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Yu, K.N., E-mail: appetery@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)

2012-07-15

In the present work, the influence of a low concentration of exogenous carbon monoxide (CO) liberated from tricarbonylchloro(glycinato)ruthenium (II) (CORM-3) on the radiation induced bystander effect (RIBE) in vivo between embryos of the zebrafish was studied. RIBE was assessed through the number of apoptotic signals revealed on embryos at 25 h post fertilization (hpf). A significant attenuation of apoptosis on the bystander embryos induced by RIBE in a CO concentration dependent manner was observed. - Highlights: Black-Right-Pointing-Pointer RIBE between zebrafish embryos in vivo was assessed by the level of apoptosis. Black-Right-Pointing-Pointer CO from 10 and 20 {mu}M CORM-3 entirely suppressed the RIBE. Black-Right-Pointing-Pointer CO from 5 {mu}M CORM-3 significantly attenuated the level of apoptosis. Black-Right-Pointing-Pointer Inactive CORM-3 did not lead to suppression of RIBE. Black-Right-Pointing-Pointer Suppression of RIBE by CO depended on the concentration of CORM-3.

Chondrosarcoma in a wild great white heron from southern Florida.

Science.gov (United States)

Spalding, M G; Woodard, J C

1992-01-01

A typical chondrosarcoma is reported from the nictitating membrane of a great white heron (Ardea herodius occidentalis). This is the first report of a neoplasm in a free flying ciconiiform, and was the only one found in a survey of 957 carcasses from Florida.

Short Note Brood parasitism in the Green-backed Heron ( Butorides ...

African Journals Online (AJOL)

Short Note Brood parasitism in the Green-backed Heron (Butorides striatus). R Yosef, P Zduniak. Abstract. Ostrich 2005, 76(1&2): 78–79. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.2989/00306520509485476 · AJOL African Journals Online.

Seasonal distribution of bird populations at the Patuxent Research Refuge

Science.gov (United States)

Hoffman, D.J.; Henny, C.J.; Hill, E.F.; Keith, J.A.; Grove, R.A.

2000-01-01

High concentrations of mercury from past mining activities have accumulated in the food chain of fish-eating birds nesting along the mid to lower Carson River. Activities of nine plasma and tissue enzymes, and concentrations of other plasma and tissue constituents were measured for black-crowned night-heron, Nycticorax nycticorax, (BCNH) and snowy egret, Egretta thula, (SE) nestlings from two high mercury sites and one low mercury site. Geometric mean blood Hg concentrations for BCNHs at the high mercury sites were 2.6 and 2.8 ppm (ww) and 0.6 ppm at the low mercury site. Blood concentrations for SEs were 3.6 and 1.9 ppm at the high mercury sites and 0.7 ppm at the low mercury site. In BCNHs plasma glutathione peroxidase (GSH peroxidase) activity was lower in both high mercury sites relative to the low mercury site. Butyryl cholinesterase (BuChe), ALT, glutathione reductase (GSSG-reductase) and LDH-L activities were lower in one high mercury site. In SEs significant differences were lower BuChe and LDH-L, but elevated GGT activities. Evidence of renal stress in both species at high mercury sites included increased plasma uric acid, blood urea nitrogen, and creatinine concentrations as well as oxidative stress in the kidney tissue itself where oxidized glutathione increased. A number of the mercury site-related effects, including decreased plasma GSH-peroxidase and hepatic G-6-PDH activities, higher GSSG-reductase activity, and lower hepatic concentrations of reduced thiols have been reported in methylmercury feeding studies with great egrets and mallards. These findings suggest the utility of herons and egrets for monitoring mercury sites.

Canada’s Evolving Crown: From a British Crown to a “Crown of Maples”

Directory of Open Access Journals (Sweden)

Romaniuk Scott Nicholas

2014-12-01

Full Text Available This article examines how instruments have changed the Crown of Canada from 1867 through to the present, how this change has been effected, and the extent to which the Canadian Crown is distinct from the British Crown. The main part of this article focuses on the manner in which law, politics, and policy (both Canadian and non-Canadian have evolved a British Imperial institution since the process by which the federal Dominion of Canada was formed nearly 150 years ago through to a nation uniquely Canadian as it exists today. The evolution of the Canadian Crown has taken place through approximately fifteen discrete events since the time of Canadian confederation on July 1, 1867. These fifteen events are loosely categorized into three discrete periods: The Imperial Crown (1867-1930, A Shared Crown (1931-1981, and The Canadian Crown (1982-present.

Dose-response relationship of cadmium or radiation-induced embryotoxicity in mouse whole embryo culture

International Nuclear Information System (INIS)

Nakashima, Kiyohito; Kawamata, Akitoshi; Matsuoka, Masato; Wakisaka, Takashi; Fujiki, Yoshishige

1988-01-01

Mouse embryos of B6C3F 1 strain were exposed in vitro to 1.2 to 2.2 μM cadmium chloride (Cd) or to 100 to 320 R x-rays, and the effects of the exposure on development were examined after 39 h of culture. Development of embryos was assessed from lethality, formation of the neural tube defect, diameter and protein of yolk sac, crown-rump and head lengths, embryonic protein, and number of somites. Incidence of the neural tube defect increased from 3.4 to 100% by 1.2 to 2.0 μM Cd, while embryo deaths increased from 13.8 to 93.3% by 2.0 to 2.2 μM Cd. Embryonic protein was significantly reduced at the teratogenic range, but the number of somites was only affected by 1.6 to 2.0 μM Cd. X-irradiation at 100 to 320 R induced the neural tube defect in 2.9 to 72.7% of the embryos. An embryolethal effect was observed only at the 320 R dose. Crown-rump and head lengths and embryonic protein were significantly affected at the teratogenic range, but the diameter and protein of yolk sac and number of somites were hardly affected. Cadmium- or radiation-induced response data of both teratogenicity and endpoints indicating inhibition of embryonic development were acceptably fitted to a linear log-probit regression. These regressions suggest that as an estimation of interference in development of embryos, embryonic protein and head length are sensitive endpoints while the number of somites is an insensitive criterion. (author)

Dinar-crown banknotes

OpenAIRE

Pantelić Svetlana

2017-01-01

Dinar-crown banknotes were: ½ dinars (i.e. 2 crowns), 1 dinar (i.e. 4 crowns), 5 dinars (i.e. 20 crowns), 10 dinars (i.e. 40 crowns), 20 dinars (i.e. 80 crowns), 100 dinars (i.e. 400 crowns), and 1000 dinars (i.e. 4000 crowns). The ½- and 1-dinar banknotes are assumed to have been issued in 1919, whereas the other five banknotes, according to one source, were released into circulation on 21.02.1920. Pursuant to the regulations, the replacement of the nostrified crown banknotes by the new crow...

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue.

Science.gov (United States)

Sharma, Brij B; Kalia, Pritam; Singh, Dinesh; Sharma, Tilak R

2017-01-01

Black rot caused by Xanthomonas campestris pv. campestris ( Xcc ) is a very important disease of cauliflower ( Brassica oleracea botrytis group) resulting into 10-50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B 1 ) were generated between cauliflower "Pusa Sharad" and Ethiopian mustard "NPC-9" employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F 1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2 n = 18, CC) × B. carinata (2 n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2 n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F 1 hybrid and BC 1 plants. The F 1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC 1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC 1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue

Science.gov (United States)

Sharma, Brij B.; Kalia, Pritam; Singh, Dinesh; Sharma, Tilak R.

2017-01-01

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a very important disease of cauliflower (Brassica oleracea botrytis group) resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1) were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2n = 18, CC) × B. carinata (2n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides. PMID:28769959

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group through Embryo Rescue

Directory of Open Access Journals (Sweden)

Brij B. Sharma

2017-07-01

Full Text Available Black rot caused by Xanthomonas campestris pv. campestris (Xcc is a very important disease of cauliflower (Brassica oleracea botrytis group resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome, therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1 were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC primers. Meiosis in the di-genomic (BCC interspecific hybrid of B. oleracea botrytis group (2n = 18, CC × B. carinata (2n = 4x = 34, BBCC was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.

Utilization of endogenous fatty acid stores for energy production in bovine preimplantation embryos.

Science.gov (United States)

Sutton-McDowall, Melanie L; Feil, Deanne; Robker, Rebecca L; Thompson, Jeremy G; Dunning, Kylie R

2012-05-01

Although current embryo culture media are based on carbohydrate metabolism of embryos, little is known about metabolism of endogenous lipids. L-carnitine is a β-oxidation cofactor absent in most culture media. The objective was to investigate the influence of L-carnitine supplementation on bovine embryo development. Abattoir-derived bovine cumulus oocyte complexes were cultured and fertilized. Post-fertilization, presumptive zygotes were transferred into a basic cleavage medium ± carbohydrates (glucose, lactate and pyruvate) ± 5 mm L-carnitine and cultured for 4 days in vitro. In the absence of carbohydrates during culture, embryos arrested at the 2- and 4-cell stages. Remarkably, +L-carnitine increased development to the morula stage compared to +carbohydrates alone (P levels were higher and ATP: ADP ratio were 1.9-fold lower (main effect, P < 0.05) compared to embryos cultured in -L-carnitine. Therefore, we inferred that +L-carnitine embryos were more metabolically active, with higher rates of ATP-ADP conversion. In conclusion, L-carnitine supplementation supported precompaction embryo development and there was an additive effect of +L-carnitine +carbohydrates on early embryo development, most likely through increased β-oxidation within embryos. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Human developmental anatomy: microscopic magnetic resonance imaging (μMRI) of four human embryos (from Carnegie Stage 10 to 20).

Science.gov (United States)

Lhuaire, Martin; Martinez, Agathe; Kaplan, Hervé; Nuzillard, Jean-Marc; Renard, Yohann; Tonnelet, Romain; Braun, Marc; Avisse, Claude; Labrousse, Marc

2014-12-01

Technological advances in the field of biological imaging now allow multi-modal studies of human embryo anatomy. The aim of this study was to assess the high magnetic field μMRI feasibility in the study of small human embryos (less than 21mm crown-rump) as a new tool for the study of human descriptive embryology and to determine better sequence characteristics to obtain higher spatial resolution and higher signal/noise ratio. Morphological study of four human embryos belonging to the historical collection of the Department of Anatomy in the Faculty of Medicine of Reims was undertaken by μMRI. These embryos had, successively, crown-rump lengths of 3mm (Carnegie Stage, CS 10), 12mm (CS 16), 17mm (CS 18) and 21mm (CS 20). Acquisition of images was performed using a vertical nuclear magnetic resonance spectrometer, a Bruker Avance III, 500MHz, 11.7T equipped for imaging. All images were acquired using 2D (transverse, sagittal and coronal) and 3D sequences, either T1-weighted or T2-weighted. Spatial resolution between 24 and 70μm/pixel allowed clear visualization of all anatomical structures of the embryos. The study of human embryos μMRI has already been reported in the literature and a few atlases exist for educational purposes. However, to our knowledge, descriptive or morphological studies of human developmental anatomy based on data collected these few μMRI studies of human embryos are rare. This morphological noninvasive imaging method coupled with other techniques already reported seems to offer new perspectives to descriptive studies of human embryology.

Evaluation of treatments with hCG and carprofen at embryo transfer in a demi-embryo and recipient virgin heifer model.

Science.gov (United States)

Torres, A; Chagas E Silva, J; Diniz, P; Lopes-da-Costa, L

2013-08-01

An in vivo model, combining a low developmental competence embryo (demi-embryo) and a high-fertility recipient (virgin dairy heifer) was used to evaluate the effects of treatment with human chorionic gonadotropin (hCG) and carprofen at embryo transfer (ET) on plasma progesterone (P₄) concentrations of recipients and on embryonic growth and survival. Embryos were bisected and each demi-embryo was transferred to a recipient on Day 7 of the estrous cycle. At ET, heifers (n = 163) were randomly allocated to treatment with hCG (2500 IU im), carprofen (500 mg iv), hCG plus carprofen or to untreated controls. Plasma P₄ concentrations were measured on Days 0, 7, 14 and 21 of all recipients plus on Days 28, 42 and 63 of pregnant recipients. Pregnancy was presumed to be present in recipients with luteal plasma P4 concentrations until Day 21 and confirmed by using transrectal ultrasonography on Days 28, 42 and 63. Embryonic measurements (crown-rump length and width) were obtained on Day 42. Treatment with hCG induced formation of secondary corpora lutea (CL) in 97% of heifers and increased (P carprofen at ET had no significant effects on plasma P₄ concentrations and rate of embryo mortality. Treatment with hCG plus carprofen at ET induced formation of secondary CL in 90% of heifers but decreased the luteotrophic effect of hCG, resulting in no effect on embryo survival. Low developmental competence embryos showed an intrinsic deficiency in overcoming the maternal recognition of pregnancy challenge and in proceeding to further development until Day 28 of pregnancy, whereas mortality beyond this point was residual. Results on pregnancy rates should be confirmed in further experiments involving a larger sample size.

Results of bald eagle, osprey and great blue heron nest site surveys near Fort MacKay, Alberta

International Nuclear Information System (INIS)

Strom, K.; Balagus, P.

1996-01-01

As part of the environmental impact assessment process, a study was conducted to assess the occurrence of bald eagle, osprey and great blue heron on Syncrude's proposed oil sand leases near Fort MacKay. The objective of the study was to determine the relative abundance, habitat preferences and nesting occurrences of these different birds. Aerial count surveys were conducted to include coverage of the shorelines of four rivers and 22 lakes. Breeding activities of the osprey, bald eagle and great blue heron were observed in the regional study area, but not in the local study area. 14 refs., 1 tab., 4 figs

Environmental contaminants in great blue herons (Ardea herodias) from the lower Columbia and Willamette Rivers, Oregon and Washington, USA

Energy Technology Data Exchange (ETDEWEB)

Thomas, C.M.; Anthony, R.G.

1999-12-01

Great blue heron (Ardea herodias) eggs and prey items were collected from six colonies in Oregon and Washington, USA, during 1994 to 1995. Contaminant concentrations, reproductive success, and biomagnification factors were determined and effects of residue levels were measured by H4IIE rat hepatoma bioassays. Mean residue concentrations in heron eggs and prey items were generally low. However, elevated concentrations of polychlorinated biphenyls (PCBs) were detected in eggs and prey from Ross Island on the Willamette River. Biomagnification factors varied among sites. Sites were not significantly different in H4IIE tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs), although the TCDD-EQ for Karlson Island was 9 to 20 times greater than that of any other site. Large differences existed between toxic equivalents calculated from egg residue concentrations and TCDD-EQs, which indicated nonadditive interactions among the compounds. Tetrachlorodibenzo-p-dioxin equivalents and nest failure were positively correlated with TCDD concentration. Fledging and reproductive rates were similar to those determined for healthy heron populations, however, indicating that any adverse effects were occurring at the individual level and not at the colony level. Their results support the use of great blue herons as a biomonitor for contamination in aquatic ecosystems. Their relatively low sensitivity to organochlorine contaminants and high trophic position allows contaminant accumulation and biomagnification without immediate adverse effects that are often seen in other, more sensitive species.

on black ironbark (Eucalyptus

African Journals Online (AJOL)

(Apis meOifera) on black ironbark. (Eucalyptus sideroxylon). B. Buys. Plant Protection Research Institute, Private Bag X5017,. Stellenbosch, 7600 Republic of South Africa. Received May /984; accepted 28 November /986. Black ironbark trees secrete nectar during the night. Argentine ants collected 42% of the nectar before ...

Dinar-crown banknotes

Directory of Open Access Journals (Sweden)

Pantelić Svetlana

2017-01-01

Full Text Available Dinar-crown banknotes were: ½ dinars (i.e. 2 crowns, 1 dinar (i.e. 4 crowns, 5 dinars (i.e. 20 crowns, 10 dinars (i.e. 40 crowns, 20 dinars (i.e. 80 crowns, 100 dinars (i.e. 400 crowns, and 1000 dinars (i.e. 4000 crowns. The ½- and 1-dinar banknotes are assumed to have been issued in 1919, whereas the other five banknotes, according to one source, were released into circulation on 21.02.1920. Pursuant to the regulations, the replacement of the nostrified crown banknotes by the new crown- dinar banknotes started on 3 February 1920 in Serbia and Montenegro and on 16 February 1920 in other parts of the country. All seven denominations of the dinar-crown banknotes were being withdrawn from circulation throughout a lengthy period of time from 21 February 1921 until May 1934. The first to be withdrawn were the 20-dinar banknotes, from 1 February to 30 April 1921, then the 5-dinar banknotes, from 20 July to 20 November 1922, and the 10-dinar banknotes, from 10 February to 10 June 1924. The 100-dinar (400-crown and 1000-dinar (4000-crown banknotes remained in circulation the longest. The withdrawal of the 100- and 1000-dinar banknotes started in 1929 and lasted until 25 May 1934. The 1924 rulebook on minting coins of ½, 1 and 2 dinars precisely defines their withdrawal from circulation and replacement by minted coins within one year after the last batch of minted coins gets released into circulation. However, in 1927 the decree of the Minister of Finance prescribed that the remaining paper banknotes be withdrawn from circulation on 30 September 1927 by being replaced by the metal coins of the same denominations.

Persistent organochlorine pollutants in eggs of colonial waterbirds from Galveston Bay and East Texas, USA

Science.gov (United States)

Frank, D.S.; Mora, M.A.; Sericano, J.L.; Blankenship, Alan L.; Kannan, K.; Giesy, J.P.

2001-01-01

Eggs of neotropic cormorants (Phalacrocorax brasilianus), black-crowned night herons (Nycticorax nycticorax), and great egrets (Ardea alba) nesting on several locations in Galveston Bay (TX, USA) and at two control sites outside the bay were collected during April–May 1996 and analyzed for chlorinated pesticides, PCBs, polychlorinated dibenzo-p-dioxins, and polychlor-inated dibenzofurans. Additionally, concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs) were determined by use of relative potency factors (TEQs) or the H4IIE-luc bioassay TCDD-EQs. Concentrations of 1,1,-dichloro-2,2-bis(p-chlo-rophenyl)ethylene (DDE) were greater in eggs of neotropic cormorants from Alexander Island (mean = 1,040 ng/g wet wt) in the Houston Ship Channel (Houston, TX, USA) and in those from Telfair Island (mean = 1,460 ng/g wet wt), a reference location outside the bay, than in most locations inside the bay (mean range = 119–453 ng/g wet wt). Mean PCB concentrations were greater in eggs of neotropic cormorants from Alexander Island (mean = 5,720 ng/g wet wt) than in eggs of cormorants from areas farther away from the ship channel, including two reference sites outside the bay (mean range = 404–3,140 ng/g wet wt). The TCDD was the main dioxin congener detected in eggs from all locations within Galveston Bay. Instrumental TEQs in eggs ranged from 67 pg/g wet weight at control sites to 452 pg/g wet weight at Alexander Island. Concentrations of TCDD-EQs determined in the H4IIE assay were correlated with instrumental TEQs and were greater in eggs of cormorants from islands within the bay, although these were farther away from the ship channel. Overall, concentrations of DDE, PCBs, TCDD, and TCDD-EQs were less than the threshold levels known to affect reproduction. However, some eggs contained concentrations of total PCBs or DDE greater than what would elicit adverse effects on birds. No identifiable deformities or abnormalities were detected in embryos

Black stain and dental caries in Filipino schoolchildren.

NARCIS (Netherlands)

Heinrich-Weltzien, R.; Monse, B.; Palenstein Helderman, W.H. van

2009-01-01

Black stain is defined as dark pigmented exogenous substance in lines or dots parallel to the gingival margin and firmly adherent to the enamel at the cervical third of the tooth crowns in the primary and permanent dentition. OBJECTIVES: This study was conducted to assess the prevalence of black

Role of melatonin in embryo fetal development.

Science.gov (United States)

Voiculescu, S E; Zygouropoulos, N; Zahiu, C D; Zagrean, A M

2014-01-01

Melatonin is an indoleamine produced by the pineal gland and secreted in a circadian manner. In the past few decades, research over this topic has been enhanced. Melatonin has many important roles in the human physiology: regulator of the circadian rhythms, sleep inducer, antioxidant, anticarcinogenic. This paper reviews the involvement of melatonin in embryo fetal development. The pineal gland develops completely postpartum, so both the embryo and the fetus are dependent on the maternal melatonin provided transplacentally. Melatonin appears to be involved in the normal outcome of pregnancy beginning with the oocyte quality and finishing with the parturition. Its pregnancy night-time concentrations increase after 24 weeks of gestation, with significantly high levels after 32 weeks. Melatonin receptors are widespread in the embryo and fetus since early stages. There is solid evidence that melatonin is neuroprotective and has a positive effect on the outcome of the compromised pregnancies. In addition, chronodisruption leads to a reproductive dysfunction. Thus, the influence of melatonin on the developing human fetus may not be limited to the entertaining of circadian rhythmicity, but further studies are needed.

Blood biomarkers and contaminant levels in feathers and eggs to assess environmental hazards in heron nestlings from impacted sites in Ebro basin (NE Spain)

International Nuclear Information System (INIS)

Barata, C.; Fabregat, M.C.; Cotin, J.; Huertas, D.; Sole, M.; Quiros, L.; Sanpera, C.; Jover, L.; Ruiz, X.; Grimalt, J.O.; Pina, B.

2010-01-01

Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant. - High levels of organochlorine and mercury levels in eggs and feathers were related with altered blood biomarkers of heron nesting chicks.

Developmental and dysmorphogenic effects of glufosinate ammonium on mouse embryos in culture.

Science.gov (United States)

Watanabe, T; Iwase, T

1996-01-01

The effects of glufosinate ammonium on embryonic development in mice were examined using whole embryo and micromass cultures of midbrain and limb bud cells. In day 8 embryos cultured for 48 hr, glufosinate caused significant overall embryonic growth retardation and increased embryolethality to 37.5% at 10 micrograms/ml (5.0 x 10(-5) M). All embryos in the treated groups exhibited specific morphological defects including hypoplasia of the prosencephalon (forebrain) (100%) and visceral arches (100%). In day 10 embryos cultured for 24 hr, glufosinate significantly reduced the crown-rump length and the number of somite pairs, and produced a high incidence of morphological defects (84.6%) at 10 micrograms/ml. These embryos were characterized by blister in the lateral head (100%), hypoplasia of prosencephalon (57.1%), and cleft lips (42.9%) at 20 micrograms/ml (10.0 x 10(-5) M). Histological examination of the treated embryos showed numerous cell death (pyknotic debris) present throughout the neuroepithelium in the brain vesicle and neural tube, but did not involve the underlying mesenchyme. In micromass culture, glufosinate inhibited the differentiation of midbrain cells in day 12 embryos with 50% inhibition occurring at 0.55 microgram/ml (2.8 x 10(-6) M). The ratios of 50% inhibition concentration for cell proliferation to cell differentiation in limb bud cells were 0.76 and 1.52 in day 11 and 12 embryos, respectively. These findings indicate that glufosinate ammonium is embryotoxic in vitro. In addition to causing growth retardation, glufosinate specifically affected the neuroepithelium of the brain vesicle and neural tube, leading to neuroepithelial cell death.

Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

Energy Technology Data Exchange (ETDEWEB)

Shirakashi, Ryo, E-mail: aa21150@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); Mischke, Miriam [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fischer, Peter [Physiologische Chemie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Memmel, Simon [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Krohne, Georg [Abteilung fuer Elektronenmikroskopie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fuhr, Guenter R. [Lehrstuhl fuer Biotechnologie und Medizintechnik, Universitaet des Saarlandes, Saarbruecken (Germany); Zimmermann, Heiko [Lehrstuhl fuer Molekulare und Zellulaere Biotechnologie, Universitaet des Saarlandes, Saarbruecken (Germany); Sukhorukov, Vladimir L., E-mail: sukhorukov@biozentrum.uni-wuerzburg.de [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany)

2012-11-09

Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.

Crown-rise and crown-length dynamics: applications to loblolly pine

Science.gov (United States)

Harry T. Valentine; Ralph L. Amateis; Jeffrey H. Gove; Annikki. Makela

2013-01-01

The original crown-rise model estimates the average height of a crown-base in an even-aged mono-species stand of trees. We have elaborated this model to reduce bias and prediction error, and to also provide crown-base estimates for individual trees. Results for the latter agree with a theory of branch death based on resource availability and allocation.We use the...

Predicting mortality of ponderosa pine regeneration after prescribed fire in the Black Hills, South Dakota, USA

Science.gov (United States)

Mike Battaglia; Frederick W. Smith; Wayne D. Shepperd

2009-01-01

Reduction of crown fire hazard in Pinus ponderosa forests in the Black Hills, SD, often focuses on the removal of overstorey trees to reduce crown bulk density. Dense ponderosa pine regeneration establishes several years after treatment and eventually increases crown fire risk if allowed to grow. Using prescribed fire to control this regeneration is...

Baseline report - tall upland shrubland at the Rocky Flats Environmental Technology Site

International Nuclear Information System (INIS)

1997-03-01

Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP). These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble's meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam's shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study

Baseline report - tall upland shrubland at the Rocky Flats Environmental Technology Site

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP). These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble`s meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam`s shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study.

Beautiful Black: A Bibliography about the Night for Young Readers from Preschool through Junior High.

Science.gov (United States)

Sumner, Mary Ann, Comp.

This bibliography offers a "magical adventure into the dark and dreamy world of the night." It contains annotations for 146 books, available for free to the blind and disabled, that cover various things associated with the night: dreams, monsters and ghosts, overcoming fear of the dark, nights in other countries that are six months long,…

Influence of the heron colony on heavy metals accumulation in soil of Dniprovsko-Orilsky nature reserve

Directory of Open Access Journals (Sweden)

M. V. Vovk

2005-01-01

Full Text Available The article is devoted to the research of the settlements of heron on the accumulation of heavy metals in the soil. The author considers accumulation of trace elements in different soil horizons. The reasons of the prohibitions has been rate.

Photometric Assessment of Night Sky Quality over Chaco Culture National Historical Park

Science.gov (United States)

Hung, Li-Wei; Duriscoe, Dan M.; White, Jeremy M.; Meadows, Bob; Anderson, Sharolyn J.

2018-06-01

The US National Park Service (NPS) characterizes night sky conditions over Chaco Culture National Historical Park using measurements in the park and satellite data. The park is located near the geographic center of the San Juan Basin of northwestern New Mexico and the adjacent Four Corners state. In the park, we capture a series of night sky images in V-band using our mobile camera system on nine nights from 2001 to 2016 at four sites. We perform absolute photometric calibration and determine the image placement to obtain multiple 45-million-pixel mosaic images of the entire night sky. We also model the regional night sky conditions in and around the park based on 2016 VIIRS satellite data. The average zenith brightness is 21.5 mag/arcsec2, and the whole sky is only ~16% brighter than the natural conditions. The faintest stars visible to naked eyes have magnitude of approximately 7.0, reaching the sensitivity limit of human eyes. The main impacts to Chaco’s night sky quality are the light domes from Albuquerque, Rio Rancho, Farmington, Bloomfield, Gallup, Santa Fe, Grants, and Crown Point. A few of these light domes exceed the natural brightness of the Milky Way. Additionally, glare sources from oil and gas development sites are visible along the north and east horizons. Overall, the night sky quality at Chaco Culture National Historical Park is very good. The park preserves to a large extent the natural illumination cycles, providing a refuge for crepuscular and nocturnal species. During clear and dark nights, visitors have an opportunity to see the Milky Way from nearly horizon to horizon, complete constellations, and faint astronomical objects and natural sources of light such as the Andromeda Galaxy, zodiacal light, and airglow.

Retrospective Study of Retention of Stainless Steel Crowns and Pre-veneered Crowns on Primary Anterior Teeth.

Science.gov (United States)

Lopez-Loverich, Angela M; Garcia, Maria Minerva; Donly, Kevin J

2015-01-01

The purpose of this retrospective chart review was to explore the retention of anterior pre-veneered stainless steel crowns (NuSmile) and conventional stainless steel crowns (3M ESPE) placed on primary anterior teeth. Records for children were reviewed over four years using the electronic record system axiUm. Data collected included child's age at time of crown placement, date of placement, tooth number, type of crown, patient behavior, treatment environment, provider type, crown presence, absence, and cementation success or failure at subsequent recall visits. A total of 637 anterior crowns in children treated with either or both crown types met this study's inclusion criteria. Of these crowns, 483 were NuSmile Signature crowns and 154 were stainless steel crowns. There was a nine percent failure rate for the NuSmile Signature crowns and a seven percent failure rate for the stainless steel crowns. There was no statistically significant difference in crown retention rates between the two groups (P<0.05). A full-coverage restoration that can follow the lifespan of the primary anterior dentition in high-risk children is needed. The results from this study indicate good crown retention rates for both crown types with no statistically significant difference between them (P<0.05).

Melas Chasma, Day and Night.

Science.gov (United States)

2002-01-01

This image is a mosaic of day and night infrared images of Melas Chasma taken by the camera system on NASA's Mars Odyssey spacecraft. The daytime temperature images are shown in black and white, superimposed on the martian topography. A single nighttime temperature image is superimposed in color. The daytime temperatures range from approximately -35 degrees Celsius (-31 degrees Fahrenheit) in black to -5 degrees Celsius (23 degrees Fahrenheit) in white. Overlapping landslides and individual layers in the walls of Melas Chasma can be seen in this image. The landslides flowed over 100 kilometers (62 miles) across the floor of Melas Chasma, producing deposits with ridges and grooves of alternating warm and cold materials that can still be seen. The temperature differences in the daytime images are due primarily to lighting effects, where sunlit slopes are warm (bright) and shadowed slopes are cool (dark). The nighttime temperature differences are due to differences in the abundance of rocky materials that retain their heat at night and stay relatively warm (red). Fine grained dust and sand (blue) cools off more rapidly at night. These images were acquired using the thermal infrared imaging system infrared Band 9, centered at 12.6 micrometers.Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for NASA's Office of Space Science in Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. Additional science partners are located at the Russian Aviation and Space Agency and at Los Alamos National Laboratories, New Mexico. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL. Aviation and Space Agency and at Los Alamos National Laboratories

Temporal trends of mercury and organohalogen contaminants in great blue heron eggs from the St. Lawrence River, Québec, Canada, 1991-2011, and relationships with tracers of feeding ecology.

Science.gov (United States)

Champoux, Louise; Boily, Monique

2017-12-31

Since 1991, great blue heron (Ardea herodias) eggs have been collected and analyzed for mercury (Hg), persistent organic contaminants (OCs), brominated and non-brominated flame retardants (FRs) as well as stable isotopes δ 13 C and δ 15 N. In the present study, temporal trends of contaminants were analyzed in eggs sampled in four regions along the St. Lawrence River (Quebec, Canada) and inland sites using new and previously published data. Most contaminants declined significantly over time in most regions. Globally, the highest annual change, -17.5%, was found for pp'-DDD, while the smallest annual decline, -0.54%, was observed for Hg. Concentrations of ΣDDT and ΣFR 8 (sum of 8 congeners) decreased by -11.6% and -7.3%, respectively. Declines in ΣPCBs differed among regions, from -5.6% in the fluvial section to -14.7% in the inland region. The highest concentration of ΣFR 8 was measured in eggs from Grande Ile in the fluvial section of the river in 1996 (2.39μg/g). Stable isotope ratios also showed temporal trends in some regions: δ 13 C decreased in the fluvial section and increased in Gulf region, while δ 15 N decreased in the fluvial section and increased in the upper estuary. Significant positive relationships were found between ΣDDT, ΣPCBs and ΣFRs and δ 15 N and δ 13 C in freshwater colonies, but not in estuarine or marine colonies. These results suggest that changes in trophic level and foraging areas over time were influential factors with respect to contaminant burden in great blue heron eggs in the fluvial section, but not in the other regions. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Assessment of crown angulations, crown inclinations, and tooth size discrepancies in a South Indian population

Directory of Open Access Journals (Sweden)

Geeta Maruti Doodamani

2011-01-01

Full Text Available Aims and Objective: The aim of this study was to assess crown angulations, crown inclinations, and tooth size discrepancy in a sample population from Davangere, South India. Materials and Methods: One hundred adults (50 male and 50 female of age 18-30 years, with Angle′s class I ideal occlusion and balanced profiles, were selected for the study. Study models were prepared and crown angulations and crown inclinations were measured using a customized protractor device. Bolton′s analysis was used to measure the tooth size discrepancies. Results: Maxillary and mandibular teeth had less crown angulations. Maxillary and mandibular incisors and maxillary molars showed increased crown inclinations, whereas mandibular molars and premolars had less crown inclinations than the original Andrews sample. The mean maxillary and mandibular tooth size ratios, overall and anterior, were similar to Bolton′s ratios. Conclusions: The finding of this study indicates that there are possible racial and ethnic factors contributing to variations in crown angulations and crown inclinations.

Hard Day’s Night: A Retrospective on the American Intervention in Somalia

Science.gov (United States)

2009-01-01

weapons storage areas, a Pakistani unit was badly mauled. In a lengthy firefight, Aideed’s militia killed 23 and wounded 59. UNOSOM II’s Malaysian ...Regiment (SOAR), equipped with MH60 Black Hawk utility helicopters and MH6 and AH6 “Little Bird ” light helicopters. Small numbers of communicators...Americans through the night. By most accounts, only the dauntless actions of the AH6 Little Bird pilots, flying all night long, kept the besieged

Does the Sun appear brighter at night in neutrinos?

International Nuclear Information System (INIS)

Bahcall, J.N.; Krastev, P.I.

1997-01-01

We calculate accurately the number of solar neutrino events expected as a function of solar zenith angle, with and without neutrino oscillations, for detectors at the locations of Super-Kamiokande, SNO, and the Gran Sasso National Laboratory. Using different Earth models to estimate geophysical uncertainties, and different solar models to estimate solar uncertainties, we evaluate distortions predicted by the Mikheyev-Smirnov-Wolfenstein (MSW) effect in the zenith angle distributions of solar neutrino events. The distortions are caused by oscillations and by ν-e interactions in the Earth that regenerate ν e from ν μ or ν τ . We show that the first two moments of the zenith-angle distribution are more sensitive to the small mixing angle MSW solution than the conventionally studied day-night asymmetry. We present iso-σ contours that illustrate the potential of Super-Kamiokande, SNO, BOREXINO, ICARUS, and HERON/HELLAZ for detecting the Earth regeneration effect at their actual locations (and at the equator). MSW solutions favored by the four pioneering solar neutrino experiments predict characteristic distortions for Super-Kamiokande, SNO, BOREXINO, and ICARUS that range from being unmeasurably small to >5σ (stat) after only a few years of observations. copyright 1997 The American Physical Society

Actinide/crown ether chemistry

International Nuclear Information System (INIS)

Benning, M.M.

1988-01-01

A structural survey of actinide/crown ether compounds was conducted in order to investigate the solid state chemistry of these complexes. Several parameters - the metal size, crown type, counterion, solvent systems and reaction and crystallization conditions - were varied to correlate their importance in complexation. Under atmospheric conditions, two types of complexes were isolated, those containing only hydrogen-bonded crown interactions and instances where the crown interacts directly with the metal center. In both cases, water seems to play a very important role. When coordinated to the metal, water molecules exhibit the necessary donor properties required for the formation of hydrogen-bonded contacts. The water molecules also provide fierce competition with the crown ethers for metal-binding sites and in most cases prohibit the formation of complexes in which direct metal-ligand association exists. The results of this study indicate that direct interaction between the metal atoms and the crown ethers, in the presence of water, can only occur with polyether conformations which limit the steric replusions within the metal coordination sphere

Contemporary permanent tooth dimensions, with comparisons to G.V. Black's data.

Science.gov (United States)

Harris, Edward F; Burris, Benjamin G

2003-01-01

The tooth dimensions most commonly cited in the dental literature are those published by the famous restorative dentist G. V. Black late in the 19th century. We report here on the crown dimensions of a large series of contemporary North American Whites and show that Black's values differ significantly from modern values, but not in any consistent or predictable fashion. Black supplied no information about the nature of his sample. We suggest that it may be time to replace Black's data with modern tooth size standards.

Third Culture Kid's Effect on Character of Cady Heron in Mean Girls

OpenAIRE

Hapsari, Laily

2017-01-01

This thesis focuses on the movie, Mean Girls, specifically one of the character, Cady Heron,as a Third Culture Kid trying to adapt in new society. The purpose of this study is to understand the effect of Third Culture Kid in the movie character in socializing with the new surroundings and explain the way how one of the characters in Mean Girls adapts to the new surroundings.The writer uses library research to collect the data with the novel as the main data, and several relevant books, journa...

Prey diversity for Three Species Herons in Pulau Dua Nature Reserve Serang Distrik, Banten Province

Directory of Open Access Journals (Sweden)

DEWI ELFIDASARI

2006-10-01

Full Text Available The diversity of prey consumed by three species herons (Casmerodius albus, Egretta garzetta and Bubulcus ibis was studied in Pulau Dua Nature Reserve Serang, Banten Province using video tapes by following a focal individual for five minutes. In the laboratory the film was analysed every minutes to select complete sequences of feeding behavior in foraging site. There were differences on diversity and size of prey that consumed by three species herons among the different feeding locations. Casmerodius albus which was feeding on mudflat and fisheries consumed Chanos chanos (15.6%, Oreochromis sp (9.4% and Periophtalmus sp. (7.3%, and 36.5% couldn’t be identified. Egretta garzetta was feeding on mudflat, fisheries and rice-field, consumed Periophtalmus sp (15.4%, Mugil dussumeieri (7.9%, Chanos chanos (4.7%, Oreochromis sp (0.5%, including small frog and crustacean (0.5%. Bubulcus ibis was feeding on rice-field and grassland, consumed many variety of insects (92 % and many variety of snail (1.9% in their diet. The insects that B. ibis consumed including grasshopper (26.8%, caterpillar (0.9% and other invertebrates (worm, crustacean that could not be identified (64.3%.

Blood biomarkers and contaminant levels in feathers and eggs to assess environmental hazards in heron nestlings from impacted sites in Ebro basin (NE Spain).

Science.gov (United States)

Barata, C; Fabregat, M C; Cotín, J; Huertas, D; Solé, M; Quirós, L; Sanpera, C; Jover, L; Ruiz, X; Grimalt, J O; Piña, B

2010-03-01

Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation

International Nuclear Information System (INIS)

MacIntosh, D.L.

1992-09-01

This report presents a pair of wildlife exposure models developed for use in investigating the risks to wildlife of releases of mercury and PCBS. The species modeled are the great blue heron and mink The models may be used to estimate the exposure experienced by mink and herons, to help establish remedial action goals and to identify research needs. Because mercury and PCBs bioaccumulate through dietary uptake, the models simulate the food webs supporting the two species. Sources of contaminants include surface water, sediment, sediment pore water, and soil. The model are stochastic equilibrium models. Two types of variance in the input parameters are distinguished: stochastic variance among individual mink and herons and ignorance concerning true parameter values. The variance in the output due to stochastic parameters indicates the expected variance among the receptors. The variance due to ignorance indicates the extent to which the model outputs could be unpaved by additional sampling and measurement. The results of the models were compared to concentrations measured in great blue heron eggs and nestlings from colonies on the Clinch and Tennessee Rivers. The predicted concentrations agreed well with the measured concentrations. In addition, the variances in measured values among individuals was approximately equal to the total stochastic variance predicted by the models

Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation

Energy Technology Data Exchange (ETDEWEB)

MacIntosh, D.L. (Indiana Univ., Bloomington, IN (United States). School of Public and Environmental Affairs); Suter, G.W. II; Hoffman, F.O. (Oak Ridge National Lab., TN (United States))

1992-09-01

This report presents a pair of wildlife exposure models developed for use in investigating the risks to wildlife of releases of mercury and PCBS. The species modeled are the great blue heron and mink The models may be used to estimate the exposure experienced by mink and herons, to help establish remedial action goals and to identify research needs. Because mercury and PCBs bioaccumulate through dietary uptake, the models simulate the food webs supporting the two species. Sources of contaminants include surface water, sediment, sediment pore water, and soil. The model are stochastic equilibrium models. Two types of variance in the input parameters are distinguished: stochastic variance among individual mink and herons and ignorance concerning true parameter values. The variance in the output due to stochastic parameters indicates the expected variance among the receptors. The variance due to ignorance indicates the extent to which the model outputs could be unpaved by additional sampling and measurement. The results of the models were compared to concentrations measured in great blue heron eggs and nestlings from colonies on the Clinch and Tennessee Rivers. The predicted concentrations agreed well with the measured concentrations. In addition, the variances in measured values among individuals was approximately equal to the total stochastic variance predicted by the models.

Fracture-resistant monolithic dental crowns.

Science.gov (United States)

Zhang, Yu; Mai, Zhisong; Barani, Amir; Bush, Mark; Lawn, Brian

2016-03-01

To quantify the splitting resistance of monolithic zirconia, lithium disilicate and nanoparticle-composite dental crowns. Fracture experiments were conducted on anatomically-correct monolithic crown structures cemented to standard dental composite dies, by axial loading of a hard sphere placed between the cusps. The structures were observed in situ during fracture testing, and critical loads to split the structures were measured. Extended finite element modeling (XFEM), with provision for step-by-step extension of embedded cracks, was employed to simulate full failure evolution. Experimental measurements and XFEM predictions were self-consistent within data scatter. In conjunction with a fracture mechanics equation for critical splitting load, the data were used to predict load-sustaining capacity for crowns on actual dentin substrates and for loading with a sphere of different size. Stages of crack propagation within the crown and support substrate were quantified. Zirconia crowns showed the highest fracture loads, lithium disilicate intermediate, and dental nanocomposite lowest. Dental nanocomposite crowns have comparable fracture resistance to natural enamel. The results confirm that monolithic crowns are able to sustain high bite forces. The analysis indicates what material and geometrical properties are important in optimizing crown performance and longevity. Copyright © 2015 Academy of Dental Materials. All rights reserved.

Biodiversity assessment at Department of Atomic Energy (DAE) campus, Kalpakkam

International Nuclear Information System (INIS)

Jahir Hussain, K.; Satpathy, K.K.; Prasad, M.V.R.; Ramesh, T.; Selvanayagam, M.

2008-01-01

A rapid assessment of biodiversity in the DAE campus, Kalpakkam was carried out. The entire DAE campus of 3000 acres, at Kalpakkam was divided into four representative plots comprising of different landscapes namely (1) undisturbed area with dense vegetation, (2) building area, (3) water bodies with riparian cover and (4) sandy area with meager vegetation for inventorying of charismatic terrestrial/semi-aquatic fauna viz., Mammals, Birds, Reptiles, Amphibians and Butterflies. For birds, early morning surveys were made whereas for mammals evening and night surveys were followed. Midday sampling was followed for butterflies and other animals. Each plot was surveyed twice in a week over a period of one year (April 07' to March 08'). Totally 128 species of animals were identified during the survey and it has highlighted the potential of biodiversity in the campus. The diversity of butterflies is remarkable. Twenty-two butterfly species were encountered. Frogs, toads, lizards and snakes are also diverse. Five species of frogs and one species of toad were recorded. Lizards are more diverse than snakes. Nine species of lizards were encountered. Calotus versicolor is abundant followed by common skink. Totally five species of snakes were recorded. Among them Common bronzedback and Green Vine Snake were predominant. Seventy species of birds were recorded during the survey period. Black crowned night heron, Common house crow, Great cormorant, Oriental white ibis, Painted stork, Cattle egret, Common mynah are more common. Sixteen species of mammals were encountered during the survey. Wild cattle, Jackal, Jungle cat, Toddy cat, Crested porcupine and Indian civet are the major wildlife found. Indian civet and Crested porcupine are elusive animals that are diminishing from wild and their presence at this campus is an indication of less human intervention. (author)

Redescription of Chabaudacuaria multispinosa (Pérez Vigueras, 1938) n. g., n. comb. (Nematoda: Spirurida: Acuariidae) based on specimens from Ardea herodias L. and Nyctanassa violacea (L.) (Ardeidae) in Florida.

Science.gov (United States)

Mutafchiev, Yasen; Kinsella, John M

2012-10-01

Chabaudacuaria n. g. is erected, as monotypic, for C. multispinosa (Pérez Vigueras, 1938) n. comb. (Spirurida: Acuariidae) [syns Cheilospirura multispinosa Pérez Vigueras, 1938; Acuaria multispinosa (Pérez Vigueras, 1938) Yamaguti, 1961]. This species, a parasite of various ardeid birds, is redescribed by means of light and scanning electron microscopy based on material from great blue herons Ardea herodias L. and yellow-crowned night herons Nyctanassa violacea (L.) in Florida, USA. Chabaudacuaria n. g. resembles Acuaria Bremser, 1811, Cheilospirura Diesing, 1861, Skrjabinocerca Schikhobalova, 1930 and Xenocordon Mawson, 1982 in its straight cordons which do not anastomose. However, it can be distinguished from them by the didelphic-prodelphic uterus and the absence of caudal alae in the males. In the pattern of its cordons (consisting of a row of plates and a longitudinal ridge) and the absence of an area rugosa, the new genus is similar to Chevreuxia Seurat, 1918, Syncuaria Gil'bert, 1927, Aviculariella Wehr, 1931, Skrjabinocara Kurashvili, 1940, Decorataria Sobolev, 1949 and Desportesius Chabaud & Campana, 1949, which are characterised by anastomosing cordons. The didelphic-prodelphic female reproductive system of Chabaudacuaria is intermediate between the didelphic-amphidelphic uterus of Chevreuxia and the monodelphic-prodelphic uterus of Syncuaria, Aviculariella, Skrjabinocara, Desportesius and Decorataria. Therefore, the straight and non-anastomosing cordons are considered to be autapomorphic for Chabaudacuaria.

Crop-tree release increases growth of 12-year-old yellow-poplar and black cherry

Science.gov (United States)

Neil I. Lamson; H. Clay. Smith; H. Clay. Smith

1989-01-01

Precommercial thinning was done in a 12-year-old Appalachian hardwood sapling stand in West Virginia. Two crop-tree release techniques were used--crown touching and crown touching plus 5 feet. Results indicated that both treatments significantly increased 5-year d.b.h. growth for released yellow-poplar and black cherry crop trees. Although there was a major increase in...

Effect of Cultural Practices in Night on Weed Density and Weed Dry Matter

Directory of Open Access Journals (Sweden)

M.H Rashed Mohasel

2011-01-01

Full Text Available Abstract In order to evaluate the response of weed seeds to light, two experiments, at two different locations were conducted at Ferdowsi university of Mashhad in 2009. At the first experiment, field was ploughed in day and night. Weed density was evaluated 70 d after plough, with 1×1 quadrate. At the second experiment, at night treatment, ploughing, potato planting and weeding with cultivator were done at night. Weed sampling was done twice at 43 and 130 days after planting with 1×1 quadrate and weeds were identified and counted. Result showed pigweed (Amaranthus retroflexus L., sowthistle (Sonchus oleraceus L., crabgrass (Digitaria sanguinalis (L. scop, jimsonweed (Datura stramonium L. and mallow (Hibiscus trionum L. did not observed at night plough, in contrast, night plough has no significance influence on common lambsquarters (Chenopodium album L., and black nightshade (Solanum nigrum L.. Only common lambsquarters had similar appearance in two treatments, indicating insusceptibility of this weed to time of plough. Interestingly, at the second experiment, result was very similar. Potato yield was higher at night treatment, but not significant. This research showed that some cultural practice like plough, planting and weeding with cultivator in night can reduce weed density and weed dry matter. Keywords: Germination, Time of plough, Sustainable weeds management, Light

Black or white? Physiological implications of roost colour and choice in a microbat.

Science.gov (United States)

Doty, Anna C; Stawski, Clare; Currie, Shannon E; Geiser, Fritz

2016-08-01

Although roost choice in bats has been studied previously, little is known about how opposing roost colours affect the expression of torpor quantitatively. We quantified roost selection and thermoregulation in a captive Australian insectivorous bat, Nyctophilus gouldi (n=12) in winter when roosting in black and white coloured boxes using temperature-telemetry. We quantified how roost choice influences torpor expression when food was provided ad libitum or restricted in bats housed together in an outdoor aviary exposed to natural fluctuations of ambient temperature. Black box temperatures averaged 5.1°C (maximum 7.5°C) warmer than white boxes at their maximum daytime temperature. Bats fed ad libitum chose black boxes on most nights (92.9%) and on 100% of nights when food-restricted. All bats used torpor on all study days. However, bats fed ad libitum and roosting in black boxes used shorter torpor and spent more time normothermic/active at night than food-restricted bats and bats roosting in white boxes. Bats roosting in black boxes also rewarmed passively more often and to a higher skin temperature than those in white boxes. Our study suggests that N. gouldi fed ad libitum select warmer roosts in order to passively rewarm to a higher skin temperature and thus save energy required for active midday rewarming as well as to maintain a normothermic body temperature for longer periods at night. This study shows that colour should be considered when deploying bat boxes; black boxes are preferable for those bats that use passive rewarming, even in winter when food availability is reduced. Copyright © 2016 Elsevier Ltd. All rights reserved.

Embryo splitting

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Karl Illmensee

2010-04-01

Full Text Available Mammalian embryo splitting has successfully been established in farm animals. Embryo splitting is safely and efficiently used for assisted reproduction in several livestock species. In the mouse, efficient embryo splitting as well as single blastomere cloning have been developed in this animal system. In nonhuman primates embryo splitting has resulted in several pregnancies. Human embryo splitting has been reported recently. Microsurgical embryo splitting under Institutional Review Board approval has been carried out to determine its efficiency for blastocyst development. Embryo splitting at the 6–8 cell stage provided a much higher developmental efficiency compared to splitting at the 2–5 cell stage. Embryo splitting may be advantageous for providing additional embryos to be cryopreserved and for patients with low response to hormonal stimulation in assisted reproduction programs. Social and ethical issues concerning embryo splitting are included regarding ethics committee guidelines. Prognostic perspectives are presented for human embryo splitting in reproductive medicine.

Reproductive success and chlorinated hydrocarbon contamination of resident great blue herons (Ardea herodias) from coastal British Columbia, Canada, 1977 to 2000

International Nuclear Information System (INIS)

Harris, M.L.; Elliott, J.E.; Butler, R.W.; Wilson, L.K.

2003-01-01

Human disturbance and loss of nesting habitat were more important factors than chlorinated hydrocarbons in changing heron reproductive success. - Over the period 1977-2000, eggs of Pacific great blue heron (Ardea herodias fannini) were collected from 23 colonies along the southern coast of British Columbia, Canada, and analyzed for persistent organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). Concentrations of OC pesticides in eggs declined sharply in the late 1970s, after which there were minimal changes. The sums of PCB congeners were not reduced appreciably during the 1980s and 1990s, but Aroclor 1260 concentrations suggested a sharp decline in PCB contamination of eggs in the late 1970s, similar to that shown for OC pesticides. Eggs collected along or near the Fraser River delta showed higher levels of most pesticides compared to other monitored colonies. Although the delta lands support a long-standing agricultural economy, the primary factors influencing OC levels in the delta colonies were thought to be driven by estuarine processes. We suggest two possible influencing factors were: 1) a greater rate of bioaccumulation in the estuary due to the deposition of particulates collected over a vast area encompassed by the Fraser River watershed; or 2) a higher rate of biomagnification in the estuary due to species differences at lower trophic levels of the heron food chain. Eggs from urban colonies contained higher levels of PCBs. The congener pattern was not clearly different from that observed in less contaminated eggs from rural and pulp mill-influenced colonies, except that colonies in Vancouver had greater proportions of PCB-66, suggesting a local source of Aroclor 1242. Productivity in the coastal heron colonies was highly variable over the period of study, with 71% of recorded colony-wide reproductive failures occurring in colonies near pulp mills. However, the predominant factors influencing reproductive success were probably disturbance

Overdenture dengan Pegangan Telescopic Crown

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Pambudi Santoso

2014-06-01

Full Text Available Kaitan presisi merupakan alat retensi mekanis yang menghubungkan antara satu atau lebih pegangan gigi tiruan, yang bertujuan untuk menambah retensi dan/atau stabilisasi. Kaitan presisi dapat digunakan secara luas pada gigi tiruan cekat, gigi tiruan sebagian lepasan, overdenture, implant untuk retensi overdenture, dan protesa maksilo fasial. Overdenture dengan kaitan presisi dapat membantu dalam pembagian beban kunyah, meminimalkan trauma pada gigi pegangan dan jaringan lunak, meminimalkan resorbsi tulang, dan meningkatkan estetik dan pengucapan suara. Salah satu jenis dari kaitan presisi adalah telescopic crown, terdiri dari 2 macam mahkota, yaitu mahkota primer yang melekat secara permanen pada gigi penyangga, dan mahkota sekunder yang melekat pada gigi tiruan. Tujuan pemaparan kasus ini adalah untuk memberikan informasi tentang rehabilitasi pasien edentulous sebagian rahang atas dengan telescopic crown..  Pasien wanita berusia 45 tahun datang ke klinik prostodonsia RSGM Prof.Soedomo dengan keluhan ingin dibuatkan gigi tiruan. Pasien kehilangan gigi 11 12 15 16 17 21 22 24 25 26 dan 27 yang diindikasikan untuk pembuatan overdenture gigi tiruan sebagian lepasan (GTS kerangka logam dengan pegangan telescopic crown pada gigi 13 dan 14 dengan sistem parallel-sided crown. Tahap-tahap pembuatan telescopic crown yaitu mencetak model study dengan catatan gigit pendahuluan. Perawatan saluran dilakukan pada akar gigi 13, dilanjutkan pemasangan pasak fiber serta rewalling dinding bukal. Gigi 13 dan 14 dilakukan preparasi mahkota penuh, dilanjutkan dengan pencetakan model kerja untuk coping primer dan kerangka logam dengan metode double impression. Coping primer disementasi pada gigi penyangga, dilanjutkan pasang coba coping sekunder beserta kerangka logam. Selanjutnya dilakukan pencatatan gigit, pencetakan model kerja, penyusunan gigi dan pasang coba penyusunan gigi pada pasien. Prosedur dilanjutkan dengan proses di laboratorium, serta insersi pada

An investigation of crown fuel bulk density effects on the dynamics of crown fire initiation in shrublands

Science.gov (United States)

Watcharapong Tachajapong; Jesse Lozano; Shankar Mahalingam; Xiangyang Zhou; David R. Weise

2008-01-01

Crown fire initiation is studied by using a simple experimental and detailed physical modeling based on Large Eddy Simulation (LES). Experiments conducted thus far reveal that crown fuel ignition via surface fire occurs when the crown base is within the continuous flame region and does not occur when the crown base is located in the hot plume gas region of the surface...

[Comparison of the clinical effects of selective laser melting deposition basal crowns and cobalt chromium alloy base crowns].

Science.gov (United States)

Li, Jing-min; Wang, Wei-qian; Ma, Jing-yuan

2014-06-01

To evaluate the clinical effects of selective laser melting (SLM) deposition basal crowns and cobalt chromium alloy casting base crowns. One hundred and sixty eight patients treated with either SLM deposition basal crowns (110 teeth) or cobalt chromium alloy casting basal crowns (110 teeth) were followed-up for 1 month, 6 months, 12 months and 24 months. The revised standard of American Public Health Association was used to evaluate the clinical effect of restoration, including the color of porcelain crowns, gingival inflammation, gingival margin discoloration, and crack or fracture. Data analysis was conducted with SPSS 20 software package for Student's t test and Chi-square test. Six cases were lost to follow-up. The patients who were treated with SLM deposition basal crowns (104 teeth) and cobalt chromium alloy casting base crowns (101 teeth) completed the study. Patients were more satisfied with SLM deposition cobalt chromium alloy porcelain crowns. There was 1 prosthesis with poor marginal fit after 24 months of restoration in SLM crowns. There were 6 prostheses with edge coloring and 8 with poor marginal fit in cobalt chromium alloy casting base crowns, which was significantly different between the 2 groups(P<0.05). The SLM deposition copings results in smaller edge coloring and better marginal fit than those of cobalt-chrome copings. Patients are pleased with short-term clinical results.

Agricultural Crown Land in Saskatchewan

International Nuclear Information System (INIS)

Pyle, W.E.

1998-01-01

The petroleum industry's interest in provincial crown land in the agricultural area of Saskatchewan has grown over the last two decades. Agricultural land is regulated by the Saskatchewan Department of Agriculture and Food, Lands Branch. Since 1974 surface lease contracts by oil and gas companies have increased from 1,400 to the present 3,700. Resource lands are regulated by Saskatchewan Environment and Resource Management. There are 8.8 million acres of crown agricultural land in Saskatchewan, most of which is held without title. Crown land management is meant to provide a long term management approach to crown lands that balances economic, environmental and social benefits for present and future generations. The oil and gas industry is an important participant in crown land management. Revenues from petroleum and gas surface leasing, and seismic licensing totals more than five million dollars annually. In 1995/96, there were 54 companies establishing new oil and gas leases on crown land in Saskatchewan. This paper provides details of current policies which apply to petroleum and gas leasing and seismic exploration, and environmental guidelines for companies developing well sites, compressor and metering stations, access roads and easements. 3 tabs

Crown rust control on oats

International Nuclear Information System (INIS)

Frey, K.J.; Browning, J.A.; Simons, M.D.

1976-01-01

Attempts have been made to test the relative effectiveness of EMS treatment for inducing tolerance to crown rust among oat strains Clintland-60 of different ploidy levels. One strain of diploid and one of tetraploid oats were treated with EMS. These two strains are as susceptible to damage from crown rust as are cultivars of hexaploid oats. Multiline cultivars of oats have been shown to provide adequate protection from economic loss due to crown-rust disease in Iowa. Since 1968, eleven multiline cultivars of oats have been released from the Iowa station for use in commercial production in the midwestern USA. During the past two winter seasons, the effectiveness of multiline oat cultivars against crown-rust disease has been researched in Texas, USA, which has a ''long rust season'' of about four months, not an Iowa ''short rust season''. The protection against crown rust afforded by the multiline cultivars appeared equally good in Texas and Iowa. The seasonal productions of crown-rust spores relative to completely resistant and susceptible checks were nearly identical in both environments. Fifteen new isolines of oats have been developed for use in multiline varieties, with seed supplies sufficiently large for immediate use

Evaluation of marginal fit of 2 CAD-CAM anatomic contour zirconia crown systems and lithium disilicate glass-ceramic crown.

Science.gov (United States)

Ji, Min-Kyung; Park, Ji-Hee; Park, Sang-Won; Yun, Kwi-Dug; Oh, Gye-Jeong; Lim, Hyun-Pil

2015-08-01

This study was to evaluate the marginal fit of two CAD-CAM anatomic contour zirconia crown systems compared to lithium disilicate glass-ceramic crowns. Shoulder and deep chamfer margin were formed on each acrylic resin tooth model of a maxillary first premolar. Two CAD-CAM systems (Prettau®Zirconia and ZENOSTAR®ZR translucent) and lithium disilicate glass ceramic (IPS e.max®press) crowns were made (n=16). Each crown was bonded to stone dies with resin cement (Rely X Unicem). Marginal gap and absolute marginal discrepancy of crowns were measured using a light microscope equipped with a digital camera (Leica DFC295) magnified by a factor of 100. Two-way analysis of variance (ANOVA) and post-hoc Tukey's HSD test were conducted to analyze the significance of crown marginal fit regarding the finish line configuration and the fabrication system. The mean marginal gap of lithium disilicate glass ceramic crowns (IPS e.max®press) was significantly lower than that of the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia) (Pmarginal discrepancy (Pmarginal gap than the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia). In terms of absolute marginal discrepancy, the CAD-CAM anatomic contour zirconia crown system (ZENOSTAR®ZR translucent) had under-extended margin, whereas the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia) and lithium disilicate glass ceramic crowns (IPS e.max®press) had overextended margins.

Viability of bovine demi embryo after splitting of fresh and frozen thawed embryo derived from in vitro embryo production

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M Imron

2007-06-01

Full Text Available In vivo embryo production was limited by number of donor, wide variability respond due to superovulation program and also immunoactifity of superovulation hormone (FSH. Splitting technology could be an alternative to increase the number of transferrable embryos into recipien cows. Splitting is done with cutting embryo becoming two equal pieces (called demi embrio base on ICM orientation. The objective of this research was to determine the viability of demi embryo obtained from embryo splitting of fresh and frozen thawed embryo. The results showed that demi embryos which performed blastocoel reexpansion 3 hours after embryo splitting using fresh and frozen thawed embryos were 76.9 and 76.2% respectively. Base on existention of inner cell mass (ICM, the number of demi embryos developed with ICM from fresh and frozen thawed embryos were not significantly different (90.6 and 85.7% respectively. The cell number of demi embryo from fresh embryos splitting was not different compared with those from frozen thawed embryos (36.1 and 35.9 respectively. These finding indicated that embryo splitting can be applied to frozen thawed embryos with certain condition as well as fresh embryos.

Host reproductive phenology drives seasonal patterns of host use in mosquitoes.

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Nathan D Burkett-Cadena

2011-03-01

Full Text Available Seasonal shifts in host use by mosquitoes from birds to mammals drive the timing and intensity of annual epidemics of mosquito-borne viruses, such as West Nile virus, in North America. The biological mechanism underlying these shifts has been a matter of debate, with hypotheses falling into two camps: (1 the shift is driven by changes in host abundance, or (2 the shift is driven by seasonal changes in the foraging behavior of mosquitoes. Here we explored the idea that seasonal changes in host use by mosquitoes are driven by temporal patterns of host reproduction. We investigated the relationship between seasonal patterns of host use by mosquitoes and host reproductive phenology by examining a seven-year dataset of blood meal identifications from a site in Tuskegee National Forest, Alabama USA and data on reproduction from the most commonly utilized endothermic (white-tailed deer, great blue heron, yellow-crowned night heron and ectothermic (frogs hosts. Our analysis revealed that feeding on each host peaked during periods of reproductive activity. Specifically, mosquitoes utilized herons in the spring and early summer, during periods of peak nest occupancy, whereas deer were fed upon most during the late summer and fall, the period corresponding to the peak in births for deer. For frogs, however, feeding on early- and late-season breeders paralleled peaks in male vocalization. We demonstrate for the first time that seasonal patterns of host use by mosquitoes track the reproductive phenology of the hosts. Peaks in relative mosquito feeding on each host during reproductive phases are likely the result of increased tolerance and decreased vigilance to attacking mosquitoes by nestlings and brooding adults (avian hosts, quiescent young (avian and mammalian hosts, and mate-seeking males (frogs.

Model of the PCB and mercury exposure of mink and great blue heron inhabiting the off-site environment downstream from the US Department of Energy Oak Ridge Reservation. Environmental Restoration Program

Energy Technology Data Exchange (ETDEWEB)

MacIntosh, D.L. [Indiana Univ., Bloomington, IN (United States). School of Public and Environmental Affairs; Suter, G.W. II; Hoffman, F.O. [Oak Ridge National Lab., TN (United States)

1992-09-01

This report presents a pair of wildlife exposure models developed for use in investigating the risks to wildlife of releases of mercury and PCBS. The species modeled are the great blue heron and mink The models may be used to estimate the exposure experienced by mink and herons, to help establish remedial action goals and to identify research needs. Because mercury and PCBs bioaccumulate through dietary uptake, the models simulate the food webs supporting the two species. Sources of contaminants include surface water, sediment, sediment pore water, and soil. The model are stochastic equilibrium models. Two types of variance in the input parameters are distinguished: stochastic variance among individual mink and herons and ignorance concerning true parameter values. The variance in the output due to stochastic parameters indicates the expected variance among the receptors. The variance due to ignorance indicates the extent to which the model outputs could be unpaved by additional sampling and measurement. The results of the models were compared to concentrations measured in great blue heron eggs and nestlings from colonies on the Clinch and Tennessee Rivers. The predicted concentrations agreed well with the measured concentrations. In addition, the variances in measured values among individuals was approximately equal to the total stochastic variance predicted by the models.

Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

Science.gov (United States)

Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

2016-01-01

In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

The Identification of Military Installations as Important Migratory Bird Stopover Sites and the Development of Bird Migration Forecast Models: A Radar Ornithology Approach

Science.gov (United States)

2012-08-01

civilian and military flights. Since 1985, nearly 38,000 bird-military aircraft collisions have been reported. These collisions have killed 33 pilots...stations in the contiguous United States. Edges of the circles are at 124 nautical mile range (230 km). and 2004, approximately 194 people were killed ... Mockingbird Wilson’s Snipe Pileated Woodpecker American Wigeon Red-bellied Woodpecker American Coot Red-cockaded Woodpecker Black-crowned Night

Urban Crowns: crown analysis software to assist in quantifying urban tree benefits

Science.gov (United States)

Matthew F. Winn; Sang-Mook Lee Bradley; Philip A. Araman

2010-01-01

UrbanCrowns is a Microsoft® Windows®-based computer program developed by the U.S. Forest Service Southern Research Station. The software assists urban forestry professionals, arborists, and community volunteers in assessing and monitoring the crown characteristics of urban trees (both deciduous and coniferous) using a single side-view digital photograph. Program output...

Embryo malposition as a potential mechanism for mercury-induced hatching failure in bird eggs

Science.gov (United States)

Herring, G.; Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

We examined the prevalence of embryo malpositions and deformities in relation to total mercury (THg) and selenium (Se) concentrations in American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster's tern (Sterna forsteri) eggs in San Francisco Bay (CA, USA) during 2005 to 2007. Overall, 11% of embryos were malpositioned in eggs ???18 d of age (n=282) and 2% of embryos were deformed in eggs ???13 d of age (n=470). Considering only those eggs that failed to hatch (n=62), malpositions occurred in 24% of eggs ???18 d of age and deformities occurred in 7% of eggs ???13 d of age. The probability of an embryo being malpositioned increased with egg THg concentrations in Forster's terns, but not in avocets or stilts. The probability of embryo deformity was not related to egg THg concentrations in any species. Using a reduced dataset with both Se and THg concentrations measured in eggs (n=87), we found no interaction between Se and THg on the probability of an embryo being malpositioned or deformed. Results of the present study indicate that embryo malpositions were prevalent in waterbird eggs that failed to hatch and the likelihood of an embryo being malpositioned increased with egg THg concentrations in Forster's terns. We hypothesize that malpositioning of avian embryos may be one reason for mercury-related hatching failure that occurs late in incubation, but further research is needed to elucidate this potential mechanism. ?? 2010 SETAC.

Embryo density and medium volume effects on early murine embryo development.

Science.gov (United States)

Canseco, R S; Sparks, A E; Pearson, R E; Gwazdauskas, F C

1992-10-01

One-cell mouse embryos were used to determine the effects of drop size and number of embryos per drop for optimum development in vitro. Embryos were collected from immature C57BL6 female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by CD1 males. Groups of 1, 5, 10, or 20 embryos were cultured in 5-, 10-, 20-, or 40-microliters drops of CZB under silicon oil at 37.5 degrees C in a humidified atmosphere of 5% CO2 and 95% air. Development score for embryos cultured in 10 microliters was higher than that of embryos cultured in 20 or 40 microliters. Embryos cultured in groups of 5, 10, or 20 had higher development scores than embryos cultured singly. The highest development score was obtained by the combination of 5 embryos per 10-microliters drop. The percentage of live embryos in 20 or 40 microliters was lower than that of embryos cultured in 10 microliters. Additionally, the percentage of live embryos cultured singly was lower than that of embryos cultured in groups. Our results suggest that a stimulatory interaction occurs among embryos possibly exerted through the secretion of growth factors. This effect can be diluted if the embryos are cultured in large drops or singly.

Spatiotemporal patterns of coral disease prevalence on Heron Island, Great Barrier Reef, Australia

Science.gov (United States)

Haapkylä, J.; Melbourne-Thomas, J.; Flavell, M.; Willis, B. L.

2010-12-01

Despite increasing research effort on coral diseases, little is known about factors driving disease dynamics on the Great Barrier Reef (GBR). This is the first study to investigate the temporal patterns of coral disease prevalence and potential drivers of disease around Heron Island, in the southern Capricorn Bunker sector of the GBR. Surveys were conducted in two austral summers and three winters between November 2007 and August 2009 on six sites around the island. Six diseases were detected: brown band syndrome (BrB), growth anomalies (GA), ulcerative white spots (UWS), white syndrome (WS), skeletal eroding band disease (SEB) and black band disease (BBD). The lowest overall mean disease prevalence was 1.87 ± 0.75% (mean ± SE) in November 2007 and the highest 4.22 ± 1.72% in August 2008. There was evidence of seasonality for two diseases: BrB and UWS. This is the first study to report a higher prevalence of BrB in the winter. BrB had a prevalence of 3.29 ± 0.58% in August 2008 and 1.53 ± 0.28% in August 2009, while UWS was the most common syndrome in the summer with a prevalence of 1.12 ± 0.31% in November 2007 and 2.67 ± 0.52% prevalence in January 2008. The prevalence of GAs and SEB did not depend on the season, although the prevalence of GAs increased throughout the study period. WS had a slightly higher prevalence in the summer, but its overall prevalence was low (disease prevalence (12% of Acropora and 3.3% of Montipora species were diseased respectively). These results highlight the correlations between coral disease prevalence, seasonally varying environmental parameters and coral community composition. Given that diseases are likely to reduce the resilience of corals, seasonal patterns in disease prevalence deserve further research.

PEEK Primary Crowns with Cobalt-Chromium, Zirconia and Galvanic Secondary Crowns with Different Tapers—A Comparison of Retention Forces

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Veronika Stock

2016-03-01

Full Text Available In prosthetic dentistry, double crown systems have proved their suitability as retainers for removable partial dentures. However, investigations in this context, regarding polyetheretherketone, are scarce. Therefore, the aim of this study was to test the retention force (RF between polyetheretherketone (PEEK primary and cobalt-chromium (CoCr, zirconia (ZrO2 and galvanic (GAL secondary crowns with three different tapers. Primary PEEK-crowns were milled with the tapers 0°, 1°, and 2° (n = 10/taper, respectively. Afterwards, 90 secondary crowns were fabricated: (i 30 CoCr-crowns milled from Ceramill Sintron (AmannGirrbach, Koblach, Austria (n = 10/taper, (ii 30 ZrO2-crowns milled from Ceramill ZI (AmannGirrbach, Koblach, Austria (n = 10/taper, and (iii 30 GAL-crowns made using electroforming (n = 10/taper. RF was measured in a pull-off test (20 pull-offs/specimen and data were analyzed using 2-/1-way Analysis of Variance (ANOVA followed by the Tukey-Honestly Significant Difference (HSD post hoc test and linear regression analyses (p < 0.05. The measured mean RF values ranged between 9.6 and 38.2 N. With regard to the 0°, 1°, and 2° tapered crowns, no statistically significant differences between CoCr and ZrO2 were observed (p > 0.141. At 0° taper, no differences in retention forces between GAL, CrCr, and ZrO2 crowns were found (p = 0.075. However, at 1° and 2° taper, lower RF for GAL-crowns were observed (p < 0.009, p < 0.001, respectively. According to this laboratory study, PEEK might be a suitable material for primary crowns, regardless of the taper and the material of secondary crown. Long-term results, however, are still necessary.

All-ceramic crowns: bonding or cementing?

Science.gov (United States)

Pospiech, Peter

2002-12-01

Despite the wide variety of all-ceramic systems available today, the majority of dental practitioners hesitate to recommend and insert all-ceramic crowns. This article regards the nature of the ceramic materials, the principles of bonding and adhesion, and the clinical problems of the acid-etch technique for crowns. Advantages and disadvantages are discussed, and the influences of different factors on the strength of all-ceramic crowns are presented. Finally, the conclusion is drawn that conventional cementing of all-ceramic crowns is possible when the specific properties of the ceramics are taken into consideration.

Digital photo monitoring for tree crown

Science.gov (United States)

Neil Clark; Sang-Mook Lee

2007-01-01

Assessing change in the amount of foliage within a tree’s crown is the goal of crown transparency estimation, a component in many forest health assessment programs. Many sources of variability limit analysis and interpretation of crown condition data. Increased precision is needed to detect more subtle changes that are important for detection of health problems....

Dentin-bonded all-ceramic crowns: current status.

Science.gov (United States)

Burke, F J; Qualtrough, A J; Hale, R W

1998-04-01

Dentin-bonded all-ceramic crowns employ contemporary techniques to lute the crown to the tooth using a resin luting material and dentin-bonding system. The advantages of these crowns are that they provide good esthetics and fracture resistance and can be used in cases of substantial tooth loss. Their principal disadvantages are that the luting procedure is more time-consuming and that these crowns should not be used where margins are subgingival. Dentin-bonded all-ceramic crowns may be a useful addition to the dentist's armamentarium, but long-term clinical studies are needed to fully assess their performance.

Pericoronal radiolucency associated with incomplete crown

Energy Technology Data Exchange (ETDEWEB)

Nah, Kyung Soo [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

2013-12-15

The author experienced 8 cases of pericoronal radiolucency involving an incomplete tooth crown that had not developed to form the cemento-enamel junction, and the underdeveloped crown sometimes appeared to be floating within the radiolucency radiographically. The first impression was that these cystic lesions had odontogenic keratocysts, but half of them turned out to be dentigerous cysts histopathologically. There has been no report concerning odontogenic cysts involving an incompletely developed crown. The purpose of this paper is to report that dentigerous cysts may develop before the completion of the cemento-enamel junction of a developing crown.

Pericoronal radiolucency associated with incomplete crown

International Nuclear Information System (INIS)

Nah, Kyung Soo

2013-01-01

The author experienced 8 cases of pericoronal radiolucency involving an incomplete tooth crown that had not developed to form the cemento-enamel junction, and the underdeveloped crown sometimes appeared to be floating within the radiolucency radiographically. The first impression was that these cystic lesions had odontogenic keratocysts, but half of them turned out to be dentigerous cysts histopathologically. There has been no report concerning odontogenic cysts involving an incompletely developed crown. The purpose of this paper is to report that dentigerous cysts may develop before the completion of the cemento-enamel junction of a developing crown.

Extraction separation of lithium isotopes with crown-ethers

International Nuclear Information System (INIS)

Tsivadze, A.Yu.; Demin, S.V.; Levkin, A.V.; Zhilov, V.I.; Nikol'skij, S.F.; Knyazev, D.A.

1990-01-01

By the method of extraction chromatography lithium isotope separation coefficients are measured during chemical isotope exchange between lithium aquocomplex and its complex in chloroform with crown-ethers: benzo-15-crown-5, 15crown-5, dicyclohexano-18-crown-6 and dibenzo-18-crown-6. Lithium perchlorate and trichloroacetate are the salts extracted. Values of 6 Li/ 7 Li isotope separation are 1.0032-1.020

Transboundary pollution: Persistent organochlorine pesticides in migrant birds of the Southwestern United States and Mexico

Science.gov (United States)

Mora, Miguel A.

1997-01-01

The hypothesis that migratory birds accumulate persistent organochlorine pesticides (POPs) during the winter in Latin America has been prevalent for many years, particularly since 1,1,1-trichloro-2,2–bis(p-chlorophenyl)ethane (DDT) was banned in the United States in 1972. It has been suggested that peregrine falcons (Falco peregrinus), black-crowned night herons (Nycticorax nycticorax), white-faced ibises (Plegadis chihi), various migratory waterfowl and shorebirds, and other avian species accumulate higher concentrations of POPs while on migration or on their wintering grounds in Latin America. Nonetheless, the data obtained thus far are limited, and there is no clear pattern to suggest that such accumulation occurs on a widespread basis. In this review wildlife contaminant studies conducted along the U.S.-Mexico border and throughout Mexico are discussed. The results for the most part seem to indicate that no major accumulation of 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene) (DDE), the most persistent organochlorine compound, has occurred or been reported for most parts of Mexico. The majority of the DDE values in birds from Mexico were similar to those reported in birds from the southwestern United States during the same years. More work needs to be done, particularly in those cotton-producing areas of Mexico where DDT was applied heavily in the past (e.g., Chiapas and Michoacan). Because DDT is still used for malaria control and may still be used in agriculture in Chiapas, this state is probably the one where most migrant species would still be at a significant risk of increased accumulation of DDE and DDT.

Factors influencing liver PCB concentrations in sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus) and herons (Ardea cinerea) in Britain

Energy Technology Data Exchange (ETDEWEB)

Wienburg, Claire L.; Shore, Richard F

2004-11-01

Large scale temporal and spatial changes in the exposure of terrestrial vertebrates to PCBs have been monitored in the UK by measuring liver residues in sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus) and grey herons (Ardea cinerea) from throughout the country. Residues in the three species are typically characterised by large intra- and inter-specific variation. Data for 306 sparrowhawks, 186 kestrels and 47 herons collected between 1992 and 1997 as part of a national Predatory Bird Monitoring Scheme were examined to determine how much of this variation was explained by body condition, age and sex, rather than other factors. In all three species, body condition was the single most important factor and accounted for up to 49% of the variation in PCB liver residues; starved birds had the highest liver concentrations. Age and sex were also significant but of lesser importance. Adult sparrowhawks and kestrels had liver PCB residues that were 2 to 10-fold higher than in first-year birds. Sex did not affect residue magnitude in a consistent manner. PCB concentrations in the liver were higher in males than females in both first-year and adult kestrels and in first-year sparrowhawks, but adult female sparrowhawks had similar PCB residues to adult males. Liver residues also varied seasonally. PCB concentrations in first-year sparrowhawks increased during the first year following fledging and a similar pattern was detected in adult female sparrowhawks following egg laying. When these physiological factors were taken into account, it was evident that while kestrels with high fat scores had significantly lower PCB concentrations than either sparrowhawks or herons, liver residues were similar in all three species when birds were in a starved condition. Overall during 1992-1997, the combined influence of body condition, age and sex explained more of the variation in liver PCB concentrations than species differences or other factors, such as geographical variation

Black-necked stilts share nesting in the Merritt Island National Wildlife Refuge

Science.gov (United States)

1999-01-01

A black-necked stilt waits near its nesting mate nest in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Stilts usually produce three or four brown-spotted buff eggs in a shallow depression lined with grass or shell fragments. In the nesting season they are particularly agressive. Stilts are identified by a distinct head pattern of black and white, very long red legs, and straight, very thin bill. Their habitat is salt marshes and shallow coastal bays from Delaware and northern South America in the East, and freshwater marshes from Oregon and Saskatchewan to the Gulf Coast. The 92,000-acre wildlife refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Preformed crowns for decayed primary molar teeth.

Science.gov (United States)

Innes, Nicola P T; Ricketts, David; Chong, Lee Yee; Keightley, Alexander J; Lamont, Thomas; Santamaria, Ruth M

2015-12-31

Crowns for primary molars are preformed and come in a variety of sizes and materials to be placed over decayed or developmentally defective teeth. They can be made completely of stainless steel (know as 'preformed metal crowns' or PMCs), or to give better aesthetics, may be made of stainless steel with a white veneer cover or made wholly of a white ceramic material. In most cases, teeth are trimmed for the crowns to be fitted conventionally using a local anaesthetic. However, in the case of the Hall Technique, PMCs are pushed over the tooth with no local anaesthetic, carious tissue removal or tooth preparation. Crowns are recommended for restoring primary molar teeth that have had a pulp treatment, are very decayed or are badly broken down. However, few dental practitioners use them in clinical practice. This review updates the original review published in 2007. Primary objectiveTo evaluate the clinical effectiveness and safety of all types of preformed crowns for restoring primary teeth compared with conventional filling materials (such as amalgam, composite, glass ionomer, resin modified glass ionomer and compomers), other types of crowns or methods of crown placement, non-restorative caries treatment or no treatment. Secondary objectiveTo explore whether the extent of decay has an effect on the clinical outcome of primary teeth restored with all types of preformed crowns compared with those restored with conventional filling materials. We searched the following electronic databases: Cochrane Oral Health Group Trials Register (to 21 January 2015), Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, 2014, Issue 12), MEDLINE via Ovid (1946 to 21 January 2015) and EMBASE via Ovid (1980 to 21 January 2015). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials and Open Grey for grey literature (to

COMPARSION EFFECTIVENES METHODS REPEIR CROWN TEETH IN DOGS

OpenAIRE

CHOOHNO V.S.

2008-01-01

Methods of dogs’ crown teeth restoration with using of anchor pin with light curable composite, glass fiber pin with light curable composite, stump crown with prosthetic crown were approved. Their effectiveness was compared. Greater reliability was shown by methods of stump crown with prosthetic crown, when using of which there was no that restoration damage in all cases, but there was no cosmetics effect. Restoration methods with using anchor pin with light curable composite and glass fiber ...

Activity relationships for aromatic crown ethers

International Nuclear Information System (INIS)

Wilson, Mark James

1998-01-01

This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities from molecular modelling and this rational has been applied to the study of proton ionisable and lariating crown ethers. The incorporation of crown ethers into polyamic acid and polyimide frameworks has also been investigated, where the resulting materials have been found to exhibit unusual cation binding and uptake properties. These results imply that the combination of the crown ethers' macrocycle and adjacent carboxylic acid residues, from the polyamic acids, are conducive to effective cationic binding. NMR measurements, in conjunction with molecular modelling, have been used to explore the geometry changes encountered as the crown ether goes from it's uncomplexed to its complexed state. The energy requirement for these geometry changes has subsequently been used to examine the cation selectivity of these materials. The electronic charge changes associated with the complexation have also been investigated and correlated with the theoretical results. (author)

Night-to-night arousal variability and interscorer reliability of arousal measurements.

Science.gov (United States)

Loredo, J S; Clausen, J L; Ancoli-Israel, S; Dimsdale, J E

1999-11-01

Measurement of arousals from sleep is clinically important, however, their definition is not well standardized, and little data exist on reliability. The purpose of this study is to determine factors that affect arousal scoring reliability and night-to-night arousal variability. The night-to-night arousal variability and interscorer reliability was assessed in 20 subjects with and without obstructive sleep apnea undergoing attended polysomnography during two consecutive nights. Five definitions of arousal were studied, assessing duration of electroencephalographic (EEG) frequency changes, increases in electromyographic (EMG) activity and leg movement, association with respiratory events, as well as the American Sleep Disorders Association (ASDA) definition of arousals. NA. NA. NA. Interscorer reliability varied with the definition of arousal and ranged from an Intraclass correlation (ICC) of 0.19 to 0.92. Arousals that included increases in EMG activity or leg movement had the greatest reliability, especially when associated with respiratory events (ICC 0.76 to 0.92). The ASDA arousal definition had high interscorer reliability (ICC 0.84). Reliability was lowest for arousals consisting of EEG changes lasting <3 seconds (ICC 0.19 to 0.37). The within subjects night-to-night arousal variability was low for all arousal definitions In a heterogeneous population, interscorer arousal reliability is enhanced by increases in EMG activity, leg movements, and respiratory events and decreased by short duration EEG arousals. The arousal index night-to-night variability was low for all definitions.

Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

OpenAIRE

Tremblay, Pascal; Boucher, Jean-Francois; Tremblay, Marc; Lord, Daniel

2013-01-01

Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP)) seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spr...

Suitability of Secondary PEEK Telescopic Crowns on Zirconia Primary Crowns: The Influence of Fabrication Method and Taper

Directory of Open Access Journals (Sweden)

Susanne Merk

2016-11-01

Full Text Available This study investigates the retention load (RL between ZrO2 primary crowns and secondary polyetheretherketone (PEEK crowns made by different fabrication methods with three different tapers. Standardized primary ZrO2 crowns were fabricated with three different tapers: 0°, 1°, and 2° (n = 10/group. Ten secondary crowns were fabricated (i milled from breCam BioHPP blanks (PM; (ii pressed from industrially fabricated PEEK pellets (PP (BioHPP Pellet; or (iii pressed from granular PEEK (PG (BioHPP Granulat. One calibrated operator adjusted all crowns. In total, the RL of 90 secondary crowns were measured in pull-off tests at 50 mm/min, and each specimen was tested 20 times. Two- and one-way ANOVAs followed by a Scheffé’s post-hoc test were used for data analysis (p < 0.05. Within crowns with a 0° taper, the PP group showed significantly higher retention load values compared with the other groups. Among the 1° taper, the PM group presented significantly lower retention loads than the PP group. However, the pressing type had no impact on the results. Within the 2° taper, the fabrication method had no influence on the RL. Within the PM group, the 2° taper showed significantly higher retention load compared with the 1° taper. The taper with 0° was in the same range value as the 1° and 2° tapers. No impact of the taper on the retention value was observed between the PP groups. Within the PG groups, the 0° taper presented significantly lower RL than the 1° taper, whereas the 2° taper showed no differences. The fabrication method of the secondary PEEK crowns and taper angles showed no consistent effect within all tested groups.

Contrasting activity patterns of sympatric and allopatric black and grizzly bears

Science.gov (United States)

Schwartz, C.C.; Cain, S.L.; Podruzny, S.; Cherry, S.; Frattaroli, L.

2010-01-01

The distribution of grizzly (Ursus arctos) and American black bears (U. americanus) overlaps in western North America. Few studies have detailed activity patterns where the species are sympatric and no studies contrasted patterns where populations are both sympatric and allopatric. We contrasted activity patterns for sympatric black and grizzly bears and for black bears allopatric to grizzly bears, how human influences altered patterns, and rates of grizzlyblack bear predation. Activity patterns differed between black bear populations, with those sympatric to grizzly bears more day-active. Activity patterns of black bears allopatric with grizzly bears were similar to those of female grizzly bears; both were crepuscular and day-active. Male grizzly bears were crepuscular and night-active. Both species were more night-active and less day-active when ???1 km from roads or developments. In our sympatric study area, 2 of 4 black bear mortalities were due to grizzly bear predation. Our results suggested patterns of activity that allowed for intra- and inter-species avoidance. National park management often results in convergence of locally high human densities in quality bear habitat. Our data provide additional understanding into how bears alter their activity patterns in response to other bears and humans and should help park managers minimize undesirable bearhuman encounters when considering needs for temporal and spatial management of humans and human developments in bear habitats. ?? 2010 The Wildlife Society.

Diagnosing night sweats.

Science.gov (United States)

Viera, Anthon J; Bond, Michael M; Yates, Scott W

2003-03-01

Night sweats are a common outpatient complaint, yet literature on the subject is scarce. Tuberculosis and lymphoma are diseases in which night sweats are a dominant symptom, but these are infrequently found to be the cause of night sweats in modern practice. While these diseases remain important diagnostic considerations in patients with night sweats, other diagnoses to consider include human immunodeficiency virus, gastroesophageal reflux disease, obstructive sleep apnea, hyperthyroidism, hypoglycemia, and several less common diseases. Antihypertensives, antipyretics, other medications, and drugs of abuse such as alcohol and heroin may cause night sweats. Serious causes of night sweats can be excluded with a thorough history, physical examination, and directed laboratory and radiographic studies. If a history and physical do not reveal a possible diagnosis, physicians should consider a purified protein derivative, complete blood count, human immunodeficiency virus test, thyroid-stimulating hormone test, erythrocyte sedimentation rate evaluation, chest radiograph, and possibly chest and abdominal computed tomographic scans and bone marrow biopsy.

Suitability of Secondary PEEK Telescopic Crowns on Zirconia Primary Crowns: The Influence of Fabrication Method and Taper.

Science.gov (United States)

Merk, Susanne; Wagner, Christina; Stock, Veronika; Eichberger, Marlis; Schmidlin, Patrick R; Roos, Malgorzata; Stawarczyk, Bogna

2016-11-08

This study investigates the retention load (RL) between ZrO₂ primary crowns and secondary polyetheretherketone (PEEK) crowns made by different fabrication methods with three different tapers. Standardized primary ZrO₂ crowns were fabricated with three different tapers: 0°, 1°, and 2° ( n = 10/group). Ten secondary crowns were fabricated (i) milled from breCam BioHPP blanks (PM); (ii) pressed from industrially fabricated PEEK pellets (PP) (BioHPP Pellet); or (iii) pressed from granular PEEK (PG) (BioHPP Granulat). One calibrated operator adjusted all crowns. In total, the RL of 90 secondary crowns were measured in pull-off tests at 50 mm/min, and each specimen was tested 20 times. Two- and one-way ANOVAs followed by a Scheffé's post-hoc test were used for data analysis ( p impact on the results. Within the 2° taper, the fabrication method had no influence on the RL. Within the PM group, the 2° taper showed significantly higher retention load compared with the 1° taper. The taper with 0° was in the same range value as the 1° and 2° tapers. No impact of the taper on the retention value was observed between the PP groups. Within the PG groups, the 0° taper presented significantly lower RL than the 1° taper, whereas the 2° taper showed no differences. The fabrication method of the secondary PEEK crowns and taper angles showed no consistent effect within all tested groups.

The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

Directory of Open Access Journals (Sweden)

Fatemeh Mirsafi

2017-05-01

Full Text Available Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group received no injections, the sham group received intraperitoneal injections of distilled water solution containing salt and polysorbate (solvent of levothyroxine, and the experimental group received once-daily, intraperitoneal injections of 0.5 mg/kg levothyroxine for a 10-day period to become hyperthyroid rats. The hyperthyroid rats were then mated, and all pregnant rats were killed on the 20th day of gestation. Fetuses were removed, fixed, and processed for histological procedures. The fetuses were sagitally sectioned at 5 µ thickness and stained with hematoxylin-eosin (H and E technique. The sections were examined using a light microscope and Motic software. Results The results showed no significant difference in the studied variables between the sham and control groups. A significantly increase in body weight and a significant decrease in crown-rump length of embryos was observed in the experimental group when compared to the control group. The mean total thickness of the parietal cortex, ventricular layer, and intermediate layer of embryos showed a significant decrease in the experimental group compared to the control and sham groups. The mean number of cells also showed a significant decrease in the intermediate and ventricular layers in the experimental group compared to the control and sham groups. Conclusions This study showed that maternal hyperthyroidism leads to a reduction in development of the parietal cortex in embryos. Maternal hyperthyroidism can disturb the growth and development of embryos.

Novel embryo selection techniques to increase embryo implantation in IVF attempts.

Science.gov (United States)

Sigalos, George Α; Triantafyllidou, Olga; Vlahos, Nikos F

2016-11-01

The final success of an IVF attempt depends on several steps and decisions taken during the ovarian stimulation, the oocyte retrieval, the embryo culture and the embryo transfer. The final selection of the embryos most likely to implant is the final step in this process and the responsibility of the lab. Apart from strict morphologic criteria that historically have been used in embryo selection, additional information on genetic, metabolomic and morphokinetic characteristics of the embryo is recently combined to morphology to select the embryo most likely to produce a pregnancy. In this manuscript, we review the most recent information on the current methods used for embryo selection presenting the predictive capability of each one. A literature search was performed on Pubmed, Medline and Cochrane Database of Systematic Reviews for published studies using appropriate key words and phrases with no limits placed on time. It seems that the combination of morphologic criteria in conjunction to embryo kinetics as documented by time-lapse technology provides the most reliable information on embryo quality. Blastocyst biopsy with subsequent comprehensive chromosome analysis allows the selection of the euploid embryos with the higher implantation potential. Embryo time-lapse imaging and blastocyst biopsy combined to comprehensive chromosome analysis are the most promising technologies to increase pregnancy rates and reduce the possibility of multiple pregnancies. However, further studies will demonstrate the capability of routinely using these technologies to significantly improve IVF outcomes.

Minor Characters in William Shakespeare's Twelfth Night and A Midsummer Night's Dream

Directory of Open Access Journals (Sweden)

Zahraa Adnan Baqer

2018-01-01

Full Text Available This paper aims at discussing the role of the minor characters in William Shakespeare's Twelfth Night and A Midsummer Night's Dream. The study assumes that without the first group of minor characters, associated with Olivia, the play Twelfth Night would lose much of its humor, and without the second group, associated with Sebastian, the play would fall apart. On the other hand, in Shakespeare's A Midsummer Night's Dream minor characters play important roles, without them, the action dose not ran smoothly, or does not ran at all. The paper falls into three sections. Section one deals with the role of each minor character in Twelfth Night.  Section two focuses on the minor characters in A Midsummer Night's Dream. Section three is a conclusion which sums up the findings of the study.

Abundance and Night Hourly Dispersal of the Vesicating Beetles of the Genus Paederus (Coleoptera: Staphylinidae) Attracted to Fluorescent, Incandescent, and Black Light Sources in the Brazilian Savanna.

Science.gov (United States)

Lima, D C B; Costa, A A V; Silva, F S

2015-01-01

Paederus beetles are cosmopolitan medically important insects that cause dermatitis linearis to humans. In Brazil, despite the medical importance of these beetles, no studies focusing directly on the abundance and ecological features of harmful species exist. Therefore, this study aims at determining the abundance and the nocturnal hourly dispersal of Paederus species attracted to fluorescent, incandescent, and black light sources in the Brazilian savanna. Paederus species were captured from May to September for three consecutive years, between 2011 and 2013. The specimens were caught hourly, from 1800 to 0600 hours. Paederus beetles were attracted to incandescent, fluorescent, and black light lamps as light sources. A total of 959 individuals of five species were collected. The collected species were Paederus protensus Sharp (59.85%), Paederus columbinus Laporte de Castelnau (29.20%), Paederus mutans Sharp (7.09%), Paederus brasiliensis Erichson (3.34%), and Paederus ferus Erichson (0.52%). The black light was the most attractive source, and the darkest collecting point was the most representative for the number of individuals. The lowest catches were captured at full moon, and the highest catches were between 2200 and 0100 hours. Future investigations are needed to better understand the role of night temperature and soil humidity affecting the seasonal growth of Paederus beetle populations of northeastern Brazil. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Adnyamathanha Night Skies

Science.gov (United States)

Curnow, Paul

2009-06-01

Aboriginal Australians have been viewing the night skies of Australia for some 45,000 years and possibly much longer. During this time they have been able to develop a complex knowledge of the night sky, the terrestrial environment in addition to seasonal changes. However, few of us in contemporary society have an in-depth knowledge of the nightly waltz of stars above.

Review of Alberta Crown Crude Oil Marketing Program

International Nuclear Information System (INIS)

Crandall, G. R.; Kromm, R. B.

1999-01-01

This report contains an independent evaluation of the operations of the private marketing agents that are currently marketing the Alberta Crown's share of royalty crude oil. The evaluation includes a review of pricing performance, working relationship, current issues and the overall performance of the marketing arrangements during the fiscal years of 1997 and 1998. Overall, the outsourcing of sales of Crown production to agents is judged to be successful. For example, it has been noted that agents are becoming more aggressive in maintaining and increasing their margins. On the other hand, the increased level of aggressiveness in marketing, while tending to maximize Crown revenues, is also creating a potential conflict on how margins should be shared between the Crown and its agents. Also, there has been evidence of some management issues between the agents and the Crown concerning the extent to which the Crown should share in any increased value which the agent generates by increased third party marketing activities. These differences need to be addressed in order to maintain the strong performance of the marketing program. The consultants also recommend additional guidelines on risk management issues that more clearly define the Crown's risk tolerance. 2 tabs., 4 figs

The crown splash

Science.gov (United States)

Deegan, Robert; Brunet, Philippe; Eggers, Jens

2008-11-01

The impact of a drop onto a liquid layer and the subsequent splash has important implications for diverse physical processes such as air-sea gas transfer, cooling, and combustion. In the crown splash parameter regime, the splash pattern is highly regular. We focus on this case as a model for the mechanism that leads to secondary droplets, and thus explain the drop size distribution resulting from the splash. We show that the mean number of secondary droplets is determined by the most unstable wavelength of the Rayleigh-Plateau instability. Variations from this mean are governed by the width of the spectrum. Our results for the crown splash will provide the basis for understanding more complicated splashes.

Experimental and numerical modeling of shrub crown fire initiation

Science.gov (United States)

Watcharapong Tachajapong; Jesse Lozano; Shakar Mahalingam; Xiangyang Zhou; David Weise

2009-01-01

The transition of fire from dry surface fuels to wet shrub crown fuels was studied using laboratory experiments and a simple physical model to gain a better understanding of the transition process. In the experiments, we investigated the effects of varying vertical distances between surface and crown fuels (crown base height), and of the wind speed on crown fire...

Elliptic Fourier analysis of crown shapes in Quercus petraea trees

Directory of Open Access Journals (Sweden)

Ovidiu Hâruţa

2011-02-01

Full Text Available Shape is a fundamental morphological descriptor, significant in taxonomic research as well as in ecomorphology, one method of estimation being from digitally processed images. In the present study, were analysed shapes of Q. petraea crowns, pertaining to five different stem diameter classes, from three similar stands. Based on measurements on terrestrial digital vertical photos, crown size analysis was performed and correlations between crown and stem variables were tested. Linear regression equations between crown volumes and dbh, and crown volumes and stem volumes were derived, explaining more than half of data variability. Employment of elliptic Fourier analysis (EFA, a powerful analysis tool, permitted the extraction of the mean shape from crowns, characterized by high morphological variability. The extracted, most important, coefficients were used to reconstruct the average shape of the crowns, using Inverse Fourier Transform. A mean shape of the crown, corresponding to stand conditions in which competition is added as influential shaping factor, aside genetic program of the species, is described for each stem diameter class. Crown regions with highest shape variability, from the perspective of stage developmentof the trees, were determined. Accordingly, the main crown shape characteristics are: crown elongation, mass center, asymmetry with regard to the main axis, lateral regions symmetrical and asymmetrical variations.

Elliptic Fourier analysis of crown shapes in Quercus petraea trees

Directory of Open Access Journals (Sweden)

Ovidiu Hâruţa

2011-06-01

Full Text Available Shape is a fundamental morphological descriptor, significant in taxonomic research as well as in ecomorphology, one method of estimation being from digitally processed images. In the present study, were analysed shapes of Q. petraea crowns, pertaining to five different stem diameter classes, from three similar stands. Based on measurements on terrestrial digital vertical photos, crown size analysis was performed and correlations between crown and stem variables were tested. Linear regression equations between crown volumes and dbh, and crown volumes and stem volumes were derived, explaining more than half of data variability. Employment of elliptic Fourier analysis (EFA, a powerful analysis tool, permitted the extraction of the mean shape from crowns, characterized by high morphological variability. The extracted, most important, coefficients were used to reconstruct the average shape of the crowns, using Inverse Fourier Transform. A mean shape of the crown, corresponding to stand conditions in which competition is added as influential shaping factor, aside genetic program of the species, is described for each stem diameter class. Crown regions with highest shape variability, from the perspective of stage development of the trees, were determined. Accordingly, the main crown shape characteristics are: crown elongation, centroid position, asymmetry with regard to the main axis, lateral regions symmetrical and asymmetrical variations. 

Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

Science.gov (United States)

Wellner, Karen L.

2014-01-01

In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns

Directory of Open Access Journals (Sweden)

Deborah Pacheco Lameira

2015-01-01

Full Text Available The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP crowns in monolithic (1.5 mm thickness and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n=10: Polished monolithic zirconia crowns (PM; Glazed monolithic zirconia crowns (GM; Bi-layer crowns (BL. Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C, and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey’s test (P=.05 indicated that monolithic zirconia crowns presented similar fracture strength (PM=3476.2 N ± 791.7; GM=3561.5 N ± 991.6, which was higher than bilayer crowns (2060.4 N ± 810.6. There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength.

[Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology].

Science.gov (United States)

Zhao, H; Teng, X M; Li, Y F

2017-11-25

Objective: To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number, the membrane potential. Methods: Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected. According to evaluation of international standard in embryos, all cleavage stage embryos were divided into class Ⅰ frozen embryo group ( n= 64), class Ⅱ frozen embryo group ( n= 42) and class Ⅲ fresh embryonic group (not transplanted embryos; n= 117). Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo. The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared. Results: The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7±1.0)×10(5) copy/μl, 1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×10(5) copy/μl, 2.66±0.21] and class Ⅱ frozen embryo group [(2.6±1.2)×10(5) copy/μl, 1.80±0.32; all Pembryo group were significantly higher than those in classⅡ frozen embryo group (both Pembryos of the better quality embryo are higher.

Evaluation of sampling strategies to estimate crown biomass

Science.gov (United States)

Krishna P Poudel; Hailemariam Temesgen; Andrew N Gray

2015-01-01

Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire...

Noninvasive embryo assessment technique based on buoyancy and its association with embryo survival after cryopreservation.

Science.gov (United States)

Wessels, Cara; Penrose, Lindsay; Ahmad, Khaliq; Prien, Samuel

2017-11-01

Embryo cryopreservation offers many benefits by allowing genetic preservation, genetic screening, cost reduction, global embryo transport and single embryo transfer. However, freezing of embryos decreases embryo viability, as intracellular ice crystal formation often damages embryos. Success rates of frozen embryo transfer are expected to be 15-20% less than fresh embryo transfer. We have developed a noninvasive embryo assessment technique (NEAT) which enables us to predict embryo viability based on buoyancy. The purpose of this research was twofold. First was to determine if a NEAT, through a specific gravity device can detect embryo survival of cryopreservation. Second, it was to relate embryo buoyancy to embryo viability for establishing pregnancies in sheep. Blastocysts descent times were measured on one-hundred sixty-nine mice blastocysts before cryopreservation, according to standard protocol and post-thawing blastocysts descent times were measured again. There was a significant difference in blastocyst post-thaw descent times with NEAT in those blastocysts which demonstrated viability from those that did not (P embryos. Further studies on a larger scale commercial setting will evaluate the efficacy of NEAT. Copyright © 2017 Elsevier Inc. All rights reserved.

Miniaturized embryo array for automated trapping, immobilization and microperfusion of zebrafish embryos.

Directory of Open Access Journals (Sweden)

Jin Akagi

Full Text Available Zebrafish (Danio rerio has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP. The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale.

Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

Science.gov (United States)

Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

2017-08-01

Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

Science.gov (United States)

Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

2016-06-01

Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

Meta-analysis on night shift work and risk of metabolic syndrome.

Science.gov (United States)

Wang, F; Zhang, L; Zhang, Y; Zhang, B; He, Y; Xie, S; Li, M; Miao, X; Chan, E Y Y; Tang, J L; Wong, M C S; Li, Z; Yu, I T S; Tse, L A

2014-09-01

This study aims to quantitatively summarize the association between night shift work and the risk of metabolic syndrome (MetS), with special reference to the dose-response relationship with years of night shift work. We systematically searched all observational studies published in English on PubMed and Embase from 1971 to 2013. We extracted effect measures (relative risk, RR; or odd ratio, OR) with 95% confidence interval (CI) from individual studies to generate pooled results using meta-analysis approach. Pooled RR was calculated using random- or fixed-effect model. Downs and Black scale was applied to assess the methodological quality of included studies. A total of 13 studies were included. The pooled RR for the association between 'ever exposed to night shift work' and MetS risk was 1.57 (95% CI = 1.24-1.98, pheterogeneity  = 0.001), while a higher risk was indicated in workers with longer exposure to night shifts (RR = 1.77, 95% CI = 1.32-2.36, pheterogeneity  = 0.936). Further stratification analysis demonstrated a higher pooled effect of 1.84 (95% CI = 1.45-2.34) for studies using the NCEP-ATPIII criteria, among female workers (RR = 1.61, 95% CI = 1.10-2.34) and the countries other than Asia (RR = 1.65, 95% CI = 1.39-1.95). Sensitivity analysis confirmed the robustness of the results. No evidence of publication bias was detected. The present meta-analysis suggested that night shift work is significantly associated with the risk of MetS, and a positive dose-response relationship with duration of exposure was indicated. © 2014 The Authors. obesity reviews © 2014 World Obesity.

History of the Night

CERN Multimedia

CERN. Geneva

2016-01-01

The definition of the night, as the period between sunset and sunrise, is consistent and unalterable, regardless of culture and time. However the perception of the night and its economic, social, and cultural roles are subject to change. Which parameters determine these changes? What can we learn by studying them about the specific character of a culture? Why do people experience the night in different ways in different historical periods and how did this affect their lives? How do references to nocturnal activities in historical sources (works of art, narratives) reveal what the artists/authors wish to communicate to their audiences? Can the night be a meaningful subject of historical and archaeological enquiry? A study of the source material in the Greek world (ca. 400 BC-ca. AD 400) shows a continuous effort to colonize the night with activities of the day, to make the night safer, more productive, more rational, more efficient. The main motors for this change were social developments and religion, no...

Digital photography for urban street tree crown conditions

Science.gov (United States)

Neil A. Clark; Sang-Mook Lee; William A. Bechtold; Gregory A. Reams

2006-01-01

Crown variables such as height, diameter, live crown ratio, dieback, transparency, and density are all collected as part of the overall crown assessment (USDA 2004). Transparency and density are related to the amount of foliage and thus the photosynthetic potential of the tree. These measurements are both currently based on visual estimates and have been shown to be...

Crown Fire Potential

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

Effect of posterior crown margin placement on gingival health.

Science.gov (United States)

Reitemeier, Bernd; Hänsel, Kristina; Walter, Michael H; Kastner, Christian; Toutenburg, Helge

2002-02-01

The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified. This study evaluated the effect of posterior crown margin placement with multivariate analysis. Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (Prisk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding. In this study, placement of crown margins was one of several parameters that affected gingival health.

Solvent Effects on Cesium Complexation with Crown Ethers from Liquid to Supercritical Fluids

International Nuclear Information System (INIS)

Wai, Chien M.; Rustenholtz, Anne; Wang, Shaofen; Lee, Su-Chen; Herman, Jamie; Porter, Richard A.

2004-01-01

Nuclear magnetic resonance (NMR) techniques were used to study crown ether-water interactions in solvents of low dielectric constants such as chloroform and carbon tetrachloride. Water forms a 1:1 complex with a number of crown ethers including 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexano-18=crown-6, dicyclohexano-24-crown 8, and dibenzl-24-crown-8 in chloroform. Among these crown ethers, the 18-crown-6-H2 complex has the largest equilibrium constant (K=545) and 97% of the crown is complexed to water in chloroform. Addition of carbon tetrachloride to chloroform lowers the equilibrium constants of the crown-water complexes. The partition coefficients of crown ethers (D=crown in water/crown in solvent) between water and organic solvent also vary with solvent composition

Rape embryogenesis. IV. Appearance and disappearance of starch during embryo development

Directory of Open Access Journals (Sweden)

Teresa Tykarska

2014-01-01

Full Text Available Starch appears first in the suspensor of the proembryo with two-cell apical part. It is observed in the embryo proper from the octant stage. At first it is visible in all the embryo cells in the form of minute transient grains which disappear during cell divisions. But the columella mother cells and their derivatives have persistent large grains. When the embryo turns green in the heart stage a gradual accumulation of storage starch begins and lasts to the end of embryogenesis. Storage starch grains appear first in the auter cortex layers of the hypocotyl where the largest grains are to be found later, and afterwards in all the other tissues. Starch is usually absent in the frequently dividing cells, but even there it appears in the form of minute grains after the end of cell divisions. Disappearance of starch starts when the intensive green colour of the seed coat begins to fade. The first to disappear are the smallest granules in the regions where they were noted latest. In the embryo axis the starch grains remain deposited longest in dermatogen and cortex cells in the lower hypocotyl part. They are visible there, still when the seed turns brown. In black seeds starch may be only found in the columella the cells of which throughout embryogenesis contain amyloplasts filled with starch. These grains disappear completely at the time when the seeds become dry.

Epicormic branching of California black oak: effect of stand and tree characteristics

Science.gov (United States)

Philip M. McDonald; Martin W. Ritchie

1994-01-01

Young California black oak (Quercus kelloggii Newb.) stands usually require thinning to increase production of acorns and wood products, but epicormic branches, which yield no acorns and constitute a serious lumber degrade. often result. A crown thinning in 60-year-old hardwood stands on a south exposure at the Challenge Experimental Forest in thenorthern Sierra Nevada...

Descriptive statistics of tree crown condition in the Northeastern United States

Science.gov (United States)

KaDonna C. Randolph; Randall S. Morin; Jim Steinman

2010-01-01

The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Connecticut, Delaware, Maine, Maryland, Massachusetts, New...

Fracture rates of IPS Empress all-ceramic crowns--a systematic review.

Science.gov (United States)

Heintze, Siegward D; Rousson, Valentin

2010-01-01

The aim of this study was to evaluate the clinical fracture rate of crowns fabricated with the pressable, leucite-reinforced ceramic IPS Empress, and relate the results to the type of tooth restored. The database SCOPUS was searched for clinical studies involving full-coverage crowns made of IPS Empress. To assess the fracture rate of the crowns in relation to the type of restored tooth and study, Poisson regression analysis was used. Seven clinical studies were identified involving 1,487 adhesively luted crowns (mean observation time: 4.5+/-1.7 years) and 81 crowns cemented with zinc-phosphate cement (mean observation time: 1.6+/-0.8 years). Fifty-seven of the adhesively luted crowns fractured (3.8%). The majority of fractures (62%) occurred between the third and sixth year after placement. There was no significant influence regarding the test center on fracture rate, but the restored tooth type played a significant role. The hazard rate (per year) for crowns was estimated to be 5 in every 1,000 crowns for incisors, 7 in every 1,000 crowns for premolars, 12 in every 1,000 crowns for canines, and 16 in every 1,000 crowns for molars. One molar crown in the zinc-phosphate group fractured after 1.2 years. Adhesively luted IPS Empress crowns showed a low fracture rate for incisors and premolars and a somewhat higher rate for molars and canines. The sample size of the conventionally luted crowns was too small and the observation period too short to draw meaningful conclusions.

[Finite element analysis of the maxillary central incisor with traditional and modified crown lengthening surgery and post-core restoration in management of crown-root fracture].

Science.gov (United States)

Zhen, M; Wei, Y P; Hu, W J; Rong, Q G; Zhang, H

2016-06-01

To construct three-dimensional finite element models with modified crown lengthening surgery and post-core restoration in management of various crown-root fracture types, to investigate the intensity and distribution of stressin models mentioned above, and to compare and analyze the indications of traditional and modified crown lengthening surgeries from the mechanic point of view. Nine three-dimensional finite element models with modified crown lengthening surgery and post-core restoration were established and analyzed by micro-CT scanning technique, dental impression scanner, Mimics 10.0, Geomagic studio 9.0 and ANSYS 14.0 software. The von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area and threshold limit value were calculated and compared with the findings of traditional crown lengthening models which had been published earlierby our research group. The von Mises stress intensity of modified crown lengthening models were: dentin>post>core>alveolar bone>periodontal ligament. The maximum von Mises stress of dentin(44.37-80.58 MPa)distributed in lingual central shoulder. The periodontal ligament area of the modified crown lengthening surgery was reduced by 6% to 28%, under the same crown-root fracture conditions, the periodontal ligament area of modified crown lengthening models was larger than that of the traditional crown lengthening models. In modified crown lengthening surgery models, the von Mises stress of periodontal ligament of B3L1m, B3L2m, B3L3m models exceeded their limit values, however, the von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their limit values in traditional crown lengthening surgery models. The modified crown lengthening surgery conserves more periodontal supporting tissues, which facilitates the long-term survival of teeth. The indication of modified crown lengthening surgery is wider than traditional method. The

Navigating through the Crown land process

Energy Technology Data Exchange (ETDEWEB)

Dawson, M. [Samsung Renewable Energy Inc., ON (Canada)

2010-07-01

Samsung Communications and Technology (Samsung C and T) and the Korea Electric Power Corporation are planning to invest approximately $7 billion to generate 2500 MW of wind and solar energy in Ontario. The plan was centred around the green energy investment agreement signed in January 2010. To date, only 1 project in Ontario has been permitted for development on Crown land, and there have been 3 different versions of the Crown land policy and procedure for the development of wind power projects. The Crown land process is challenged by issues related to grandfathering, timing, competing processes, and the Endangered Species Act. Guidance is needed to identify requirements for studies and evaluation processes. Additional studies are often required by government agencies when new documents and results are reviewed. Projects are also delayed when new species are added to the endangered species list. Wind power developers must keep abreast of proposed regulations and guidelines to ensure that work programs are not delayed. An overview of the current Crown land development process was included. tabs., figs.

Fatigue resistance of CAD/CAM resin composite molar crowns.

NARCIS (Netherlands)

Shembish, F.A.; Tong, H.; Kaizer, M.; Janal, M.N.; Thompson, V.P.; Opdam, N.J.M.; Zhang, Y.

2016-01-01

OBJECTIVE: To demonstrate the fatigue behavior of CAD/CAM resin composite molar crowns using a mouth-motion step-stress fatigue test. Monolithic leucite-reinforced glass-ceramic crowns were used as a reference. METHODS: Fully anatomically shaped monolithic resin composite molar crowns (Lava

Fracture Resistance Force of Primary Molar Crowns Milled from ...

African Journals Online (AJOL)

2018-04-04

Apr 4, 2018 ... molar stainless steel crown (SSC) and stored in water at 37°C for 30 days. The crowns were seated on Cr‑Co ... model) or chairside (in‑office system model) CAD/ ..... crowns, deformation may be observed instead of fracture.

Bis(hydroxyammonium hexachloridoplatinate(IV–18-crown-6 (1/2

Directory of Open Access Journals (Sweden)

Evgeny Bulatov

2014-01-01

Full Text Available In the title complex, (NH3OH2[PtCl6]·2C12H24O6, the PtIV atom is coordinated by six chloride anions in a slightly distorted octahedral geometry. The Pt—Cl bond lengths are comparable to those reported for other hexachloridoplatinate(IV species. The hydroxyammonium groups act as linkers between the [PtCl6]2− anion and the crown ether molecules. The anion is linked to two hydroxyammonium cations via O—H...Cl hydrogen bonds and each hydroxyammonium moiety is linked to a crown ether molecule by hydrogen bonds between ammonium H atoms and 18-crown-6 O atoms. The crown ether molecules have the classic crown shape in which all O atoms are located in the inner part of the crown ether ring and all –CH2– groups are turned to the outside.

[Association of human chorionic gonadotropin level in embryo culture media with early embryo development].

Science.gov (United States)

Wang, Haiying; Zhang, Renli; Han, Dong; Liu, Caixia; Cai, Jiajie; Bi, Yanling; Wen, Anmin; Quan, Song

2014-06-01

To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development. Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02). ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.

AB INITIO INVESTIGATION OF 12-CROWN-4 AND BENZO-12-CROWN-4 COMPLEXES WITH Li+, Na+, K+, Zn2+, Cd2+, AND Hg2+

Directory of Open Access Journals (Sweden)

Yahmin Yahmin

2010-06-01

Full Text Available The structure and binding energies of 12-crown-4 and benzo-12-crown-4 complexes with Li+, Na+, K+, Zn2+, Cd2+, and Hg2+were investigated with ab initio calculations using Hartree-Fock approximation and second-order perturbation theory. The basis set used in this study is lanl2mb. The structure optimization of cation-crown ether complexes was evaluated at HF/lanl2mb level of theory and interaction energy of the corresponding complexes was calculated at MP2/lanl2mb level of theory (MP2/lanl2mb//HF/lanl2mb. Interactions of the crown ethers and the cations were discussed in term of the structure parameter of crown ether. The binding energies of the complexes show that all complex formed from transition metal cations is more stable than the complexes formed from alkali metal cations.   Keywords: 12-crown-4, benzo-12-crown-4, alkali metals, transition metals

Black-footed ferrets and Siberian polecats as ecological surrogates and ecological equivalents

Science.gov (United States)

Biggins, D.E.; Hanebury, L.R.; Miller, B.J.; Powell, R.A.

2011-01-01

Ecologically equivalent species serve similar functions in different communities, and an ecological surrogate species can be used as a substitute for an equivalent species in a community. Siberian polecats (Mustela eversmanii) and black-footed ferrets (M. nigripes) have long been considered ecological equivalents. Polecats also have been used as investigational surrogates for black-footed ferrets, yet the similarities and differences between the 2 species are poorly understood. We contrasted activity patterns of radiotagged polecats and ferrets released onto ferret habitat. Ferrets tended to be nocturnal and most active after midnight. Polecats were not highly selective for any period of the day or night. Ferrets and polecats moved most during brightly moonlit nights. The diel activity pattern of ferrets was consistent with avoidance of coyotes (Canis latrans) and diurnal birds of prey. Similarly, polecat activity was consistent with avoidance of red foxes (Vulpes vulpes) in their natural range. Intraguild predation (including interference competition) is inferred as a selective force influencing behaviors of these mustelines. Examination of our data suggests that black-footed ferrets and Siberian polecats might be ecological equivalents but are not perfect surrogates. Nonetheless, polecats as surrogates for black-footed ferrets have provided critical insight needed, especially related to predation, to improve the success of ferret reintroductions. ?? 2011 American Society of Mammalogists.

Potential of human twin embryos generated by embryo splitting in assisted reproduction and research.

Science.gov (United States)

Noli, Laila; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

2017-03-01

Embryo splitting or twinning has been widely used in veterinary medicine over 20 years to generate monozygotic twins with desirable genetic characteristics. The first human embryo splitting, reported in 1993, triggered fierce ethical debate on human embryo cloning. Since Dolly the sheep was born in 1997, the international community has acknowledged the complexity of the moral arguments related to this research and has expressed concerns about the potential for reproductive cloning in humans. A number of countries have formulated bans either through laws, decrees or official statements. However, in general, these laws specifically define cloning as an embryo that is generated via nuclear transfer (NT) and do not mention embryo splitting. Only the UK includes under cloning both embryo splitting and NT in the same legislation. On the contrary, the Ethics Committee of the American Society for Reproductive Medicine does not have a major ethical objection to transferring two or more artificially created embryos with the same genome with the aim of producing a single pregnancy, stating that 'since embryo splitting has the potential to improve the efficacy of IVF treatments for infertility, research to investigate the technique is ethically acceptable'. Embryo splitting has been introduced successfully to the veterinary medicine several decades ago and today is a part of standard practice. We present here an overview of embryo splitting experiments in humans and non-human primates and discuss the potential of this technology in assisted reproduction and research. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies on embryo splitting in humans and non-human primates. 'Embryo splitting' and 'embryo twinning' were used as the keywords, alone or in combination with other search phrases relevant to the topics of biology of preimplantation embryos. A very limited number of studies have been conducted in humans and non

Coast redwood live crown and sapwood

Science.gov (United States)

John-Pascal Berrill; Jesse L. Deffress; Jessica M. Engle

2012-01-01

Understanding crown rise and sapwood taper will help meet management objectives such as producing long branch-free boles for clear wood and old-growth restoration, or producing sawlogs with a high proportion of heartwood. Coast redwood (Sequoia sempervirens) tree crown ratio data were collected 20 years after partial harvesting in a 65-year-old second growth stand....

Retention Load Values of Telescopic Crowns Made of Y-TZP and CoCr with Y-TZP Secondary Crowns: Impact of Different Taper Angles

Directory of Open Access Journals (Sweden)

Susanne Merk

2016-05-01

Full Text Available This study aimed to examine and compare the retention load values (RL of different telescopic crown assemblies (Y-TZP and CoCr primary crowns with electroformed and Y-TZP secondary crowns each with three different taper angles (0°, 1° and 2°. Thirty Y-TZP primary crowns with electroformed gold copings (Z/G group and Y-TZP secondary crowns (Z/Z group and 30 CoCr primary crowns with electroformed gold copings (C/G group and Y-TZP secondary crowns (C/Z group, each with taper angles of 0°, 1° and 2°, were fabricated, respectively. With the exception of the electroformed gold copings, all specimens were Computer-Aided-Design/Computer-Aided-Manufacturing (CAD/CAM-milled, then sintered and afterwards manually adapted. In order to stabilize the gold copings, they were fixed in a tertiary structure. The secondary crowns were constructed with a hook, which ensured self-alignment with an upper chain. Afterwards, 20 pull-off test cycles were performed in a universal testing machine under artificial saliva and after weighing the secondary crowns with a 5 kg object for 20 s. Data were analyzed by one-way and two-way Analysis of Variance (ANOVA. C/Z with 1° showed higher (p = 0.009 RL than 0° and 2° tapers. C/G at 1° also showed higher (p = 0.001 RL than at tapers of 0° and 2°. Z/G and C/G at 0° showed lower RL than Z/Z and C/Z (p < 0.001. Primary crowns had no impact on the 0° group. Z/G showed lower RL as compared to C/Z within the 1° group (p = 0.007 and Z/Z in the 2° group (p = 0.006. The primary crown material had no influence on RL. Electroformed copings showed lower RL. Further investigations for 1° as well as for the long-term performance after thermomechanical aging are necessary.

New atraumatic easy removal technique for permanently cemented crown

Directory of Open Access Journals (Sweden)

Pravinkumar G Patil

2012-01-01

Full Text Available Removal of a permanently cemented crown or fixed partial denture is a cumbersome procedure for a prosthodontist, especially when there is no purchase point available to remove it. The technique described in this article consists of sectioning of a crown on facial surface followed by removal of the crown with orthodontic plier. This technique does not damage the gingival/periodontal tissues or underlying tooth structure as the crown need not to be removed with jerky back-action force.

Root-Crown Relations of Young Sugar Maple and Yellow Birch

Science.gov (United States)

Carl H. Tubbs

1977-01-01

Young forest-grown sugar maple and yellow birch (1 to 6 inches d.b.h.) crowns were mapped and roots excavated. Crown dimensions were compared. Sugar maple roots usually terminated within a few feet of the crown perimeter. Yellow birch roots frequently terminated well outside crown perimeters and roots of birch were more irregularly distributed than those of maple....

Extracting oil palm crown from WorldView-2 satellite image

Science.gov (United States)

Korom, A.; Phua, M.-H.; Hirata, Y.; Matsuura, T.

2014-02-01

Oil palm (OP) is the most commercial crop in Malaysia. Estimating the crowns is important for biomass estimation from high resolution satellite (HRS) image. This study examined extraction of individual OP crown from a WorldView-2 image using twofold algorithms, i.e., masking of Non-OP pixels and detection of individual OP crown based on the watershed segmentation of greyscale images. The study site was located in Beluran district, central Sabah, where matured OPs with the age ranging from 15 to 25 years old have been planted. We examined two compound vegetation indices of (NDVI+1)*DVI and NDII for masking non-OP crown areas. Using kappa statistics, an optimal threshold value was set with the highest accuracy at 90.6% for differentiating OP crown areas from Non-OP areas. After the watershed segmentation of OP crown areas with additional post-procedures, about 77% of individual OP crowns were successfully detected in comparison to the manual based delineation. Shape and location of each crown segment was then assessed based on a modified version of the goodness measures of Möller et al which was 0.3, indicating an acceptable CSGM (combined segmentation goodness measures) agreements between the automated and manually delineated crowns (perfect case is '1').

Extracting oil palm crown from WorldView-2 satellite image

International Nuclear Information System (INIS)

Korom, A; Phua, M-H; Hirata, Y; Matsuura, T

2014-01-01

Oil palm (OP) is the most commercial crop in Malaysia. Estimating the crowns is important for biomass estimation from high resolution satellite (HRS) image. This study examined extraction of individual OP crown from a WorldView-2 image using twofold algorithms, i.e., masking of Non-OP pixels and detection of individual OP crown based on the watershed segmentation of greyscale images. The study site was located in Beluran district, central Sabah, where matured OPs with the age ranging from 15 to 25 years old have been planted. We examined two compound vegetation indices of (NDVI+1)*DVI and NDII for masking non-OP crown areas. Using kappa statistics, an optimal threshold value was set with the highest accuracy at 90.6% for differentiating OP crown areas from Non-OP areas. After the watershed segmentation of OP crown areas with additional post-procedures, about 77% of individual OP crowns were successfully detected in comparison to the manual based delineation. Shape and location of each crown segment was then assessed based on a modified version of the goodness measures of Möller et al which was 0.3, indicating an acceptable CSGM (combined segmentation goodness measures) agreements between the automated and manually delineated crowns (perfect case is '1')

DYNAMICS OF NUMBER OF GREY HERONS (ARDEA CINEREA L. COLONY IN THE UPPER COURSE OF ZAPOROZHYE (DNEPROVSKOYE RESERVOIR

Directory of Open Access Journals (Sweden)

Vovk M.V.

2012-11-01

Full Text Available The research was performed in the area of natural reserve "Dneprovsko-Orelsky" and its adjacent territory – the island Pogorely. We discovered the changes of number of grey heron in colonial settlements, determined the principal factors influencing the formation of spatial structure of island bird communities. The analysis of nest distribution towards tree breeding biotopes was performed and stability of spatial structure of bird colonies was proved. We were tracking the number dynamics of pioneer colony and revealed the principal ecological and anthropogenic factors influencing the fluctuation of its abundance.

Embryo aggregation does not improve the development of interspecies somatic cell nuclear transfer embryos in the horse.

Science.gov (United States)

Gambini, Andrés; De Stéfano, Adrián; Jarazo, Javier; Buemo, Carla; Karlanian, Florencia; Salamone, Daniel Felipe

2016-09-01

The low efficiency of interspecies somatic cell nuclear transfer (iSCNT) makes it necessary to investigate new strategies to improve embryonic developmental competence. Embryo aggregation has been successfully applied to improve cloning efficiency in mammals, but it remains unclear whether it could also be beneficial for iSCNT. In this study, we first compared the effect of embryo aggregation over in vitro development and blastocyst quality of porcine, bovine, and feline zona-free (ZF) parthenogenetic (PA) embryos to test the effects of embryo aggregation on species that were later used as enucleated oocytes donors in our iSCNT study. We then assessed whether embryo aggregation could improve the in vitro development of ZF equine iSCNT embryos after reconstruction with porcine, bovine, and feline ooplasm. Bovine- and porcine-aggregated PA blastocysts had significantly larger diameters compared with nonaggregated embryos. On the other hand, feline- and bovine-aggregated PA embryos had higher blastocyst cell number. Embryo aggregation of equine-equine SCNT was found to be beneficial for embryo development as we have previously reported, but the aggregation of three ZF reconstructed embryos did not improve embryo developmental rates on iSCNT. In vitro embryo development of nonaggregated iSCNT was predominantly arrested around the stage when transcriptional activation of the embryonic genome is reported to start on the embryo of the donor species. Nevertheless, independent of embryo aggregation, equine blastocyst-like structures could be obtained in our study using domestic feline-enucleated oocytes. Taken together, these results reported that embryo aggregation enhance in vitro PA embryo development and embryo quality but effects vary depending on the species. Embryo aggregation also improves, as expected, the in vitro embryo development of equine-equine SCNT embryos; however, we did not observe positive effects on equine iSCNT embryo development. Among oocytes

Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

International Nuclear Information System (INIS)

Ju, Yan; Liu, Chunying; Lu, Wenwen; Zhang, Quan; Sodmergen

2016-01-01

The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysis revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.

Arabidopsis mitochondrial protein slow embryo development1 is essential for embryo development

Energy Technology Data Exchange (ETDEWEB)

Ju, Yan; Liu, Chunying; Lu, Wenwen; Zhang, Quan; Sodmergen, E-mail: sodmergn@pku.edu.cn

2016-05-27

The plant seeds formation are crucial parts in reproductive process in seed plants as well as food source for humans. Proper embryo development ensure viable seed formation. Here, we showed an Arabidopsis T-DNA insertion mutant slow embryo development1 (sed1) which exhibited retarded embryogenesis, led to aborted seeds. Embryo without SED1 developed slower compared to normal one and could be recognized at early globular stage by its white appearance. In later development stage, storage accumulated poorly with less protein and lipid body production. In vitro culture did not rescue albino embryo. SED1 encoded a protein targeted to mitochondria. Transmission electron microscopic analysis revealed that mitochondria developed abnormally, and more strikingly plastid failed to construct grana in time in sed1/sed1 embryo. These data indicated that SED1 is indispensable for embryogenesis in Arabidopsis, and the mitochondria may be involved in the regulation of many aspects of seed development. -- Highlights: •Arabidopsis SED1 is essential for embryo development. •The sed1 embryo accumulates less storage and has abnormal ultrastructure. •SED1 localizes to the mitochondrion.

A short-term clinical evaluation of IPS Empress 2 crowns.

Science.gov (United States)

Toksavul, Suna; Toman, Muhittin

2007-01-01

The aim of this study was to evaluate the clinical performance of all-ceramic crowns made with the IPS Empress 2 system after an observation period of 12 to 60 months. Seventy-nine IPS Empress 2 crowns were placed in 21 patients. The all-ceramic crowns were evaluated clinically, radiographically, and using clinical photographs. The evaluations took place at baseline (2 days after cementation) and at 6-month intervals for 12 to 60 months. Survival rate of the crowns was determined using Kaplan-Meier statistical analysis. Based on the US Public Health Service criteria, 95.24% of the crowns were rated satisfactory after a mean follow-up period of 58 months. Fracture was registered in only 1 crown. One endodontically treated tooth failed as a result of fracture at the cervical margin area. In this in vivo study, IPS Empress 2 crowns exhibited a satisfactory clinical performance during an observation period ranging from 12 to 60 months.

Twenty-nine-month follow-up of a paediatric zirconia dental crown.

Science.gov (United States)

Lopez Cazaux, Serena; Hyon, Isabelle; Prud'homme, Tony; Dajean Trutaud, Sylvie

2017-06-14

The aim of this paper is to present the long-term follow-up of one paediatric zirconia crown on a deciduous molar. Preformed crowns are part of the armamentarium in paediatric dentistry. In recent years, aesthetic alternatives to preformed metal crowns have been developed, first preveneered crowns and then zirconia crowns. This paper describes the restoration of a primary molar with a zirconia crown (EZ-Pedo, Loomis, California, USA) in an 8-year-old boy. In this clinical case, the protocol for the implementation and maintenance of zirconia crowns is detailed. The patient was followed up for 29 months until the natural exfoliation of his primary molar. The adaptation of the zirconia crown, the gingival health and the wear on the opposing tooth were considered. In this case, the paediatric zirconia crown allowed sustainable functional restoration while restoring a natural appearance of the tooth. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Re/crowning the Jowo Śākyamuni

DEFF Research Database (Denmark)

Warner, Cameron

2011-01-01

of ritual observance and visions received.  In 1409, Tsongkhapa Lozang Drakpa  (1357-1419) crowned the Jowo, changing his doctrinal and iconographic representations.  I connect the controversy surrounding Tsongkhapa's decision to re/crown the Jowo in 1409 to the significance placed on authenticity...

Crown Ether Complexes of Alkali-Metal Chlorides from SO2.

Science.gov (United States)

Reuter, Kirsten; Rudel, Stefan S; Buchner, Magnus R; Kraus, Florian; von Hänisch, Carsten

2017-07-18

The structures of alkali-metal chloride SO 2 solvates (Li-Cs) in conjunction with 12-crown-4 or 1,2-disila-12-crown-4 show strong discrepancies, despite the structural similarity of the ligands. Both types of crown ethers form 1:1 complexes with LiCl to give [Li(1,2-disila-12-crown-4)(SO 2 Cl)] (1) and [Li(12-crown-4)Cl]⋅4 SO 2 (2). However, 1,2-disila-12-crown-4 proved unable to coordinate cations too large for the cavity diameter, for example, by the formation of sandwich-type complexes. As a result, 12-crown-4 reacts exclusively with the heavier alkali-metal chlorides NaCl, KCl and RbCl. Compounds [Na(12-crown-4) 2 ]Cl⋅4 SO 2 (3) and [M(12-crown-4) 2 (SO 2 )]Cl⋅4 SO 2 (4: M=K; 5: M=Rb) all showed S-coordination to the chloride ions through four SO 2 molecules. Compounds 4 and 5 additionally exhibit the first crystallographically confirmed non-bridging O,O'-coordination mode of SO 2 . Unexpectedly, the disila-crown ether supports the dissolution of RbCl and CsCl in the solvent and gives the homoleptic SO 2 -solvated alkali-metal chlorides [MCl⋅3 SO 2 ] (6: M=Rb; 7: M=Cs), which incorporate bridging μ-O,O'-coordinating moieties and the unprecedented side-on O,O'-coordination mode. All compounds were characterised by single-crystal X-ray diffraction. The crown ether complexes were additionally studied by using NMR spectroscopy, and the presence of SO 2 at ambient temperature was revealed by IR spectroscopy of the neat compounds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Embryos, individuals, and persons: an argument against embryo creation and research.

Science.gov (United States)

Tollefsen, C

2001-01-01

One strategy for arguing that it should be legally permissible to create human embryos, or to use spare human embryos, for scientific research purposes involves the claim that such embryos cannot be persons because they are not human individuals while twinning may yet take place. Being a human individual is considered to be by most people a necessary condition for being a human person. I argue first that such an argument against the personhood of embryos must be rationally conclusive if their destruction in public places such as laboratories is to be countenanced. I base this argument on a popular understanding of the role that the notion of privacy plays in abortion laws. I then argue that such arguments against personhood are not rationally conclusive. The claim that the early embryos is not a human individual is not nearly as obvious as some assert.

21 CFR 872.3770 - Temporary crown and bridge resin.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such as...

Single-embryo transfer versus multiple-embryo transfer.

Science.gov (United States)

Gerris, Jan

2009-01-01

Despite the progress made in assisted reproductive technology, live birth rates remain disappointingly low. Multiple-embryo transfer has been an accepted practice with which to increase the success rate. This has led to a higher incidence of multiple-order births compared with natural conception, which not only increase the risk of mortality and morbidity to both mother and children but are also associated with social and economic consequences. Elective single-embryo transfer (eSET) was developed in an effort to increase singleton pregnancies in assisted reproduction. Studies comparing eSET with multiple-embryo transfer highlight the benefit of this approach and suggest that, with careful patient selection and the transfer of good-quality embryos, the risk of a multiple-order pregnancy can be reduced without significantly decreasing live birth rates. Although the use of eSET has gradually increased in clinical practice, its acceptance has been limited by factors such as availability of funding and awareness of the procedure. An open discussion of eSET is warranted in an effort to enable a broader understanding by physicians and patients of the merits of this approach. Ultimately, eSET may provide a more cost-effective, potentially safer approach to patients undergoing assisted reproduction technology.

Randomized, Controlled Clinical Trial of Bilayer Ceramic and Metal-Ceramic Crown Performance

Science.gov (United States)

Esquivel-Upshaw, Josephine; Rose, William; Oliveira, Erica; Yang, Mark; Clark, Arthur E.; Anusavice, Kenneth

2013-01-01

Purpose Analyzing the clinical performance of restorative materials is important, as there is an expectation that these materials and procedures will restore teeth and do no harm. The objective of this research study was to characterize the clinical performance of metal-ceramic crowns, core ceramic crowns, and core ceramic/veneer ceramic crowns based on 11 clinical criteria. Materials and Methods An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study. The following three types of full crowns were fabricated: (1) metal-ceramic crown (MC) made from a Pd-Au-Ag-Sn-In alloy (Argedent 62) and a glass-ceramic veneer (IPS d.SIGN veneer); (2) non-veneered (glazed) lithium disilicate glass-ceramic crown (LDC) (IPS e.max Press core and e.max Ceram Glaze); and (3) veneered lithia disilicate glass-ceramic crown (LDC/V) with glass-ceramic veneer (IPS Empress 2 core and IPS Eris). Single-unit crowns were randomly assigned. Patients were recalled for each of 3 years and were evaluated by two calibrated clinicians. Thirty-six crowns were placed in 31 patients. A total of 12 crowns of each of the three crown types were studied. Eleven criteria were evaluated: tissue health, marginal integrity, secondary caries, proximal contact, anatomic contour, occlusion, surface texture, cracks/chips (fractures), color match, tooth sensitivity, and wear (of crowns and opposing enamel). Numerical rankings ranged from 1 to 4, with 4 being excellent, and 1 indicating a need for immediate replacement. Statistical analysis of the numerical rankings was performed using a Fisher’s exact test. Results There was no statistically significant difference between performance of the core ceramic crowns and the two veneered crowns at year 1 and year 2 (p > 0.05). All crowns were rated either as excellent or good for each of the clinical criteria; however, between years 2 and 3, gradual roughening of the occlusal surface occurred in some of the ceramic-ceramic crowns

Mouse Embryo Compaction.

Science.gov (United States)

White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

2016-01-01

Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

IPS Empress crown system: three-year clinical trial results.

Science.gov (United States)

Sorensen, J A; Choi, C; Fanuscu, M I; Mito, W T

1998-02-01

The IPS Empress system is a highly esthetic hot pressed glass ceramic material for fabrication of single crowns. Adhesive cementation of the system not only contributes to the esthetics but is necessary for increased strength of the crown. The purpose of this prospective clinical trials was to evaluate the longevity of 75 adhesively cemented Empress full crowns. An additional aim was to assess the adhesive cementation methodology and potential side effects. At the three-year point, one molar crown fractured for a 1.3 percent failure rate. The resin cementation technique that was employed exhibited a low incidence of microleakage with few clinical side effects. There was a 5.6 percent incidence of post-cementation sensitivity, with all symptoms subsiding by eight weeks. None of the crowns in the study required endodontic therapy.

"Chrono-functional milk": The difference between melatonin concentrations in night-milk versus day-milk under different night illumination conditions.

Science.gov (United States)

Asher, A; Shabtay, A; Brosh, A; Eitam, H; Agmon, R; Cohen-Zinder, M; Zubidat, A E; Haim, A

2015-01-01

Pineal melatonin (MLT) is produced at highest levels during the night, under dark conditions. We evaluated differences in MLT-concentration by comparing daytime versus night time milk samples, from two dairy farms with different night illumination conditions: (1) natural dark (Dark-Night); (2) short wavelength Artificial Light at Night (ALAN, Night-Illuminated). Samples were collected from 14 Israeli Holstein cows from each commercial dairy farm at 04:30 h ("Night-milk") 12:30 h ("Day-milk") and analyzed for MLT-concentration. In order to study the effects of night illumination conditions on cows circadian rhythms, Heart Rate (HR) daily rhythms were recorded. MLT-concentrations of Night-milk samples from the dark-night group were significantly (p Night-illuminated conditions (30.70 ± 1.79 and 17.81 ± 0.33 pg/ml, respectively). Interestingly, night illumination conditions also affected melatonin concentrations at daytime where under Dark-Night conditions values are significantly (p Night-Illuminated conditions, (5.36 ± 0.33 and 3.30 ± 0.18 pg/ml, respectively). There were no significant differences between the two treatments in the milk yield and milk composition except somatic cell count (SCC), which was significantly lower (p = 0.02) in the Dark-Night group compared with the Night-Illuminated group. Cows in both groups presented a significant (p night illuminated cows feeding and milking time are the "time keeper", while in the Dark-night cows, HR rhythms were entrained by the light/dark cycle. The higher MLT-concentration in Dark-night cows with the lower SCC values calls upon farmers to avoid exposure of cows to ALAN. Therefore, under Dark-night conditions milk quality will improve by lowering SCC values where separation between night and day of such milk can produce chrono-functional milk, naturally rich with MLT.

Night Terrors in Children

OpenAIRE

Feferman, Irv

1988-01-01

Night terrors are a bizarre sleep disorder that affects young children. The child partially awakes during the night agitated, afraid and terrified, and cannot be consoled. These events, which may be related to emotional turmoil, are self-limiting. Psychiatric evaluation is indicated in certain cases, and drug therapy is almost never necessary. Parents should be reassured that night terrors are not dangerous and do not reflect any serious pathology.

Bromine-rich Zinc Bromides: Zn6Br12(18-crown-6)2×(Br2)5, Zn4Br8(18-crown-6)2×(Br2)3, and Zn6Br12(18-crown-6)2×(Br2)2.

Science.gov (United States)

Hausmann, David; Feldmann, Claus

2016-06-20

The bromine-rich zinc bromides Zn6Br12(18-crown-6)2×(Br2)5 (1), Zn4Br8(18-crown-6)2×(Br2)3 (2), and Zn6Br12(18-crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-crown-6), Zn2Br4(18-crown-6)) or ionic (e.g., [Zn2Br3(18-crown-6)](+), [(Zn2Br6)×(Br2)2](2-)) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape.

Selective crystallization of cations with crown ethers

International Nuclear Information System (INIS)

Heffels, Dennis Egidius

2014-01-01

The aim of this work was to study the selectivity and preferences of the incorporation of differently sized cations in the cavities of various crown ethers and the characterization of the resulting compounds. The coordination preferences of crown ethers with different cavities have long been known, and the impact of other effects on the structure formation have increasingly become the focus of attention. In this work a comparative overview of the coordination preferences depending on various factors was undertaken. The focus was mainly on the variation of the cavity of the crown ether in the presence of differently sized cations. In addition, the effects of the solvent and differently coordinating anions have been investigated. Within the framework of this work, basic coordination preferences could be detected with rare earth nitrates, which are affected particularly by the choice of the solvent. The formation of different types of structures could be controlled by varying the conditions such that the incorporation of the cation in the cavity of the crown ether was influenced and the formation of a particular type of structure can be influenced partly by the choice of solvent. In this case no direct preferences for the incorporation into the cavity of the crown ether in relation to the cation size were observed for rare earth cations. However, the coordination of the crown ether leads in each case - for lanthanides - to rather high coordination numbers. A total of five new rare earth complexes and two structural variants could be observed with crown ethers. In the study of the selectivity of the incorporation into the cavity, known structures were also reproduced and further structures were characterized but the crystal structures not entirely solved. With the use of monovalent cations such as potassium, lithium or silver a total of nine new compounds could be synthesized, while no clear preferences for the incorporation of certain cations were detected. The

How do different definitions of night shift affect the exposure assessment of night work?

DEFF Research Database (Denmark)

Garde, Anne Helene; Hansen, Johnni; Kolstad, Henrik A

2016-01-01

the reference definition (at least 3 h of work between 24:00 and 05:00) and definitions using a period during the night. The overlap with definitions based on starting and ending time was less pronounced (64-71 %). The proportion of classified night shifts differs little when night shifts are based...

Night-vision goggles for night-blind subjects : subjective evaluation after 2 years of use

NARCIS (Netherlands)

Hartong, D. T.; Kooijman, A. C.

Purpose: To evaluate the usefulness of night-vision goggles (NVG) for night-blind subjects after 1 and 2 years of use. Methods: Eleven night-blind subjects with retinitis pigmentosa used NVG for a 2-year period. At the end of each year, they were requested to fill-in two questionnaires regarding

Assay using embryo aggregation chimeras for the detection of nonlethal changes in X-irradiated mouse preimplantation embryos

International Nuclear Information System (INIS)

Obasaju, M.F.; Wiley, L.M.; Oudiz, D.J.; Miller, L.; Samuels, S.J.; Chang, R.J.; Overstreet, J.W.

1988-01-01

We have developed a short-term in vitro assay for the detection of sublethal effects produced by very low levels of ionizing radiation. The assay utilizes mouse embryo aggregation chimeras consisting of one irradiated embryo paired with an unirradiated embryo whose blastomeres have been labeled with fluorescein isothiocyanate (FITC). X irradiation (from 0.05 to 2 Gy) and chimera construction were performed with four-cell stage embryos, and the chimeras were cultured for 40 h to the morula stage. The morulae were partially dissociated with calcium-free culture medium and viewed under phase contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution of irradiated (unlabeled) and control (FITC labeled) embryos per chimera. In chimeras where neither embryo was irradiated, the ratio of the unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.50 (17.8 +/- 5.6 cells per unlabeled embryo and 17.4 +/- 5.5 cells per FITC-labeled partner embryo). However, in chimeras formed after the unlabeled embryos were irradiated with as little as 0.05 Gy, the ratio of unlabeled blastomeres to the total number of blastomeres per chimera embryo was 0.43 (P less than 0.01). The apparent decreases in cell proliferation were not observed in irradiated embryos that were merely cocultured with control embryos, regardless of whether the embryos were zona enclosed or zona free. We conclude that very low levels of radiation induce sublethal changes in cleaving embryos that are expressed as a proliferative disadvantage within two cell cycles when irradiated embryos are in direct cell-to-cell contact with unirradiated embryos

Wind Tunnel Experiments to Study Chaparral Crown Fires.

Science.gov (United States)

Cobian-Iñiguez, Jeanette; Aminfar, AmirHessam; Chong, Joey; Burke, Gloria; Zuniga, Albertina; Weise, David R; Princevac, Marko

2017-11-14

The present protocol presents a laboratory technique designed to study chaparral crown fire ignition and spread. Experiments were conducted in a low velocity fire wind tunnel where two distinct layers of fuel were constructed to represent surface and crown fuels in chaparral. Chamise, a common chaparral shrub, comprised the live crown layer. The dead fuel surface layer was constructed with excelsior (shredded wood). We developed a methodology to measure mass loss, temperature, and flame height for both fuel layers. Thermocouples placed in each layer estimated temperature. A video camera captured the visible flame. Post-processing of digital imagery yielded flame characteristics including height and flame tilt. A custom crown mass loss instrument developed in-house measured the evolution of the mass of the crown layer during the burn. Mass loss and temperature trends obtained using the technique matched theory and other empirical studies. In this study, we present detailed experimental procedures and information about the instrumentation used. The representative results for the fuel mass loss rate and temperature filed within the fuel bed are also included and discussed.

Crown condition dynamics of oak in southern Sweden 1988-1999.

Science.gov (United States)

Drobyshev, Igor; Anderson, Stefan; Sonesson, Kerstin

2007-11-01

Crown defoliation of oak (Quercus robur and Q. petraea) was analysed in 808 trees during three forest condition surveys (1988, 1993, and 1999) in the southern Sweden. From 1988 to 1999 crown defoliation increased by more than 20%. Changes in crown defoliation were related to the pH in the upper 20-30 cm of the mineral soils, which was closely connected to other measures of soil fertility (cation exchange capacity, CEC and C/N ratio). Trees growing on soils with a high pH (> or =4.00, in BaCl2 filtrate), high CEC and low C/N ratio had significantly lower crown defoliation than trees growing on more acid soils (pH trees with respect to crown defoliation, indicating that decline in crown condition was not due to an age-related increase in crown transparency. Considering only trees younger than 100 years, a significant interaction was observed between changes in crown defoliation and soil pH. Trees younger than 100 years old growing on more acidic soils had a greater increase in crown transparency than trees on more basic soils between 1988 and 1999. Trees > or =100 years old had significantly higher defoliation on more acidic than on more basic soils, however defoliation dynamics of these trees over 1988-99 was not related to soil acidity. Two biotic agents (insect and fungal leaf infections) evaluated in this study did not prove to be important drivers of defoliation dynamics.

INDIRECT EFFECT OF EXTREME FLOODING: DISAPPEARANCE OF WADING BIRDS ROOST CAUSED BY VEGETATION TURN

Czech Academy of Sciences Publication Activity Database

Rajchard, J.; Balounová, Z.; Novák, R.; Kindlmann, Pavel

2007-01-01

Roč. 26, č. 1 (2007), s. 64-67 ISSN 1335-342X R&D Projects: GA AV ČR IAA6093105; GA AV ČR(CZ) KSK6005114 Keywords : extreme flooding * night heron * spoonbill * little egret * shrubs Subject RIV: EH - Ecology, Behaviour Impact factor: 0.085, year: 2005

Descriptive statistics of tree crown condition in the North Central United States

Science.gov (United States)

KaDonna C. Randolph; Randall S. Morin; Jim Steinman

2010-01-01

The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Illinois, Indiana, Michigan, Minnesota, Missouri, and Wisconsin...

Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort.

Science.gov (United States)

Sun, Miaomiao; Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P C; Tse, Gary; Wong, Martin C S; Tang, Jin-Ling; Wong, Samuel Y S; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

2018-01-01

This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants' demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97-1.41) and 1.27 (95% CI, 0.74-2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01-1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40-11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19-9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13-2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94-1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies.

Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort

Science.gov (United States)

Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P. C.; Tse, Gary; Wong, Martin C. S.; Tang, Jin-ling; Wong, Samuel Y. S.; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

2018-01-01

Aims This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. Methods A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants’ demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Results Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97–1.41) and 1.27 (95% CI, 0.74–2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01–1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40–11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19–9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13–2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94–1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Conclusion Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies. PMID:29763461

Epilithic Cyanobacterial Communities of a Marine Tropical Beach Rock (Heron Island, Great Barrier Reef): Diversity and Diazotrophy▿

Science.gov (United States)

Díez, Beatriz; Bauer, Karolina; Bergman, Birgitta

2007-01-01

The diversity and nitrogenase activity of epilithic marine microbes in a Holocene beach rock (Heron Island, Great Barrier Reef, Australia) with a proposed biological calcification “microbialite” origin were examined. Partial 16S rRNA gene sequences from the dominant mat (a coherent and layered pink-pigmented community spread over the beach rock) and biofilms (nonstratified, differently pigmented microbial communities of small shallow depressions) were retrieved using denaturing gradient gel electrophoresis (DGGE), and a clone library was retrieved from the dominant mat. The 16S rRNA gene sequences and morphological analyses revealed heterogeneity in the cyanobacterial distribution patterns. The nonheterocystous filamentous genus Blennothrix sp., phylogenetically related to Lyngbya, dominated the mat together with unidentified nonheterocystous filaments of members of the Pseudanabaenaceae and the unicellular genus Chroococcidiopsis. The dominance and three-dimensional intertwined distribution of these organisms were confirmed by nonintrusive scanning microscopy. In contrast, the less pronounced biofilms were dominated by the heterocystous cyanobacterial genus Calothrix, two unicellular Entophysalis morphotypes, Lyngbya spp., and members of the Pseudanabaenaceae family. Cytophaga-Flavobacterium-Bacteroides and Alphaproteobacteria phylotypes were also retrieved from the beach rock. The microbial diversity of the dominant mat was accompanied by high nocturnal nitrogenase activities (as determined by in situ acetylene reduction assays). A new DGGE nifH gene optimization approach for cyanobacterial nitrogen fixers showed that the sequences retrieved from the dominant mat were related to nonheterocystous uncultured cyanobacterial phylotypes, only distantly related to sequences of nitrogen-fixing cultured cyanobacteria. These data stress the occurrence and importance of nonheterocystous epilithic cyanobacteria, and it is hypothesized that such epilithic cyanobacteria

Descriptive statistics of tree crown condition in the United States Interior West

Science.gov (United States)

KaDonna C. Randolph; Mike T. Thompson

2010-01-01

The U.S. Forest Service Forest Inventory and Analysis (FIA) Program uses visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes four crown condition indicators (crown dieback, crown density, foliage transparency, and sapling crown vigor) measured in Colorado, Idaho, Nevada, Utah, and Wyoming between 1996 and...

Crowns and Crypts

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 6. Crowns and Crypts - A Fascinating Group of Multidentate Macrocyclic Ligands. Debasis Bandyopadhyay. General Article Volume 6 Issue 6 June 2001 pp 71-79. Fulltext. Click here to view fulltext PDF. Permanent link:

In vitro fracture resistance of three commercially available zirconia crowns for primary molars.

Science.gov (United States)

Townsend, Janice A; Knoell, Patrick; Yu, Qingzhao; Zhang, Jian-Feng; Wang, Yapin; Zhu, Han; Beattie, Sean; Xu, Xiaoming

2014-01-01

The purpose of this study was to measure the fracture resistance of primary mandibular first molar zirconia crowns from three different manufacturers-EZ Pedo (EZP), NuSmile (NSZ), and Kinder Krowns (KK)-and compare it with the thickness of the zirconia crowns and the measured fracture resistance of preveneered stainless steel crowns (SSCs). The thickness of 20 zirconia crowns from three manufacturers were measured. The mean force required to fracture the crowns was determined. Preveneered NuSmile (NSW) SSCs were tested as a control. EZP crowns were significantly thicker in three of the six measured locations. The force required to fracture the EZP crown was significantly higher than that required for NSZ and KK. There was a positive correlation between fracture resistance and crown thickness in the mesial, distal, mesioocclusal, and distoocclusal dimensions. None of the zirconia crowns proved to be as resistant to fracture as the preveneered SSCs. Statistically significant differences were found among the forces required to fracture zirconia crowns by three different manufacturers. The increase in force correlated with crown thickness. The forces required to fracture the preveneered stainless steel crowns were greater than the forces required to fracture all manufacturers' zirconia crowns.

[Clinical application of IPS-empress 2 pressable all-ceramic crowns].

Science.gov (United States)

Wang, Ai-jun; He, Xiao-ming; Liu, Li-xia; Zhang, Chao-biao; Zhang, Min; Shen, Bei-yong

2007-02-01

To evaluate the clinical prosthetic effect of IPS-Empress 2 pressahie ceramic crowns. 198 teeth of 70 patients were restored with IPS-Empress 2 pressahie ceramic crowns. The patients were asked to return in one week and every half year. The clinical prosthetic effect was evaluated. Through follow-up of 3-38 months, the veneer porcelain crowns of 3 teeth were broken. 2 crowns fall off due to teeth fracture, gingivitis occurred in 2 teeth, pulpitis or periapical periodontitis occurred in 3 teeth. The shades of 3 crowns were darkening. The prosthetic effect of 185 teeth was satisfied. The rate of satisfaction was 93.4%. IPS-Empress 2 pressable all-ceramic crown has the advantages of aesthetic effect, good hiocompatihility and simple fabrication. But its strength is not enough for posterior teeth and it can not cover the deep color of non-vital teeth and metal materials.

Night Eating Disorders

Directory of Open Access Journals (Sweden)

Deniz Tuncel

2009-08-01

Full Text Available Hunger is an awakening related biological impulse. The relationship between hunger and sleep is moderated by the control of homeostatic and circadian rhytms of the body. Abnormal eating behavior during sleep period could result from different causes. Abnormal eating during the main sleep period has been categorized as either night eating syndrome or sleep related eating disorder. Night eating syndrome (NES is an eating disorder characterised by the clinical features of morning anorexia, evening hyperphagia, and insomnia with awakenings followed by nocturnal food ingestion. Recently night eating syndrome, conceptualized as a delayed circadian intake of food. Sleep-related eating disorder, thought to represent a parasomnia and as such included within the revised International Classification of Sleep Disorders (ICSD-2, and characterized by nocturnal partial arousals associated with recurrent episodes of involuntary food consumption and altered levels of consciousness. Whether, however, sleep-related eating disorder and night eating syndrome represent different diseases or are part of a continuum is still debated. This review summarizes their characteristics, treatment outcomes and differences between them.

Migration and growth of protoplanetary embryos. I. Convergence of embryos in protoplanetary disks

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaojia; Lin, Douglas N. C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Liu, Beibei [Kavli Institute for Astronomy and Astrophysics and Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Li, Hui, E-mail: xzhang47@ucsc.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2014-12-10

According to the core accretion scenario, planets form in protostellar disks through the condensation of dust, coagulation of planetesimals, and emergence of protoplanetary embryos. At a few AU in a minimum mass nebula, embryos' growth is quenched by dynamical isolation due to the depletion of planetesimals in their feeding zone. However, embryos with masses (M{sub p} ) in the range of a few Earth masses (M {sub ⊕}) migrate toward a transition radius between the inner viscously heated and outer irradiated regions of their natal disk. Their limiting isolation mass increases with the planetesimals surface density. When M{sub p} > 10 M {sub ⊕}, embryos efficiently accrete gas and evolve into cores of gas giants. We use a numerical simulation to show that despite stream line interference, convergent embryos essentially retain the strength of non-interacting embryos' Lindblad and corotation torques by their natal disks. In disks with modest surface density (or equivalently accretion rates), embryos capture each other in their mutual mean motion resonances and form a convoy of super-Earths. In more massive disks, they could overcome these resonant barriers to undergo repeated close encounters, including cohesive collisions that enable the formation of massive cores.

Who abandons embryos after IVF?

LENUS (Irish Health Repository)

Walsh, A P H

2010-04-01

This investigation describes features of in vitro fertilisation (IVF) patients who never returned to claim their embryos following cryopreservation. Frozen embryo data were reviewed to establish communication patterns between patient and clinic; embryos were considered abandoned when 1) an IVF patient with frozen embryo\\/s stored at our facility failed to make contact with our clinic for > 2 yrs and 2) the patient could not be located after a multi-modal outreach effort was undertaken. For these patients, telephone numbers had been disconnected and no forwarding address was available. Patient, spouse and emergency family contact\\/s all escaped detection efforts despite an exhaustive public database search including death records and Internet directory portals. From 3244 IVF cycles completed from 2000 to 2008, > or = 1 embryo was frozen in 1159 cases (35.7%). Those without correspondence for > 2 yrs accounted for 292 (25.2%) patients with frozen embryos; 281 were contacted by methods including registered (signature involving abandoned embryos did not differ substantially from other patients. The goal of having a baby was achieved by 10\\/11 patients either by spontaneous conception, adoption or IVF. One patient moved away with conception status unconfirmed. The overall rate of embryo abandonment was 11\\/1159 (< 1%) in this IVF population. Pre-IVF counselling minimises, but does not totally eliminate, the problem of abandoned embryos. As the number of abandoned embryos from IVF accumulates, their fate urgently requires clarification. We propose that clinicians develop a policy consistent with relevant Irish Constitutional provisions to address this medical dilemma.

Calorimetric study of binding of some disaccharides with crown ethers

Energy Technology Data Exchange (ETDEWEB)

Davydova, Olga I.; Lebedeva, Nataliya Sh.; Parfenyuk, Elena V

2004-11-01

Isothermal titration calorimetry has been applied to the determination of the thermodynamic parameters of binding of {beta}-lactose, {alpha},{alpha}-trehalose and sucrose with 15-crown-5 and 18-crown-6 in water at 298.15 K. The formation of 1:1 molecular associates has been found for the systems studied except 18-crown-6 and {beta}-lactose. The associates are preferentially or completely entropy stabilized. The most stable associate is formed between {alpha},{alpha}-trehalose and 18-crown-6. The obtained values of thermodynamic parameters of binding are discussed from the point of view of solute-solvent interactions as well as conformational and structural peculiarities of the disaccharides (DS) and crown ethers (CE)

Calorimetric study of binding of some disaccharides with crown ethers

International Nuclear Information System (INIS)

Davydova, Olga I.; Lebedeva, Nataliya Sh.; Parfenyuk, Elena V.

2004-01-01

Isothermal titration calorimetry has been applied to the determination of the thermodynamic parameters of binding of β-lactose, α,α-trehalose and sucrose with 15-crown-5 and 18-crown-6 in water at 298.15 K. The formation of 1:1 molecular associates has been found for the systems studied except 18-crown-6 and β-lactose. The associates are preferentially or completely entropy stabilized. The most stable associate is formed between α,α-trehalose and 18-crown-6. The obtained values of thermodynamic parameters of binding are discussed from the point of view of solute-solvent interactions as well as conformational and structural peculiarities of the disaccharides (DS) and crown ethers (CE)

Ceramic molar crown reproducibility by digital workflow manufacturing: An in vitro study.

Science.gov (United States)

Jeong, Ii-Do; Kim, Woong-Chul; Park, Jinyoung; Kim, Chong-Myeong; Kim, Ji-Hwan

2017-08-01

This in vitro study aimed to analyze and compare the reproducibility of zirconia and lithium disilicate crowns manufactured by digital workflow. A typodont model with a prepped upper first molar was set in a phantom head, and a digital impression was obtained with a video intraoral scanner (CEREC Omnicam; Sirona GmbH), from which a single crown was designed and manufactured with CAD/CAM into a zirconia crown and lithium disilicate crown (n=12). Reproducibility of each crown was quantitatively retrieved by superimposing the digitized data of the crown in 3D inspection software, and differences were graphically mapped in color. Areas with large differences were analyzed with digital microscopy. Mean quadratic deviations (RMS) quantitatively obtained from each ceramic group were statistically analyzed with Student's t-test (α=.05). The RMS value of lithium disilicate crown was 29.2 (4.1) µm and 17.6 (5.5) µm on the outer and inner surfaces, respectively, whereas these values were 18.6 (2.0) µm and 20.6 (5.1) µm for the zirconia crown. Reproducibility of zirconia and lithium disilicate crowns had a statistically significant difference only on the outer surface ( P <.001). The outer surface of lithium disilicate crown showed over-contouring on the buccal surface and under-contouring on the inner occlusal surface. The outer surface of zirconia crown showed both over- and under-contouring on the buccal surface, and the inner surface showed under-contouring in the marginal areas. Restoration manufacturing by digital workflow will enhance the reproducibility of zirconia single crowns more than that of lithium disilicate single crowns.

A Midsummer Night's Science

CERN Multimedia

2001-01-01

Last year, the first Science Night attracted nearly 1500 people. Dipping into history for the space of one night? This is the idea of Geneva's Museum of the History of Science, which is organizing its second Science Night, on 7 and 8 July, on the history of science. The first such event, held last year, was a considerable success with almost 15 000 visitors. The second Science Night, to be held in the magnificent setting of the Perle du Lac Park in Geneva, promises to be a winner too. By making science retell its own history, this major event is intended to show how every scientific and technical breakthrough is the culmination of a long period of growth that began hundreds of years in the past. Dozens of activities and events are included in this programme of time travel: visitors can study the night sky through telescopes and see what Galileo first observed, and then go to see a play on the life of the Italian scientist. Another play, commissioned specially for the occasion, will honour Geneva botanist De ...

[Fractographic analysis of clinically failed anterior all ceramic crowns].

Science.gov (United States)

DU, Qian; Zhou, Min-bo; Zhang, Xin-ping; Zhao, Ke

2012-04-01

To identify the site of crack initiation and propagation path of clinically failed all ceramic crowns by fractographic analysis. Three clinically failed anterior IPS Empress II crowns and two anterior In-Ceram alumina crowns were retrieved. Fracture surfaces were examined using both optical stereo and scanning electron microscopy. Fractographic theory and fracture mechanics principles were applied to disclose the damage characteristics and fracture mode. All the crowns failed by cohesive failure within the veneer on the labial surface. Critical crack originated at the incisal contact area and propagated gingivally. Porosity was found within the veneer because of slurry preparation and the sintering of veneer powder. Cohesive failure within the veneer is the main failure mode of all ceramic crown. Veneer becomes vulnerable when flaws are present. To reduce the chances of chipping, multi-point occlusal contacts are recommended, and layering and sintering technique of veneering layer should also be improved.

Mitochondrial DNA content in embryo culture medium is significantly associated with human embryo fragmentation.

Science.gov (United States)

Stigliani, S; Anserini, P; Venturini, P L; Scaruffi, P

2013-10-01

Is the amount of cell-free DNA released by human embryos into culture medium correlated with embryo morphological features? The mitochondrial DNA (mtDNA) content of culture medium is significantly associated with the fragmentation rate on Days 2 and 3 of embryo development, whether the oocyte came from women ≤ 35 or >35 years old. Cellular fragmentation is often utilized as one of the morphological parameters for embryo quality assessment. The amount of cellular fragments is considered to be an important morphological parameter for embryo implantation potential. It has been hypothesized that fragments are apoptotic bodies or anuclear cytoplasmatic pieces of blastomeres, although no definitive conclusion has been drawn about their pathogenesis. Human fertilized oocytes were individually cultured from Day 1 to Days 2 and 3. A total of 800 samples (166 spent media from Day 2 and 634 from Day 3) were enrolled into the present study. Double-stranded DNA (dsDNA) was quantified in 800 spent embryo culture media by Pico Green dye fluorescence assay. After DNA purification, genomic DNA (gDNA) and mtDNA were profiled by specific quantitative PCR. Statistical analyses defined correlations among DNA contents, embryo morphology and maternal age. Different independent tests confirmed the presence of DNA into embryo culture medium and, for the first time, we demonstrate that both gDNA and mtDNA are detectable in the secretome. The amount of DNA is larger in embryos with bad quality cleavage compared with high-grade embryos, suggesting that the DNA profile of culture medium is an objective marker for embryo quality assessment. In particular, DNA profiles are significantly associated with fragmentation feature (total dsDNA: P = 0.0010; mtDNA; P = 0.0247) and advanced maternal age. It is necessary to establish whether DNA profiling of spent embryo culture medium is a robust onsite test that can improve the prediction of blastulation, implantation and/or pregnancy rate. The

Mesiodistal Crown Dimensions of Permanent Teeth in Bangladeshi Population

Directory of Open Access Journals (Sweden)

Saeed Hossain Khan

2011-09-01

Full Text Available Background: Variation in tooth size is influenced by genetic and environmental factors. Several studies have reported tooth size variation between and within different racial groups. In order to improve the quality of dental care available, there is a great need for data on the mesiodistal crown dimensions of the individual teeth of Bangladeshi population. Objectives: To find nominative data on the mesiodistal crown dimensions of permanent teeth in Bangladeshi population and to compare the findings with those reported in other populations. Methods: This observational study was done from January, 2008 to June, 2010 in the Department of Orthodontics, Faculty of Dentistry, Bangabandhu Sheikh Mujib Medical University. A total of 244 Bangladeshi subjects (77 males and 167 females, aged 7 – 36 years (mean 18.3 years with no age limit who attended at the above mentioned place for treatment were included in the study. Main outcome measure was mesiodistal crown dimension of each tooth class of permanent dentition. Mesiodistal crown dimensions were measured from dental casts of the permanent teeth. Results: Males had significantly larger teeth than females for maxillary central incisors (p < 0.05 and for the mandibular second premolars (p < 0.001. In both sexes, the maxillary lateral incisors showed the greatest variability [coefficient of variation (CV 10.7%] and the maxillary canines the least (CV 6.9% in mesiodistal crown dimension. Mandibular canines displayed greater sexual dimorphism in mesiodistal crown size than in any other tooth classes. Comparisons of the mesiodistal crown dimensions between population groups showed that Bangladeshis have tooth sizes close to those of North Indians, Icelanders and Jordanians but larger than those of North American Whites. Conclusions: From this study, a standard for the mesiodistal crown dimensions of permanent dentition of Bangladeshi males and females are obtained. Key Words: Crown dimension; Mesio

In vitro evaluation of the marginal integrity of CAD/CAM interim crowns.

Science.gov (United States)

Kelvin Khng, Kwang Yong; Ettinger, Ronald L; Armstrong, Steven R; Lindquist, Terry; Gratton, David G; Qian, Fang

2016-05-01

The accuracy of interim crowns made with computer-aided design and computer-aided manufacturing (CAD/CAM) systems has not been well investigated. The purpose of this in vitro study was to evaluate the marginal integrity of interim crowns made by CAD/CAM compared with that of conventional polymethylmethacrylate (PMMA) crowns. A dentoform mandibular left second premolar was prepared for a ceramic crown and scanned for the fabrication of 60 stereolithical resin dies, half of which were scanned to fabricate 15 Telio CAD-CEREC and 15 Paradigm MZ100-E4D-E4D crowns. Fifteen Caulk and 15 Jet interim crowns were made on the remaining resin dies. All crowns were cemented with Tempgrip under a 17.8-N load, thermocycled for 1000 cycles, placed in 0.5% acid fuschin for 24 hours, and embedded in epoxy resin before sectioning from the mid-buccal to mid-lingual surface. The marginal discrepancy was measured using a traveling microscope, and dye penetration was measured as a percentage of the overall length under the crown. The mean vertical marginal discrepancy of the conventionally made interim crowns was greater than for the CAD/CAM crowns (P=.006), while no difference was found for the horizontal component (P=.276). The mean vertical marginal discrepancy at the facial surface of the Caulk crowns was significantly greater than that of the other 3 types of interim crowns (Pmargin, the mean horizontal component of the Telio crowns was significantly larger than that of the other 3 types, with no difference at the lingual margins (P=.150). The mean percentage dye penetration for the Paradigm MZ100-E4D crowns was significantly greater and for Jet crowns significantly smaller than for the other 3 crowns (Pmarginal discrepancies of the Jet interim crowns at the facial surface and with the horizontal marginal discrepancies of the Caulk interim crowns at the lingual surface (Pmarginal discrepancy was found with the interim crowns fabricated by CAD/CAM as compared with PMMA crowns

Crown ether derivatives of EDTA: Pt. 6

International Nuclear Information System (INIS)

Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

1988-01-01

EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

A Neural Network Approach to Infer Optical Depth of Thick Ice Clouds at Night

Science.gov (United States)

Minnis, P.; Hong, G.; Sun-Mack, S.; Chen, Yan; Smith, W. L., Jr.

2016-01-01

One of the roadblocks to continuously monitoring cloud properties is the tendency of clouds to become optically black at cloud optical depths (COD) of 6 or less. This constraint dramatically reduces the quantitative information content at night. A recent study found that because of their diffuse nature, ice clouds remain optically gray, to some extent, up to COD of 100 at certain wavelengths. Taking advantage of this weak dependency and the availability of COD retrievals from CloudSat, an artificial neural network algorithm was developed to estimate COD values up to 70 from common satellite imager infrared channels. The method was trained using matched 2007 CloudSat and Aqua MODIS data and is tested using similar data from 2008. The results show a significant improvement over the use of default values at night with high correlation. This paper summarizes the results and suggests paths for future improvement.

Response of roseate tern to a shoreline protection project on Falkner Island, Connecticut

Science.gov (United States)

Rogers, C.J.; Spendelow, J.A.; Guilfoyle, Michael P.; Fischer, Richard A.; Pashley, David N.; Lott, Casey A.

2007-01-01

subterranean channels, especially in the main revetment area, made it difficult to measure chick growth and productivity as had been done for more than 12 years prior to construction. Also, observations of color-banded adults that were unable to locate and feed their young inside the main revetment, and of adults returning to courtship behavior and renesting after having hatched chicks from their initial clutches, indicated that a minimum of 20% of the chicks (mostly first hatched A-chicks, which usually have high rates of survival to fledging) that entered the main revetment died after doing so in 2001. The mortality rate of Roseate Tern chicks that entered the secondary revetment on the southwest shelf, however, was not unusually high in 2001. In an attempt to reduce the likelihood of nesting and chick losses in these sub-colonies, a research team led by the USGS in 2002-2003 did not put nest boxes on the northeast and east shelf areas where previous losses had been high. However, losses of tern eggs and young chicks to predatory Black-crowned Night Herons (Nycticorax nycticorax) were so great in 2002?2003 that few Roseate Tern chicks survived long enough to move into the main revetment area and little comparative survival data were collected. The USFWS continues to remove predatory night herons, to monitor the location and success of nesting Roseate Terns and to fill in some of problem areas near the tern nests in the main revetment. The extensive chick-searching fieldwork and observational procedures used by the USGS-led research team to determine the growth and survival of the Roseate Tern chicks at Falkner Island were not used in 2004?2005. The number of chicks lost in the revetment during these years is not known. Without additional fill, loss of chicks of this endangered species in the main revetment may rise again even though the night heron predation problem has been reduced.

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from HERON ISLAND, KANGAROO ISLAND and others in the Coral Sea, Great Australian Bight and Tasman Sea from 2009-10-09 to 2012-11-28 (NODC Accession 0100062)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0100062 includes chemical, meteorological, physical and time series data collected from HERON ISLAND, KANGAROO ISLAND, MARIA ISLAND, MOORING_HERON...

Optical effects of different colors of artificial gingiva on ceramic crowns.

Science.gov (United States)

Wang, Jian; Lin, Jin; Gil, Mindy; Da Silva, John D; Wright, Robert; Ishikawa-Nagai, Shigemi

2013-08-01

The interaction between gingival color and the shade of ceramic restorations has never been fully studied. The purpose of this study is to investigate the optical effects of altering artificial gingival color on the ceramic crown shade in the cervical area. Thirty-one all-ceramic crowns of different shades were used in this study with six different artificial gingival colors. Using a spectrophotometer (Crystaleye(®) Olympus, Japan), we measured the shade of crowns in cervical areas with each of six different artificial gingiva. The crown color measured in the presence of pink artificial gingiva (control) was compared with the crown color with five other artificial gingiva. color difference values ΔE* were calculated and compared between the control group and test groups and the correlation of the artificial gingival color with the crown color was also assessed. Significant differences were found in the mean L* and a* values of all-ceramic crowns at the cervical regions in all six gingival color groups (pcolors of artificial gingiva generated clinically detectable shade differences in the cervical region of ceramic crowns. Copyright © 2013. Published by Elsevier Ltd.

Clinical Performance of Pedo Jacket Crowns in Maxillary Anterior Primary Teeth.

Science.gov (United States)

Castro, Aimee; Badr, Sherine B Y; El-Badrawy, Wafa; Kulkarni, Gajanan

2016-09-15

To assess the clinical performance of Pedo Jacket crowns for restoration of carious primary anterior teeth. A total of 129 carious primary incisors and canines of 48 children younger than 71 months of age- were restored with Pedo Jacket crowns and resin-modified glass ionomer cementation. They were assessed for: ease of use; presence of recurrent decay; wear; partial or complete loss of the crown; color stability; gingival health; and overall clinical success over a 12-month follow-up. The patient's behavior at the restorative appointment during crown placement was also assessed. An overall clinical success of 89.5 percent of the teeth in 87.3 percent of the children was seen one year later. The crowns were easy to use, even in uncooperative children. The color stability, wear, plaque accumulation, and gingival health were acceptable. Discoloration, wear, or complete loss of the crown were found in 13.1 percent, 5.4 percent, and 7.6 percent of children, respectively. Although not statistically significant, failures were associated with poor patient cooperation at the time of crown placement, poor oral hygiene, or operator error. Pedo Jacket crowns are a viable treatment alternative for carious maxillary primary anterior teeth.

A multi-omics based ecological analysis of coastal marine sediments from Gladstone, in Australia's Central Queensland, and Heron Island, a nearby fringing platform reef.

Science.gov (United States)

Beale, D J; Crosswell, J; Karpe, A V; Ahmed, W; Williams, M; Morrison, P D; Metcalfe, S; Staley, C; Sadowsky, M J; Palombo, E A; Steven, A D L

2017-12-31

The impact of anthropogenic factors arising from point and non-point pollution sources at a multi commodity marine port and its surrounding ecosystems were studied using sediment samples collected from a number of onshore (Gladstone Harbour and Facing Island) and offshore (Heron Island and Fitzroy Reefs) sites in Australia's Central Queensland. Sediment samples were analyzed for trace metals, organic carbon, polycyclic aromatic hydrocarbons (PAH), emerging chemicals of concern (ECC) and sterols. Similarly, the biological and biochemical interaction between the reef and its environment was analyzed by the multi-omic tools of next-generation sequencing characterization of the bacterial community and microbial community metabolic profiling. Overall, the trace elements were observed at the lower end of the Australian environmental guideline values at the offshore sites, while higher values were observed for the onshore locations Nickel and copper were observed above the high trigger value threshold at the onshore sites. The levels of PAH were below limits of detection across all sites. However, some of the ECC and sterols were observed at higher concentrations at both onshore and offshore locations, notably, the cholesterol family sterols and 17α-ethynylestradiol. Multi-omic analyses also indicated possible thermal and photo irradiation stressors on the bacterial communities at all the tested sites. The observed populations of γ-proteobacteria were found in combination with an increased pool of fatty acids that indicate fatty acid synthesis and utilisation of the intermediates of the shikimate pathways. This study demonstrates the value of applying a multi-omics approach for ecological assessments, in which a more detailed assessment of physical and chemical contaminants and their impact on the community bacterial biome is obtained. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Frozen-Thawed Embryo Transfer Cycles Have a Lower Incidence of Ectopic Pregnancy Compared With Fresh Embryo Transfer Cycles.

Science.gov (United States)

Zhang, Xinyu; Ma, Caihong; Wu, Zhangxin; Tao, Liyuan; Li, Rong; Liu, Ping; Qiao, Jie

2017-01-01

To evaluate the risk of ectopic pregnancy of embryo transfer. A retrospective cohort study on the incidence of ectopic pregnancy in fresh and frozen-thawed embryo transfer cycles from January 1 st , 2010, to January 1 st , 2015. Infertile women undergoing frozen-thawed transfer cycles or fresh transfer cycles. In-vitro fertilization, fresh embryo transfer, frozen-thawed embryo transfer, ectopic pregnancy. Ectopic pregnancy rate and clinical pregnancy rate. A total of 69 756 in vitro fertilization-embryo transfer cycles from 2010 to 2015 were analyzed, including 45 960 (65.9%) fresh and 23 796 (34.1%) frozen-thawed embryo transfer cycles. The clinical pregnancy rate per embryo transfer was slightly lower in fresh embryo transfer cycles compared with frozen-thawed embryo transfer cycles (40.8% vs 43.1%, P cycles, blastocyst transfer shows a significantly lower incidence of ectopic pregnancy (0.8% vs 1.8%, P = .002) in comparison with day 3 cleavage embryo transfer. The risk of ectopic pregnancy is lower in frozen-thawed embryo transfer cycles than fresh embryo transfer cycles, and blastocyst transfer could further decrease the ectopic pregnancy rate in frozen-thawed embryo transfer cycles.

Dissolved inorganic carbon, total alkalinity, nitrate, phosphate, temperature and other variables collected from time series observations at Heron Island Reef Flat from 2010-06-01 to 2010-12-13 (NODC Accession 0127256)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains carbonate chemistry and environmental parameters data that were collected from a 200-day time series monitoring on the Heron Island...

Nightmares and Night Terrors

Science.gov (United States)

... able to tell you what happened in the dream and why it was scary. Your child may have trouble going back to sleep. Your child might have the same dream again on other nights. What are night terrors? ...

Influence of foliar fertilization on walnut foliar zinc levels and nut production in black walnut

Science.gov (United States)

William R. Reid; Andrew L. Thomas

2013-01-01

The impact of foliar zinc fertilizer application on nut-bearing black walnut (Juglans nigra L.) trees was studied. Foliar sprays were applied three times per season on two cultivars during four growing seasons by wetting the foliage of the entire crown using a tank mix containing 500 ppm zinc, starting at leaf burst and continuing at 2 week intervals...

Effects of melatonin administration on embryo implantation and offspring growth in mice under different schedules of photoperiodic exposure.

Science.gov (United States)

Zhang, Lu; Zhang, Zhenzhen; Wang, Feng; Tian, Xiuzhi; Ji, Pengyun; Liu, Guoshi

2017-10-02

Embryo implantation is crucial for animal reproduction. Unsuccessful embryo implantation leads to pregnancy failure, especially in human-assisted conception. Environmental factors have a profound impact on embryo implantation. Because people are being exposed to more light at night, the influence of long-term light exposure on embryo implantation should be explored. The effects of long photoperiodic exposure and melatonin on embryo implantation and offspring growth were examined. Long photoperiodic exposure (18:6 h light:dark) was selected to resemble light pollution. Melatonin (10 -2 , 10 -3 , 10 -4 , 10 -5  M) was added to the drinking water of mice starting at Day 1 (vaginal plugs) until delivery. Melatonin treatment (10 -4 ,10 -5  M) significantly increased litter sizes compared to untreated controls (12.9 ± 0.40 and 12.2 ± 1.01 vs. 11.5 ± 0.43; P melatonin (10 -4  M) was selected for further investigation. No remarkable differences were found between melatonin-treated mice and controls in terms of the pups' birth weights, weaning survival rates, and weaning weights. Long photoperiodic exposure significantly reduced the number of implantation sites in treated mice compared to controls (light/dark, 12/12 h), and melatonin rescued this negative effect. Mechanistic studies revealed that melatonin enhanced the serum 17β-estradiol (E 2 ) levels in the pregnant mice and upregulated the expression of the receptors MT1 and MT2 and p53 in uterine tissue. All of these factors may contribute to the beneficial effects of melatonin on embryo implantation in mice. Melatonin treatment was associated with beneficial effects in pregnant mice, especially those subjected to long photoperiodic exposure. This was achieved by enhanced embryo implantation. At the molecular level, melatonin administration probably increases the E 2 level during pregnancy and upregulates p53 expression by activating MT1/2 in the uterus. All of the changes may improve the

Congenital Absence of a Teat in a Japanese Black Heifer

Directory of Open Access Journals (Sweden)

Mohamed Elshabrawy Ghanem

2011-01-01

Full Text Available A case of Japanese Black heifer with a congenital absence of teat (athelia was observed at Highashi-Hiroshima Agricultural High School, Hiroshima Prefecture, Japan. The heifer was born after transfer of embryo from Japanese Black cattle. The sire of the heifer was a proven Japanese Black. The birth weight of the heifer was 27 kg. On physical examination of the heifer at 21 months after birth, the teat at fore left was absent and the remaining three teats were normal in shape without any physical abnormalities. Per rectal palpation of the genital organs revealed the normal cervix and uterine horns. It was difficult to palpate the ovaries due to the fat around the organs. Blood samples were taken for cytogenetic and DNA testing. The heifer had normal chromosomal set. The heifer was culled due to its mammary abnormality. This might be the first to report a case of congenital absence of a teat in Japanese Black heifers.

Provisional crown failures in dental school predoctoral clinics.

Science.gov (United States)

Hyde, Jeffrey D; Bader, James A; Shugars, Daniel A

2007-11-01

Following a preliminary study indicating that at least 10 percent of single-unit crown temporary restorations failed in patients who received treatment by predoctoral students, a comprehensive examination of provisional crown failure was initiated to identify strategies to reduce the failure rate. For all provisionalized, natural tooth, single-unit crown preparations in University of North Carolina School of Dentistry predoctoral clinics for one year (N=1008), we noted tooth type, type of crown, student level, faculty coverage experience, treatment clinic, temporary material and luting agent, and retreatment (failure) of the provisional restoration. For failures, we also noted the stage of crown preparation at failure and the time since initial placement of the temporary. We analyzed these data using simple cross-tabs and logistic regression on need for retreatment (alpha =0.05). The failure rate was 18.75 percent (N=189). The median time to failure was twelve days; the 25(th) and 75(th) percentiles were six and twenty-six days. Significant risk factors, in order of odds ratio estimates, were molar tooth, second- or third-year student, and inexperienced faculty. Most provisional failures occurred during the final preparation phase of treatment. Provisional restoration failure is more frequent than was initially suspected from preliminary studies. Strategies for institutional intervention to reduce provisional restoration failure include greater attention to evaluating provisional crowns placed by inexperienced students (sophomores and juniors) and placing more emphasis on the retentiveness of provisional restorations reused following the final impression. Review of provisional evaluation procedures is also indicated for faculty who do not routinely supervise these procedures.

4-Bromoanilinium perchlorate 18-crown-6 clathrate

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Min Guo

2010-11-01

Full Text Available The reaction of 4-bromoaniline, 18-crown-6, and perchloric acid in methanol yields the title compound, C6H7BrN+·ClO4−·C12H24O6, in which the protonated –NH3+ group forms three bifurcated N—H...O hydrogen bonds to the O atoms of the crown ether.

Intra-Night Variability of OJ 287 with Long-Term Multiband Optical Monitoring

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Wei Zeng

2017-11-01

Full Text Available We present long-term optical multi-band photometric monitoring of the blazar OJ 287 from 6 March 2010 to 3 April 2016, with high temporal resolution in the V R I -bands. The flux variations and colour-magnitude variations on long and short timescales were investigated to understand the emission mechanisms. In our observation, the major outbursts occurred in January 2016, as predicted by the binary pair of black holes model for OJ 287, with F v a r of 1.3∼2.1%, and variability amplitude (Amp of 5.8∼9.0%. The intra-night variability (IDV durations were from 18.5 to 51.3 min, and the minimal variability timescale was about 4.7 min. The colour-magnitude variation showed a weak positive correlation on the long timescale with Pearson’s r = 0 . 450 , while a negative correlation was found on intra-night timescales. We briefly discuss the possible physical mechanisms that are most likely to be responsible for the observed flux and colour-magnitude correlation variability.

Consequences of crown shortening canine teeth in Greenland sled dogs

DEFF Research Database (Denmark)

Kortegaard, H E; Anthony Knudsen, T; Dahl, S

2015-01-01

OBJECTIVES: To evaluate the consequences of crown shortening, focusing on the prevalence of pulp exposure and periapical pathology in Greenland sled dogs that had had their canine crowns shortened at an early age. METHODS: Five cadaver heads and 54 sled dogs underwent an oral examination for dental...... fractures and pulp exposure of canines. All canines were radiographed and evaluated for periapical pathology. RESULTS: The prevalence of canine pulp exposure in 12 (5 heads and 7 dogs) crown shortened dogs was 91 · 7%, and 21 · 3% in 47 not-crown shortened dogs. A significant (P pulp...... exposure of the canines in the crown shortened group compared to the not-crown shortened group was seen with a relative risk of 4 · 3 on a dog basis and a relative risk of 12 · 2 on a tooth basis. In dogs with pulp exposure of canines (n = 51) the prevalence of periapical pathology was 82 · 4%, but only 0...

Crown and crown-root fractures: an evaluation of the treatment plans for management proposed by 154 specialists in restorative dentistry.

Science.gov (United States)

de Castro, Mara Antonio Monteiro; Poi, Wilson Roberto; de Castro, José Carlos Monteiro; Panzarini, Sônia Regina; Sonoda, Celso Koogi; Trevisan, Carolina Lunardelli; Luvizuto, Eloá Rodrigues

2010-06-01

Traumatic tooth injuries involve function and aesthetics and cause damage that range from minimal enamel loss to complex fractures involving the pulp tissue and even loss of the tooth crown. Technical knowledge and clinical experience are essential to establish an accurate diagnosis and provide a rational treatment. The purpose of this study was to evaluate the knowledge of Restorative Dentistry specialists about the management of crown and crown-root fractures based on treatment plans proposed by these professionals for these cases. A descriptive questionnaire was mailed to 245 Restorative Dentistry specialists with questions referring to their professional profile and the treatment plans they would propose for the management of crown and crow-root fractures resulting from dental trauma. One hundred and fifty-four questionnaires were returned properly filled. The data were subjected to descriptive statistics and the chi-square test was used to determine the frequency and the level of the significance among the variables. The analysis of data showed that in spite of having a specialist title, all interviewees had great difficulty in planning the treatments. As much as 42.8% of the participants were unable to treat all types of dental trauma. Complicated and uncomplicated crown-root fractures posed the greatest difficulties for the dentists to establish adequate treatment plans because these fractures require multidisciplinary knowledge and approach for a correct case planning and prognosis.

Periodontal response to all-ceramic crowns (IPS Empress) in general practice.

Science.gov (United States)

Al-Wahadni, A M; Mansour, Y; Khader, Y

2006-02-01

The purpose of this study was to investigate the periodontal response to the presence of all-ceramic crowns (IPS Empress) in general practice patients. The convenience sample included 82 IPS Empress crowns placed in 64 patients. These crowns had been in place for an average of 16.27 (SD 9.26) months and ranged from 6.2 to 48.87 months at the time of clinical examination. Periodontal health status (as determined by dental plaque, gingival health status, periodontal pockets) was assessed around all crowned teeth and around matched contralateral teeth by one calibrated examiner. Periodontal indices utilized included the Plaque Index (PI), Gingival Index (GI) and pocket depth (PD) with calibrated probes graduated in millimetres. Plaque, gingival and PD values for crowned teeth were compared with those for control teeth using Wilcoxon signed-rank test for each clinical parameters. Chi-square was used to test the significance of the difference in their distribution between crowns and control teeth. Statistically, PI (0.35), GI (0.41) and mean PD scores (1.42) of IPS Empress crowned teeth compared less favourably with scores of the control teeth (0.27, 0.23 and 0.86 respectively). Teeth with IPS Empress crowns had poorer periodontal health and more clinically evident plaque than uncrowned teeth.

Determinants of day-night difference in blood pressure, a comparison with determinants of daytime and night-time blood pressure.

Science.gov (United States)

Musameh, M D; Nelson, C P; Gracey, J; Tobin, M; Tomaszewski, M; Samani, N J

2017-01-01

Blunted day-night difference in blood pressure (BP) is an independent cardiovascular risk factor, although there is limited information on determinants of diurnal variation in BP. We investigated determinants of day-night difference in systolic (SBP) and diastolic (DBP) BP and how these compared with determinants of daytime and night-time SBP and DBP. We analysed the association of mean daytime, mean night-time and mean day-night difference (defined as (mean daytime-mean night-time)/mean daytime) in SBP and DBP with clinical, lifestyle and biochemical parameters from 1562 adult individuals (mean age 38.6) from 509 nuclear families recruited in the GRAPHIC Study. We estimated the heritability of the various BP phenotypes. In multivariate analysis, there were significant associations of age, sex, markers of adiposity (body mass index and waist-hip ratio), plasma lipids (total and low-density lipoprotein cholesterol and triglycerides), serum uric acid, alcohol intake and current smoking status on daytime or night-time SBP and/or DBP. Of these, only age (P=4.7 × 10 -5 ), total cholesterol (P=0.002), plasma triglycerides (P=0.006) and current smoking (P=3.8 × 10 -9 ) associated with day-night difference in SBP, and age (P=0.001), plasma triglyceride (P=2.2 × 10 -5 ) and current smoking (3.8 × 10 -4 ) associated with day-night difference in DBP. 24-h, daytime and night-time SBP and DBP showed substantial heritability (ranging from 18-43%). In contrast day-night difference in SBP showed a lower heritability (13%) while heritability of day-night difference in DBP was not significant. These data suggest that specific clinical, lifestyle and biochemical factors contribute to inter-individual variation in daytime, night-time and day-night differences in SBP and DBP. Variation in day-night differences in BP is largely non-genetic.

Determinants of day–night difference in blood pressure, a comparison with determinants of daytime and night-time blood pressure

Science.gov (United States)

Musameh, M D; Nelson, C P; Gracey, J; Tobin, M; Tomaszewski, M; Samani, N J

2017-01-01

Blunted day–night difference in blood pressure (BP) is an independent cardiovascular risk factor, although there is limited information on determinants of diurnal variation in BP. We investigated determinants of day–night difference in systolic (SBP) and diastolic (DBP) BP and how these compared with determinants of daytime and night-time SBP and DBP. We analysed the association of mean daytime, mean night-time and mean day–night difference (defined as (mean daytime−mean night-time)/mean daytime) in SBP and DBP with clinical, lifestyle and biochemical parameters from 1562 adult individuals (mean age 38.6) from 509 nuclear families recruited in the GRAPHIC Study. We estimated the heritability of the various BP phenotypes. In multivariate analysis, there were significant associations of age, sex, markers of adiposity (body mass index and waist–hip ratio), plasma lipids (total and low-density lipoprotein cholesterol and triglycerides), serum uric acid, alcohol intake and current smoking status on daytime or night-time SBP and/or DBP. Of these, only age (P=4.7 × 10−5), total cholesterol (P=0.002), plasma triglycerides (P=0.006) and current smoking (P=3.8 × 10−9) associated with day–night difference in SBP, and age (P=0.001), plasma triglyceride (P=2.2 × 10−5) and current smoking (3.8 × 10−4) associated with day–night difference in DBP. 24-h, daytime and night-time SBP and DBP showed substantial heritability (ranging from 18–43%). In contrast day–night difference in SBP showed a lower heritability (13%) while heritability of day–night difference in DBP was not significant. These data suggest that specific clinical, lifestyle and biochemical factors contribute to inter-individual variation in daytime, night-time and day–night differences in SBP and DBP. Variation in day–night differences in BP is largely non-genetic. PMID:26984683

The molecular genetics of crown gall tumorigenesis

International Nuclear Information System (INIS)

Hooykaas, P.J.J.; Schilperoort, R.A.

1984-01-01

The phytopathogenic bacteria Agrobacterium tumefaciens and A. rhizogenes are the causative agents of the widespread plant diseases ''crown gall'' and ''hairy root'' respectively. It is now well established that virulent strains of these bacterial species transfer a piece of bacterial DNA into plant cells, thereby transforming these into tumor cells. In research much attention has been paid to the agrobacteria for several reasons. First is the desire to develop a system for the genetic engineering of plant cells based on the natural system for gene transfer between Agrobacterium species and plant cells. Second, there is a striking resemblance between the etiology of animal cancers and the plant cancer crown gall that was recognized as early as in 1927. This led to basic studies on the process of plant tumor induction and on the recovery of plant cells from the tumorous state. A third important interest lies in crown gall as a disease that is the cause of economically important losses in agriculture an horticulture in Europe, North America, and Austrailia. Research has been aimed at finding means to prevent crown gall and to cure plants of this disease

THE GENERATIVE REPRODUCTIVE CHARACTERISTICS OF RED DRAGON FRUIT (Hylocereus.polyrhizus (Web. Britton & Rose, CACTACEAE

Directory of Open Access Journals (Sweden)

Eniek Kriswiyanti

2013-04-01

Full Text Available This study aimed to investigate the generative reproductive characteristics of red dragon fruit (Hylocereus polyrhizus (Web. Britton & Rose, that is the characteristics and the development of male and female reproductive system and the embryo. The flowering morphology was observed through the gametogenesis process and the process of embryogenesis was observed using the methods of squash, cytolysis, and embedding of flower before anthesis, during and after anthesis. The results showed that the flower funnelled form with many calyxes, stamens and crowns. The pollen was circular, sulcus, trilate, reticulate, and spheroid. The development of microgametophyte was at the 2nd stages with three nucleuses and the pistil developed after anthesis.  Anthesis was taken place at night time, fertilization and pollen developed before anthesis and has not germinating. A single pistil, the head of pistil with many branches, the style longer than the stamen, open type.  Seeds anathrophus, endosperm and embryo with the globular shaped, developed 5 days after anthesis, the embryo torpedo likes and the differentiation of primer tissues seen in the seeds 7 days after anthesis, and arilus generated from development of megasporangium. Keywords: embedding, self incompatibility, sferoidal, anatrophus, arillus.

Asymptomatic ''crowned dens'' calcification in CT images for the craniovertebral junction

International Nuclear Information System (INIS)

Kubota, Gen; Mori, Masataka; Fukushima, Tatsuro

2007-01-01

Calcification around the odontoid process suggests 'crowned dens' syndrome, when accompanied with acute occipital headache or neck pain and with inflammatory signs. We retrospectively searched for calcification around the odontoid process in routine CT images of 282 patients emcompassing the craniovertebral junction, and found 13 (4.6%) had 'crowned dens' calcifications with neither characteristic symptoms nor signs suggestive for crowned dens' syndrome. Females of older ages frequently showed asymptomatic crowned dens' calcifications. (author)

Acetylene–ammonia–18-crown-6 (1/2/1

Directory of Open Access Journals (Sweden)

Tobias Grassl

2012-10-01

Full Text Available The title compound, C2H2·C12H24O6·2NH3, was formed by co-crystallization of 18-crown-6 and acetylene in liquid ammonia. The 18-crown-6 molecule has threefold rotoinversion symmetry. The acteylene molecule lies on the threefold axis and the whole molecule is generated by an inversion center. The two ammonia molecules are also located on the threefold axis and are related by inversion symmetry. In the crystal, the ammonia molecules are located below and above the crown ether plane and are connected by intermolecular N—H...O hydrogen bonds. The acetylene molecules are additionally linked by weak C—H...N interactions into chains that propagate in the direction of the crystallographic c axis. The 18-crown-6 molecule [occupancy ratio 0.830 (4:0.170 (4] is disordered and was refined using a split model.

Surgical manipulation of mammalian embryos in vitro.

Science.gov (United States)

Naruse, I; Keino, H; Taniguchi, M

1997-04-01

Whole-embryo culture systems are useful in the fields of not only embryology but also teratology, toxicology, pharmacology, and physiology. Of the many advantages of whole-embryo culture, we focus here on the surgical manipulation of mammalian embryos. Whole-embryo culture allows us to manipulate mammalian embryos, similarly to fish, amphibian and avian embryos. Many surgical experiments have been performed in mammalian embryos in vitro. Such surgical manipulation alters the destiny of morphogenesis of the embryos and can answer many questions concerning developmental issues. As an example of surgical manipulation using whole-embryo culture systems, one of our experiments is described. Microsurgical electrocauterization of the deep preaxial mesodermal programmed cell death zone (fpp) in the footplate prevented the manifestation of polydactyly in genetic polydactyly mouse embryos (Pdn/Pdn), in which fpp was abolished.

Evaluation of sampling strategies to estimate crown biomass

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Krishna P Poudel

2015-01-01

Full Text Available Background Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire modeling. However, crown biomass is difficult to predict because of the variability within and among species and sites. Thus the allometric equations used for predicting crown biomass should be based on data collected with precise and unbiased sampling strategies. In this study, we evaluate the performance different sampling strategies to estimate crown biomass and to evaluate the effect of sample size in estimating crown biomass. Methods Using data collected from 20 destructively sampled trees, we evaluated 11 different sampling strategies using six evaluation statistics: bias, relative bias, root mean square error (RMSE, relative RMSE, amount of biomass sampled, and relative biomass sampled. We also evaluated the performance of the selected sampling strategies when different numbers of branches (3, 6, 9, and 12 are selected from each tree. Tree specific log linear model with branch diameter and branch length as covariates was used to obtain individual branch biomass. Results Compared to all other methods stratified sampling with probability proportional to size estimation technique produced better results when three or six branches per tree were sampled. However, the systematic sampling with ratio estimation technique was the best when at least nine branches per tree were sampled. Under the stratified sampling strategy, selecting unequal number of branches per stratum produced approximately similar results to simple random sampling, but it further decreased RMSE when information on branch diameter is used in the design and estimation phases. Conclusions Use of

[Finite element analysis of the maxillary central incisor with crown lengthening surgery and post-core restoration in management of crown-root fracture].

Science.gov (United States)

Zhen, Min; Hu, Wen-jie; Rong, Qi-guo

2015-12-18

To construct the finite element models of maxillary central incisor and the simulations with crown lengthening surgery and post-core restoration in management of different crown-root fracture types, to investigate the stress intensity and distributions of these models mentioned above, and to analyze the indications of crown lengthening from the point of view of mechanics. An extracted maxillary central incisor and alveolar bone plaster model were scanned by Micro-CT and dental impression scanner (3shape D700) respectively. Then the 3D finite element models of the maxillary central incisor and 9 simulations with crown lengthening surgery and post-core restoration were constructed by Mimics 10.0, Geomagic studio 9.0 and ANSYS 14.0 software. The oblique static force (100 N) was applied to the palatal surface (the junctional area of the incisal 1/3 and middle 1/3), at 45 degrees to the longitudinal axis, then the von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area, were calculated. A total of 10 high-precision three-dimensional finite element models of maxillary central incisor were established. The von Mises stress of models: post>dentin>alveolar bone>core>periodontal ligament, and the von Mises stress increased linearly with the augmentation of fracture degree (besides the core). The periodontal ligament area of the crown lengthening was reduced by 12% to 33%. The von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their threshold limit value, respectively. The maxillary central incisors with the labial fracture greater than three-quarter crown length and the palatal fracture deeper than 1 mm below the alveolar crest are not the ideal indications of the crown lengthening surgery.

Fatigue resistance and microleakage of CAD/CAM ceramic and composite molar crowns.

Science.gov (United States)

Kassem, Amr S; Atta, Osama; El-Mowafy, Omar

2012-01-01

The aim of this study was to determine effect of compressive cyclic loading on fatigue resistance and microleakage of monolithic CAD/CAM molar ceramic and composite crowns. Thirty-two extracted molars were prepared to receive CEREC crowns according to manufacturer's guidelines using a special paralleling device (Parallel-A-Prep). Sixteen feldspathic ceramic crowns (VITABLOCS Mark II) (VMII) and 16 resin-composite crowns (Paradigm-MZ100 blocks) (PMZ) were milled using a CEREC-3D machine. Eight crowns of each group were cemented to their respective teeth using self-etching resin cement (Panavia-F-2.0) (PAN), and eight were cemented using self-adhesive resin cement (RelyX-Unicem-Clicker) (RXU). Following storage for 1 week in water, specimens were subjected to uniaxial compressive cyclic loading in an Instron testing machine at 12 Hz for 1,000,000 cycles. Load was applied at the central fossa, and the cycle range was 60-600 N. Specimens were then subjected to microleakage testing. Data were statistically analyzed using factorial ANOVA and Post Hoc (Tukey HSD) tests. All composite crowns survived compressive cyclic loading without fracture, while three ceramic crowns from the subgroup cemented with RXU developed surface cracks at the center of occlusal surfaces, extending laterally. Microleakage scores of ceramic crowns cemented with PAN were significantly lower than those of the other three subgroups (p < 0.05). After 1,000,000 cycles of compressive cyclic loading, PMZ composite molar crowns were more fatigue-resistant than VMII ceramic crowns. Cement type had a significant effect on fatigue resistance of the ceramic crowns but not the composite ones. Microleakage scores of ceramic crowns cemented with PAN were significantly lower than those of the other subgroups (p < 0.05). © 2011 by The American College of Prosthodontists.

30 CFR 250.404 - What are the requirements for the crown block?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the requirements for the crown block... General Requirements § 250.404 What are the requirements for the crown block? You must have a crown block safety device that prevents the traveling block from striking the crown block. You must check the device...

The effect of oil sands tailings pond sediments on embryo-larval walleye (Sander vitreus).

Science.gov (United States)

Raine, J C; Turcotte, D; Tumber, V; Peru, K M; Wang, Z; Yang, C; Headley, J V; Parrott, J L

2017-10-01

Walleye (Sander vitreus) are a commercially important North American fish species that inhabit the Athabasca River. This river flows through the Athabasca oil sands where natural sources of bitumen erode from the McMurray formation. Little information is available on responses of walleye embryos to oil sands tailings pond sediments in a laboratory setting. The current study describes the design and implementation of a daily-renewal bioassay to assess the potential effects of tailings pond sediments from the Athabasca oil sands area on walleye development. Developing walleye embryos were exposed to increasing concentrations of two tailings pond sediments (collected in the Athabasca oil sands area) until the completion of yolk absorption in control fish. Sediments from the tailings pond represent a mixture of polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs. During the 31 day exposure, the walleye were examined for mortalities, weight, length and developmental abnormalities to provide an initial evaluation of the effects of the oil sands tailings pond sediments. Walleye embryo survival differed between the tailings pond sediments, and survival decreased with increasing sediment concentration. Alkylated PAH content differed between the two tailings pond sediments and lower embryo survival corresponded to higher total and alkylated PAH content. Tailings pond sediment-exposed walleye exhibited a delay in development, as well as increased percentages of larvae with heart and yolk sac edema, and cranial and spinal malformations. These abnormalities in development are often associated with PAH and alkylated PAH exposure. This study provides an exposure design that can be used to assess sediment toxicity to early developmental stages of a fish species not commonly tested in the lab, and lays the groundwork for future studies with this and other difficult-to-culture species. These results offer information on the potential effects of tailings pond sediments

Phytohemagglutinin facilitates the aggregation of blastomere pairs from Day 5 donor embryos with Day 4 host embryos for chimeric bovine embryo multiplication.

Science.gov (United States)

Simmet, Kilian; Reichenbach, Myriam; Reichenbach, Horst-Dieter; Wolf, Eckhard

2015-12-01

Multiplication of bovine embryos by the production of aggregation chimeras is based on the concept that few blastomeres of a donor embryo form the inner cell mass (ICM) and thus the embryo proper, whereas cells of a host embryo preferentially contribute to the trophectoderm (TE), the progenitor cells of the embryonic part of the placenta. We aggregated two fluorescent blastomeres from enhanced green fluorescent protein (eGFP) transgenic Day 5 morulae with two Day 4 embryos that did not complete their first cleavage until 27 hours after IVF and tested the effect of phytohemagglutinin-L (PHA) on chimeric embryo formation. The resulting blastocysts were characterized by differential staining of cell lineages using the TE-specific factor CDX2 and confocal laser scanning microscopy to facilitate the precise localization of eGFP-positive cells. The proportions of blastocyst development of sandwich aggregates with (n = 99) and without PHA (n = 46) were 85.9% and 54.3% (P chimeric blastocysts analyzed by confocal laser scanning microscopy, nine had eGFP-positive cells (three of them in the ICM, three in the TE, and three in both lineages). When integration in the ICM occurred, the number of eGFP-positive cells in this compartment was 8.3 ± 2.3 (mean ± standard error of the mean). We conclude that PHA is advantageous for the formation of aggregation chimeras, but the approach tested in the present study with only two donor blastomeres and two host embryos did not result in multiplication of genetically valuable donor embryos. Copyright © 2015 Elsevier Inc. All rights reserved.

Spectrophotometric evaluation of crown fragment a year after ...

African Journals Online (AJOL)

Background: Crown fracture is the most common type of fracture and frequently affects the anterior teeth. Crown fractures have been treated in several ways depending on the location and kind of fracture. This case emphasizes reattachment of fractured fragments using fiber-reinforced post. Also this case report underlines ...

SYNTHESIS OF 4’-ALLYLBENZO-3N-CROWN-N ETHERS AND THEIR MASS SPECTRA COMPARED WITH BENZO-3N-CROWN-N ETHERS

OpenAIRE

Anwar, Chairil

2008-01-01

Synthesis of 4’allylbenzo-3n-crown-n ethers was carried out by reacting demethylated eugenol with α,ω-dichloro-oligoethylene glycols in 1-butanol under basic condition. The mass spectra of 4’allylbenzo-3n-crown-n and benzo-3n-crown-n were investigated by mass spectrometry using electron impact under 70 eV of electron bombardment as ionisation method. The difference between the group of compounds is only the present of allyl moiety as a side chain at the other side of benzene ring. The first g...

Ovarian stimulation and embryo quality

NARCIS (Netherlands)

Baart, Esther; Macklon, Nick S.; Fauser, Bart J. C. M.

To Study the effects of different ovarian stimulation approaches on oocyte and embryo quality, it is imperative to assess embryo quality with a reliable and objective method. Embryos rated as high quality by standardized morphological assessment are associated with higher implantation and pregnancy

Ontogenetic behavior and dispersal of Sacramento River white sturgeon, Acipenser transmontanus, with a note on body color

Science.gov (United States)

Kynard, B.; Parker, E.

2005-01-01

We studied Sacramento River white sturgeon, Acipenser transmontanus, in the laboratory to develop a conceptual model of ontogenetic behavior and provide insight into probable behavior of wild sturgeon. After hatching, free embryos initiated a low intensity, brief downstream dispersal during which fish swam near the bottom and were photonegative. The weak, short dispersal style and behavior of white sturgeon free embryos contrasts greatly with the intense, long dispersal style and behavior (photopositive and swimming far above the bottom) of dispersing free embryos of other sturgeon species. If spawned eggs are concentrated within a few kilometers downstream of a spawning site, the adaptive significance of the free embryo dispersal is likely to move fish away from the egg deposition site to avoid predation and reduce fish density prior to feeding. Larvae foraged on the open bottom, swam innate fish dispersal and post-dispersal rearing habitat, which is now highly altered by damming and reservoirs. Sacramento River white sturgeon has a two-step downstream dispersal by the free embryo and juvenile life intervals. Diel activity of all life intervals peaked at night, whether fish were dispersing or foraging. Nocturnal behavior is likely a response to predation, which occurs during both activities. An intense black-tail body color was present on foraging larvae, but was weak or absent on the two life intervals that disperse. Black-tail color may be an adaptation for avoiding predation, signaling among aggregated larvae, or both, but not for dispersal. ?? Springer 2005.

Survival of embryo irradiated with gamma rays by embryo culture in Brassica pekinensis Rupr

International Nuclear Information System (INIS)

Moue, T.

1984-01-01

The effect of irradiation on the survival rates and embryonic development of Brassica pekinensis RUPR. (Varieties; Kashin, Kohai 65 nichi and kairyochitose) was investigated. The purpose of this study was to seek ways of increasing the survival rates of embryos such as B.oleracea obtained through embryo culture techniques after irradiation doses affecting seed fertility and germination, for the purpose of increasing mutation rates. Embryos at different developmental stages ranging from the globular to the early heart stages were irradiated with 20 KR of gamma rays at the daily rate 0L 20 KR or 10 KR (Fig.1 and Table 1). The embryos were excised from ovules 4 to 10 days after irradiation and cultured on White's medium. The shooting and rooting rates on the 34th day of culture were higher at the dose of 10 KR/day than 20 KR/day and were lower when the materials were irradiated at the young embryonic stage (Table 3). Varietal differences in the shooting and rooting rates were also observed. The irradiated embryos survived mainly in the state of callus. It was concluded that the embryo culture technique was successful when applied to irradiated embryos excised at the young embryonic stage and that the technique affected B.pekinensis less than B.oleracea

Stress distribution difference between Lava Ultimate full crowns and IPS e.max CAD full crowns on a natural tooth and on tooth-shaped implant abutments.

Science.gov (United States)

Krejci, Ivo; Daher, René

2017-04-01

The goal of this short communication is to present finite element analysis comparison of the stress distribution between CAD/CAM full crowns made of Lava Ultimate and of IPS e.max CAD, adhesively luted to natural teeth and to implant abutments with the shape of natural teeth. Six 3D models were prepared using a 3D content-creating software, based on a micro-CT scan of a human mandibular molar. The geometry of the full crown and of the abutment was the same for all models representing Lava Ultimate full crowns (L) and IPS e.max CAD full crowns (E) on three different abutments: prepared natural tooth (n), titanium abutment (t) and zirconia abutment (z). A static load of 400 N was applied on the vestibular and lingual cusps, and fixtures were applied to the base of the models. After running the static linear analysis, the post-processing data we analyzed. The stress values at the interface between the crown and the abutment of the Lt and Lz groups were significantly higher than the stress values at the same interface of all the other models. The high stress concentration in the adhesive at the interface between the crown and the abutment of the Lava Ultimate group on implants might be one of the factors contributing to the reported debondings of crowns.

Visual Spatial Disorientation: Re-Visiting the Black Hole Illusion

Science.gov (United States)

2007-01-24

National Transportation Safety Board. Controlled Flight into Terrain, Korean Air Flight 801 , Nimitz Hill, Guam; 1997. 50. National Transportation Safety...According to a Boeing study of worldwide commercial airline accidents, the approach and landing phase of flying, although only accounting for 4% of the...VISUAL SPATIAL DISORIENTATION Kraft (31) described four night visual, landing airline accidents. Black Hole Illusion 5 1. In 1965, a United Airlines

Response to crop-tree release by 7-year-old stems of yellow-poplar and black cherry

Science.gov (United States)

G.R. Jr. Trimble; G.R. Jr. Trimble

1973-01-01

Five years after crop-tree release of yellow-poplar and black cherry sterns in a 7-year-old stand of Appalachian hardwoods, measurements indicated that released trees were but slightly superior to control trees in height, diameter, and crown position. Sprout regrowth of cut tree stems and grapevines had largely nullified the effects of release. Indications are that for...

Night Eating Disorders

OpenAIRE

Deniz Tuncel; Fatma Özlem Orhan

2009-01-01

Hunger is an awakening related biological impulse. The relationship between hunger and sleep is moderated by the control of homeostatic and circadian rhytms of the body. Abnormal eating behavior during sleep period could result from different causes. Abnormal eating during the main sleep period has been categorized as either night eating syndrome or sleep related eating disorder. Night eating syndrome (NES) is an eating disorder characterised by the clinical features of morning anorexia, even...

Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns

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Adil Othman ABDULLAH

Full Text Available ABSTRACT Objective This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns. Material and Methods An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone “PEEK”, Telio CAD-Temp, and Protemp™4 (control group. The crowns were divided into four groups (n=10, Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0. Results The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99 µm, PEEK 46.75 (±8.26 µm, Telio CAD-Temp 56.10 (±5.65 µm, and Protemp™4 193.07(±35.96 µm (P0.05. Conclusions CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns.

Ionic complexation of N 2O 4 by 18-crown-6

Science.gov (United States)

Ricard, S.; Audet, P.; Savoie, R.

1988-08-01

An ionic complex has been obtained from N 2O 4 in the presence of the macrocyclic ether 18-crown-6. This crystalline compound has been shown from its Raman spectrum to have the formula NO +·crown·H(NO 3) 2-, with the nitrosonium ion closely associated with the crown ether rather than with the hydrogen dinitrate accompanying ion. This adduct decomposes readily in moist air to give the known complex (HNO 3·H 2O) 2·crown.

Night shift work and modifiable lifestyle factors.

Science.gov (United States)

Pepłońska, Beata; Burdelak, Weronika; Krysicka, Jolanta; Bukowska, Agnieszka; Marcinkiewicz, Andrzej; Sobala, Wojciech; Klimecka-Muszyńska, Dorota; Rybacki, Marcin

2014-10-01

Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more) - 434 individuals currently working night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI), number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Recreational inactivity (defined here as less than one hour per week of recreational physical activity) was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22) among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029). This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

Night shift work and modifiable lifestyle factors

Directory of Open Access Journals (Sweden)

Beata Pepłońska

2014-10-01

Full Text Available Objectives: Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. Material and Methods: The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more - 434 individuals currently wor­king night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI, number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Results: Recreational inactivity (defined here as less than one hour per week of recreational physical activity was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22 among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029. Conclusions: This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

Dioxin, PCB and PBDE exposure in grey heron (ardea cinerea)

Energy Technology Data Exchange (ETDEWEB)

Fernandes, A.; Thompson, H.; Dsilva, K.; White, S.; Rose, M. [Central Science Laboratory, York (United Kingdom)

2004-09-15

In the United Kingdom recent investigations have detected elevated levels of mortality and bone disease in grey herons at an established colony in Nottinghamshire along the course of the river Trent (4). The causes of mortality are unclear but deformities recorded in the other birds include multiple fracture of the tarsus, tibia and metacarpal bones. These findings have prompted a pilot study into assessing the level of environmental contaminants in the tissue and eggs of these birds. Two classes of contaminants have the potential to cause the deformities observed in the birds - heavy metals such as selenium, cadmium, arsenic mercury and lead, and halogenated organic contaminants such as dioxins, and PCBs. This paper discusses levels of these contaminants in the samples of eggs taken from the colony. Additional samples of eggs were also collected from a colony in Hertfordshire and from a site in the north of the country. The discussion will be limited to the halogenated organic contaminants as the levels of heavy metals were similar in all sites and were generally at or above background levels. Given the increased utilisation of brominated flame retardant chemicals over the last decade and the similarities in structure and environmental persistence of some of these compounds to the dioxins and PCBs, polybrominated diphenylethers (PBDEs) were also measured in the samples.

Embryo-maternal communication

DEFF Research Database (Denmark)

Østrup, Esben; Hyttel, Poul; Østrup, Olga

2011-01-01

Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms dire...... directing the placentation. An increasing knowledge of the embryo-maternal communication might not only help to improve the fertility of our farm animals but also our understanding of human health and reproduction.......Communication during early pregnancy is essential for successful reproduction. In this review we address the beginning of the communication between mother and developing embryo; including morphological and transcriptional changes in the endometrium as well as epigenetic regulation mechanisms...

Marginal Assessment of Crowns by the Aid of Parallel Radiography

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Farnaz Fattahi

2015-03-01

Full Text Available Introduction: Marginal adaptation is the most critical item in long-term prognosis of single crowns. This study aimed to assess the marginal quality as well asthe discrepancies in marginal integrity of some PFM single crowns of posterior teeth by employing parallel radiography in Shiraz Dental School, Shiraz, Iran. Methods: In this descriptive study, parallel radiographies were taken from 200 fabricated PFM single crowns of posterior teeth after cementation and before discharging the patient. To calculate the magnification of the images, a metallic sphere with the thickness of 4 mm was placed in the direction of the crown margin on the occlusal surface. Thereafter, the horizontal and vertical space between the crown margins, the margin of preparations and also the vertical space between the crown margin and the bone crest were measured by using digital radiological software. Results: Analysis of data by descriptive statistics revealed that 75.5% and 60% of the cases had more than the acceptable space (50µm in the vertical (130±20µm and horizontal (90±15µm dimensions, respectively. Moreover, 85% of patients were found to have either horizontal or vertical gap. In 77% of cases, the margins of crowns invaded the biologic width in the mesial and 70% in distal surfaces. Conclusion: Parallel radiography can be expedient in the stage of framework try-in to yield some important information that cannot be obtained by routine clinical evaluations and may improve the treatment prognosis

Night and day in the VA: associations between night shift staffing, nurse workforce characteristics, and length of stay.

Science.gov (United States)

de Cordova, Pamela B; Phibbs, Ciaran S; Schmitt, Susan K; Stone, Patricia W

2014-04-01

In hospitals, nurses provide patient care around the clock, but the impact of night staff characteristics on patient outcomes is not well understood. The aim of this study was to examine the association between night nurse staffing and workforce characteristics and the length of stay (LOS) in 138 veterans affairs (VA) hospitals using panel data from 2002 through 2006. Staffing in hours per patient day was higher during the day than at night. The day nurse workforce had more educational preparation than the night workforce. Nurses' years of experience at the unit, facility, and VA level were greater at night. In multivariable analyses controlling for confounding variables, higher night staffing and a higher skill mix were associated with reduced LOS. © 2014 Wiley Periodicals, Inc.

Displacement of screw-retained single crowns into implants with conical internal connections.

Science.gov (United States)

Yilmaz, Burak; Seidt, Jeremy D; McGlumphy, Edwin A; Clelland, Nancy L

2013-01-01

Internal conical implant-abutment connections without platforms may lead to axial displacement of crowns during screw tightening. This displacement may affect proximal contacts, incisal edge position, or occlusion. This study aimed to measure the displacement of screw-retained single crowns into an implant in three dimensions during screw tightening by hand or via torque driver. A stereolithic acrylic resin cast was created using computed tomography data from a patient missing the maxillary right central incisor. A 4.0- × 11-mm implant was placed in the edentulous site. Five porcelain-fused-to-metal single crowns were made using "cast-to" abutments. Crowns were tried on the stereolithic model, representing the patient, and hand tightened. The spatial relationship of crowns to the model after hand tightening was determined using three-dimensional digital image correlation (3D DIC), an optical measurement technique. The crowns were then tightened using a torque driver to 20 Ncm and the relative crown positions were again recorded. Testing was repeated three times for each crown, and displacement of the crowns was compared between the hand-tightened and torqued states. Commercial image correlation software was used to analyze the data. Mean vertical and horizontal crown displacement values were calculated after torqueing. The interproximal contacts were evaluated before and after torquing using an 8-μm aluminum foil shim. There were vertical and horizontal differences in crown positions between hand tightening and torqueing. Although these were small in magnitude, detectable displacements occurred in both apical and facial directions. After hand tightening, the 8-μm shim could be dragged without tearing. However, after torque tightening, the interproximal contacts were too tight and the 8-μm shim could not be dragged without tearing. Differences between hand tightening and torque tightening should be taken into consideration during laboratory and clinical

Automatic crown cover mapping to improve forest inventory

Science.gov (United States)

Claude Vidal; Jean-Guy Boureau; Nicolas Robert; Nicolas Py; Josiane Zerubia; Xavier Descombes; Guillaume Perrin

2009-01-01

To automatically analyze near infrared aerial photographs, the French National Institute for Research in Computer Science and Control developed together with the French National Forest Inventory (NFI) a method for automatic crown cover mapping. This method uses a Reverse Jump Monte Carlo Markov Chain algorithm to locate the crowns and describe those using ellipses or...

Biomedical potentials of crown ethers: prospective antitumor agents.

Science.gov (United States)

Kralj, Marijeta; Tusek-Bozić, Ljerka; Frkanec, Leo

2008-10-01

Crown ethers are of enormous interest and importance in chemistry, biochemistry, materials science, catalysis, separation, transport and encapsulated processes, as well as in the design and synthesis of various synthetic systems with specific properties, diverse capabilities, and programmable functions. Classical crown ethers are macrocyclic polyethers that contain 3-20 oxygen atoms separated from each other by two or more carbon atoms. They are exceptionally versatile in selectively binding a range of metal ions and a variety of organic neutral and ionic species. Crown ethers are currently being studied and used in a variety of applications beyond their traditional place in chemistry. This review presents additional applications and the ever-increasing biomedical potentials of these intriguing compounds, with particular emphasis on the prospects of their relevance as anticancer agents. We believe that further research in this direction should be encouraged, as crown compounds could either induce toxicities that are different from those of conventional antitumor drugs, or complement drugs in current use, thereby providing a valuable adjunct to therapy.

Clinical performance of IPS-Empress 2 ceramic crowns inserted by general dental practitioners.

Science.gov (United States)

Mansour, Yasar F; Al-Omiri, Mahmoud K; Khader, Yousef Saleh; Al-Wahadni, Ahed

2008-05-01

The aim of this study was to evaluate the clinical performance of IPS-Empress 2(R) all-ceramic crowns placed by general dental practitioners. Eighty-two IPS-Empress 2 crowns placed in 64 patients (27 females and 37 males) were evaluated. These crowns had been in place for 15.2 to 57.2 months (mean 25.3 months, SD=9.3). Survival analysis was conducted using the Kaplan-Meier method. Of the 82 crowns 93.9% were rated satisfactory. In terms of the integrity of the restorations, fracture was observed in three crowns and two showed a crack upon transillumination. Five crowns were rated unsatisfactory for color match; one for marginal adaptation; and none for discoloration, secondary caries, or sensitivity. IPS-Empress 2(R) is a suitable material to fabricate all-ceramic crowns; when these all-ceramic crowns were inserted by general dental practitioners, they functioned satisfactorily with low failure rates during an observation period ranging between 15.2 to 57.2 months.

Getting a Good Night's Sleep in Adolescence: Do Strategies for Coping With Stress Matter?

Science.gov (United States)

Matthews, Karen A; Hall, Martica H; Cousins, Jennifer; Lee, Laisze

2016-01-01

Getting a good night's sleep is challenging for adolescents because of early school start times and adolescents' substantial social and physical changes. We tested whether key indices of sleep health are associated with usual styles of coping with stress and interpersonal conflict in healthy black and white adolescents. Two hundred forty-two (57% female, 56% black) high school students completed daily sleep diaries, questionnaires, and actigraphy across a school week. Linear regression models tested associations, independent of race, gender, and other covariates. Students who reported using disengagement coping exhibited poor sleep health. They had shorter sleep duration, more fragmented sleep, delayed sleep, and increased daytime sleepiness. Unexpectedly, positive engagement coping was related to daytime sleepiness and delayed sleep, although not in models that included disengagement coping. Coping strategies may be an important influence on adolescent sleep. Future research should evaluate the antecedent-consequent relationships among coping, sleep, and stress.

The marginal fit of selective laser melting-fabricated metal crowns: an in vitro study.

Science.gov (United States)

Xu, Dan; Xiang, Nan; Wei, Bin

2014-12-01

The selective laser melting technique is attracting interest in prosthetic dentistry. The marginal fit is a key criterion for fixed restorations. The purpose of the study was to evaluate the marginal fit of cast cobalt-chromium alloy crowns versus the fit of selective laser melting-fabricated crowns. The marginal gap widths of 36 single crowns (18 selective laser melting-fabricated cobalt-chromium metal crowns and 18 cobalt-chromium cast crowns) were determined with a silicone replica technique. Each crown specimen was cut into 4 sections, and the marginal gap width of each cross section was evaluated by stereomicroscopy (× 100). The Student t test was used to evaluate whether significant differences occurred in the marginal gap widths between the selective laser melting-fabricated and cast cobalt-chromium metal crowns (α=.05). The mean marginal gap width of the cast crowns (170.19 μm) was significantly wider than that of the selective laser melting-fabricated crowns (102.86 μm). Selective laser melting-fabricate cobalt-chromium dental crowns found improved marginal gap widths compared with traditional cast crowns. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

Directory of Open Access Journals (Sweden)

Mirković Nemanja

2012-01-01

Full Text Available Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60 ceramic crowns were made on non-carious extracted human premolars. Thirty (30 crowns were made on the basis of feather-edge preparation (experimental group I. The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system “Zirkonzahn” (Zirkonzahn GMBH, Gais, Germany. The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and

Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in waterbird nests

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ± 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ± 1.6 days and 1.9 ± 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ± 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ± 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates.

Online recovery of radiocesium from soil, cellulose and plant samples by supercritical fluid extraction employing crown ethers and calix-crown derivatives as extractants

International Nuclear Information System (INIS)

Kanekar, A.S.; Pathak, P.N.; Mohapatra, P.K.

2014-01-01

Two crown ethers (CEs) viz. dibenzo18crown6, and dibenzo12crown7 and three calix-crown derivatives viz. (octyloxy)calix[4]arene-mono-crown-6 (CMC), calix[4]arene-bis(o-benzocrown-6) (CBC), and calix[4]arene-bis(naphthocrown-6) (CNC) were evaluated for the recovery of 137 Cs from synthetic soil, cellulose (tissue paper), and plant samples by supercritical fluid extraction (SFE) route. CEs showed poor extraction of 137 Cs from soil matrix. SFE experiments using 1 × 10 -3 M solutions of CMC, CBC and CNC in acetonitrile at 3 M HNO 3 as modifiers displayed better extraction of 137 Cs, viz. 21(±2) % (CMC), 16.5(±3) % (CBC), and 4(±1) % (CNC). It was not possible to recover 137 Cs quantitatively from soil matrix. The inefficient extraction of 137 Cs from soil matrix was attributed to its incorporation into the interstitial sites. Experiments on tissue papers using CMC showed near quantitative 137 Cs recovery. On the other hand, recovery from plant samples varied between 50(±5) % (for stems) and 75(±5) % (for leaves). (author)

Effect of embryo density on in vitro developmental characteristics of bovine preimplantative embryos with respect to micro and macroenvironments.

Science.gov (United States)

Hoelker, M; Rings, F; Lund, Q; Phatsara, C; Schellander, K; Tesfaye, D

2010-10-01

To overcome developmental problems as a consequence of single embryo culture, the Well of the Well (WOW) culture system has been developed. In this study, we aimed to examine the effect of embryo densities with respect to both microenvironment and macroenvironment on developmental rates and embryo quality to get a deeper insight into developmentally important mechanisms. WOW diameter and depth significantly affected developmental rates (p < 0.05). WOWs with diameter of 500 μm reached significantly higher blastocyst rates (32.5 vs 21.1% vs 20.3%) compared to embryos cultured in WOWs of 300 μm diameter or plain cultured controls. Embryos cultured in WOWs with 700 μm depth reached significant higher developmental rates compared with embryos cultured in WOWs of 300 μm depth and control embryos (30.6 vs 22.6% vs 20.3%). Correlation of the embryo per WOW volume with developmental rates was higher (r(2) = 0.92, p = 0.0004) than correlation of WOW diameter or WOW depth with developmental rates. However, the embryo per WOW volume did not affect differential cell counts. An embryo per culture dish volume of 1 : 30 μl was identified to be optimal when the embryo per WOW volume was 1 : 0.27 μl increasing developmental rates up to the level of mass embryo production. Giving the opportunity to track each embryo over the complete culture period while keeping high developmental rates with normal mitotic dynamics, the results of this work will provide benefit for the single culture of embryos in human assisted reproduction, mammalian embryos with high economic interest as well as for scientific purpose. © 2009 Blackwell Verlag GmbH.

Patrones de crecimiento postnatal en ocho especies de garzas (Ciconiiformes: Ardeidae

Directory of Open Access Journals (Sweden)

Dennis Denis Ávila

2011-06-01

Gompertz equations were adjusted to data using non-lineal regression models with adult values as the asymptote. For each species, the following were determined and recorded: growth rate, age at inflexion, instantaneous growth rates at each age interval, and time taken to reach 90% of adult size. Reported hatchling sizes were similar in other localities, with a variation coefficient ranging between 10-19%. At hatch, each species exhibited differing sizes relative to adult values. In all cases, Gompertz equations were best fitted to explain more variance and lesser residuals. Rates of weight change and tarsus growth were alometrically related to the log of adult weight. Two main growth processes were identified: a physical extension in dimensions of each measure ment reflecting inter-specific morphometric differences, and a lineal increase of the growth period from Green Heron to Great Egret. The Black-crowned Night Heron, Cattle Egret and Reddish Egret exhibited some unique measurement characteristics in comparison to the remaining members of the family. All results support the hypothesis that hypermorphosis, as the main evolutionary process in the microevolution of Ardeidae, is caused by a delayed final moment of growth. Rev. Biol. Trop. 59 (2: 771-787. Epub 2011 June 01.

Oxidative DNA damage during night shift work.

Science.gov (United States)

Bhatti, Parveen; Mirick, Dana K; Randolph, Timothy W; Gong, Jicheng; Buchanan, Diana Taibi; Zhang, Junfeng Jim; Davis, Scott

2017-09-01

We previously reported that compared with night sleep, day sleep among shift workers was associated with reduced urinary excretion of 8-hydroxydeoxyguanosine (8-OH-dG), potentially reflecting a reduced ability to repair 8-OH-dG lesions in DNA. We identified the absence of melatonin during day sleep as the likely causative factor. We now investigate whether night work is also associated with reduced urinary excretion of 8-OH-dG. For this cross-sectional study, 50 shift workers with the largest negative differences in night work versus night sleep circulating melatonin levels (measured as 6-sulfatoxymelatonin in urine) were selected from among the 223 shift workers included in our previous study. 8-OH-dG concentrations were measured in stored urine samples using high performance liquid chromatography with electrochemical detection. Mixed effects models were used to compare night work versus night sleep 8-OH-dG levels. Circulating melatonin levels during night work (mean=17.1 ng/mg creatinine/mg creatinine) were much lower than during night sleep (mean=51.7 ng/mg creatinine). In adjusted analyses, average urinary 8-OH-dG levels during the night work period were only 20% of those observed during the night sleep period (95% CI 10% to 30%; psleep, is associated with reduced repair of 8-OH-dG lesions in DNA and that the effect is likely driven by melatonin suppression occurring during night work relative to night sleep. If confirmed, future studies should evaluate melatonin supplementation as a means to restore oxidative DNA damage repair capacity among shift workers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

DEFF Research Database (Denmark)

Peng, Min; Fei, Wei; Hosseini, Mandana

2013-01-01

The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one of ...... abutments and did not necessarily result in an increased crown length. The distal implant papilla heightwas obviously shorter, althoughthe mesial papilla height was similar to thatof the healthy dentition.The papilla index score was tested to be a valid index for papilla fill....

Metabolite profiling of somatic embryos of Cyclamen persicum in comparison to zygotic embryos, endosperm and testa

Directory of Open Access Journals (Sweden)

Traud eWinkelmann

2015-08-01

Full Text Available Somatic embryogenesis has been shown to be an efficient in vitro plant regeneration system for many crops such as the important ornamental plant Cyclamen persicum, for which this regeneration pathway of somatic embryogenesis is of interest for the vegetative propagation of parental lines as well as elite plants. However, somatic embryogenesis is not commercially used in many crops due to several unsolved problems, such as malformations, asynchronous development, deficiencies in maturation and germination of somatic embryos. In contrast, zygotic embryos in seeds develop and germinate without abnormalities in most cases. Instead of time-consuming and labor-intensive experiments involving tests of different in vitro culture conditions and plant growth regulator supplements, we follow a more directed approach. Zygotic embryos served as a reference and were compared to somatic embryos in metabolomic analyses allowing the future optimization of the in vitro system. The aims of this study were to detect differences in the metabolite profiles of torpedo stage somatic and zygotic embryos of C. persicum. Moreover, major metabolites in endosperm and testa were identified and quantified.Two sets of extracts of two to four biological replicates each were analyzed. In total 52 metabolites were identified and quantified in the different tissues. One of the most significant differences between somatic and zygotic embryos was that the proline concentration in the zygotic embryos was about 40 times higher than that found in somatic embryos. Epicatechin, a scavenger for reactive oxygen species, was found in highest abundance in the testa. Sucrose, the most abundant metabolite was detected in significantly higher concentrations in zygotic embryos. Also, a yet unknown trisaccharide, was significantly enriched in zygotic embryos.

A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer.

Science.gov (United States)

Wang, F; Yeung, K L; Chan, W C; Kwok, C C H; Leung, S L; Wu, C; Chan, E Y Y; Yu, I T S; Yang, X R; Tse, L A

2013-11-01

This study aimed to conduct a systematic review to sum up evidence of the associations between different aspects of night shift work and female breast cancer using a dose-response meta-analysis approach. We systematicly searched all cohort and case-control studies published in English on MEDLINE, Embase, PSYCInfo, APC Journal Club and Global Health, from January 1971 to May 2013. We extracted effect measures (relative risk, RR; odd ratio, OR; or hazard ratio, HR) from individual studies to generate pooled results using meta-analysis approaches. A log-linear dose-response regression model was used to evaluate the relationship between various indicators of exposure to night shift work and breast cancer risk. Downs and Black scale was applied to assess the methodological quality of included studies. Ten studies were included in the meta-analysis. A pooled adjusted relative risk for the association between 'ever exposed to night shift work' and breast cancer was 1.19 [95% confidence interval (CI) 1.05-1.35]. Further meta-analyses on dose-response relationship showed that every 5-year increase of exposure to night shift work would correspondingly enhance the risk of breast cancer of the female by 3% (pooled RR = 1.03, 95% CI 1.01-1.05; Pheterogeneity night shifts would result in a 13% (RR = 1.13, 95% CI 1.07-1.21; Pheterogeneity = 0.06) increase in breast cancer risk. This systematic review updated the evidence that a positive dose-response relationship is likely to present for breast cancer with increasing years of employment and cumulative shifts involved in the work.

Elliptic Fourier analysis of crown shapes in Quercus petraea trees

OpenAIRE

Ovidiu Hâruţa

2011-01-01

Shape is a fundamental morphological descriptor, significant in taxonomic research as well as in ecomorphology, one method of estimation being from digitally processed images. In the present study, were analysed shapes of Q. petraea crowns, pertaining to five different stem diameter classes, from three similar stands. Based on measurements on terrestrial digital vertical photos, crown size analysis was performed and correlations between crown and stem variables were tested. Linear regression ...

Fractal approach to computer-analytical modelling of tree crown

International Nuclear Information System (INIS)

Berezovskaya, F.S.; Karev, G.P.; Kisliuk, O.F.; Khlebopros, R.G.; Tcelniker, Yu.L.

1993-09-01

In this paper we discuss three approaches to the modeling of a tree crown development. These approaches are experimental (i.e. regressive), theoretical (i.e. analytical) and simulation (i.e. computer) modeling. The common assumption of these is that a tree can be regarded as one of the fractal objects which is the collection of semi-similar objects and combines the properties of two- and three-dimensional bodies. We show that a fractal measure of crown can be used as the link between the mathematical models of crown growth and light propagation through canopy. The computer approach gives the possibility to visualize a crown development and to calibrate the model on experimental data. In the paper different stages of the above-mentioned approaches are described. The experimental data for spruce, the description of computer system for modeling and the variant of computer model are presented. (author). 9 refs, 4 figs

Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

International Nuclear Information System (INIS)

Myasoedova, T.G.; Ponomareva, A.V.; Zagorets, P.A.; Filippov, E.A.

1984-01-01

Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lgβ depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6

Determination of stability constants of K and Cs nitrate complex with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Myasoedova, T G; Ponomareva, A V; Zagorets, P A; Filippov, E A [Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR)

1984-08-01

Total stability constants of K and Cs nitrate complexes with dicyclohexyl-18-crown-6 and dibenzo-18-crown-6 in isopropanol aqueous solutions were determined by the method of low-frequency contact conductometry. Clearly defined K/Cs selectivity is observed for the system with dibenzo-18-crown-6. It is shown that lg..beta.. depends on permittivity of the solvent. The decrease of permittivity of isopropanol aqueous solutions results in reduction of K/Cs selectivity of DB18C6.

RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

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Yadav

2015-07-01

Full Text Available Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatment alternative for restoration of such teeth. The Richmond crown was introduced in 1878 and incorporated a threaded tube in the canal with a screw retained crown. It was later modified to eliminate the threaded tube and was redesigned as a one piece dowel and crown. This case report shows restoration of badly mutilated posterior teeth with Richmond crown.

The relationship of initial embryo crown--rump length to pregnancy outcome and abortus karyotype based on new growth curves for the 2-31 mm embryo.

Science.gov (United States)

Dickey, R P; Gasser, R F; Olar, T T; Curole, D N; Taylor, S N; Matulich, E M; West, J D; Tsien, F

1994-02-01

The objective of this study was to determine if measurement of initial crown--rump length (CRL) is helpful in predicting low birth weight, newborn length, spontaneous abortions, or abortus karyotype. We measured CRL prospectively in 837 consecutive singleton pregnancies at the time a heart rate was first detectable with transvaginal ultrasonography and compared these measurements to normal values for the 10th through 90th centiles determined from 227 transvaginal ultrasound measurements in in-vitro fertilization and gamete intra-Fallopian transfer pregnancies with known ovulation dates. The relationship of initial CRL to birth weight and length and to abortion and abortus karyotype was analysed after all pregnancies had delivered. Initial CRL measured after the 28th post-ovulation day was predictive of subsequent abortion, but not of low birth weight or length. The abortion rate was 3.3% [95% confidence interval (CI) 1.5%, 5.1%] when initial CRL > or = 50th centile, compared to 19.4% (95% CI 15.4%, 23.4%) when aborti. These results indicate that initial CRL measured after the 28th post-ovulation day may help to identify pregnancies at increased risk of abortion due to abnormal karyotypes.

Generation of single-copy transgenic mouse embryos directly from ES cells by tetraploid embryo complementation

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Zhao Roong

2001-12-01

Full Text Available Abstract Background Transgenic mice have been used extensively to analyze gene function. Unfortunately, traditional transgenic procedures have only limited use in analyzing alleles that cause lethality because lines of founder mice cannot be established. This is frustrating given that such alleles often reveal crucial aspects of gene function. For this reason techniques that facilitate the generation of embryos expressing such alleles would be of enormous benefit. Although the transient generation of transgenic embryos has allowed limited analysis of lethal alleles, it is expensive, time consuming and technically challenging. Moreover a fundamental limitation with this approach is that each embryo generated is unique and transgene expression is highly variable due to the integration of different transgene copy numbers at random genomic sites. Results Here we describe an alternative method that allows the generation of clonal mouse embryos harboring a single-copy transgene at a defined genomic location. This was facilitated through the production of Hprt negative embryonic stem cells that allow the derivation of embryos by tetraploid embryo complementation. We show that targeting transgenes to the hprt locus in these ES cells by homologous recombination can be efficiently selected by growth in HAT medium. Moreover, embryos derived solely from targeted ES cells containing a single copy LacZ transgene under the control of the α-myosin heavy chain promoter exhibited the expected cardiac specific expression pattern. Conclusion Our results demonstrate that tetraploid embryo complementation by F3 hprt negative ES cells facilitates the generation of transgenic mouse embryos containing a single copy gene at a defined genomic locus. This approach is simple, extremely efficient and bypasses any requirement to generate chimeric mice. Moreover embryos generated by this procedure are clonal in that they are all derived from a single ES cell lines. This

Rapid crown root development confers tolerance to zinc deficiency in rice

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Amrit Kaur eNanda

2016-03-01

Full Text Available Zinc (Zn deficiency is one of the leading nutrient disorders in rice (Oryza sativa. Many studies have identified Zn efficient rice genotypes, but causal mechanisms for Zn deficiency tolerance remain poorly understood. Here we report a detailed study of the impact of Zn deficiency on crown root development of rice genotypes, differing in their tolerance to this stress. Zn deficiency delayed crown root development and plant biomass accumulation in both Zn efficient and inefficient genotypes, with the effects being much stronger in the latter. Zn efficient genotypes had developed new crown roots as early as three days after transplanting (DAT to a Zn deficient field and that was followed by a significant increase in total biomass by 7 DAT. Zn-inefficient genotypes developed few new crown roots and did not increase biomass during the first seven days following transplanting. This correlated with Zn efficient genotypes retranslocating a higher proportion of shoot Zn to their roots, compared to Zn inefficient genotypes. These latter genotypes were furthermore not efficient in utilizing the limited Zn for root development. Histological analyses indicated no anomalies in crown tissue of Zn-efficient or inefficient genotypes that would have suggested crown root emergence was impeded. We therefore conclude that the rate of crown root initiation was differentially affected by Zn deficiency between genotypes. Rapid crown root development, following transplanting, was identified as a main causative trait for tolerance to Zn deficiency and better Zn retranslocation from shoot to root was a key attribute of Zn-efficient genotypes.

Nano-nutrition of chicken embryos

DEFF Research Database (Denmark)

Sawosz, Filip; Pineda, Lane Manalili; Hotowy, Anna

2013-01-01

It has been suggested that the quantity and quality of nutrients stored in the egg might not be optimal for the fast rate of chicken embryo development in modern broilers, and embryos could be supplemented with nutrients by in ovo injection. Recent experiments showed that in ovo feeding reduces...... broiler eggs was randomly divided into a Control group without injection and injected groups with hydrocolloids of Nano-Ag, ATP or a complex of Nano-Ag and ATP (Nano-Ag/ATP). The embryos were evaluated on day 20 of incubation. The results indicate that the application of ATP to chicken embryos increases...

Organization and management of ATLAS nightly builds

International Nuclear Information System (INIS)

Luehring, F; Obreshkov, E; Quarrie, D; Rybkine, G; Undrus, A

2010-01-01

The automated multi-platform software nightly build system is a major component in the ATLAS collaborative software organization, validation and code approval schemes. Code developers from ATLAS participating Institutes spread all around the world use about 30 branches of nightly releases for testing new packages, verification of patches to existing software, and migration to new platforms and compilers. The nightly releases lead up to, and are the basis of, stable software releases used for data processing worldwide. The ATLAS nightly builds are managed by the fully automated NICOS framework on the computing farm with 44 powerful multiprocessor nodes. The ATN test tool is embedded within the nightly system and provides results shortly after full compilations complete. Other test frameworks are synchronized with NICOS jobs and run larger scale validation jobs using the nightly releases. NICOS web pages dynamically provide information about the progress and results of the builds. For faster feedback, E-mail notifications about nightly releases problems are automatically distributed to the developers responsible.

Radionuclide transfer from mother to embryo

International Nuclear Information System (INIS)

Toader, M.; Vasilache, R.A.; Scridon, R.; Toader, M.L.

1998-01-01

The transfer of radionuclides from mother to embryo is still a matter of high interest. Therefore, the relation was investigated between the amount of radionuclides in the embryo and the dietary intake of the mother, this for two scenarios: a recurrent intake of variable amounts of radionuclides, and a long-term intake of a relatively constant amount of radionuclides, the radionuclide being 137 Cs. In the first case, the amount of radionuclides present in the embryo increases with the age of the embryo and with the intake of the mother. In the second case, no correlation could be found between the age of the embryo and its radioactive content; only the correlation between the intake of the mother and the radionuclide content of the embryo remained. (A.K.)

Manipulating early pig embryos.

Science.gov (United States)

Niemann, H; Reichelt, B

1993-01-01

On the basis of established surgical procedures for embryo recovery and transfer, the early pig embryo can be subjected to various manipulations aimed at a long-term preservation of genetic material, the generation of identical multiplets, the early determination of sex or the alteration of the genetic make-up. Most of these procedures are still at an experimental stage and despite recent considerable progress are far from practical application. Normal piglets have been obtained after cryopreservation of pig blastocysts hatched in vitro, whereas all attempts to freeze embryos with intact zona pellucida have been unsuccessful. Pig embryos at the morula and blastocyst stage can be bisected microsurgically and the resulting demi-embryos possess a high developmental potential in vitro, whereas their development in vivo is impaired. Pregnancy rates are similar (80%) but litter size is reduced compared with intact embryos and twinning rate is approximately 2%. Pig blastomeres isolated from embryos up to the 16-cell stage can be grown in culture and result in normal blastocysts. Normal piglets have been born upon transfer of blastocysts derived from isolated eight-cell blastomeres, clearly underlining the totipotency of this developmental stage. Upon nuclear transfer the developmental capacity of reconstituted pig embryos is low and culture. Sex determination can be achieved either by separation of X and Y chromosome bearing spermatozoa by flow cytometry or by analysing the expression of the HY antigen in pig embryos from the eight-cell to morula stage. Microinjection of foreign DNA has been successfully used to alter growth and development of transgenic pigs, and to produce foreign proteins in the mammary gland or in the bloodstream, indicating that pigs can be used as donors for valuable human pharmaceutical proteins. Another promising area of gene transfer is the increase of disease resistance in transgenic lines of pigs. Approximately 30% of pig spermatozoa bind

Accurate and noninvasive embryos screening during in vitro fertilization (IVF) assisted by Raman analysis of embryos culture medium Accurate and noninvasive embryos screening during IVF

Science.gov (United States)

Shen, A. G.; Peng, J.; Zhao, Q. H.; Su, L.; Wang, X. H.; Hu, J. M.; Yang, J.

2012-04-01

In combination with morphological evaluation tests, we employ Raman spectroscopy to select higher potential reproductive embryos during in vitro fertilization (IVF) based on chemical composition of embryos culture medium. In this study, 57 Raman spectra are acquired from both higher and lower quality embryos culture medium (ECM) from 10 patients which have been preliminarily confirmed by clinical assay. Data are fit by using a linear combination model of least squares method in which 12 basis spectra represent the chemical features of ECM. The final fitting coefficients provide insight into the chemical compositions of culture medium samples and are subsequently used as criterion to evaluate the quality of embryos. The relative fitting coefficients ratios of sodium pyruvate/albumin and phenylalanine/albumin seem act as key roles in the embryo screening, attaining 85.7% accuracy in comparison with clinical pregnancy. The good results demonstrate that Raman spectroscopy therefore is an important candidate for an accurate and noninvasive screening of higher quality embryos, which potentially decrease the time-consuming clinical trials during IVF.

CAD/CAM glass ceramics for single-tooth implant crowns: a finite element analysis.

Science.gov (United States)

Akça, Kvanç; Cavusoglu, Yeliz; Sagirkaya, Elcin; Aybar, Buket; Cehreli, Murat Cavit

2013-12-01

To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area. A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.5 × 1.5 cm geometric matrix for evaluation of mechanical behavior of mono-ceramic CAD/CAM aluminosilicate and leucite glass crown materials. Laterally positioned axial load of 300 N was applied on the crowns. Resulting principal stresses in the mono-ceramic crowns were evaluated in relation to different glass ceramic materials. The highest compressive stresses were observed at the cervical region of the buccal aspect of the crowns and were 89.98 and 89.99 MPa, for aluminosilicate and leucite glass ceramics, respectively. The highest tensile stresses were observed at the collar of the lingual part of the crowns and were 24.54 and 25.39 MPa, respectively. Stresses induced upon 300 N static loading of CAD/CAM aluminosalicate and leucite glass ceramics are below the compressive strength of the materials. Impact loads may actuate the progress to end failure of mono-ceramic crowns supported by metallic implant abutments.

What Drives Embryo Development? Chromosomal Normality or Mitochondria?

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A. Bayram

2017-01-01

Full Text Available Objective. To report the arrest of euploid embryos with high mtDNA content. Design. A report of 2 cases. Setting. Private fertility clinic. Patients. 2 patients, 45 and 40 years old undergoing IVF treatment. Interventions. Mature oocytes were collected and vitrified from two ovarian stimulations. Postthaw, survived mature oocytes underwent fertilization by intracytoplasmic sperm injection (ICSI. Preimplantation genetic screening (PGS and mitochondrial DNA (mtDNA copy number were done using next generation sequencing (NGS. The only normal embryo among the all-biopsied embryos had the highest “Mitoscore” value and was the only arrested embryo in both cases. Therefore, the embryo transfer was cancelled. Main Outcome Measures. Postthaw survival and fertilization rate, embryo euploidy, mtDNA copy number, and embryo development. Results. In both patients, after PGS only 1 embryo was euploid. Both embryos had the highest mtDNA copy number from all tested embryos and both embryos were arrested on further development. Conclusions. These cases clearly demonstrate the lack of correlation between mtDNA value (Mitoscore and chromosomal status of embryo.

Evaluation of different sterilization and disinfection methods on commercially made preformed crowns.

Science.gov (United States)

Yilmaz, Y; Guler, C

2008-12-01

The aim of this study was to evaluate the changes caused by different sterilization or disinfection methods on the vestibular surface of four commercially made preformed crowns using stereomicroscopy and scanning electron microscopy (SEM). Preformed crowns (NuSmile Primary Anterior Crown (NSC), Kinder Krowns (KK), Pedo Pearls (PP) and polycarbonate crowns (PC)) were sterilized and/or disinfected by one of the following techniques: no sterilization or disinfection (G1 control group); steam autoclaving at 134 degrees C (30 psi) for 4 min (G2); steam autoclaving at 134 degrees C (30 psi) for 12 min (G3); steam autoclaving at 121 degrees C (15 psi) for 30 min (G4); and ultrasonication in a bath containing 4% Lysetol AF for 5 min at room temperature (chemical disinfection) (G5). Scanning electron micrographs of the crowns were taken before and after their sterilization or disinfection. The changes on the vestibular surface were then scored for the presence or absence of crazing, contour alteration, fracturing, and vestibular surface changes. The data were analyzed statistically using the chi-square test. No changes were observed before and after sterilization or disinfection in the stereomicroscopic evaluation of the vestibular surface of the crowns. However, all methods in which steam autoclaving was used to sterilize the crowns caused significant (P < 0.05) crazing and contour alterations of the vestibular surface of the crowns when they were examined by SEM. Chemical disinfection using an aldehyde-free disinfectant is the preferred method of disinfection for crowns that have been used previously in other dental patients.

Associations between number of consecutive night shifts and impairment of neurobehavioral performance during a subsequent simulated night shift.

Science.gov (United States)

Magee, Michelle; Sletten, Tracey L; Ferguson, Sally A; Grunstein, Ronald R; Anderson, Clare; Kennaway, David J; Lockley, Steven W; Rajaratnam, Shantha Mw

2016-05-01

This study aimed to investigate sleep and circadian phase in the relationships between neurobehavioral performance and the number of consecutive shifts worked. Thirty-four shift workers [20 men, mean age 31.8 (SD 10.9) years] worked 2-7 consecutive night shifts immediately prior to a laboratory-based, simulated night shift. For 7 days prior, participants worked their usual shift sequence, and sleep was assessed with logs and actigraphy. Participants completed a 10-minute auditory psychomotor vigilance task (PVT) at the start (~21:00 hours) and end (~07:00 hours) of the simulated night shift. Mean reaction times (RT), number of lapses and RT distribution was compared between those who worked 2-3 consecutive night shifts versus those who worked 4-7 shifts. Following 4-7 shifts, night shift workers had significantly longer mean RT at the start and end of shift, compared to those who worked 2-3 shifts. The slowest and fastest 10% RT were significantly slower at the start, but not end, of shift among participants who worked 4-7 nights. Those working 4-7 nights also demonstrated a broader RT distribution at the start and end of shift and had significantly slower RT based on cumulative distribution analysis (5 (th), 25 (th), 50 (th), 75 (th)percentiles at the start of shift; 75th percentile at the end of shift). No group differences in sleep parameters were found for 7 days and 24 hours prior to the simulated night shift. A greater number of consecutive night shifts has a negative impact on neurobehavioral performance, likely due to cognitive slowing.

Critical windows in embryonic development: Shifting incubation temperatures alter heart rate and oxygen consumption of Lake Whitefish (Coregonus clupeaformis) embryos and hatchlings.

Science.gov (United States)

Eme, J; Mueller, C A; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

2015-01-01

Critical windows are periods of developmental susceptibility when the phenotype of an embryonic, juvenile or adult animal may be vulnerable to environmental fluctuations. Temperature has pervasive effects on poikilotherm physiology, and embryos are especially vulnerable to temperature shifts. To identify critical windows, we incubated whitefish embryos at control temperatures of 2°C, 5°C, or 8°C, and shifted treatments among temperatures at the end of gastrulation or organogenesis. Heart rate (fH) and oxygen consumption ( [Formula: see text] ) were measured across embryonic development, and [Formula: see text] was measured in 1-day old hatchlings. Thermal shifts, up or down, from initial incubation temperatures caused persistent changes in fH and [Formula: see text] compared to control embryos measured at the same temperature (2°C, 5°C, or 8°C). Most prominently, when embryos were measured at organogenesis, shifting incubation temperature after gastrulation significantly lowered [Formula: see text] or fH. Incubation at 2°C or 5°C through gastrulation significantly lowered [Formula: see text] (42% decrease) and fH (20% decrease) at 8°C, incubation at 2°C significantly lowered [Formula: see text] (40% decrease) and fH (30% decrease) at 5°C, and incubation at 5°C and 8°C significantly lowered [Formula: see text] at 2°C (27% decrease). Through the latter half of development, [Formula: see text] and fH in embryos were not different from control values for thermally shifted treatments. However, in hatchlings measured at 2°C, [Formula: see text] was higher in groups incubated at 5°C or 8°C through organogenesis, compared to 2°C controls (43 or 65% increase, respectively). Collectively, these data suggest that embryonic development through organogenesis represents a critical window of embryonic and hatchling phenotypic plasticity. This study presents an experimental design that identified thermally sensitive periods for fish embryos. Crown Copyright �

AHP 47: A NIGHT DATE

Directory of Open Access Journals (Sweden)

Phun tshogs dbang rgyal ཕུན་ཚོགས་དབང་རྒྱལ།

2017-04-01

Full Text Available The author was born in 1993 in Ska chung (Gaqun Village, Nyin mtha' (Ningmute Township, Rma lho (Henan Mongolian Autonomous County, Rma lho (Huangnan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province, PR China. Night dating was popular for teenage boys some years ago. They rode horses and yaks when they went night dating. They generally rode yaks, because horses were important for their families and used for such important tasks as pursuing bandits and going to the county town for grain and supplies. An early experience with night dating is described.

Theory about the Embryo Cryo-Treatment.

Science.gov (United States)

Vladimirov, Iavor K; Tacheva, Desislava; Diez, Antonio

2017-04-01

To create hypothesis, which can give a logical explanation related to the benefits of freezing/thawing embryos. Cryopreservation is not only a technology used for storing embryos, but also a method of embryo treatment that can potentially improve the success rate in infertile couples. From the analysis of multiple results in assisted reproductive technology, which have no satisfactory explanation to date, we found evidence to support a 'therapeutic' effect of the freezing/thawing of embryos on the process of recovery of the embryo and its subsequent implantation. Freezing/thawing is a way to activate the endogenous survival and repair responses in preimplantation embryos. Several molecular mechanisms can explain the higher success rate of ET using thawed embryos compared to fresh ET in women of advanced reproductive age, the higher miscarriage rate in cases of thawed blastocyst ET compared to thawed ET at early cleavage embryo, and the higher perinatal parameters of born children after thawed ET. Embryo thawing induces a stress. Controlled stress is not necessarily detrimental, because it generates a phenomenon that is counteracted by several known biological responses aimed to repair mitochondrial damage of membrane and protein misfolding. The term for favorable biological responses to low exposures to stress is called hormesis. This thesis will summarize the role of cryopreservation in the activation of a hormetic response, preserving the mitochondrial function, improving survival, and having an impact on the process of implantation, miscarriage, and the development of pregnancy.

[The destiny of cryopreserved embryos].

Science.gov (United States)

Karpel, L; Achour-Frydman, N; Frydman, R; Flis-Trèves, M

2007-12-01

To know the psychological motivations of couples who keep their embryos so long (five years and more) and do not make a decision about them. We studied 84 couples refrained from making a decision on their cryopreserved embryos for at least five years. They were invited to fill out a questionnaire focusing on three points: the reasons of the indecision, their own representation of the cryopreserved embryos and their choice for the future: donation to another couple, to research, pregnancy or no solution for the moment. Mean (S.D.) women's and men's age were respectively, 38.8 (2.5)- and 41.3 (2.5)-years old. On average, three (1-9) embryos are preserved since 7.5 (5-12) years. Most of couples are parents. Four major reasons explain their attitudes: feeling of being too aged (25%), fear of a multiple pregnancy (45%), disagreement between members of couple (20%) and fear of failure (42.5%). Multiple choices were given to the future of the embryos: 25% wanted a pregnancy, 8% wanted to give them to infertile couples, 20% to research and 27.5% did not find any solution. Twenty percent were hesitating. The representation of those embryos is more symbolic than material. Most of the time, they see them like a potential child, a hope for the future or a brother or sister of their alive children. Those embryos are symbolized. They are a proof of fertility, a hope for another child. So, whatever the legal statement, couples will be in a dilemma because it is never easy for an infertile person to renounce to embryos, and the hope for children.

Usurpation of a Crowned Lapwing Vanellus coronatus nest by ...

African Journals Online (AJOL)

I report an instance of usurpation of a Crowned Lapwing Vanellus coronatus nest by a pair of African Wattled Lapwings Vanellus senegalensis. The nest, which originally contained a single Crowned Lapwing egg, eventually contained an additional three Wattled Lapwing eggs, before it was predated. Although parents of ...

Laboratory techniques for human embryos.

Science.gov (United States)

Geber, Selmo; Sales, Liana; Sampaio, Marcos A C

2002-01-01

This review is concerned with laboratory techniques needed for assisted conception, particularly the handling of gametes and embryos. Such methods are being increasingly refined. Successive stages of fertilization and embryogenesis require especial care, and often involve the use of micromanipulative methods for intracytoplasmic sperm injection (ICSI) or preimplantation genetic diagnosis. Embryologists must take responsibility for gamete collection and preparation, and for deciding on the means of insemination or ICSI. Embryos must be assessed in culture, during the 1-cell, cleaving and morula/blastocyst stages, and classified according to quality. Co-culture methods may be necessary. The best embryos for transfer must be selected and loaded into the transfer catheter. Embryos not transferred must be cryopreserved, which demands the correct application of current methods of media preparation, seeding and the correct speed for cooling and warming. Before too long, methods of detecting abnormal embryos and avoiding their transfer may become widespread.

In vitro embryo culture of rarely endangered musella lasiocarpa (musaceae) with embryo dormancy

International Nuclear Information System (INIS)

Anjun, T.

2014-01-01

Musella lasiocarpa (Musaceae) is an ornamental annually producing many viable seeds, but seldom recruited by seeds in the wild. One mature Musella seed has a small mushroom-shaped embryo without discernible organ differentiation. Therefore, freshly-harvested mature seeds are dormant. When the seeds gradually finished differentiation during warm stratification at 23 degree C, they germinated to 82%. Besides, extracted embryos from fresh seeds did not germinate on the basal medium of Murshige and Skoog medium (MS) supplemented with 3% sucrose and 0.8% agar, but they were induced to form calli and root by media. The optimum medium for inducing calli was MS + 1.0 mg/L 6-BA + 0.05 mg/L NAA + 100 mg/L Vc with the highest proliferation coefficient (7.3) in 35 days. Moreover, the embryos from the 6-month warm stratified seeds could proliferate on the suitable medium. The optimal medium for rooting was MS + 0.5 mg/L 2, 4-D + Vitamin C 100 mg/L. The results confirmed that both the embryo developmental stage and appropriate combination of chemicals significantly affected seed germination and In vitro embryo culture of this species. (author)

Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in water bird nests

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ?? 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ?? 1.6 days and 1.9 ?? 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ?? 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ?? 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates. ?? The Cooper Ornithological Society 2010.

Effects of embryo-derived exosomes on the development of bovine cloned embryos.

Directory of Open Access Journals (Sweden)

Pengxiang Qu

Full Text Available The developmental competence of in vitro cultured (IVC embryos is markedly lower than that of their in vivo counterparts, suggesting the need for optimization of IVC protocols. Embryo culture medium is routinely replaced three days after initial culture in bovine, however, whether this protocol is superior to continuous nonrenewal culture method under current conditions remains unclear. Using bovine somatic cell nuclear transfer (SCNT embryos as the model, our results showed that compared with routine renewal treatment, nonrenewal culture system significantly improved blastocyst formation, blastocyst quality (increased total cell number, decreased stress and apoptosis, enhanced Oct-4 expression and ratio of ICM/TE, as well as following development to term. Existence and function of SCNT embryo-derived exosomes were then investigated to reveal the cause of impaired development induced by culture medium replacement. Exosomes were successfully isolated through differential centrifugation and identified by both electron microscopy and immunostaining against exosomal membrane marker CD9. Supplementation of extracted exosomes into freshly renewed medium significantly rescued not only blastocyst formation and quality (in vitro development, but also following growth to term (in vivo development. Notably, ratio of ICM/TE and calving rate were enhanced to a similar level as that in nonrenewal group. In conclusion, our results for the first time indicate that 1: bovine SCNT embryos can secrete exosomes into chemically defined culture medium during IVC; 2: secreted exosomes are essential for SCNT blastocyst formation, blastocyst quality, and following development to term; 3: removal of exosomes induced by culture medium replacement impairs SCNT embryo development, which can be avoided by nonrenewal culture procedure or markedly recovered by exosome supplementation.

Feminists on the inalienability of human embryos.

Science.gov (United States)

McLeod, Carolyn; Baylis, Francoise

2006-01-01

The feminist literature against the commodification of embryos in human embryo research includes an argument to the effect that embryos are "intimately connected" to persons, or morally inalienable from them. We explore why embryos might be inalienable to persons and why feminists might find this view appealing. But, ultimately, as feminists, we reject this view because it is inconsistent with full respect for women's reproductive autonomy and with a feminist conception of persons as relational, embodied beings. Overall, feminists should avoid claims about embryos' being inalienable to persons in arguments for or against the commodification of human embryos.

An economic assessment of embryo diagnostics (Dx) - the costs of introducing non-invasive embryo diagnostics into IVF standard treatment practices.

Science.gov (United States)

Fugel, Hans-Joerg; Connolly, Mark; Nuijten, Mark

2014-10-09

New techniques in assessing oocytes and embryo quality are currently explored to improve pregnancy and delivery rates per embryo transfer. While a better understanding of embryo quality could help optimize the existing "in vitro fertilization" (IVF) therapy schemes, it is essential to address the economic viability of such technologies in the healthcare setting. An Embryo-Dx economic model was constructed to assess the cost-effectiveness of 3 different IVF strategies from a payer's perspective; it compares Embryo-Dx with single embryo transfer (SET) to elective single embryo transfer (eSET) and to double embryo transfer (DET) treatment practices. The introduction of a new non-invasive embryo technology (Embryo-Dx) associated with a cost up to €460 is cost-effective compared to eSET and DET based on the cost per live birth. The model assumed that Embryo-Dx will improve ongoing pregnancy rate/realize an absolute improvement in live births of 9% in this case. This study shows that improved embryo diagnosis combined with SET may have the potential to reduce the cost per live birth per couple treated in IVF treatment practices. The results of this study are likely more sensitive to changes in the ongoing pregnancy rate and consequently the live birth rate than the diagnosis costs. The introduction of a validated Embryo-Dx technology will further support a move towards increased eSET procedures in IVF clinical practice and vice versa.

Discover POPSCIENCE on Researchers' Night

CERN Multimedia

The POPSCIENCE Team

2014-01-01

On Friday 26 September 2014, CERN will be celebrating European Researchers' Night at three venues in Geneva and St. Genis-Pouilly. Inspired by Andy Warhol, this year's theme is “Pop science is for everyone”.     Every year, on the last Friday of September, the European Researchers’ Night takes place in about 300 cities all over Europe, with funding from the EU, to promote research and highlight researchers in engaging and fun ways for the general public. Andy Warhol said, “Pop art is for everyone”. This year, “Pop science is for everyone” is the motto of the Researchers’ Night event organised by CERN and its partners*. The night will offer everyone the opportunity to learn about the latest discoveries in physics and cosmology through poetry, theatre and music. This will be in addition to the event's traditional activities for the general public. To attract new audiences,...

In vitro culture of individual mouse preimplantation embryos: the role of embryo density, microwells, oxygen, timing and conditioned media.

Science.gov (United States)

Kelley, Rebecca L; Gardner, David K

2017-05-01

Single embryo culture is suboptimal compared with group culture, but necessary for embryo monitoring, and culture systems should be improved for single embryos. Pronucleate mouse embryos were used to assess the effect of culture conditions on single embryo development. Single culture either before or after compaction reduced cell numbers (112.2 ± 3.1; 110.2 ± 3.5) compared with group culture throughout (127.0 ± 3.4; P media volume from 20 µl to 2 µl increased blastocyst cell numbers in single embryos cultured in 5% oxygen (84.4 ± 3.2 versus 97.8 ± 2.8; P Culture in microwell plates for the EmbryoScope and Primo Vision time-lapse systems changed cleavage timings and increased inner cell mass cell number (24.1 ± 1.0; 23.4 ± 1.2) compared with a 2 µl microdrop (18.4 ± 1.0; P media to single embryos increased hatching rate and blastocyst cell number (91.5 ± 4.7 versus 113.1 ± 4.4; P culture before or after compaction is therefore detrimental; oxygen, media volume and microwells influence single embryo development; and embryo-conditioned media may substitute for group culture. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Non-invasive metabolomic profiling of embryo culture media and morphology grading to predict implantation outcome in frozen-thawed embryo transfer cycles.

Science.gov (United States)

Li, Xiong; Xu, Yan; Fu, Jing; Zhang, Wen-Bi; Liu, Su-Ying; Sun, Xiao-Xi

2015-11-01

Assessment of embryo viability is a crucial component of in vitro fertilization and currently relies largely on embryo morphology and cleavage rate. Because morphological assessment remains highly subjective, it can be unreliable in predicting embryo viability. This study investigated the metabolomic profiling of embryo culture media using near-infrared (NIR) spectroscopy for predicting the implantation potential of human embryos in frozen-thawed embryo transfer (FET) cycles. Spent embryo culture media was collected on day 4 after thawed embryo transfer (n = 621) and analysed using NIR spectroscopy. Viability scores were calculated using a predictive multivariate algorithm of fresh embryos with known pregnancy outcomes. The mean viability indices of embryos resulting in clinical pregnancy following FET were significantly higher than those of non-implanted embryos and differed between the 0, 50, and 100 % implantation groups. Notably, the 0 % group index was significantly lower than the 100 % implantation group index (-0.787 ± 0.382 vs. 1.064 ± 0.331, P  0.05). NIR metabolomic profiling of thawed embryo culture media is independent of morphology and correlates with embryo implantation potential in FET cycles. The viability score alone or in conjunction with morphologic grading is a more objective marker for implantation outcome in FET cycles than morphology alone.

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

Science.gov (United States)

González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

2014-01-01

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

Embryo quality and impact of specific embryo characteristics on ongoing implantation in unselected embryos derived from modified natural cycle in vitro fertilization

NARCIS (Netherlands)

Pelinck, Marie-Jose; Hoek, Annemieke; Simons, Arnold H. M.; Heineman, Maas Jan; van Echten-Arends, Janny; Arts, Eus G. J. M.

Objective: To study the implantation potential of unselected embryos derived from modified natural cycle IVF according to their morphological characteristics. Design: Cohort study. Setting: Academic department of reproductive medicine. Patient(S): A series of 449 single embryo transfers derived from

Canopy Fuel Load Mapping of Mediterranean Pine Sites Based on Individual Tree-Crown Delineation

Directory of Open Access Journals (Sweden)

Giorgos Mallinis

2013-12-01

Full Text Available This study presents an individual tree-crown-based approach for canopy fuel load estimation and mapping in two Mediterranean pine stands. Based on destructive sampling, an allometric equation was developed for the estimation of crown fuel weight considering only pine crown width, a tree characteristic that can be estimated from passive imagery. Two high resolution images were used originally for discriminating Aleppo and Calabrian pines crown regions through a geographic object based image analysis approach. Subsequently, the crown region images were segmented using a watershed segmentation algorithm and crown width was extracted. The overall accuracy of the tree crown isolation expressed through a perfect match between the reference and the delineated crowns was 34.00% for the Kassandra site and 48.11% for the Thessaloniki site, while the coefficient of determination between the ground measured and the satellite extracted crown width was 0.5. Canopy fuel load values estimated in the current study presented mean values from 1.29 ± 0.6 to 1.65 ± 0.7 kg/m2 similar to other conifers worldwide. Despite the modest accuracies attained in this first study of individual tree crown fuel load mapping, the combination of the allometric equations with satellite-based extracted crown width information, can contribute to the spatially explicit mapping of canopy fuel load in Mediterranean areas. These maps can be used among others in fire behavior prediction, in fuel reduction treatments prioritization and during active fire suppression.

Methanol as a cryoprotectant for equine embryos.

Science.gov (United States)

Bass, L D; Denniston, D J; Maclellan, L J; McCue, P M; Seidel, G E; Squires, E L

2004-09-15

Equine embryos (n=43) were recovered nonsurgically 7-8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 48% (15M) methanol (n=22) or 10% (136 M) glycerol (n=21). Embryos (300-1000 microm) were measured at five intervals after exposure to glycerol (0, 2, 5, 10 and 15 min) or methanol (0, 15, 35, 75 and 10 min) to determine changes (%) in diameter over time (+/-S.D.). Embryos were loaded into 0.25-ml plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22 degrees C) to -6 degrees C. Straws were then seeded, held at -6 degrees C for 10 min and then cooled to -33 degrees C before being plunged into liquid nitrogen. Two or three embryos within a treatment group were thawed and assigned to be either cultured for 12 h prior to transfer or immediately nonsurgically transferred to a single mare. Embryo diameter decreased in all embryos upon initial exposure to cryoprotectant. Embryos in methanol shrank and recovered slightly to 76+/-8 % of their original diameter; however, embryos in glycerol continued to shrink, reaching 57+/-6 % of their original diameter prior to cryopreservation. Survival rates of embryos through Day 16 of pregnancy were 38 and 23%, respectively (P>0.05) for embryos cryopreserved in the presence of glycerol or methanol. There was no difference in pregnancy rates of mares receiving embryos that were cultured prior to transfer or not cultured (P>0.05). Preliminary experiments indicated that 48% methanol was not toxic to fresh equine embryos but methanol provided no advantage over glycerol as a cryoprotectant for equine blastocysts.

Failure analysis of various monolithic posterior aesthetic dental crowns using finite element method

Science.gov (United States)

Porojan, Liliana; Topală, Florin

2017-08-01

The aim of the study was to assess the effect of material stiffness and load on the biomechanical performance of the monolithic full-coverage posterior aesthetic dental crowns using finite element analysis. Three restorative materials for monolithic dental crowns were selected for the study: zirconia; lithium disilicate glass-ceramic, and resin-based composite. Stresses were calculated in the crowns for all materials and in the teeth structures, under different load values. The experiments show that dental crowns made from all this new aesthetic materials processed by CAD/CAM technologies would be indicated as monolithic dental crowns for posterior areas.

Non-invasive analysis of bovine embryo metabolites during in vitro embryo culture using nuclear magnetic resonance

Directory of Open Access Journals (Sweden)

Marcello Rubessa

2016-12-01

Full Text Available The ability to identify embryos that have the highest developmental potential from a cohort would significantly increase the chances of achieving pregnancy. Metabolic analysis is a well-established analytical approach in biological systems. Starting from this idea, we chose to use high-resolution nuclear magnetic resonance (1H-NMR spectroscopy. The aim of this study was to determine if it is possible to select viable embryos after 48 h of culture using metabolic activity as the parameter. We evaluated embryo metabolism after the first 48 h of culture and compared the activity of cleaved embryos that became blastocysts to cleaved embryos that did not develop to blastocysts, and in vitro fertilized (IVF blastocysts and parthenogenetic-activated (PA blastocysts. Our results show that citrate, pyruvate, myo-inositol and lysine have great impact on predicting embryo development. When we compared IVF and PA blastocysts, we found that acetate and phenylalanine concentrations are excellent parameters for evaluating blastocyst quality. Combining all these results, we were able to create a formula that predicts zygote development after 2 days of culture. In conclusion, we found that it is possible predict the future development of in vitro produced bovine embryos after only 2 days of culture using 1H-NMR.

Genome-Wide Association Mapping of Crown Rust Resistance in Oat Elite Germplasm.

Science.gov (United States)

Klos, Kathy Esvelt; Yimer, Belayneh A; Babiker, Ebrahiem M; Beattie, Aaron D; Bonman, J Michael; Carson, Martin L; Chong, James; Harrison, Stephen A; Ibrahim, Amir M H; Kolb, Frederic L; McCartney, Curt A; McMullen, Michael; Fetch, Jennifer Mitchell; Mohammadi, Mohsen; Murphy, J Paul; Tinker, Nicholas A

2017-07-01

Oat crown rust, caused by f. sp. , is a major constraint to oat ( L.) production in many parts of the world. In this first comprehensive multienvironment genome-wide association map of oat crown rust, we used 2972 single-nucleotide polymorphisms (SNPs) genotyped on 631 oat lines for association mapping of quantitative trait loci (QTL). Seedling reaction to crown rust in these lines was assessed as infection type (IT) with each of 10 crown rust isolates. Adult plant reaction was assessed in the field in a total of 10 location-years as percentage severity (SV) and as infection reaction (IR) in a 0-to-1 scale. Overall, 29 SNPs on 12 linkage groups were predictive of crown rust reaction in at least one experiment at a genome-wide level of statistical significance. The QTL identified here include those in regions previously shown to be linked with seedling resistance genes , , , , , and and also with adult-plant resistance and adaptation-related QTL. In addition, QTL on linkage groups Mrg03, Mrg08, and Mrg23 were identified in regions not previously associated with crown rust resistance. Evaluation of marker genotypes in a set of crown rust differential lines supported as the identity of . The SNPs with rare alleles associated with lower disease scores may be suitable for use in marker-assisted selection of oat lines for crown rust resistance. Copyright © 2017 Crop Science Society of America.

Improving embryo quality in assisted reproduction

NARCIS (Netherlands)

Mantikou, E.

2013-01-01

The goal of this thesis was to improve embryo quality in assisted reproductive technologies by gaining more insight into human preimplantation embryo development and by improving in vitro culture conditions. To do so, we investigated an intriguing feature of the human preimplantation embryo, i.e.

Traffic Light Detection at Night

DEFF Research Database (Denmark)

Jensen, Morten Bornø; Philipsen, Mark Philip; Bahnsen, Chris

2015-01-01

Traffic light recognition (TLR) is an integral part of any in- telligent vehicle, it must function both at day and at night. However, the majority of TLR research is focused on day-time scenarios. In this paper we will focus on detection of traffic lights at night and evalu- ate the performance...... of three detectors based on heuristic models and one learning-based detector. Evaluation is done on night-time data from the public LISA Traffic Light Dataset. The learning-based detector out- performs the model-based detectors in both precision and recall. The learning-based detector achieves an average...

Zirconia crowns for rehabilitation of decayed primary incisors: an esthetic alternative.

Science.gov (United States)

Ashima, G; Sarabjot, K Bhatia; Gauba, K; Mittal, H C

2014-01-01

Esthetic management of extensively decayed primary maxillary anterior teeth requiring full coronal coverage restoration is usually challenging to the pediatric dentists especially in very young children. Many esthetic options have been tried over the years each having its own advantages, disadvantages and associated technical, functional or esthetic limitations. Zirconia crowns have provided a treatment alternative to address the esthetic concerns and ease of placement of extra-coronal restorations on primary anterior teeth. The present article presents a case where grossly decayed maxillary primary incisors were restored esthetically and functionally with ready made zirconia crowns (ZIRKIZ, HASS Corp; Korea). After endodontic treatment the decayed teeth were restored with zirconia crowns. Over a 30 months period, the crowns have demonstrated good retention and esthetic results. Dealing with esthetic needs in children with extensive loss of tooth structure, using Zirconia crowns would be practical and successful. The treatment described is simple and effective and represents a promising alternative for rehabilitation of decayed primary teeth.

Application of terrestrial laser scanning for measuring tree crown structures

International Nuclear Information System (INIS)

Pretzsch, H.; Seifert, S.; Huang, P.

2011-01-01

This paper addresses the potential of terrestrial laser scanning (TLS) for describing and modelling of tree crown structure and dynamics. We first present a general approach for the metabolic and structural scaling of tree crowns. Out of this approach we emphasize those normalization and scaling parameters which become accessible by TLS. For example we show how the individual tree leaf area index, convex hull, and its space-filling by leaves can be extracted out of laser scan data. This contributes to a theoretical and empirical substantiation of crown structure models which were missing so far for e.g. quantification of structural and species diversity in forest stands, inventory of crown biomass, species detection by remote sensing, and understanding of self- and alien-thinning in pure and mixed stands. Up to now works on this topic delivered a rather scattered empirical knowledge mainly by single inventories of trees and stands. In contrast, we recommend to start with a model approach, and to complete existing data with repeated TLS inventories in order to come to a consistent and theoretically based model of tree crowns. (author) [de

Experimental investigation of the abrasive crown dynamics in orbital atherectomy.

Science.gov (United States)

Zheng, Yihao; Belmont, Barry; Shih, Albert J

2016-07-01

Orbital atherectomy is a catheter-based minimally invasive procedure to modify the plaque within atherosclerotic arteries using a diamond abrasive crown. This study was designed to investigate the crown motion and its corresponding contact force with the vessel. To this end, a transparent arterial tissue-mimicking phantom made of polyvinyl chloride was developed, a high-speed camera and image processing technique were utilized to visualize and quantitatively analyze the crown motion in the vessel phantom, and a piezoelectric dynamometer measured the forces on the phantom during the procedure. Observed under typical orbital atherectomy rotational speeds of 60,000, 90,000, and 120,000rpm in a 4.8mm caliber vessel phantom, the crown motion was a combination of high-frequency rotation at 1000, 1500, and 1660.4-1866.1Hz and low-frequency orbiting at 18, 38, and 40Hz, respectively. The measured forces were also composed of these high and low frequencies, matching well with the rotation of the eccentric crown and the associated orbital motion. The average peak force ranged from 0.1 to 0.4N at different rotational speeds. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Lipid content and cryotolerance of in vitro-produced bovine embryos treated with forskolin before vitrification

Directory of Open Access Journals (Sweden)

Melissa Meneghel

Full Text Available ABSTRACT: The aim of the present study was to evaluate the intracytoplasmic lipid content, development and cryotolerance of in vitro-produced bovine embryos treated with different concentrations of forskolin before vitrification. Embryos were produced from abattoir-derived ovaries and allocated into four groups. In the treatment groups, forskolin was added to the in vitro culture medium on Day 6 and incubated for 24 hours in one of the following concentrations: 2.5μM (Forsk 2.5 group, 5.0μM (Forsk 5.0 group or 10.0μM (Forsk 10.0 group. Embryos from the control group were cultured without forskolin. On Day 7 of culture, the expanded blastocysts were stained with the lipophilic dye Sudan Black B for determination of the intracytoplasmic lipid content or were cryopreserved via the Vitri-Ingá® procedure. Although there were no significant differences (P>0.05 in the blastocyst rates between the Control group (44.9% and the other treatments, the embryo production was lower (P0.05 to that found in Forsk 2.5 (0.92±0.03 and Forsk 10.0 groups (1.06±0.03 groups; however the lipid accumulation in blastocysts from Forsk 5.0 group (0.82±0.04 was lower than in the Control group (P<0.05. Based on these results, Forsk 5.0 treatment was tested for cryotolerance and it was observed that the blastocoel re-expansion rate evaluated 24 hours after warming was greater (P<0.05 in Forsk 5.0 group (72.2% compared to the Control group (46.2%. In conclusion, pre-treatment with forskolin at a concentration of 5.0 μM for 24 hours before vitrification is effective in reducing the intracytoplasmic lipid content and, consequently, improves cryotolerance of IVP bovine embryos.

Effect of embryo age and recipient asynchrony on pregnancy rates in a commercial equine embryo transfer program.

Science.gov (United States)

Jacob, J C F; Haag, K T; Santos, G O; Oliveira, J P; Gastal, M O; Gastal, E L

2012-04-01

In the present study, 809 uterine flushes and 454 embryo transfers performed in mares over a 4-yr interval were examined to evaluate the effects of: (1) the day of embryo collection on recovery rates; (2) the degree of synchrony between donor and recipient mares on pregnancy rates; (3) the recipient day post ovulation on pregnancy rates; and (4) the age of the embryo at recovery on pregnancy rates at 60 days. Uterine flushes were performed on Days 6, 7, 8, 9, and 10 (Day 0 = ovulation) and embryos were transferred to recipients with degrees of synchrony varying between +1 to -6 (recipient ovulated 1 day before through 6 days after the donor). Recipient mares ranged from 2 to 8 days post ovulation. Embryo recovery rates were similar for flushes performed on Day 7 (61%), Day 8 (66%), Day 9 (59%), and Day 10 (56%), but the embryo recovery rate was lower (P recipient mares on Day 2 (33%) compared with mares on Day 3 (66%), Day 4 (66%), Day 5 (62%), Day 6 (55%), Day 7 (58%), and Day 8 (56%). Pregnancy rate was higher (P recipient mares does not need to be as restricted as previously reported in horses. Acceptable pregnancy rates (e.g., 70%, 99/142) were obtained even when recipient mares ovulated 4 to 5 days after the donors; (3) similar pregnancy rates were obtained when recipient mares received embryos within a large range of days post ovulation (Days 3 to 8); and (4) Day 7 embryos produced higher pregnancy rates when compared with Days 8 and 9 embryos. In clinical terms, the application of these new findings will be beneficial to large equine embryo transfer operations in producing more pregnancies per season. Copyright © 2012 Elsevier Inc. All rights reserved.

Laser confers less embryo exposure than acid tyrode for embryo biopsy in preimplantation genetic diagnosis cycles: a randomized study.

Science.gov (United States)

Geber, Selmo; Bossi, Renata; Lisboa, Cintia B; Valle, Marcelo; Sampaio, Marcos

2011-04-28

We compared two methods of zona pellucida drilling. 213 embryos were biopsied with acid Tyrode. Each biopsy took 3 minutes and the entire procedure ~29 minutes. 5% of blastomeres lysed, 49% of embryos became blastocyst and 36% of patients became pregnant. 229 embryos were biopsied with laser. Each biopsy took 30 seconds and the entire procedure ~7 minutes. 2.5% of blastomeres lysed, 50.6% of embryos became blastocyst and 47% of patients became pregnant. We can conclude that laser can be used for embryo biopsy. Reduction of embryo exposure and of removed blastomeres is associated with increased blastocysts available for transfer and a better clinical outcome.

Laser confers less embryo exposure than acid tyrode for embryo biopsy in preimplantation genetic diagnosis cycles: a randomized study

Directory of Open Access Journals (Sweden)

Valle Marcelo

2011-04-01

Full Text Available Abstract We compared two methods of zona pellucida drilling. 213 embryos were biopsied with acid Tyrode. Each biopsy took 3 minutes and the entire procedure ~29 minutes. 5% of blastomeres lysed, 49% of embryos became blastocyst and 36% of patients became pregnant. 229 embryos were biopsied with laser. Each biopsy took 30 seconds and the entire procedure ~7 minutes. 2.5% of blastomeres lysed, 50.6% of embryos became blastocyst and 47% of patients became pregnant. We can conclude that laser can be used for embryo biopsy. Reduction of embryo exposure and of removed blastomeres is associated with increased blastocysts available for transfer and a better clinical outcome.

Uniform versus asymmetric shading mediates crown recession in conifers.

Directory of Open Access Journals (Sweden)

Amanda L Schoonmaker

Full Text Available In this study we explore the impact of asymmetrical vs. uniform crown shading on the mortality and growth of upper and lower branches within tree crowns, for two conifer species: shade intolerant lodgepole pine (Pinus contorta and shade tolerant white spruce (Picea glauca. We also explore xylem hydraulics, foliar nutrition, and carbohydrate status as drivers for growth and expansion of the lower and upper branches in various types of shading. This study was conducted over a two-year period across 10 regenerating forest sites dominated by lodgepole pine and white spruce, in the lower foothills of Alberta, Canada. Trees were assigned to one of four shading treatments: (1, complete uniform shading of the entire tree, (2 light asymmetric shading where the lower 1/4-1/3 of the tree crown was shaded, (3 heavy asymmetric shading as in (2 except with greater light reduction and (4 control in which no artificial shading occurred and most of the entire crown was exposed to full light. Asymmetrical shading of only the lower crown had a larger negative impact on the bud expansion and growth than did uniform shading, and the effect was stronger in pine relative to spruce. In addition, lower branches in pine also had lower carbon reserves, and reduced xylem-area specific conductivity compared to spruce. For both species, but particularly the pine, the needles of lower branches tended to store less C than upper branches in the asymmetric shade, which could suggest a movement of reserves away from the lower branches. The implications of these findings correspond with the inherent shade tolerance and self-pruning behavior of these conifers and supports a carbon based mechanism for branch mortality--mediated by an asymmetry in light exposure of the crown.

Volunteers for Researchers’ Night wanted

CERN Multimedia

Katarina Anthony

2015-01-01

Every year, on the last Friday of September, the European Researchers’ Night (see here) takes place in about 300 cities all over Europe - promoting research in engaging and fun ways for the general public. This year, CERN will be participating once again, hosting dozens of events across the Balexert shopping centre – and we’ll need YOUR help to make the celebration a success.   From film screenings and celebrity Q&A sessions to “Ask a Researcher” and build-your-own LEGO LHC events, this year’s Researchers’ Night is going to be jam-packed! The fun will kick off prior to the night itself with a mock-up of the LHC tunnel installed in the central court of the Balexert shopping centre, 8-12 September*. CERN people will be on hand to speak to shoppers about the LHC, and to encourage them to participate in Researchers’ Night! The CERN organisers are recruiting volunteers and support staff for Researchers’ ...

Psychological study of in vitro fertilization-embryo transfer participants' attitudes toward the destiny of their supernumerary embryos.

Science.gov (United States)

Laruelle, C; Englert, Y

1995-05-01

To study the motivations underlying IVF-ET participants' choice to donate or destroy their supernumerary embryos. Couples' opinions are studied through a questionnaire and a psychological interview. Two hundred couples about to undergo IVF-ET. The fertility unit of an academic hospital. Couples' choice for supernumerary embryos' destiny; opinions on embryo status, on importance of genetic lineage in the filial bonding, on gamete donation, and on multiple pregnancy risk. Donation is the most frequent choice but destruction is tolerated by almost all the couples (92%). Couples considering the embryo as a child choose destruction as frequently as donation but refuse experimentation on the embryo. Donation is highest among couples who stress education more than genetic lineage in parental bonding. This is confirmed by the choice of the couples requiring donor gametes. Couples express differing attitudes toward risks of twins and risks of triplets: twins are much more desired than triplets, which are frequently refused. Couples' opinions on the respective importance of genetic lineage and education in defining parental bonding are more determinant in their decision to destroy or to donate their supernumerary embryos than their opinions on the in vitro embryo status, which only determines their attitude toward experimentation.

Mechanistic dissection of plant embryo initiation

NARCIS (Netherlands)

Radoeva, T.M.

2016-01-01

Land plants can reproduce sexually by developing an embryo from a fertilized egg cell, the zygote. After fertilization, the zygote undergoes several rounds of controlled cell divisions to generate a mature embryo. However, embryo formation can also be induced in a variety of other cell types in

The First Human Cloned Embryo.

Science.gov (United States)

Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

2002-01-01

Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

5 CFR 532.505 - Night shift differentials.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Night shift differentials. 532.505... PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.505 Night shift differentials. (a) Employees shall be entitled to receive night shift differentials in accordance with section 5343 of title 5...

Effect of culture medium volume and embryo density on early mouse embryonic development: tracking the development of the individual embryo.

Science.gov (United States)

Dai, Shan-Jun; Xu, Chang-Long; Wang, Jeffrey; Sun, Ying-Pu; Chian, Ri-Cheng

2012-07-01

To determine the optimal volume or density of embryos for the well-of-the-well (WOW) system in order to track the development of individual embryos and to determine whether the WOW system can reverse the negative impact of culturing embryos singly. (1) Mouse embryos (groups of nine at the 2-cell stage) were cultured in 6.25 μl, 12.50 μl, 25.00 μl and 50.00 μl of droplets of culture medium under paraffin oil; (2) Groups of three, six, nine and twelve embryos at the 2-cell stage were cultured in 50 μl of droplet of culture medium under paraffin oil; (3) Groups of nine embryos at the 2-cell stage were cultured in 50 μl of droplet under paraffin oil with or without nine micro-wells made on the bottom of the Petri dish into each of which were placed one of the nine embryos (WOW system). Also single 2-cell stage embryos was cultured individually in 5.5 μl of droplet of culture medium under paraffin oil with or without a single micro-well made on the bottom of the Petri dish (WOW system for single culture). At the end of culture, the percentages of blastocyst development, hatching and hatched blastocysts were compared in each group. The blastocysts were fixed for differential staining. The blastocyst development was significantly higher (P WOW system. The blastocyst development was not improved when single embryo cultured individually in a micro-well was compared to single embryo cultured individually without micro-well. The total cell numbers of blastocysts were significantly higher in group embryo culture than single embryo culture regardless of whether the WOW system was used. In addition, the total cell numbers of blastocysts were significantly higher (P WOW system than without. Group embryo culture is superior to single embryo culture for blastocyst development. The WOW system with 50 μl of droplet of culture medium can be used to track the individual development of embryo cultured in groups while preserving good embryonic development. The reduced

Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

Science.gov (United States)

Shi, Li-Hong; Miao, Yi-Liang; Ouyang, Ying-Chun; Huang, Jun-Cheng; Lei, Zi-Li; Yang, Ji-Wen; Han, Zhi-Ming; Song, Xiang-Fen; Sun, Qing-Yuan; Chen, Da-Yuan

2008-03-01

The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development. (c) 2008 Wiley-Liss, Inc.

Noninvasive metabolomic profiling as an adjunct to morphology for noninvasive embryo assessment in women undergoing single embryo transfer

NARCIS (Netherlands)

Seli, E.; Vergouw, C.G.; Morita, H.; Botros, L.; Roos, P.; Lambalk, C.B.; Yamashita, N.; Kato, O.; Sakkas, D.

2010-01-01

Objective: To determine whether metabolomic profiling of spent embryo culture media correlates with reproductive potential of human embryos. Design: Retrospective study. Setting: Academic and a private assisted reproductive technology (ART) programs. Patient(s): Women undergoing single embryo

Phototaxis and polarotaxis hand in hand: night dispersal flight of aquatic insects distracted synergistically by light intensity and reflection polarization

Science.gov (United States)

Boda, Pál; Horváth, Gábor; Kriska, György; Blahó, Miklós; Csabai, Zoltán

2014-05-01

Based on an earlier observation in the field, we hypothesized that light intensity and horizontally polarized reflected light may strongly influence the flight behaviour of night-active aquatic insects. We assumed that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of these insects than they would have separately. We tested this hypothesis in a multiple-choice field experiment using horizontal test surfaces laid on the ground. We offered simultaneously the following visual stimuli for aerial aquatic insects: (1) lamplit matte black canvas inducing phototaxis alone, (2) unlit shiny black plastic sheet eliciting polarotaxis alone, (3) lamplit shiny black plastic sheet inducing simultaneously phototaxis and polarotaxis, and (4) unlit matte black canvas as a visually unattractive control. The unlit matte black canvas trapped only a negligible number (13) of water insects. The sum (16,432) of the total numbers of water beetles and bugs captured on the lamplit matte black canvas (7,922) and the unlit shiny black plastic sheet (8,510) was much smaller than the total catch (29,682) caught on the lamplit shiny black plastic sheet. This provides experimental evidence for the synergistic interaction of phototaxis (elicited by the unpolarized direct lamplight) and polarotaxis (induced by the strongly and horizontally polarized plastic-reflected light) in the investigated aquatic insects. Thus, horizontally polarizing artificial lamplit surfaces can function as an effective ecological trap due to this synergism of optical cues, especially in the urban environment.

Die Behandlung menschliches Embryos und Menschenwurde

OpenAIRE

Matsui, Fumio

2002-01-01

We are confronted with an old and new problem, which has come up with the progress of modern biotechnologies: what is a life or when does a life begin? The expectation of order-made medicine has build up since the discovery of Embryo Stem cell called "a dream master cell", while there is any condemnation against the destruction of human embryo in order to gain it. It is a question whether a human embryo is a human being in the world. Human dignity(=HD) is a principle that keeps human embryos ...

Fracture load of different crown systems on zirconia implant abutments.

Science.gov (United States)

Albrecht, T; Kirsten, A; Kappert, H F; Fischer, H

2011-03-01

The purpose of this study was to evaluate the fracture load of single zirconia abutment restorations using different veneering techniques and materials. The abutment restorations were divided into 6 groups with 20 samples each: test abutments (control group A), lithium disilicate ceramic crowns bonded on incisor abutments (group B), leucite ceramic crowns bonded on incisor abutments (group C), premolar abutments directly veneered with a fluor apatite ceramic (group D (layered) and group E (pressed)) and premolar abutments bonded with lithium disilicate ceramic crowns (group F). The fracture load of the restorations was evaluated using a universal testing machine. Half of each group was artificially aged (chewing simulation and thermocycling) before evaluating the fracture load with the exception of the test abutments. The fracture load of the test abutments was 705 ± 43N. Incisor abutments bonded with lithium disilicate or leucite ceramic crowns (groups B and C) showed fracture loads of about 580N. Premolar restorations directly veneered with fluor apatite ceramic (groups D and E) showed fracture loads of about 850N. Premolar restorations bonded with lithium disilicate ceramic crowns (group F) showed fracture loads of about 1850N. The artificial ageing showed no significant influence on the strength of the examined restorations. All ceramic crowns made of lithium disilicate glass-ceramic, adhesively bonded to premolar abutments showed the highest fracture loads in this study. However, all tested groups can withstand physiological bite forces. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Telescopic crowns as attachments for implant supported restorations: a case series.

Science.gov (United States)

Hoffmann, Oliver; Beaumont, Christian; Tatakis, Dimitris N; Zafiropoulos, Gregory-George

2006-01-01

The use of dental implants to support mandibular or maxillary overdentures is a widely used treatment modality. Advantages are an increase in retention, an increase in chewing ability, and easy access for oral hygiene procedures. While telescopic and conical crowns have been used for decades to connect natural teeth to overdentures, not many cases have been reported in the literature of telescopic crowns placed on implants to support overdentures. This article describes 7 patients with overdentures supported by telescopic crowns who received 65 implants (ITI Straumann). The cases presented in this report have been in function for up to 4.5 years. During that time no adverse events were reported. The use of telescopic crowns as attachments for implant-supported overdentures may be a viable treatment option.

Night airglow in RGB mode

Directory of Open Access Journals (Sweden)

Mikhalev А.V.

2016-09-01

Full Text Available To study dynamics of the upper atmosphere, we consider results of the night sky photometry, using a color CCD camera and taking into account the night airglow and features of its spectral composition. We use night airglow observations for 2010–2015, which have been obtained at the ISTP SB RAS Geophysical Observatory (52° N, 103° E by the camera with KODAK KAI-11002 CCD sensor. We estimate average brightness of the night sky in R, G, B channels of the color camera for eastern Siberia with typical values ranging from ~0.008 to 0.01 erg·cm–2·s–1. Besides, we determine seasonal variations in the night sky luminosities in R, G, B channels of the color camera. In these channels, luminosities decrease in spring, increase in autumn, and have a pronounced summer maximum, which can be explained by scattered light and is associated with the location of the Geophysical Observatory. We consider geophysical phenomena with their optical effects in R, G, B channels of the color camera. For some geophysical phenomena (geomagnetic storms, sudden stratospheric warmings, we demonstrate the possibility of quantitative relationship between enhanced signals in R and G channels and increases in intensities of discrete 557.7 and 630 nm emissions, which are predominant in the airglow spectrum

Patients' Attitudes towards the Surplus Frozen Embryos in China

Directory of Open Access Journals (Sweden)

Xuan Jin

2013-01-01

Full Text Available Background. Assisted reproductive techniques have been used in China for more than 20 years. This study investigates the attitudes of surplus embryo holders towards embryos storage and donation for medical research. Methods. A total of 363 couples who had completed in vitro fertilization (IVF treatment and had already had biological children but who still had frozen embryos in storage were invited to participate. Interviews were conducted by clinics in a narrative style. Results. Family size was the major reason for participants’ (discontinuation of embryo storage; moreover, the moral status of embryos was an important factor for couples choosing embryo storage, while the storage fee was an important factor for couples choosing embryo disposal. Most couples discontinued the storage of their embryos once their children were older than 3 years. In our study, 58.8% of the couples preferred to dispose of surplus embryos rather than donate them to research, citing a lack of information and distrust in science as significant reasons for their decision. Conclusions. Interviews regarding frozen embryos, including patients’ expectations for embryo storage and information to assist them with decisions regarding embryo disposal, are beneficial for policies addressing embryo disposition and embryo donation in China.

Clinical performance - a reflection of damage accumulation in ceramic dental crowns

Energy Technology Data Exchange (ETDEWEB)

Rekow, D.E. [Univ. of Medicine and Dentistry of New Jersey, Newark, NJ (United States). Dept. of Orthodontics; Thompson, V.P. [Univ. of Medicine and Dentistry of New Jersey, Newark, NJ (United States). New Jersey Dental School

2001-07-01

All-ceramic dental crowns have tremendous appeal for patients - their esthetics nearly match those of natural teeth. Unfortunately, the most esthetic materials are brittle and, consequently, are vulnerable to damage relating to shaping which is exacerbated during cyclic loading during normal chewing. Clinical performance of all-ceramic dental prostheses are directly dependent on damage introduced during fabrication and during fatigue loading associated with function. The accumulation of damage results in unacceptably high failure rates (where failure is defined as a complete fracture requiring replacement of the prosthesis). The relation between shaping damage and fatigue damage on clinical performance of all-ceramic dental crowns was investigated. Materials used commercially for all-ceramic crowns and investigated in this study included a series of different microstructures of machinable glass ceramics (Corning), aluminas and porcelains (Vita Zahnfabrik), and zirconia (Norton). As monolithic materials, strong, tough, fatigue-resistant materials are not sufficiently esthetic for crowns. Crowns fabricated from monolithic esthetic materials have high failure rates. Layering ceramics could provide acceptable strength through management of damage accumulation. (orig.)

Effects of crown release on growth and quality of even-aged red maple stands

Science.gov (United States)

Terry F. Strong; Audra E. Hubbell; Adam H. Weise; Gayne G. Erdmann

2006-01-01

The effects of six crown-release treatments on growth and bole quality of 54 dominant, codominant, and intermediate red maples (Acer rubrum L.) were examined in an even-aged stand in upper Michigan. Treatments included an unreleased control, a single-tree and a two-tree crown release, and a full crown-to-crown release of 5, 10, and 15ft. Twenty-two...

Meanings of the embryo in Japan: narratives of IVF experience and embryo ownership

NARCIS (Netherlands)

Kato, M.; Sleeboom-Faulkner, M.

2011-01-01

This article explores the sociocultural meanings of the embryo implied in the narratives of 58 women who have undergone in vitro fertilisation in Japan over a period from 2006 to 2008. We argue that a lack of sufficient analysis of the sociocultural meanings of the embryo result in a situation where

[Comparative adaptation of crowns of selective laser melting and wax-lost-casting method].

Science.gov (United States)

Li, Guo-qiang; Shen, Qing-yi; Gao, Jian-hua; Wu, Xue-ying; Chen, Li; Dai, Wen-an

2012-07-01

To investigate the marginal adaptation of crowns fabricated by selective laser melting (SLM) and wax-lost-casting method, so as to provide an experimental basis for clinic. Co-Cr alloy full crown were fabricated by SLM and wax-lost-casting for 24 samples in each group. All crowns were cemented with zinc phosphate cement and cut along longitudinal axis by line cutting machine. The gap between crown tissue surface and die was measured by 6-point measuring method with scanning electron microscope (SEM). The marginal adaptation of crowns fabricated by SLM and wax-lost-casting were compared statistically. The gap between SLM crowns were (36.51 ± 2.94), (49.36 ± 3.31), (56.48 ± 3.35), (42.20 ± 3.60) µm, and wax-lost-casting crowns were (68.86 ± 5.41), (58.86 ± 6.10), (70.62 ± 5.79), (69.90 ± 6.00) µm. There were significant difference between two groups (P casting method and SLM method provide acceptable marginal adaptation in clinic, and the marginal adaptation of SLM is better than that of wax-lost-casting method.

The general properties of water - nitrobenzene - crown - bis-1,2-dicarbollylcobaltate extraction systems

International Nuclear Information System (INIS)

Vanura, P.

2003-01-01

The extraction and stability constants in the system water - nitrobenzene have been collected and general rules valid for water - nitrobenzene - crown - bis-1,2-dicarbollylcobaltate extraction system have been found. The main principles are size compatibility of ion diameter and crown cavity diameters, the flexibility of crown, the basicity of crown and the steric factor of both the ligand and the extracted ion. The extraction in the system water - mineral acid or salt polyoxyethylene compound - bis-1,2-dicarbollylcobaltate - nitrobenzene is more complicated than can be expected from usually used ion diameter - crown cavity diameter compatibility principle. The other important factors are the basicity and the deformability of crown, steric aspect and the angles of bonds of extracted ion. The binuclear 'sandwich' complexes with H + ion and Sr 2+ or Ba 2+ ions have been proved for dibenzo-18-crown-6 (DB18C6). On the other hand, only SrL 2 and BaL 2 (L = 15C5) complexes are formed in nitrobenzene saturated with water. The addition of polyoxyethylene compound usually increases the distribution ratio of alkali earth metal ions and the selectivity of its mutual separation. (authors)

Fit of interim crowns fabricated using photopolymer-jetting 3D printing.

Science.gov (United States)

Mai, Hang-Nga; Lee, Kyu-Bok; Lee, Du-Hyeong

2017-08-01

The fit of interim crowns fabricated using 3-dimensional (3D) printing is unknown. The purpose of this in vitro study was to evaluate the fit of interim crowns fabricated using photopolymer-jetting 3D printing and to compare it with that of milling and compression molding methods. Twelve study models were fabricated by making an impression of a metal master model of the mandibular first molar. On each study model, interim crowns (N=36) were fabricated using compression molding (molding group, n=12), milling (milling group, n=12), and 3D polymer-jetting methods. The crowns were prepared as follows: molding group, overimpression technique; milling group, a 5-axis dental milling machine; and polymer-jetting group using a 3D printer. The fit of interim crowns was evaluated in the proximal, marginal, internal axial, and internal occlusal regions by using the image-superimposition and silicone-replica techniques. The Mann-Whitney U test and Kruskal-Wallis tests were used to compare the results among groups (α=.05). Compared with the molding group, the milling and polymer-jetting groups showed more accurate results in the proximal and marginal regions (P3D printing significantly enhanced the fit of interim crowns, particularly in the occlusal region. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns.

Science.gov (United States)

Abdullah, Adil Othman; Tsitrou, Effrosyni A; Pollington, Sarah

2016-01-01

This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns. An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone "PEEK", Telio CAD-Temp, and Protemp™4 (control group). The crowns were divided into four groups (n=10), Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0. The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99) µm, PEEK 46.75 (±8.26) µm, Telio CAD-Temp 56.10 (±5.65) µm, and Protemp™4 193.07(±35.96) µm (PCAD-Temp® 124.94 (±22.96) µm, PEEK 113.14 (±23.55) µm, Telio CAD-Temp 110.95 (±11.64) µm, and Protemp™4 143.48(±26.74) µm. The average fracture strength was: VITA CAD-Temp® 361.01 (±21.61) N, PEEK 802.23 (±111.29) N, Telio CAD-Temp 719.24 (±95.17) N, and Protemp™4 416.40 (±69.14) N. One-way ANOVA test showed a statistically significant difference for marginal gap, internal gap, and fracture strength between all groups (p0.05). CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns.

Fracture strength testing of crowns made of CAD/CAM composite resins.

Science.gov (United States)

Okada, Ryota; Asakura, Masaki; Ando, Akihiro; Kumano, Hirokazu; Ban, Seiji; Kawai, Tatsushi; Takebe, Jun

2018-03-28

The purpose of this study was to ascertain whether computer aided design/computer aided manufacturing (CAD/CAM) composite resin crowns have sufficient strength to withstand the bite force of the molar teeth. The null hypothesis was that the fracture strength of CAD/CAM composite resin crowns is lower than the average maximum bite force of the molar tooth. The crowns, which shape is the right maxillary first molar, were fabricated using four CAD/CAM blanks made of composite resins (Block HC: HC, KZR-CAD HR: HR, KZR-CAD HR2: HR2, Avencia Block: AVE) and one CAD/CAM blank made of lithium disilicate glass-ceramic (IPS e.max CAD: IPS), which was used as a control. Fracture strength of fabricated crowns bonded to metal abutment and biaxial flexural strength of the materials were evaluated. The results of fracture strength test and biaxial flexural strength test showed different tendencies. The fracture strength of CAD/CAM composite resin crowns except HC ranged from 3.3kN to 3.9kN, and was similar to that of IPS (3.3kN). In contrast, biaxial flexural strength of CAD/CAM composite resins ranged from 175MPa to 247MPa, and was significantly lower than that of IPS (360MPa). All CAD/CAM composite resin crowns studied presented about 3-4 times higher fracture strength than the average maximum bite force of the molar tooth (700-900N), which result leads to the conclusion that CAD/CAM composite resin crowns would have sufficient strength to withstand the bite force of the molar teeth. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Effect of embryo density on in vitro development and gene expression in bovine in vitro-fertilized embryos cultured in a microwell system.

Science.gov (United States)

Sugimura, Satoshi; Akai, Tomonori; Hashiyada, Yutaka; Aikawa, Yoshio; Ohtake, Masaki; Matsuda, Hideo; Kobayashi, Shuji; Kobayashi, Eiji; Konishi, Kazuyuki; Imai, Kei

2013-01-01

To identify embryos individually during in vitro development, we previously developed the well-of-the-well (WOW) dish, which contains 25 microwells. Here we investigated the effect of embryo density (the number of embryos per volume of medium) on in vitro development and gene expression of bovine in vitro-fertilized embryos cultured in WOW dishes. Using both conventional droplet and WOW culture formats, 5, 15, and 25 bovine embryos were cultured in 125 μl medium for 168 h. The blastocysts at Day 7 were analyzed for number of cells and expression of ten genes (CDX2, IFN-tau, PLAC8, NANOG, OCT4, SOX2, AKR1B1, ATP5A1, GLUT1 and IGF2R). In droplet culture, the rates of formation of >4-cell cleavage embryos and blastocysts were significantly lower in embryos cultured at 5 embryos per droplet than in those cultured at 15 or 25 embryos per droplet, but not in WOW culture. In both droplet and WOW culture, developmental kinetics and blastocyst cell numbers did not differ among any groups. IFN-tau expression in embryos cultured at 25 embryos per droplet was significantly higher than in those cultured at 15 embryos per droplet and in artificial insemination (AI)-derived blastocysts. Moreover, IGF2R expression was significantly lower in the 25-embryo group than in the 5-embryo group and in AI-derived blastocysts. In WOW culture, these expressions were not affected by embryo density and were similar to those in AI-derived blastocysts. These results suggest that, as compared with conventional droplet culture, in vitro development and expression of IFN-tau and IGF2R in the microwell system may be insensitive to embryo density.

Menstrual characteristics and night work among nurses.

Science.gov (United States)

Moen, Bente E; Baste, Valborg; Morken, Tone; Alsaker, Kjersti; Pallesen, Ståle; Bjorvatn, Bjørn

2015-01-01

Night work has been associated with adverse effects in terms of reproductive health. Specifically, menstruation has been suggested to be negatively impacted by night work, which again may influence fertility. This study investigated whether working nights is related to menstrual characteristics and if there is a relationship between shift work disorder (SWD) and menstruation. The study was cross-sectional, response rate 38%. The sample comprised female nurses who were members of the Norwegian Nurses Association; below 50 yr of age, who were not pregnant, did not use hormonal pills or intrauterine devices and who had not reached menopause (n=766). The nurses answered a postal survey including questions about night work and menstrual characteristics. Fifteen per cent reported to have irregular menstruations. Thirty-nine per cent of the nurses were classified as having SWD. Logistic regression analyses concerning the relationship between irregular menstruations and night work did not show any associations. Furthermore, no associations were found between cycle length or bleeding period and night work parameters. No associations were found between menstrual characteristics and SWD.

Radium separation through complexation by aqueous crown ethers and ion exchange or solvent extraction

Energy Technology Data Exchange (ETDEWEB)

Chiarizia, R.; Dietz, M.L.; Horwitz, E.P. [Argonne National Lab., IL (United States). Chemistry Div.; Burnett, W.C. [Florida State Univ., Tallahassee, FL (United States). Dept. of Oceanography

1997-11-01

The effect of three water-soluble, unsubstituted crown ethers (15-crown-5 (15C5), 18-crown-6 (18C6) and 21-crown-7 (21C7)) on the uptake of Ca, Sr, Ba and Ra cations by a sulfonic acid cation exchange resin, and on the extraction of the same cations by xylene solutions of dinonylnaphthalenesulfonic acid (HDNNS) from aqueous hydrochloric acid solutions has been investigated. The crown ethers enhance the sorption of the larger cations by the ion exchange resin, thereby improving the resin selectivity over calcium, a result of a synergistic interaction between the crown ether and the ionic functional groups of the resin. Similarly, the extraction of the larger alkaline earth cations into xylene by HDNNS is strongly synergized by the presence of the crown ethers in the aqueous phase. Promising results for intra-Group IIa cation separations have been obtained using each of the three crown ethers as the aqueous ligands and the sulfonic acid cation exchange resin. Even greater separation factors for the radium-calcium couple have been measured with the crown-ethers and HDNNS solutions in the solvent extraction mode. The application of the uptake and extraction results to the development of radium separation schemes is discussed and a possible flowchart for the determination of {sup 226}Ra/{sup 228}Ra in natural waters is presented.

Influence of coping design on the cervical color of ceramic crowns.

Science.gov (United States)

Paniz, Gianluca; Kang, Ki-Ho; Kim, Yongjeong; Kumagai, Naota; Hirayama, Hiroshi

2013-12-01

The replication of natural teeth, especially with single-tooth restorations, represents a challenge. Similar to metal ceramic crowns, different designs of zirconia substructures have been suggested to improve the esthetic results of zirconia ceramic crowns. The purpose of the study was to analyze the color of the cervical portion of single zirconia ceramic crowns fabricated with different zirconia coping designs. The color, measured on the CIELAB color scale, of 3 different groups of restorations (n=10) fabricated with zirconia coping (Lava) and feldspathic porcelain (Noritake Super Porcelain) was analyzed with a spectrophotometer. Conventional zirconia crowns with zirconia facial margins were compared with ceramic crowns with porcelain facial margins and either a horizontal reduction of the zirconia coping (1.0 mm reduction) or an additional vertical reduction (1.0 mm additional reduction). The 3 groups, each with a different coping extension, were examined with a 1-way ANOVA and the Fisher exact test, and the differences of the groups were evaluated by applying ΔE thresholds (α=.05). The mean color difference among all the groups was not clinically significant (ΔEcolor differences were present between the 2 porcelain butt margin groups of crowns (ΔE=1.06, between group H and V). Increased differences were present between the zirconia margin group and the porcelain butt margin group (ΔE=2.54 between group C and H; ΔE=2.41 between group C and V). Lab* values were examined in all the groups of crowns to determine the clinical implications. Within the limitation of the study, no significant differences were present among the tested groups of crowns. Nevertheless, although some differences were present between the zirconia margin group and the porcelain butt margin group, reduced differences were present between the 2 different cutback designs. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights

Absorption infrared spectra of interaction products of cyclic polyethers 18-crown-6 and dibenzo-18-crown-6 with uranyl dinitrate hexahydrate

International Nuclear Information System (INIS)

Chumaevskij, N.A.; Belomestnykh, V.I.; Razgonyaeva, G.A.; Shabel'nik, K.S.; Afanas'eva, E.E.

1988-01-01

Using the method of IR spectroscopy it is established that during interaction of uranyl nitrate hexahydrate (UNH) with crown-ethers under investigation macrocycles adhere to UO 2 2+ via hydrogen bonds between water molecules and oxygen of polyethers. Interaction of UNH with the above-mentioned crowns leads to conformational rearrangement of cycles of polyethers and improvement of their symmetry, reflecting in noticeable simplification of IR spectra of interaction products as compared to spectra of initial cyclic polyethers

Numerical modeling of laboratory-scale surface-to-crown fire transition

Science.gov (United States)

Castle, Drew Clayton

Understanding the conditions leading to the transition of fire spread from a surface fuel to an elevated (crown) fuel is critical to effective fire risk assessment and management. Surface fires that successfully transition to crown fires can be very difficult to suppress, potentially leading to damages in the natural and built environments. This is relevant to chaparral shrub lands which are common throughout parts of the Southwest U.S. and represent a significant part of the wildland urban interface. The ability of the Wildland-Urban Interface Fire Dynamic Simulator (WFDS) to model surface-to-crown fire transition was evaluated through comparison to laboratory experiments. The WFDS model is being developed by the U.S. Forest Service (USFS) and the National Institute of Standards and Technology. The experiments were conducted at the USFS Forest Fire Laboratory in Riverside, California. The experiments measured the ignition of chamise (Adenostoma fasciculatum) crown fuel held above a surface fire spreading through excelsior fuel. Cases with different crown fuel bulk densities, crown fuel base heights, and imposed wind speeds were considered. Cold-flow simulations yielded wind speed profiles that closely matched the experimental measurements. Next, fire simulations with only the surface fuel were conducted to verify the rate of spread while factors such as substrate properties were varied. Finally, simulations with both a surface fuel and a crown fuel were completed. Examination of specific surface fire characteristics (rate of spread, flame angle, etc.) and the corresponding experimental surface fire behavior provided a basis for comparison of the factors most responsible for transition from a surface fire to the raised fuel ignition. The rate of spread was determined by tracking the flame in the Smokeview animations using a tool developed for tracking an actual flame in a video. WFDS simulations produced results in both surface fire spread and raised fuel bed

Fracture strength and failure mode of maxillary implant-supported provisional single crowns: a comparison of composite resin crowns fabricated directly over PEEK abutments and solid titanium abutments.

Science.gov (United States)

Santing, Hendrik Jacob; Meijer, Henny J A; Raghoebar, Gerry M; Özcan, Mutlu

2012-12-01

Polyetheretherketone (PEEK) temporary abutments have been recently introduced for making implant-supported provisional single crowns. Little information is available in the dental literature on the durability of provisional implant-supported restorations. The objectives of this study were to evaluate the fracture strength of implant-supported composite resin crowns on PEEK and solid titanium temporary abutments, and to analyze the failure types. Three types of provisional abutments, RN synOcta Temporary Meso Abutment (PEEK; Straumann), RN synOcta Titanium Post for Temporary Restorations (Straumann), and Temporary Abutment Engaging NobRplRP (Nobel Biocare) were used, and provisional screw-retained crowns using composite resin (Solidex) were fabricated for four different locations in the maxilla. The specimens were tested in a universal testing machine at a crosshead speed of 1 mm/minute until fracture occurred. The failure types were analyzed and further categorized as irreparable (Type 1) or reparable (Type 2). No significant difference was found between different abutment types. Only for the position of the maxillary central incisor, composite resin crowns on PEEK temporary abutments showed significantly lower (p Provisional crowns on PEEK abutments showed similar fracture strength as titanium temporary abutments except for central incisors. Maxillary right central incisor composite resin crowns on PEEK temporary abutments fractured below the mean anterior masticatory loading forces reported to be approximately 206 N. © 2010 Wiley Periodicals, Inc.

Crown-Level Tree Species Classification Using Integrated Airborne Hyperspectral and LIDAR Remote Sensing Data

Science.gov (United States)

Wang, Z.; Wu, J.; Wang, Y.; Kong, X.; Bao, H.; Ni, Y.; Ma, L.; Jin, J.

2018-05-01

Mapping tree species is essential for sustainable planning as well as to improve our understanding of the role of different trees as different ecological service. However, crown-level tree species automatic classification is a challenging task due to the spectral similarity among diversified tree species, fine-scale spatial variation, shadow, and underlying objects within a crown. Advanced remote sensing data such as airborne Light Detection and Ranging (LiDAR) and hyperspectral imagery offer a great potential opportunity to derive crown spectral, structure and canopy physiological information at the individual crown scale, which can be useful for mapping tree species. In this paper, an innovative approach was developed for tree species classification at the crown level. The method utilized LiDAR data for individual tree crown delineation and morphological structure extraction, and Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery for pure crown-scale spectral extraction. Specifically, four steps were include: 1) A weighted mean filtering method was developed to improve the accuracy of the smoothed Canopy Height Model (CHM) derived from LiDAR data; 2) The marker-controlled watershed segmentation algorithm was, therefore, also employed to delineate the tree-level canopy from the CHM image in this study, and then individual tree height and tree crown were calculated according to the delineated crown; 3) Spectral features within 3 × 3 neighborhood regions centered on the treetops detected by the treetop detection algorithm were derived from the spectrally normalized CASI imagery; 4) The shape characteristics related to their crown diameters and heights were established, and different crown-level tree species were classified using the combination of spectral and shape characteristics. Analysis of results suggests that the developed classification strategy in this paper (OA = 85.12 %, Kc = 0.90) performed better than LiDAR-metrics method (OA = 79

Surface topography of two trematodes parasites infecting grey heron Ardea cinerea Jouyi (Aves, Ciconiiformes) in Qena, Egypt.

Science.gov (United States)

Ammar, Khalaf Nour Abd El-Wahed

2015-04-01

Apharyngostrigea ardeolina and Echinoparyphium recurvatum are two important digenean parasites that were recovered from small intestine of grey heron with an infection rate (16.2%) and (8.8%) respectively. The surface topography of two species was redescribed by both light and scanning electron microscopy. Using SEM studies showed that the body surface of two trematodes were covered by contact receptors, several types of sensory tegumental papillae which may have useful function in orientation and feeding through increasing the surface area of absorption, could also play a role in sensation or in selection of the materials for ingestion by the fluke. The head collar of E. recurvatum is reniform in shape, bearing uninterrupted double row of 41 collar finger-like spines, a total including 4 end group ones on both ventral corners., tegumental spines were tongue-shaped without a terminal tip.

Hot Flashes amd Night Sweats (PDQ)

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... Professionals Questions to Ask about Your Treatment Research Hot Flashes and Night Sweats (PDQ®)–Patient Version Overview ... quality of life in many patients with cancer. Hot flashes and night sweats may be side effects ...

Investigating assumptions of crown archetypes for modelling LiDAR returns

NARCIS (Netherlands)

Calders, K.; Lewis, P.; Disney, M.; Verbesselt, J.; Herold, M.

2013-01-01

LiDAR has the potential to derive canopy structural information such as tree height and leaf area index (LAI), via models of the LiDAR signal. Such models often make assumptions regarding crown shape to simplify parameter retrieval and crown archetypes are typically assumed to contain a turbid

The night sky brightness at McDonald Observatory

Science.gov (United States)

Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.

1975-01-01

Baseline observations of the night sky brightness in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky brightness are found. Possible causes for these variations are discussed. The largest variation in sky brightness found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow brightness. The data are used to comment on the accuracy of previously published surface photometry of M 81.

Clinical examination of leucite-reinforced glass-ceramic crowns (Empress) in general practice: a retrospective study.

Science.gov (United States)

Sjögren, G; Lantto, R; Granberg, A; Sundström, B O; Tillberg, A

1999-01-01

The purpose of this study was to retrospectively evaluate leucite reinforced-glass ceramic crowns (Empress) placed in patients who regularly visit general practices. One hundred ten Empress crowns, placed in 29 patients who visited a general practice on a regular basis, were evaluated according to the California Dental Association's (CDA) quality evaluation system. In addition, the occurrence of plaque and certain gingival conditions was evaluated. All crowns were luted with resin composite cement. The mean and median years in function for the crowns were 3.6 and 3.9 years, respectively. Based on the CDA criteria, 92% of the 110 crowns were rated "satisfactory." Eighty-six percent were given the CDA rating "excellent" for margin integrity. Fracture was registered in 6% of the 110 crowns. Of the remaining 103 crowns, the CDA rating excellent was given to 74% for anatomic form, 86% for color, and 90% for surface. No significant differences (P > 0.05) were observed regarding fracture rates between anterior and posterior crowns. With regard to the occurrence of plaque and bleeding on probing, no significant differences (P > 0.05) were observed between the Empress crowns and the controls. Most of the fractured crowns had been placed on molars or premolars. Although the difference between anterior and posterior teeth was not statistically significant with respect to the fracture rates obtained, the number of fractured crowns placed on posterior teeth exceeded that of those placed on anterior teeth. The difference between the fracture rates may have clinical significance, and the risk of fracture has to be taken into consideration when placing crowns on teeth that are likely to be subjected to high stress levels.

Modelling initial mortality of Abies religiosa in a crown fire in Mexico

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Salomé Temiño-Villota

2016-04-01

Full Text Available Aim of study: The objectives of this work were to determine which morphological and fire severity variables may help explain the mortality of adult Abies religiosa (Kunth Schltdl. & Cham., to model the probability of this species after being affected by crown fire, and to obtain more elements to classify the sacred fir in terms of fire resistance. This type of studies are relevant to estimate the impact of crown fires on the climax forests that forms this species.Area of study: The burned forest was located in the southern Mexico City, borough.Material and methods: Morphological variables and fire severity indicators were collected for 335 Abies religiosa trees burned by a mixed severity fire. Logistic regression was used to analyze data and develop models that best explained tree mortality.Main results: Survival was 26.9%. The models for height (p≤0.0001, diameter at breast height (p=0.0082, crown length (p≤0.0001 and crown base height (p≤0.0001 were significant, with a negative relationship between each one of these variables and probability of mortality. The significant severity variables were lethal scorch height (p≤0.0001 and crown kill (p≤ 0.0001, which have a direct relationship with probability of mortality.Highlights: This species is moderately fire-resistant. Crown kill ≥ 70% markedly increases mortality. Silvicultural activities such as pruning, thinning and fuel management can reduce the risk of crown fires.

Modelling initial mortality of Abies religiosa in a crown fire in Mexico

Energy Technology Data Exchange (ETDEWEB)

Temiño-Villota, S.; Rodríguez-Trejo, D.A.; Molina Terrén, D.M.; Ryan, K.

2016-07-01

Aim of the study: The objectives of this work were to determine which morphological and fire severity variables may help explain the mortality of adult Abies religiosa (Kunth) Schltdl. & Cham., to model the probability of this species after being affected by crown fire, and to obtain more elements to classify the sacred fir in terms of fire resistance. This type of studies are relevant to estimate the impact of crown fires on the climax forests that forms this species. Area of study: The burned forest was located in the southern Mexico City, borough. Material and methods: Morphological variables and fire severity indicators were collected for 335 Abies religiosa trees burned by a mixed severity fire. Logistic regression was used to analyze data and develop models that best explained tree mortality. Main results: Survival was 26.9%. The models for height (p≤0.0001), diameter at breast height (p=0.0082), crown length (p≤0.0001) and crown base height (p≤0.0001) were significant, with a negative relationship between each one of these variables and probability of mortality. The significant severity variables were lethal scorch height (p≤0.0001) and crown kill (p≤ 0.0001), which have a direct relationship with probability of mortality. Highlights: This species is moderately fire-resistant. Crown kill ≥ 70% markedly increases mortality. Silvicultural activities such as pruning, thinning and fuel management can reduce the risk of crown fires. (Author)

Expression of Aquaporins in Human Embryos and Potential Role of AQP3 and AQP7 in Preimplantation Mouse Embryo Development

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Yun Xiong

2013-05-01

Full Text Available Background/Aims: Water channels, also named aquaporins (AQPs, play crucial roles in cellular water homeostasis. Methods: RT-PCR indicated the mRNA expression of AQPs 1-5, 7, 9, and 11-12, but not AQPs 0, 6, 8, and 10 in the 2∼8-cell stage human embryos. AQP3 and AQP7 were further analyzed for their mRNA expression and protein expression in the oocyte, zygote, 2-cell embryo, 4-cell embryo, 8-cell embryo, morula, and blastocyst from both human and mouse using RT-PCR and immunofluorescence, respectively. Results: AQP3 and AQP7 were detected in all these stages. Knockdown of either AQP3 or AQP7 by targeted siRNA injection into 2-cell mouse embryos significantly inhibited preimplantation embryo development. However, knockdown of AQP3 in JAr spheroid did not affect its attachment to Ishikawa cells. Conclusion: These data demonstrate that multiple aquaporins are expressed in the early stage human embryos and that AQP3 and AQP7 may play a role in preimplantation mouse embryo development.

Unique case of a geminated supernumerary tooth with trifid crown

International Nuclear Information System (INIS)

Ather, Amber; Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi

2012-01-01

Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

Effect of the microenvironment and embryo density on developmental characteristics and gene expression profile of bovine preimplantative embryos cultured in vitro.

Science.gov (United States)

Hoelker, Michael; Rings, Franka; Lund, Qamaruddin; Ghanem, Nasser; Phatsara, Chirawath; Griese, Josef; Schellander, Karl; Tesfaye, Dawit

2009-03-01

The Well of the Well (WOW) system has been developed to culture embryos in small groups or to track the development of single embryos. In the present study, we aimed to examine the effects of the microenvironment provided by the WOW system and embryo density on developmental rates, embryo quality and preimplantative gene expression profile of the resulting embryos. Embryos cultured in a group of 16 reached the blastocyst stage at a significantly lower level than zygotes cultured in a group of 50 (22.2 vs 30.3%), whereas zygotes cultured in WOW were able to compensate against low embryo densities, reaching a blastocyst rate as high as embryos cultured in a group of 50 (31.3 vs 30.3%). Moreover, embryos derived from WOW culture did not differ in terms of differential cell counts and apoptotic cell index compared with controls. The gene expression analysis revealed 62 transcripts to be upregulated and 33 transcripts to be downregulated by WOW culture. Comparing the in vivo derived blastocysts with the blastocysts derived from WOW culture, and group culture, expression of ATP5A1, PLAC8 and KRT8 was more similar to the embryos derived from WOW culture, whereas expression of S100A10 and ZP3 genes was more similar to blastocysts cultured in a group. In conclusion, microenvironment as well as embryo density significantly affected developmental rates. While subsequent blastocysts did not differ in terms of differential cell counts and apoptotic cell index, significant differences were observed in terms of the relative abundance of transcripts in the resulting embryos.

Embryo apoptosis identification: Oocyte grade or cleavage stage?

Science.gov (United States)

Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

2015-01-01

Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced. PMID:26858565

Comprehensive embryo testing. Experts' opinions regarding future directions: an expert panel study on comprehensive embryo testing.

Science.gov (United States)

Hens, Kristien; Dondorp, Wybo J; Geraedts, Joep P M; de Wert, Guido M

2013-05-01

What do scientists in the field of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) consider to be the future direction of comprehensive embryo testing? Although there are many biological and technical limitations, as well as uncertainties regarding the meaning of genetic variation, comprehensive embryo testing will impact the IVF/PGD practice and a timely ethical reflection is needed. Comprehensive testing using microarrays is currently being introduced in the context of PGD and PGS, and it is to be expected that whole-genome sequencing will also follow. Current ethical and empirical sociological research on embryo testing focuses on PGD as it is practiced now. However, empirical research and systematic reflection regarding the impact of comprehensive techniques for embryo testing is missing. In order to understand the potential of this technology and to be able to adequately foresee its implications, we held an expert panel with seven pioneers in PGD. We conducted an expert panel in October 2011 with seven PGD pioneers from Belgium, The Netherlands, Germany and the UK. Participants expected the use of comprehensive techniques in the context of PGD. However, the introduction of these techniques in embryo testing requires timely ethical reflection as it involves a shift from choosing an embryo without a particular genetic disease (i.e. PGD) or most likely to result in a successful pregnancy (i.e. PGS) to choosing the best embryo based on a much wider set of criteria. Such ethical reflection should take account of current technical and biological limitations and also of current uncertainties with regard to the meaning of genetic variance. However, ethicists should also not be afraid to look into the future. There was a general agreement that embryo testing will be increasingly preceded by comprehensive preconception screening, thus enabling smart combinations of genetic testing. The group was composed of seven participants from

Influence of the radiation (Co60) in pre-implants rabbit embryos: effect on atypic mitotic index and embryo pole development

International Nuclear Information System (INIS)

Approbato, Mario S.; Oliveira Moura, Katia K.V. de; Souza Florencio, Rodopiano de; Garcia, Ricardo; Faria, Renato S.; Benedetti, Leonardo N.; Goulart, Flamarion B.

1995-01-01

We studied the effect of ionizing irradiation on 12 New Zealand rabbits (65 embryos), at three different times: at match time (zero hour), two days after and four days after, with two different irradiation doses: five c Gy and ten c Gy. Six rabbits (36 blastocysts) were used as controls. the matching instant was the zero hour. Exactly six days after (± 60 minutes) the embryos of each rabbit was picked up by flushing the uterus with culture media. the embryos were fixed in methanol for 48 hours, and colored with acid Mayer hematoxylin. The following embryo parameters were studied: embryo pole development; percentage of abnormal mitotic figures. irradiation time was associated with lower scores of embryo pole development, but not with irradiation dose. There were no gross abnormalities of embryo pole. The abnormal mitotic cells was affected both by the time and dose of irradiation. (author)

Treatment Recommendations for Single-Unit Crowns: Findings from The National Dental Practice-Based Research Network

Science.gov (United States)

McCracken, Michael S.; Louis, David R.; Litaker, Mark S.; Minyé, Helena M.; Mungia, Rahma; Gordan, Valeria V.; Marshall, Don G.; Gilbert, Gregg H.

2016-01-01

Background Objectives were to: (1) quantify practitioner variation in likelihood to recommend a crown; and (2) test whether certain dentist, practice, and clinical factors are significantly associated with this likelihood. Methods Dentists in the National Dental Practice-Based Research Network completed a questionnaire about indications for single-unit crowns. In four clinical scenarios, practitioners ranked their likelihood of recommending a single-unit crown. These responses were used to calculate a dentist-specific “Crown Factor” (CF; range 0–12). A higher score implies a higher likelihood to recommend a crown. Certain characteristics were tested for statistically significant associations with the CF. Results 1,777 of 2,132 eligible dentists responded (83%). Practitioners were most likely to recommend crowns for teeth that were fractured, cracked, endodontically-treated, or had a broken restoration. Practitioners overwhelmingly recommended crowns for posterior teeth treated endodontically (94%). Practice owners, Southwest practitioners, and practitioners with a balanced work load were more likely to recommend crowns, as were practitioners who use optical scanners for digital impressions. Conclusions There is substantial variation in the likelihood of recommending a crown. While consensus exists in some areas (posterior endodontic treatment), variation dominates in others (size of an existing restoration). Recommendations varied by type of practice, network region, practice busyness, patient insurance status, and use of optical scanners. Practical Implications Recommendations for crowns may be influenced by factors unrelated to tooth and patient variables. A concern for tooth fracture -- whether from endodontic treatment, fractured teeth, or large restorations -- prompted many clinicians to recommend crowns. PMID:27492046

Beneficial effect of two culture systems with small groups of embryos on the development and quality of in vitro-produced bovine embryos.

Science.gov (United States)

Cebrian-Serrano, A; Salvador, I; Silvestre, M A

2014-02-01

Currently, in vitro-produced embryos derived by ovum pick up (OPU) and in vitro fertilization (IVF) technologies represent approximately one-third of the embryos worldwide in cattle. Nevertheless, the culture of small groups of embryos from an individual egg donor is an issue that OPU-IVF laboratories have to face. In this work, we tested whether the development and quality of the preimplantation embryos in vitro cultured in low numbers (five embryos) could be improved by the addition of epidermal growth factor, insulin, transferrin and selenium (EGF-ITS) or by the WOW system. With this aim, immature oocytes recovered from slaughtered heifers were in vitro matured and in vitro fertilized. Presumptive zygotes were then randomly cultured in four culture conditions: one large group (LG) (50 embryos/500 μl medium) and three smaller groups [five embryos/50 μl medium without (control) or with EGF-ITS (EGF-ITS) and five embryos per microwell in the WOW system (WOW)]. Embryos cultured in LG showed a greater ability to develop to blastocyst stage than embryos cultured in smaller groups, while the blastocyst rate of WOW group was significantly higher than in control. The number of cells/blastocyst in LG was higher than control or WOW, whereas the apoptosis rate per blastocyst was lower. On the other hand, the addition of EGF-ITS significantly improved both parameters compared to the control and resulted in similar embryo quality to LG. In conclusion, the WOW system improved embryo development, while the addition of EGF-ITS improved the embryo quality when smaller groups of embryos were cultured. © 2013 Blackwell Verlag GmbH.

Stress and Reliability Analysis of a Metal-Ceramic Dental Crown

Science.gov (United States)

Anusavice, Kenneth J; Sokolowski, Todd M.; Hojjatie, Barry; Nemeth, Noel N.

1996-01-01

Interaction of mechanical and thermal stresses with the flaws and microcracks within the ceramic region of metal-ceramic dental crowns can result in catastrophic or delayed failure of these restorations. The objective of this study was to determine the combined influence of induced functional stresses and pre-existing flaws and microcracks on the time-dependent probability of failure of a metal-ceramic molar crown. A three-dimensional finite element model of a porcelain fused-to-metal (PFM) molar crown was developed using the ANSYS finite element program. The crown consisted of a body porcelain, opaque porcelain, and a metal substrate. The model had a 300 Newton load applied perpendicular to one cusp, a load of 30ON applied at 30 degrees from the perpendicular load case, directed toward the center, and a 600 Newton vertical load. Ceramic specimens were subjected to a biaxial flexure test and the load-to-failure of each specimen was measured. The results of the finite element stress analysis and the flexure tests were incorporated in the NASA developed CARES/LIFE program to determine the Weibull and fatigue parameters and time-dependent fracture reliability of the PFM crown. CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/Or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program.

Crown sealing and buckling instability during water entry of spheres

KAUST Repository

Marston, J. O.

2016-04-05

We present new observations from an experimental investigation of the classical problem of the crown splash and sealing phenomena observed during the impact of spheres onto quiescent liquid pools. In the experiments, a 6 m tall vacuum chamber was used to provide the required ambient conditions from atmospheric pressure down to of an atmosphere, whilst high-speed videography was exploited to focus primarily on the above-surface crown formation and ensuing dynamics, paying particular attention to the moments just prior to the surface seal. In doing so, we have observed a buckling-type azimuthal instability of the crown. This instability is characterised by vertical striations along the crown, between which thin films form that are more susceptible to the air flow and thus are drawn into the closing cavity, where they atomize to form a fine spray within the cavity. To elucidate to the primary mechanisms and forces at play, we varied the sphere diameter, liquid properties and ambient pressure. Furthermore, a comparison between the entry of room-temperature spheres, where the contact line pins around the equator, and Leidenfrost spheres (i.e. an immersed superheated sphere encompassed by a vapour layer), where there is no contact line, indicates that the buckling instability appears in all crown sealing events, but is intensified by the presence of a pinned contact line. © 2016 Cambridge University Press.

Biology and control of the raspberry crown borer (Lepidoptera: Sesiidae).

Science.gov (United States)

McKern, Jacquelyn A; Johnson, Donn T; Lewis, Barbara A

2007-04-01

This study explored the biology of raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), in Arkansas and the optimum timing for insecticide and nematode applications. The duration of P. marginata's life cycle was observed to be 1 yr in Arkansas. Insecticide trials revealed that bifenthrin, chlorpyrifos, imidacloprid, metaflumizone, and metofluthrin efficacy were comparable with that of azinphosmethyl, the only labeled insecticide for P. marginata in brambles until 2005. Applications on 23 October 2003 for plots treated with bifenthrin, chlorpyrifos, and azinphosmethyl resulted in >88% reduction in larvae per crown. Applications on 3 November 2004 of metaflumizone, metofluthrin, and bifenthrin resulted in >89% reduction in larvae per crown. Applications on 7 April 2005 for metofluthrin, imidacloprid, bifenthrin, metaflumizone, and benzoylphenyl urea resulted in >64% reduction in the number of larvae per crown. Applications on 6 May 2004 did not reduce larval numbers. The optimum timing for treatments was found to be between October and early April, before the larvae tunneled into the crowns of plants. Applying bifenthrin with as little as 468 liters water/ha (50 gal/acre) was found to be as effective against larvae as higher volumes of spray. Nematode applications were less successful than insecticides. Nematode applications of Steinernemafeltiae, Steinernema carpocapsae, and Heterorhabditis bacteriophora reduced larvae counts per plant by 46, 53, and 33%, respectively.

An in-vitro investigation of the accuracy of fit of Procera and Empress crowns.

Science.gov (United States)

Fleming, Garry J R; Dobinson, Marie M; Landini, Gabriel; Harris, Jonathan J

2005-09-01

The current study aimed to investigate the accuracy of fit and the reproducibility of inner crown profile for two types of high strength ceramics, IPS Empress and Procera. Procera and Empress crowns with four different morphologies were cemented to dies using zinc phosphate dental cement. Vertical and horizontal sections were made through each of the crown/die preparations and images of the vertical sections were compared for curvature reproduction by alignment using image processing. Measurements were made on horizontal sections to determine cement layer thickness. Alignment of the crowns using image analysis identified quantifiable variations in the inner surface profile compared with the outer surface of the die. The largest differences occurred from the cusp tips to the occlusal adaptation area and differences in surface profile were less pronounced for Procera than Empress crowns. Marginal gap varied independently of ceramic or internal crown shape from 7-529 microm for Procera and 26-548 microm for Empress. IPS Empress has a superior ability to reproduce the inner surface profile of the crown morphologies investigated compared with Procera. The reduced reproduction of surface profile was associated with an increased cement thickness at the occlusal contact area that may inadvertently lead to failure of the crowns functional characteristics.

The aesthetic treatment for anterior teeth with lost crown by endorestoration

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Nanik Zubaidah

2009-06-01

Full Text Available Background: The aesthetic has an important role in social life, especially the anterior teeth. The aesthetic abnormality of anterior teeth i.e. discoloration, malpotition or the anterior teeth with crown damage for more than one third or all part of crown is lost due to caries or other causes, will influence its appearance especially during smile. Purpose: The aim of this case report, therefore, is to show how teeth with clinical crown lost or only the root left still can be treated by endorestoration treatment in order to reconstruct the shape and function of the teeth similar to the original ones. Case: Female 52 years old with the lost crown of anterior teeth. The patient did not want her teeth to be extracted. Case Management: The abnormality of these teeth are still able to be reconstructed by endorestoration i.e. endodontic treatment with post and core insertion in the root canal will increase its retention and recovery by the porcelain crown fused to metal to recover the original formation and aesthetic and thus has the normal refunction. The treatment, it improve the confidence of the patient, and also can function normally. The patient did not feel pain. Ronsenography showed the periapical lesion diminished, the neighbor gingival was going better in both function and color. Conclusion: Endorestoration treatment on the anterior teeth with lost crown could recover the normal function, dental aesthetic and self confidence.

DNA methylation mediated control of gene expression is critical for development of crown gall tumors.

Directory of Open Access Journals (Sweden)

Jochen Gohlke

Full Text Available Crown gall tumors develop after integration of the T-DNA of virulent Agrobacterium tumefaciens strains into the plant genome. Expression of the T-DNA-encoded oncogenes triggers proliferation and differentiation of transformed plant cells. Crown gall development is known to be accompanied by global changes in transcription, metabolite levels, and physiological processes. High levels of abscisic acid (ABA in crown galls regulate expression of drought stress responsive genes and mediate drought stress acclimation, which is essential for wild-type-like tumor growth. An impact of epigenetic processes such as DNA methylation on crown gall development has been suggested; however, it has not yet been investigated comprehensively. In this study, the methylation pattern of Arabidopsis thaliana crown galls was analyzed on a genome-wide scale as well as at the single gene level. Bisulfite sequencing analysis revealed that the oncogenes Ipt, IaaH, and IaaM were unmethylated in crown galls. Nevertheless, the oncogenes were susceptible to siRNA-mediated methylation, which inhibited their expression and subsequently crown gall growth. Genome arrays, hybridized with methylated DNA obtained by immunoprecipitation, revealed a globally hypermethylated crown gall genome, while promoters were rather hypomethylated. Mutants with reduced non-CG methylation developed larger tumors than the wild-type controls, indicating that hypermethylation inhibits plant tumor growth. The differential methylation pattern of crown galls and the stem tissue from which they originate correlated with transcriptional changes. Genes known to be transcriptionally inhibited by ABA and methylated in crown galls became promoter methylated upon treatment of A. thaliana with ABA. This suggests that the high ABA levels in crown galls may mediate DNA methylation and regulate expression of genes involved in drought stress protection. In summary, our studies provide evidence that epigenetic processes

The influence of climate variability on numbers of three waterbird species in Western Port, Victoria, 1973 2002

Science.gov (United States)

Chambers, Lynda E.; Loyn, Richard H.

2006-05-01

Seasonal and annual movements of Australian waterbirds are generally more complex than those of their Northern Hemisphere counterparts, and long-term data are needed to understand their relationships with climatic variables. This paper explores a long-term (1973 2002) set of waterbird counts from coastal Victoria and relates them to climatic data at local and continental scales. Three species (Black Swan Cygnus atratus, White-faced Heron Egretta novaehollandiae and Grey Teal Anas gracilis) were chosen for this analysis. Black Swans have large local breeding populations near the study region; White-faced Herons have smaller local breeding populations and Grey Teal breed extensively in ephemeral inland floodplains, such as those in the Murray-Darling Basin. All showed significant relationships with streamflow, regional rainfall and the Southern Oscillation Index (SOI) at appropriate scales and time-lags, with streamflow explaining the most variance. Black Swans showed a strong seasonal cycle in abundance and local climate variables had the greatest influence on the counts. Numbers were positively correlated with streamflow in southern Victoria three to six seasons before each count. Broader-scale climatic patterns were more important for the other two species. Numbers of White-faced Herons were positively correlated with streamflow or rainfall over various parts of Australia seven to nine seasons before each count. Numbers of Grey Teal showed weak seasonal cycles, and were negatively correlated with rainfall in Victoria or the Murray-Darling Basin in the seasons before or during each count, and positively with streamflow in the Murray-Darling Basin 15 18 months before each count.

Using fertile couples as embryo donors: An ethical dilemma.

Science.gov (United States)

Alizadeh, Leila; Omani Samani, Reza

2014-03-01

The use of donated embryos has offered hope for infertile couples who have no other means to have children. In Iran, fertility centers use fertile couples as embryo donors. In this paper, the advantages and disadvantages of this procedure will be discussed. We conclude that embryo-donation should be performed with frozen embryos thus preventing healthy donors from being harmed by fertility drugs. There must be guidelines for choosing the appropriate donor families. In countries where commercial egg donation is acceptable, fertile couples can be procured as embryo donors thus fulfilling the possible shortage of good quality embryos. Using frozen embryos seems to have less ethical, religious and legal problems when compared to the use of fertile embryo donors.

Dark nights reverse metabolic disruption caused by dim light at night.

Science.gov (United States)

Fonken, L K; Weil, Z M; Nelson, R J

2013-06-01

The increasing prevalence of obesity and related metabolic disorders coincides with increasing exposure to light at night. Previous studies report that mice exposed to dim light at night (dLAN) develop symptoms of metabolic syndrome. This study investigated whether mice returned to dark nights after dLAN exposure recover metabolic function. Male Swiss-Webster mice were assigned to either: standard light-dark (LD) conditions for 8 weeks (LD/LD), dLAN for 8 weeks (dLAN/dLAN), LD for 4 weeks followed by 4 weeks of dLAN (LD/dLAN), and dLAN for 4 weeks followed by 4 weeks of LD (dLAN/LD). After 4 weeks in their respective lighting conditions both groups initially placed in dLAN increased body mass gain compared to LD mice. Half of the dLAN mice (dLAN/LD) were then transferred to LD and vice versa (LD/dLAN). Following the transfer dLAN/dLAN and LD/dLAN mice gained more weight than LD/LD and dLAN/LD mice. At the conclusion of the study dLAN/LD mice did not differ from LD/LD mice with respect to weight gain and had lower fat pad mass compared to dLAN/dLAN mice. Compared to all other groups dLAN/dLAN mice decreased glucose tolerance as indicated by an intraperitoneal glucose tolerance test at week 7, indicating that dLAN/LD mice recovered glucose metabolism. dLAN/dLAN mice also increased MAC1 mRNA expression in peripheral fat as compared to both LD/LD and dLAN/LD mice, suggesting peripheral inflammation is induced by dLAN, but not sustained after return to LD. These results suggest that re-exposure to dark nights ameliorates metabolic disruption caused by dLAN exposure. Copyright © 2013 The Obesity Society.

A semi-empirical model for predicting crown diameter of cedrela ...

African Journals Online (AJOL)

A semi-empirical model relating age and breast height has been developed to predict individual tree crown diameter for Cedrela odorata (L) plantation in the moist evergreen forest zones of Ghana. The model was based on field records of 269 trees, and could determine the crown cover dynamics, forecast time of canopy ...

Incorporating crown dimensions into stem height and basal area for ...

African Journals Online (AJOL)

These increment models, with and without crown dimension were fitted to a modelling data set and the statistical significance of each of the crown dimensions was examined. All the models were then compared for predictive ability using an independent validation data set. The results obtained were similar for both the total ...

Developmental competence of porcine chimeric embryos produced by aggregation

DEFF Research Database (Denmark)

Li, Juan; Jakobsen, Jannik E.; Xiong, Qiang

2015-01-01

The purpose of our study was to compare the developmental competence and blastomere allocation of porcine chimeric embryos formed by micro-well aggregation. Chimeras were created by aggregating either two blastomeres originating from 2-cell embryos or two whole embryos, where embryos were produced...... either by parthenogenetic activation (PA) or handmade cloning (HMC). Results showed that the developmental competence of chimeric embryos, evaluated based on their blastocyst rate and total cell number per blastocyst, was increased when two whole 2-cell stage embryos (PA or HMC) were aggregated....... In comparison, when two blastomeres were aggregated, the developmental competence of the chimeric embryos decreased if the blastomeres were either from PA or from HMC embryos, but not if they were from different sources, i.e. one PA and one HMC blastomere. To evaluate the cell contribution in embryo formation...

[Effects of repeated firing on microleakage of selective laser melting ceramic crowns].

Science.gov (United States)

Zhong, Qun; Peng, Yan; Wu, Xue-Ying; Weng, Jia-Wei

2016-12-01

To investigate the effects of repeated firing on microleakage of selective laser melting ceramic crowns. Fifty molars were randomly divided into 2 groups (25 teeth in each group). Teeth in group A received a chamfer finish line preparation, whereas teeth in group B received a shoulder finish line. After SLM metal crowns were fabricated, all the crowns received initial oxidation step, opaque firing, dentin firing and glaze firing, then crowns in each group were randomly divided into 5 sub-groups according to different time of clinical firings. Glass ionomer was applied for bonding. After 5000 thermocycles ranging from 5degrees centigrade to 55degrees centigrade, all the specimens was evaluated by dye penetration and then microleakage was examined under light microscopy. The data were analyzed with SPSS 20.0 software package. Microleakage between all specimens of group A were not statistically significant (P>0.05) whereas that of group B were statistically significant (P<0.05); After the fifth time of clinical firing, microleakage of specimens in group B(B5) were significantly higher than that of group A(A5). Repeated firings had no significant influence on marginal microleakage of SLM ceramic crowns whereas the crowns of chamfer finish lines result in better clinical performance after repeated firings.

The impact of short night-time naps on performance, sleepiness and mood during a simulated night shift.

Science.gov (United States)

Centofanti, Stephanie A; Hilditch, Cassie J; Dorrian, Jillian; Banks, Siobhan

2016-01-01

Short naps on night shift are recommended in some industries. There is a paucity of evidence to verify the sustained recovery benefits of short naps in the last few hours of the night shift. Therefore, the current study aimed to investigate the sustained recovery benefits of 30 and 10-min nap opportunities during a simulated night shift. Thirty-one healthy participants (18F, 21-35 y) completed a 3-day, between-groups laboratory study with one baseline night (22:00-07:00 h time in bed), followed by one night awake (time awake from 07:00 h on day two through 10:00 h day three) with random allocation to: a 10-min nap opportunity ending at 04:00 h, a 30-min nap opportunity ending at 04:00 h or no nap (control). A neurobehavioral test bout was administered approximately every 2 h during wake periods. There were no significant differences between nap conditions for post-nap psychomotor vigilance performance after controlling for pre-nap scores (p > 0.05). The 30-min nap significantly improved subjective sleepiness compared to the 10-min nap and no-nap control (p effect.

Physiological and foliar symptom response in the crowns of Prunus serotina, Fraxinus americana and Acer rubrum canopy trees to ambient ozone under forest conditions

International Nuclear Information System (INIS)

Schaub, M.; Skelly, J.M.; Zhang, J.W.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E.; Davis, D.D.; Steiner, K.C.

2005-01-01

The crowns of five canopy dominant black cherry (Prunus serotina Ehrh.), five white ash (Fraxinus americana L.), and six red maple (Acer rubrum L.) trees on naturally differing environmental conditions were accessed with scaffold towers within a mixed hardwood forest stand in central Pennsylvania. Ambient ozone concentrations, meteorological parameters, leaf gas exchange and leaf water potential were measured at the sites during the growing seasons of 1998 and 1999. Visible ozone-induced foliar injury was assessed on leaves within the upper and lower crown branches of each tree. Ambient ozone exposures were sufficient to induce typical symptoms on cherry (0-5% total affected leaf area, LAA), whereas foliar injury was not observed on ash or maple. There was a positive correlation between increasing cumulative ozone uptake (U) and increasing percent of LAA for cherry grown under drier site conditions. The lower crown leaves of cherry showed more severe foliar injury than the upper crown leaves. No significant differences in predawn leaf water potential (ψ L ) were detected for all three species indicating no differing soil moisture conditions across the sites. Significant variation in stomatal conductance for water vapor (g wv ) was found among species, soil moisture, time of day and sample date. When comparing cumulative ozone uptake and decreased photosynthetic activity (P n ), red maple was the only species to show higher gas exchange under mesic vs. drier soil conditions (P wv and P n demonstrate the strong influence of heterogeneous environmental conditions within forest canopies. - Within the heterogeneous environment of a mature forest, many factors in addition to soil moisture play a significant role in determining exposure/response relationships to ozone

Earth Pressure on Tunnel Crown

DEFF Research Database (Denmark)

Andersen, Lars

Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

Wave Forces on Crown Walls

DEFF Research Database (Denmark)

Pedersen, Jan; Burcharth, H. F.

1993-01-01

This paper presents some of the results from a large parametric laboratory study including more than 200 long-duration model tests. The study addresses both the wave forces imposed on the breakwater crown wall as well as the performance of the structure in reducing the wave overtopping. The testing...

[An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

Science.gov (United States)

Wei, Xue; Li, Yan

2009-12-01

To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

NMR studies of preimplantation embryo metabolism in human assisted reproductive techniques: a new biomarker for assessment of embryo implantation potential.

Science.gov (United States)

Pudakalakatti, Shivanand M; Uppangala, Shubhashree; D'Souza, Fiona; Kalthur, Guruprasad; Kumar, Pratap; Adiga, Satish Kumar; Atreya, Hanudatta S

2013-01-01

There has been growing interest in understanding energy metabolism in human embryos generated using assisted reproductive techniques (ART) for improving the overall success rate of the method. Using NMR spectroscopy as a noninvasive tool, we studied human embryo metabolism to identify specific biomarkers to assess the quality of embryos for their implantation potential. The study was based on estimation of pyruvate, lactate and alanine levels in the growth medium, ISM1, used in the culture of embryos. An NMR study involving 127 embryos from 48 couples revealed that embryos transferred on Day 3 (after 72 h in vitro culture) with successful implantation (pregnancy) exhibited significantly (p < 10(-5) ) lower pyruvate/alanine ratios compared to those that failed to implant. Lactate levels in media were similar for all embryos. This implies that in addition to lactate production, successfully implanted embryos use pyruvate to produce alanine and other cellular functions. While pyruvate and alanine individually have been used as biomarkers, the present study highlights the potential of combining them to provide a single parameter that correlates strongly with implantation potential. Copyright © 2012 John Wiley & Sons, Ltd.

CROWN-LEVEL TREE SPECIES CLASSIFICATION USING INTEGRATED AIRBORNE HYPERSPECTRAL AND LIDAR REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

Z. Wang

2018-05-01

Full Text Available Mapping tree species is essential for sustainable planning as well as to improve our understanding of the role of different trees as different ecological service. However, crown-level tree species automatic classification is a challenging task due to the spectral similarity among diversified tree species, fine-scale spatial variation, shadow, and underlying objects within a crown. Advanced remote sensing data such as airborne Light Detection and Ranging (LiDAR and hyperspectral imagery offer a great potential opportunity to derive crown spectral, structure and canopy physiological information at the individual crown scale, which can be useful for mapping tree species. In this paper, an innovative approach was developed for tree species classification at the crown level. The method utilized LiDAR data for individual tree crown delineation and morphological structure extraction, and Compact Airborne Spectrographic Imager (CASI hyperspectral imagery for pure crown-scale spectral extraction. Specifically, four steps were include: 1 A weighted mean filtering method was developed to improve the accuracy of the smoothed Canopy Height Model (CHM derived from LiDAR data; 2 The marker-controlled watershed segmentation algorithm was, therefore, also employed to delineate the tree-level canopy from the CHM image in this study, and then individual tree height and tree crown were calculated according to the delineated crown; 3 Spectral features within 3 × 3 neighborhood regions centered on the treetops detected by the treetop detection algorithm were derived from the spectrally normalized CASI imagery; 4 The shape characteristics related to their crown diameters and heights were established, and different crown-level tree species were classified using the combination of spectral and shape characteristics. Analysis of results suggests that the developed classification strategy in this paper (OA = 85.12 %, Kc = 0.90 performed better than Li

Influence of cement film thickness on the retention of implant-retained crowns.

Science.gov (United States)

Mehl, Christian; Harder, Sönke; Steiner, Martin; Vollrath, Oliver; Kern, Matthias

2013-12-01

The main goal of this study was to establish a new, high precision procedure to evaluate the influence of cement film thickness on the retention of cemented implant-retained crowns. Ninety-six tapered titanium abutments (6° taper, 4.3 mm diameter, Camlog) were shortened to 4 mm. Computer-aided design was used to design the crowns, and selective laser sintering, using a cobalt-chromium alloy, was used to produce the crowns. This method used a focused high-energy laser beam to fuse a localized region of metal powder to build up the crowns gradually. Before cementing, preset cement film thicknesses of 15, 50, 80, or 110 μm were established. Glass ionomer, polycarboxylate, or resin cements were used for cementation. After 3 days storage in demineralized water, the retention of the crowns was measured in tension using a universal testing machine. The cement film thicknesses could be achieved with a high level of precision. Interactions between the factors cement and cement film thickness could be found (p ≤ 0.001). For all cements, crown retention decreased significantly between a cement film thickness of 15 and 50 μm (p ≤ 0.001). At 15 μm cement film thickness, the resin cement was the most retentive cement, followed by the polycarboxylate and then the glass ionomer cement (p ≤ 0.05). The results suggest that cement film thickness has an influence on the retentive strength of cemented implant-retained crowns. © 2013 by the American College of Prosthodontists.

What is the preferred number of consecutive night shifts?

DEFF Research Database (Denmark)

Nabe-Nielsen, Kirsten; Jensen, Marie Aarrebo; Hansen, Åse Marie

2016-01-01

% preferred '2 + 2' and 26% preferred '7 + 7'. Participants, who preferred longer spells of night work experienced that night work was less demanding, found it easier to sleep at different times of the day, and were more frequently evening types compared with participants who preferred shorter spells of night...... the longer spells of night work found night work less demanding, found it easier to sleep at different times of the day, and were more frequently evening types....

Comparative evaluation of marginal leakage of provisional crowns cemented with different temporary luting cements: In vitro study.

Science.gov (United States)

Arora, Sheen Juneja; Arora, Aman; Upadhyaya, Viram; Jain, Shilpi

2016-01-01

As, the longevity of provisional restorations is related to, a perfect adaptation and a strong, long-term union between restoration and teeth structures, therefore, evaluation of marginal leakage of provisional restorative materials luted with cements using the standardized procedures is essential. To compare the marginal leakage of the provisional crowns fabricated from Autopolymerizing acrylic resin crowns and bisphenol A-glycidyl dimethacrylate (BIS-GMA) resin crowns. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin crowns and BIS-GMA resin crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin (SC-10) crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from BIS-GMA resin crowns (Protemp 4) cemented with different temporary luting cements. Freshly extracted 60 maxillary premolars of approximately similar dimensions were mounted in dental plaster. Tooth reduction with shoulder margin was planned to use a customized handpiece-holding jig. Provisional crowns were prepared using the wax pattern fabricated from computer aided designing/computer aided manufacturing milling machine following the tooth preparation. Sixty provisional crowns were made, thirty each of SC-10 and Protemp 4 and were then cemented with three different luting cements. Specimens were thermocycled, submerged in a 2% methylene blue solution, then sectioned and observed under a stereomicroscope for the evaluation of marginal microleakage. A five-level scale was used to score dye penetration in the tooth/cement interface and the results of this study was analyzed using the Chi-square test, Mann-Whitney U-test, Kruskal-Wallis H-test and the results were statistically significant P provisional crowns cemented with three different luting cements along the axial walls of

Accurate and noninvasive embryos screening during in vitro fertilization (IVF) assisted by Raman analysis of embryos culture medium

International Nuclear Information System (INIS)

Shen, A G; Peng, J; Su, L; Wang, X H; Hu, J M; Zhao, Q H; Yang, J

2012-01-01

In combination with morphological evaluation tests, we employ Raman spectroscopy to select higher potential reproductive embryos during in vitro fertilization (IVF) based on chemical composition of embryos culture medium. In this study, 57 Raman spectra are acquired from both higher and lower quality embryos culture medium (ECM) from 10 patients which have been preliminarily confirmed by clinical assay. Data are fit by using a linear combination model of least squares method in which 12 basis spectra represent the chemical features of ECM. The final fitting coefficients provide insight into the chemical compositions of culture medium samples and are subsequently used as criterion to evaluate the quality of embryos. The relative fitting coefficients ratios of sodium pyruvate/albumin and phenylalanine/albumin seem act as key roles in the embryo screening, attaining 85.7% accuracy in comparison with clinical pregnancy. The good results demonstrate that Raman spectroscopy therefore is an important candidate for an accurate and noninvasive screening of higher quality embryos, which potentially decrease the time-consuming clinical trials during IVF

Night Rover Challenge

Data.gov (United States)

National Aeronautics and Space Administration — The objective of the Night Rover Challenge was to foster innovations in energy storage technology. Specifically, this challenge asked competitors to create an energy...

Zirconia- versus metal-based, implant-supported abutments and crowns

DEFF Research Database (Denmark)

Hosseini, Mandana

, the selection of restoration materials should be based on proper optical characteristics in addition to biocompatibility and sufficient strength of materials. Abutments and crowns based on zirconia are one of the most recent alternatives to metal abutments and metal-ceramic crowns. To date, only few comparative...... and to estimate long-term biomechanical results of zirconia-based versus metal-based restorations. The aim of study I was to analyse the mode of fracture and number of cyclic loadings until veneering fracture of zirconia-based all-ceramic restorations compared to metal-ceramic restorations. The aim of study II...... was to test the reliability and validity of six aesthetic parameters used at the Copenhagen Dental School to assess the aesthetic outcome of implant-supported restorations. The aims of study III and IV were to compare the influence of different abutment and crown materials on biological, biomechanical...

Influence of structure of crown ethers on their radiation stability

International Nuclear Information System (INIS)

Grigor'ev, E.I.; Myasoedova, T.G.; Nesterov, S.V.; Trakhtenberg, L.I.

1988-01-01

Primary products of γ-radiolysis of crown ethers with the same size of the macrocyclic ring and different substituents were studied by EPR and mass spectrometry. It was shown that introduction of substituents into the polyether ring increases the radiation stability of crown ethers due to intramolecular transfer of energy from the polyether ring to a substituent

[Computer aided design and manufacture of the porcelain fused to metal crown].

Science.gov (United States)

Nie, Xin; Cheng, Xiaosheng; Dai, Ning; Yu, Qing; Hao, Guodong; Sun, Quanping

2009-04-01

In order to satisfy the current demand for fast and high-quality prosthodontics, we have carried out a research in the fabrication process of the porcelain fused to metal crown on molar with CAD/CAM technology. Firstly, we get the data of the surface mesh on preparation teeth through a 3D-optical grating measuring system. Then, we reconstruct the 3D-model crown with the computer-aided design software which was developed by ourselves. Finally, with the 3D-model data, we produce a metallic crown on a high-speed CNC carving machine. The result has proved that the metallic crown can match the preparation teeth ideally. The fabrication process is reliable and efficient, and the restoration is precise and steady in quality.

Limited importance of pre-embryo pronuclear morphology (zygote score) in assisted reproduction outcome in the absence of embryo cryopreservation.

Science.gov (United States)

Nicoli, Alessia; Valli, Barbara; Di Girolamo, Roberta; Di Tommaso, Barbara; Gallinelli, Andrea; La Sala, Giovanni B

2007-10-01

To investigate the hypothesis that Z-score criteria represent a reliable predictor of implantation rate and pregnancy outcome in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles, excluding the possibility of embryo selection before the embryo transfer. Retrospective clinical study. Centre of Reproductive Medicine, Department of Obstetrics and Gynecology, Arcispedale S. Maria Nuova (ASMN), Reggio Emilia, Italy. We analyzed 393 pregnancies obtained by IVF or ICSI cycles. Morphologic evaluations of Z-score in pre-embryos obtained from IVF or ICSI cycles. Evaluations of Z-scores, implantation rate, and clinical pregnancy outcome. We did not find any statistically significant correlation between the Z-score of 1032 embryos transferred in 393 embryo transfers and the implantation rate or the pregnancy outcome. In particular, the best Z-score identified (Z1, 7.2%) did not seem to correlate with embryo implantation rate or pregnancy outcomes any better than those with worse scores (Z2, 6.9% and Z3, 85.9%). Our results seem to confirm that Z-score alone cannot be considered a better tool than standard morphologic criteria for identifying, controlling, or selecting embryos with a better chance of successful ongoing pregnancy.

Night sky a falcon field guide

CERN Document Server

Nigro, Nicholas

2012-01-01

Night Sky: A Falcon Field Guide covers both summer and winter constellations, planets, and stars found in the northern hemisphere. Conveniently sized to fit in a pocket and featuring detailed photographs, this informative guide makes it easy to identify objects in the night sky even from one's own backyard. From information on optimal weather conditions, preferred viewing locations, and how to use key tools of the trade, this handbook will help you adeptly navigate to and fro the vast and dynamic nighttime skies, and you'll fast recognize that the night sky's the limit.

Relationship between thyroid stimulating hormone and night shift work.

Science.gov (United States)

Moon, So-Hyun; Lee, Bum-Joon; Kim, Seong-Jin; Kim, Hwan-Cheol

2016-01-01

Night shift work has well-known adverse effects on health. However, few studies have investigated the relationship between thyroid diseases and night shift work. This study aimed to examine night shift workers and their changes in thyroid stimulating hormones (TSH) levels over time. Medical check-up data (2011-2015) were obtained from 967 female workers at a university hospital in Incheon, Korea. Data regarding TSH levels were extracted from the records, and 2015 was used as a reference point to determine night shift work status. The relationships between TSH levels and night shift work in each year were analyzed using the general linear model (GLM). The generalized estimating equation (GEE) was used to evaluate the repeated measurements over the 5-year period. The GEE analysis revealed that from 2011 to 2015, night shift workers had TSH levels that were 0.303 mIU/L higher than the levels of non-night shift workers (95 % CI: 0.087-0.519 mIU/L, p  = 0.006) after adjusting for age and department. When we used TSH levels of 4.5 ≥ mIU/L to identify subclinical hypothyroidism, night shift workers exhibited a 1.399 fold higher risk of subclinical hypothyroidism (95 % CI: 1.050-1.863, p  = 0.022), compared to their non-night shift counterparts. This result of this study suggests that night shift workers may have an increased risk of thyroid diseases, compared to non-night shift workers.

Increasing the thermopower of crown-ether-bridged anthraquinones

Science.gov (United States)

Ismael, Ali K.; Grace, Iain; Lambert, Colin J.

2015-10-01

We investigate strategies for increasing the thermopower of crown-ether-bridged anthraquinones. The novel design feature of these molecules is the presence of either (1) crown-ether or (2) diaza-crown-ether bridges attached to the side of the current-carrying anthraquinone wire. The crown-ether side groups selectively bind alkali-metal cations and when combined with TCNE or TTF dopants, provide a large phase-space for optimising thermoelectric properties. We find that the optimum combination of cations and dopants depends on the temperature range of interest. The thermopowers of both 1 and 2 are negative and at room temperature are optimised by binding with TTF alone, achieving thermpowers of -600 μV K-1 and -285 μV K-1 respectively. At much lower temperatures, which are relevant to cascade coolers, we find that for 1, a combination of TTF and Na+ yields a maximum thermopower of -710 μV K-1 at 70 K, whereas a combination of TTF and Li+ yields a maximum thermopower of -600 μV K-1 at 90 K. For 2, we find that TTF doping yields a maximum thermopower of -800 μV K-1 at 90 K, whereas at 50 K, the largest thermopower (of -600 μV K-1) is obtain by a combination TTF and K+ doping. At room temperature, we obtain power factors of 73 μW m-1 K-2 for 1 (in combination with TTF and Na+) and 90 μW m-1 K-2 for 2 (with TTF). These are higher or comparable with reported power factors of other organic materials.We investigate strategies for increasing the thermopower of crown-ether-bridged anthraquinones. The novel design feature of these molecules is the presence of either (1) crown-ether or (2) diaza-crown-ether bridges attached to the side of the current-carrying anthraquinone wire. The crown-ether side groups selectively bind alkali-metal cations and when combined with TCNE or TTF dopants, provide a large phase-space for optimising thermoelectric properties. We find that the optimum combination of cations and dopants depends on the temperature range of interest. The

Direct composite restoration of permanent anterior teeth uncomplicated crown fractures

Directory of Open Access Journals (Sweden)

Ashley Evans Nicholas

2018-01-01

Full Text Available An uncomplicated crown fracture is a fracture that involves only the tooth enamel or the dentin and tooth enamel without any damage or exposure to the pulp. Crown fracture of the anterior teeth usually caused by traumatic forces such as falls, accidents, violence, or sports activities. Traumatic injuries of the oral region frequently involve the anterior teeth, especially maxillary incisors due to the anatomic factors which may affect the functional and aesthetical values of the teeth. The objective of this literature study was to know more about uncomplicated crown fracture of the anterior teeth and its restoration. This research was a literature study performed by researching, highlighting various interesting facts and compiling the relevant published journals. The most common and ideal direct restoration of the anterior teeth was the composite resin restoration. The anterior teeth restoration was considered to be a complex and challenging case to solves due to the fact that besides reconstructing the tooth and regaining the function, the aesthetical aspect was also becoming the main objectives. The permanent anterior teeth uncomplicated crown fracture was the most common case of tooth fractures which was mainly caused by traumatic injuries such as falls, accidents, excessive forces, violence, and also sports activities. Dental injuries of the anterior teeth also affected the aesthetical properties and the function of the tooth. Composite resin restoration was able to performed directly on the permanent anterior teeth uncomplicated crown fracture.

A novel approach to internal crown characterization for coniferous tree species classification

Science.gov (United States)

Harikumar, A.; Bovolo, F.; Bruzzone, L.

2016-10-01

The knowledge about individual trees in forest is highly beneficial in forest management. High density small foot- print multi-return airborne Light Detection and Ranging (LiDAR) data can provide a very accurate information about the structural properties of individual trees in forests. Every tree species has a unique set of crown structural characteristics that can be used for tree species classification. In this paper, we use both the internal and external crown structural information of a conifer tree crown, derived from a high density small foot-print multi-return LiDAR data acquisition for species classification. Considering the fact that branches are the major building blocks of a conifer tree crown, we obtain the internal crown structural information using a branch level analysis. The structure of each conifer branch is represented using clusters in the LiDAR point cloud. We propose the joint use of the k-means clustering and geometric shape fitting, on the LiDAR data projected onto a novel 3-dimensional space, to identify branch clusters. After mapping the identified clusters back to the original space, six internal geometric features are estimated using a branch-level analysis. The external crown characteristics are modeled by using six least correlated features based on cone fitting and convex hull. Species classification is performed using a sparse Support Vector Machines (sparse SVM) classifier.

Action of uranium on pre implanted mouse embryos

International Nuclear Information System (INIS)

Kundt, Miriam S.

2001-01-01

The cultured preimplantation embryos are normally employed to evaluate the effects of environmental pollutants specially metals. Embryos were obtained from hybrid females CBA x C57 Bl following induction of super ovulation. They were incubated from 1 cell stage during 120 hs. in M16 cultured medium. Three different experiments were carried out: A, B and C using uranyl nitrate UO 2 (NO 3 ) 2 6H 2 O as source of uranium. In experiment 'A' the embryos were cultivated in the same culture dish containing final U concentrations of 13, 26, 52, 104 and 208 μgU/ml. In experiment 'B' embryos in a one cell stage were placed in culture medium with uranyl nitrate with final U concentrations of 26, 52, 104 μgU/ml. After 24 hours those embryos which had reached the two-cell stage were transferred to another culture dish to which fresh solutions of uranyl nitrate were added, maintaining the same concentrations of the previous one. In experiment 'C' the embryos were cultivated containing final U concentrations of 26, 52 and 104 μgU/ml and they were transferred to another culture dish every day to which fresh solutions of uranyl nitrate were added. Different embryos parameters were analyzed: 1) Development grade; 2) Number of cell per embryo and metaphases index; and 3) Embryo ploidy. 1) Embryos were observed each 24 hs. to evaluate development grade: 2, 4 and 8 cell stage, morula, early -expanded- hatched blastocysts and atresic embryos. No significant differences were observed in the proportion of embryos arrested either in the one-cell or in the two cell stages in control culture medium regarding different concentrations of U, in a total of 4388 embryos analyzed. From 2 cell stage, moment that the embryo begins to synthesize its own ARNm, the delay in embryonic development increased dose dependent. On the other hand, the toxicological effects in the same concentration are increase from 'A' treatment to 'C' treatment. Embriotoxicology effects are evidenced by an increment in

Influence of irradiation (Co60) in pre-implant rabbits embryos: effect on blastocyst diameters and embryos smaller than 2 mm

International Nuclear Information System (INIS)

Approbato, Mario S.; Oliveira Moura, Katia K.V. de; Souza Florencio, Rodopiano de; Cunha Junior, Carlos; Garcia, Ricardo; Faria, Renato S.; Benedetti, Leonardo N.; Goulart, Flamarion B.

1995-01-01

We studied the effect of ionizing irradiation on 12 New Zealand rabbits (65 embryos), in three different times: at match time (zero hour), two days after and four days after, with two different irradiation doses, 5 c Gy and 10 c Gy. Six rabbits (36 blastocysts) were used as controls. The matching instant was the zero hour. Exactly six days after (± 60 minutes) the embryos of each rabbit was picked up by flushing the uterus with culture media. The embryos were fixed in methanol for 48 hours, and colored with acid Mayer hematoxylin. The following embryos parameters were studied: diameter growth; percentage of embryos smaller than 2 mm. We observed that only the irradiation time influenced the blastocysts diameter (no irradiation dose). There was no relation between percentage of embryos smaller than 2 mm and the irradiation. (author)

Noninvasive Metabolomic Profiling of Human Embryo Culture Media Using a Simple Spectroscopy Adjunct to Morphology for Embryo Assessment in in Vitro Fertilization (IVF

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Jiming Hu

2013-03-01

Full Text Available Embryo quality is crucial to the outcome of in vitro fertilization (IVF; however, the ability to precisely distinguish the embryos with higher reproductive potential from others is poor. Morphologic evaluation used to play an important role in assessing embryo quality, but it is somewhat subjective. The culture medium is the immediate environment of the embryos in vitro, and a change of the substances in the culture medium is possibly related to the embryo quality. Thus, the present study aims to determine whether metabolomic profiling of the culture medium using Raman spectroscopy adjunct to morphology correlates with the reproductive potential of embryos in IVF and, thus, to look for a new method of assessing embryo quality. Fifty seven spent media samples were detected by Raman spectroscopy. Combined with embryo morphology scores, we found that embryos in culture media with less than 0.012 of sodium pyruvate and more than −0.00085 phenylalanine have a high reproductive potential, with up to 85.7% accuracy compared with clinical pregnancy. So, sodium pyruvate and phenylalanine in culture medium play an important role in the development of the embryo. Raman spectroscopy is an important tool that provides a new and accurate assessment of higher quality embryos.

Glassfrog embryos hatch early after parental desertion.

Science.gov (United States)

Delia, Jesse R J; Ramírez-Bautista, Aurelio; Summers, Kyle

2014-06-22

Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

Glassfrog embryos hatch early after parental desertion

Science.gov (United States)

Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

2014-01-01

Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations. PMID:24789892

Role of microRNAs in embryo implantation

Directory of Open Access Journals (Sweden)

Jingjie Liang

2017-11-01

Full Text Available Abstract Failure of embryo implantation is a major limiting factor in early pregnancy and assisted reproduction. Determinants of implantation include the embryo viability, the endometrial receptivity, and embryo-maternal interactions. Multiple molecules are involved in the regulation of implantation, but their specific regulatory mechanisms remain unclear. MicroRNA (miRNA, functioning as the transcriptional regulator of gene expression, has been widely reported to be involved in embryo implantation. Recent studies reveal that miRNAs not only act inside the cells, but also can be released by cells into the extracellular environment through multiple packaging forms, facilitating intercellular communication and providing indicative information associated with physiological and pathological conditions. The discovery of extracellular miRNAs shed new light on implantation studies. MiRNAs provide new mechanisms for embryo-maternal communication. Moreover, they may serve as non-invasive biomarkers for embryo selection and assessment of endometrial receptivity in assisted reproduction, which improves the accuracy of evaluation while reducing the mechanical damage to the tissue. In this review, we discuss the involvement of miRNAs in embryo implantation from several aspects, focusing on the role of extracellular miRNAs and their potential applications in assisted reproductive technologies (ART to promote fertility efficiency.

Night time cooling by ventilation or night sky radiation combined with in-room radiant cooling panels including phase change materials

DEFF Research Database (Denmark)

Bourdakis, Eleftherios; Olesen, Bjarne W.; Grossule, Fabio

Night sky radiative cooling technology using PhotoVoltaic/Thermal panels (PVT) and night time ventilation have been studied both by means of simulations and experiments to evaluate their potential and to validate the created simulation model used to describe it. An experimental setup has been...... depending on the sky clearness. This cooling power was enough to remove the stored heat and regenerate the ceiling panels. The validation simulation model results related to PCM were close to the corresponding results extracted from the experiment, while the results related to the production of cold water...... through the night sky radiative cooling differed significantly. The possibility of night time ventilation was studied through simulations for three different latitudes. It was concluded that for Danish climatic conditions night time ventilation would also be able to regenerate the panels while its...

Biomass in monospecific and mixed stands of eucalyptus and black wattle and corn in an agroforestry system

Directory of Open Access Journals (Sweden)

Márcio Viera

2011-06-01

Full Text Available This study aimed at quantifying the production and distribution of aboveground biomass from the plants in monospecific and mixed stands of eucalyptus (hybrid E. urophylla x E. grandis and black wattle (Acacia mearnsii and, of corn (Zea mays in agrosilvicultural systems. The biomass evaluation (leaf, branch, bark and wood from the forest species at 6 and 18 months of age were performed at the treatments: 100E (100% of eucalyptus + corn; - 100A (100% of black wattle + corn; - 50E:50A (50% of eucalyptus + 50% of black wattle + corn. The corn biomass evaluation (stem, leaves, straw, cob and grains was performed at treatments 100E; 100A; 50E:50A; 75E:25A (75% of eucalyptus + 25% of black wattle + corn; and - 25E:75A (25% of eucalyptus + 75% of black wattle + corn. The biomass production from eucalyptus and from the black wattle, in both monospecific and mixed planting, did not differ in any of the assessed ages but, when evaluated by plants compartments, it was verified an interspecific competitive interaction from the eucalyptus on the black wattle, reducing the formation of crown biomass. The total production of corn biomass in agrosilvicutural systems with eucalyptus and with black wattle in monospecific or mixed plantings did not differ in the studied treatments.

Cryopreservation of preimplantation embryos of cattle, sheep, and goats.

Science.gov (United States)

Youngs, Curtis R

2011-08-05

Preimplantation embryos from cattle, sheep, and goats may be cryopreserved for short- or long-term storage. Preimplantation embryos consist predominantly of water, and the avoidance of intracellular ice crystal formation during the cryopreservation process is of paramount importance to maintain embryo viability. Embryos are placed into a hypertonic solution (1.4 - 1.5 M) of a cryoprotective agent (CPA) such as ethylene glycol (EG) or glycerol (GLYC) to create an osmotic gradient that facilitates cellular dehydration. After embryos reach osmotic equilibrium in the CPA solution, they are individually loaded in the hypertonic CPA solution into 0.25 ml plastic straws for freezing. Embryos are placed into a controlled rate freezer at a temperature of -6°C. Ice crystal formation is induced in the CPA solution surrounding the embryo, and crystallization causes an increase in the concentration of CPA outside of the embryo, causing further cellular dehydration. Embryos are cooled at a rate of 0.5°C/min, enabling further dehydration, to a temperature of -34°C before being plunged into liquid nitrogen (-196°C). Cryopreserved embryos must be thawed prior to transfer to a recipient (surrogate) female. Straws containing the embryos are removed from the liquid nitrogen dewar, held in room temperature air for 3 to 5 sec, and placed into a 37°C water bath for 25 to 30 sec. Embryos cryopreserved in GLYC are placed into a 1 M solution of sucrose for 10 min for removal of the CPA before transfer to a recipient (surrogate) female. Embryos cryopreserved in EG, however, may be directly transferred to the uterus of a recipient.

Radioactive marking of proteins in cultured mouse embryos

International Nuclear Information System (INIS)

Nowak, J.

1984-01-01

The purpose of this work was to build an in vitro test system, with which on the one hand postimplantation embryos of the mouse could be cultured without morphological of physiological damage and on the other hand their protein could be as highly marked as possible. With this radioactively marked proteins were to be won, which are optimally suited for a high separation by two-dimensional electrophoresis. In addition incubation and preparation methods were found for the ages of day 10, 11 and 12 of the embryonic development. With the use of 3 H-marked amino acids in the culture medium it was determined that embryos without embryonic membranes, so-called N-embryos, built in more radioactivity into their proteins than the embryos with embryonic membranes, the so-called DAO-embryos or the DO-embryos. On the contrary, the embryos with intact blood circulation (DO-embryos) showed an even distribution of radioactive marker in their bodies. Since an even distribution of the marker in the embryo is a necessary prerequisite for a representative presentation of the proteins by 2DE, the DO-preparation was considered the best suited method. In order to increase the amount of radioactivity incorporated into the proteins of the DO-embryos, the concentration of the used isotope or the incubation length could be increased. A combination of both proved to be the best method. A 14 C-marked amino acid mixture of 20 μCi/corresponds to 20 μl instead of the usual 150 μCi 3 H-marked amino acids in a culture medium proved to be equally suitable. Notable changes which would have indicated a damaging affect of the used radioactivity or the in vitro culturing were not observed. The achieved methodical conditions were used for the presentation of the embryo proteins by two-dimensional electrophoresis and fluorography. (orig./MG) [de

Embryo selection: the role of time-lapse monitoring.

Science.gov (United States)

Kovacs, Peter

2014-12-15

In vitro fertilization has been available for over 3 decades. Its use is becoming more widespread worldwide, and in the developed world, up to 5% of children have been born following IVF. It is estimated that over 5 million children have been conceived in vitro. In addition to giving hope to infertile couples to have their own family, in vitro fertilization has also introduced risks as well. The risk of multiple gestation and the associated maternal and neonatal morbidity/mortality has increased significantly over the past few decades. While stricter transfer policies have eliminated the majority of the high-order multiples, these changes have not yet had much of an impact on the incidence of twins. A twin pregnancy can be avoided by the transfer of a single embryo only. However, the traditionally used method of morphologic embryo selection is not predictive enough to allow routine single embryo transfer; therefore, new screening tools are needed. Time-lapse embryo monitoring allows continuous, non-invasive embryo observation without the need to remove the embryo from optimal culturing conditions. The extra information on the cleavage pattern, morphologic changes and embryo development dynamics could help us identify embryos with a higher implantation potential. These technologic improvements enable us to objectively select the embryo(s) for transfer based on certain algorithms. In the past 5-6 years, numerous studies have been published that confirmed the safety of time-lapse technology. In addition, various markers have already been identified that are associated with the minimal likelihood of implantation and others that are predictive of blastocyst development, implantation potential, genetic health and pregnancy. Various groups have proposed different algorithms for embryo selection based on mostly retrospective data analysis. However, large prospective trials are needed to study the full benefit of these (and potentially new) algorithms before their

Impact of a drop onto a wetted wall: description of crown formation and propagation

Science.gov (United States)

Roisman, I. V.; Tropea, C.

2002-12-01

The impact of a drop onto a liquid film with a relatively high impact velocity, leading to the formation of a crown-like ejection, is studied theoretically. The motion of a kinematic discontinuity in the liquid film on the wall due to the drop impact, the formation of the upward jet at this kinematic discontinuity and its elevation are analysed. Four main regions of the drop and film are considered: the perturbed liquid film on the wall inside the crown, the unperturbed liquid film on the wall outside the crown, the upward jet forming a crown, and the free rim bounding this jet. The theory of Yarin & Weiss (1995) for the propagation of the kinematic discontinuity is generalized here for the case of arbitrary velocity vectors in the inner and outer liquid films on the wall. Next, the mass, momentum balance and Bernoulli equations at the base of the crown are considered in order to obtain the velocity and the thickness of the jet on the wall. Furthermore, the dynamic equations of motion of the crown are developed in the Lagrangian form. An analytical solution for the crown shape is obtained in the asymptotic case of such high impact velocities that the surface tension and the viscosity effects can be neglected in comparison to inertial effects. The edge of the crown is described by the motion of a rim, formed due to the surface tension.

Experiments on the breakup of drop-impact crowns by Marangoni holes

KAUST Repository

Aljedaani, Abdulrahman Barakat

2018-04-04

We investigate experimentally the breakup of the Edgerton crown due to Marangoni instability when a highly viscous drop impacts on a thin film of lower-viscosity liquid, which also has different surface tension than the drop liquid. The presence of this low-viscosity film modifies the boundary condition, giving effective slip to the drop along the solid substrate. This allows the high-viscosity drop to form a regular bowl-shaped crown, which rises vertically away from the solid and subsequently breaks up through the formation of a multitude of Marangoni holes. Previous experiments have proposed that the breakup of the crown results from a spray of fine droplets ejected from the thin low-viscosity film on the solid, e.g. Thoroddsen et al. (J. Fluid Mech., vol. 557, 2006, pp. 63–72). These droplets can hit the inner side of the crown forming spots with lower surface tension, which drives a thinning patch leading to the hole formation. We test the validity of this assumption with close-up imaging to identify individual spray droplets, to show how they hit the crown and their lower surface tension drive the hole formation. The experiments indicate that every Marangoni-driven patch/hole is promoted by the impact of such a microdroplet. Surprisingly, in experiments with pools of higher surface tension, we also see hole formation. Here the Marangoni stress changes direction and the hole formation looks qualitatively different, with holes and ruptures forming in a repeatable fashion at the centre of each spray droplet impact. Impacts onto films of the same liquid, or onto an immiscible liquid, do not in general form holes. We furthermore characterize the effects of drop viscosity and substrate-film thickness on the overall evolution of the crown. We also measure the three characteristic velocities associated with the hole formation: i.e. the Marangoni-driven growth of the thinning patches, the rupture speed of the resulting thin films inside these patches and finally the

Automation and Optimization of Multipulse Laser Zona Drilling of Mouse Embryos During Embryo Biopsy.

Science.gov (United States)

Wong, Christopher Yee; Mills, James K

2017-03-01

Laser zona drilling (LZD) is a required step in many embryonic surgical procedures, for example, assisted hatching and preimplantation genetic diagnosis. LZD involves the ablation of the zona pellucida (ZP) using a laser while minimizing potentially harmful thermal effects on critical internal cell structures. Develop a method for the automation and optimization of multipulse LZD, applied to cleavage-stage embryos. A two-stage optimization is used. The first stage uses computer vision algorithms to identify embryonic structures and determines the optimal ablation zone farthest away from critical structures such as blastomeres. The second stage combines a genetic algorithm with a previously reported thermal analysis of LZD to optimize the combination of laser pulse locations and pulse durations. The goal is to minimize the peak temperature experienced by the blastomeres while creating the desired opening in the ZP. A proof of concept of the proposed LZD automation and optimization method is demonstrated through experiments on mouse embryos with positive results, as adequately sized openings are created. Automation of LZD is feasible and is a viable step toward the automation of embryo biopsy procedures. LZD is a common but delicate procedure performed by human operators using subjective methods to gauge proper LZD procedure. Automation of LZD removes human error to increase the success rate of LZD. Although the proposed methods are developed for cleavage-stage embryos, the same methods may be applied to most types LZD procedures, embryos at different developmental stages, or nonembryonic cells.

Cryopreservation of Embryos and Oocytes in Human Assisted Reproduction

Directory of Open Access Journals (Sweden)

János Konc

2014-01-01

Full Text Available Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. Embryo cryopreservation has decreased the number of fresh embryo transfers and maximized the effectiveness of the IVF cycle. The data shows that women who had transfers of fresh and frozen embryos obtained 8% additional births by using their cryopreserved embryos. Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification of human embryos and oocytes are summarized.

Cryopreservation of embryos and oocytes in human assisted reproduction.

Science.gov (United States)

Konc, János; Kanyó, Katalin; Kriston, Rita; Somoskői, Bence; Cseh, Sándor

2014-01-01

Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. Embryo cryopreservation has decreased the number of fresh embryo transfers and maximized the effectiveness of the IVF cycle. The data shows that women who had transfers of fresh and frozen embryos obtained 8% additional births by using their cryopreserved embryos. Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification) of human embryos and oocytes are summarized.

[Shift and night work and mental health].

Science.gov (United States)

Sancini, Angela; Ciarrocca, Manuela; Capozzella, Assunta; Corbosiero, Paola; Fiaschetti, Maria; Caciari, Tiziana; Cetica, Carlotta; Scimitto, Lara; Ponticiello, Barnaba Giuseppina; Tasciotti, Zaira; Schifano, Maria Pia; Andreozzit, Giorgia; Tomei, Francesco; Tomei, Gianfranco

2012-01-01

Aim of our study was to evaluate the influence that shift work and night work could have on mental health. A review of literary articles from 1990 to 2011 on shift work and night work was carried out. The results of this review confirmed that the shift work and night work affect mental health with the onset of neuropsychological disorders such as mood disorders, anxiety, nervousness, depressive anxiety syndromes, chronic fatigue and chronic insomnia irritability, sleep disturbances, reduction in levels of attention, cognitive impairments, alteration of circadian rhythm. Night work and shift work cause severe desynchronization of the cronobiological rhythms and a disruption of social life with negative effects on performance at work, on health and on social relationships. In the light of these results and recognizing shift work and night work as risk factors for the health of workers is necessary to implement preventive and periodic health checks by the occupational doctor to ensure the health and safety of workers taking account of the different environmental and individual factors.

Efficiency of assisted hatching of the cryopreserved–melted embryos

Directory of Open Access Journals (Sweden)

V. A. Pitko

2018-04-01

Full Text Available Purpose. To measure outcomes of clinical research of efficiency of assisted hatching of cryopreserved embryos. Materials and methods. Patients who had un successful cycles IVF/ICSI with transfer of fresh embryos have been selected for participation in the research between 2014 and 2016 years. Patients were distributed in a random way for participation in the experiment and control groups. Results of embryos transfer of one or two cryopreserved and melted embryos were considered only. Embryos were cryopreserved at a stage of blastocyst, 5 days after extraction of oocytes by method of vitrification. Melting procedure was conducted in the morning of a day of embryos transfer following the instructions of the vitrification medium producer Cryotech (Japan. Assisted hatching was conducted with use of micropipettes of Holding Pipette Cook Medical (Australia and Assisted Hatching/Zona Drilling Pipette Cook Medical (Australia. The treated embryos were cultivated up to a repeated estimation of morphology of embryos before transfer. Transfer of embryos has been conducted by a standard method with the use of catheter for non-invasive transfer of embryo Sydney IVF Cook Medical (Australia. The quantity of the transferred embryos varied from one to two. Results. 100 cryopreserved embryos were transferred which have been distributed in a random way either to the group with the assisted hatching or to the control group (without assisted hatching. A number of parameters of patients from both groups was analyzed, i.e. age of the patient at the time of melting of embryos, duration of infertility, causes of infertility, quantity of previous unsuccessful cycles IVF/ICSI. Any essential differences between patients within two groups based on the aforementioned parameters were not revealed. Also, there were no essential differences in number of the melted embryos, survival rate of embryos, quantity of the embryos transferred to patients. However, at the same time

Neural network classification of sweet potato embryos

Science.gov (United States)

Molto, Enrique; Harrell, Roy C.

1993-05-01

Somatic embryogenesis is a process that allows for the in vitro propagation of thousands of plants in sub-liter size vessels and has been successfully applied to many significant species. The heterogeneity of maturity and quality of embryos produced with this technique requires sorting to obtain a uniform product. An automated harvester is being developed at the University of Florida to sort embryos in vitro at different stages of maturation in a suspension culture. The system utilizes machine vision to characterize embryo morphology and a fluidic based separation device to isolate embryos associated with a pre-defined, targeted morphology. Two different backpropagation neural networks (BNN) were used to classify embryos based on information extracted from the vision system. One network utilized geometric features such as embryo area, length, and symmetry as inputs. The alternative network utilized polar coordinates of an embryo's perimeter with respect to its centroid as inputs. The performances of both techniques were compared with each other and with an embryo classification method based on linear discriminant analysis (LDA). Similar results were obtained with all three techniques. Classification efficiency was improved by reducing the dimension of the feature vector trough a forward stepwise analysis by LDA. In order to enhance the purity of the sample selected as harvestable, a reject to classify option was introduced in the model and analyzed. The best classifier performances (76% overall correct classifications, 75% harvestable objects properly classified, homogeneity improvement ratio 1.5) were obtained using 8 features in a BNN.

Kinetically inert lanthanide complexes as reporter groups for binding of potassium by 18-crown-6

DEFF Research Database (Denmark)

Junker, Anne Kathrine Ravnsborg; Tropiano, Manuel; Faulkner, Stephen

2016-01-01

in a copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) “click” reaction with azide-functionalized crown ethers. The resulting complexes were investigated using NMR and optical methods. Titrations with potassium chloride in methanol observing the sensititzed europium- and terbium-centered emissions were......-centered emission to report on the binding of potassium in an 18-crown-6 binding pocket. The responsive systems were made by linking a crown ether to a kinetically inert lanthanide binding pocket using a molecular building block approach. Specifically, an alkyne-appended Ln.DO3A was used as a building block...... used to investigate the response of the systems. The molecular reporters based on aliphatic crown ethers were found to have strongly inhibited binding of potassium, while the benzo-18-crown-6 derived systems had essentially the same association constants as the native crown ethers. The shape...

Effect of Crystallization Firing on Marginal Gap of CAD/CAM Fabricated Lithium Disilicate Crowns.