WorldWideScience

Sample records for black brant xii

  1. Winter movement dynamics of black brant

    Science.gov (United States)

    Lindberg, Mark S.; Ward, David H.; Tibbitts, T. Lee; Roser, John

    2007-01-01

    Although North American geese are managed based on their breeding distributions, the dynamics of those breeding populations may be affected by events that occur during the winter. Birth rates of capital breeding geese may be influenced by wintering conditions, mortality may be influenced by timing of migration and wintering distribution, and immigration and emigration among breeding populations may depend on winter movement and timing of pair formation. We examined factors affecting movements of black brant (Branta bernicla nigricans) among their primary wintering sites in Mexico and southern California, USA, (Mar 1998–Mar 2000) using capture–recapture models. Although brant exhibited high probability (>0.85) of monthly and annual fidelity to the wintering sites we sampled, we observed movements among all wintering sites. Movement probabilities both within and among winters were negatively related to distance between sites. We observed a higher probability both of southward movement between winters (Mar to Dec) and northward movement between months within winters. Between-winter movements were probably most strongly affected by spatial and temporal variation in habitat quality as we saw movement patterns consistent with contrasting environmental conditions (e.g., La Niña and El Niño southern oscillation cycles). Month-to-month movements were related to migration patterns and may also have been affected by differences in habitat conditions among sites. Patterns of winter movements indicate that a network of wintering sites may be necessary for effective conservation of brant.

  2. Black brant from Alaska staging and wintering in Japan

    Science.gov (United States)

    Derksen, Dirk V.; Bollinger, K.S.; Ward, David H.; Sedinger, J.S.; Miyabayashi, Y.

    1996-01-01

    Black brant (Branta bernicla nigricans) nest in colonies in arctic Canada, Alaska, and Russia (Derksen and Ward 1993, Sedinger et al. 1993). Virtually the entire population stages in fall at Izembek Lagoon near the tip of the Alaska Peninsula (Bellrose 1976) before southward migration (Dau 1992) to winter habitats in British Columbia, Washington, Oregon, California, and Baja California (Subcommittee on Black Brant 1992). A small number of black brant winter in Japan, Korea, and China (Owen 1980). In Japan 3,000–5,000 brant of unknown origin stop over in fall, and a declining population (in the northern islands (Brazil 1991, Miyabayashi et al. 1994). Here, we report sightings of brant in Japan that were marked in Alaska and propose a migration route based on historical and recent observations and weather patterns.

  3. Temporal and spatial shifts in habitat use by Black Brant immediately following flightless molt

    Science.gov (United States)

    Lewis, Tyler L.; Flint, Paul L.; Schmutz, Joel A.; Derksen, Dirk V.

    2010-01-01

    Each year thousands of Pacific Black Brant (Branta bernicla nigricans) undergo flightless wing molt in the Teshekpuk Lake Special Area (TLSA), Alaska, in two distinct habitats: inland, freshwater lakes and coastal, brackish wetlands. Brant lose body mass during wing molt and likely must add reserves upon regaining flight to help fuel their 2,500 km migration to autumn staging areas. We characterized movements and habitat use by Brant during post-molt (the period immediately following the recovery of flight) by (1) marking individual Brant with GPS (global positioning system) transmitters, and (2) conducting a series of replicate aerial surveys. Individuals molting in inland habitats promptly abandoned their molt wetland during the post-molt and moved into coastal habitats. Consequently, inland habitats were nearly deserted by early August when Brant had regained flight, a decrease of >5,000 individuals from the flightless period of early July. Conversely, coastal molting Brant largely remained in coastal habitats during the post-molt and many coastal wetlands were occupied by large flocks (>1,000 birds). Our results indicate that inland, freshwater wetlands were less suitable post-molt habitats for Brant, while coastal wetlands were preferred as they transitioned from flightless molt. The immediacy with which Brant vacated inland habitats upon regaining flight suggests that food may be limiting during molt and they are not selecting inland molt sites strictly for food resources, but rather a balance of factors including predator avoidance and acquisition of protein for feather growth. Our data clearly demonstrate that patterns of habitat use by Brant in the TLSA change over the course of the molt season, an important consideration for management of future resource development activities in this area.

  4. Temporal and geographic variation in survival of juvenile black brant

    Science.gov (United States)

    Ward, D.H.; Schmutz, J.A.; Sedinger, J.S.; Bollinger, K.S.; Martin, P.D.; Anderson, B.A.

    2004-01-01

    First-year survival has important implications for the structure and growth of populations. We examined variation in seasonal survival of first-year Pacific Black Brant (Branta bernicla nigricans) marked late in summer in Alaska at two brood-rearing areas on the Yukon-Kuskokwim Delta (Tutakoke and Kokechik) and one area on the Arctic Coastal Plain to provide insight into the magnitude and timing of mortality during fall migration. First-year survival was lower in early fall (15 July-1 October), when birds fledged from brood-rearing areas and migrated to their primary fall staging area at Izembek Lagoon, Alaska, than during late fall and early winter (1 October-15 February), when birds made a long-distance transoceanic flight (>5000 km) to wintering areas in Baja California, Mexico. When compared to other years, monthly survival during early fall was 20-24% lower in 1992, the year of latest hatch dates and slowest growth of goslings. There was strong evidence to indicate that survival varied geographically within the early fall period. Monthly survival estimates during early fall were lowest for birds from Tutakoke, highest for birds from the Arctic Coastal Plain, and intermediate at Kokechik. Our findings revealed that most juvenile mortality occurred during the first 2 months following banding, and variation in juvenile survival during this period was likely influenced significantly by environmental parameters and habitat conditions on the breeding grounds. Monthly survival estimates during the subsequent 4 months were similar across geographic areas, and long-distance migration was likely the most important contributor to juvenile mortality during this period.

  5. Nutritional condition of Pacific Black Brant wintering at the extremes of their range

    Science.gov (United States)

    Mason, D.D.; Barboza, P.S.; Ward, D.H.

    2006-01-01

    Endogenous stores of energy allow birds to survive periods of severe weather and food shortage during winter. We documented changes in lipid, protein, moisture, and ash in body tissues of adult female Pacific Black Brant (Branta bernicla nigricans) and modeled the energetic costs of wintering. Birds were collected at the extremes of their winter range, in Alaska and Baja California, Mexico. Body lipids decreased over winter for birds in Alaska but increased for those in Baja California. Conversely, body protein increased over winter for Brant in Alaska and remained stable for birds in Baja California. Lipid stores likely fuel migration for Brant wintering in Baja California and ensure winter survival for those in Alaska. Increases in body protein may support earlier reproduction for Brant in Alaska. Predicted energy demands were similar between sites during late winter but avenues of expenditure were different. Birds in Baja California spent more energy on lipid synthesis while those in Alaska incurred higher thermoregulatory costs. Estimated daily intake rates of eelgrass were similar between sites in early winter; however, feeding time was more constrained in Alaska because of high tides and short photoperiods. Despite differences in energetic costs and foraging time, Brant wintering at both sites appeared to be in good condition. We suggest that wintering in Alaska may be more advantageous than long-distance migration if winter survival is similar between sites and constraints on foraging time do not impair body condition. ?? The Cooper Ornithological Society 2006.

  6. Blood selenium concentrations in female Pacific black brant molting in Arctic Alaska: Relationships with age and habitat salinity

    Science.gov (United States)

    Franson, J. Christian; Flint, Paul L.; Schmutz, Joel A.

    2016-01-01

    Blood samples collected from 81 female Pacific black brant (Branta bernicla nigricans) molting near Teshekpuk Lake, Alaska, were analyzed for selenium concentration. The concentration of selenium in blood of after second year (hatched two or more years ago) females (0.84 μg/g wet weight) was significantly greater than the concentration in second year (hatched the previous year) females (0.61 μg/g wet weight). The concentrations of selenium we found in blood of black brant were 1.5 to 2 times greater than baseline values typical of freshwater birds, but considerably lower than reported in other marine waterfowl sampled in Alaska. This finding may be attributable in part to the nearly exclusive herbivorous diet of black brant. No relationship was noted between blood selenium concentration and molting habitat salinity. We are unaware of any previous reports of blood selenium concentrations in black brant.

  7. Reference intervals for serum biochemistries of molting Pacific Black Brant (Branta bernicla nigricans) in Northern Alaska, USA

    Science.gov (United States)

    Franson, J. Christian; Flint, Paul L.; Schmutz, Joel A.

    2017-01-01

    We determined reference intervals for nine serum biochemistries in samples from 329 molting, after-hatch-year, Pacific Black Brant (Branta bernicla nigricans) in Alaska, US. Cholesterol and nonesterified fatty acids differed by sex, but no other differences were noted.

  8. Intercolony variation in growth of black brant goslings on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Fondell, T.F.; Flint, P.L.; Sedinger, J.S.; Nicolai, C.A.; Schamber, J.L.

    2011-01-01

    Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence future survival and productivity. In 2006-2008, we studied gosling growth at 3 of the 4 major colonies on the Yukon-Kuskokwim Delta, Alaska. Estimates of age-adjusted gosling mass at the 2 southern colonies (approx. 30% of the world population of breeding black brant) was low (gosling mass at 30.5 days ranged 346.7 ?? 42.5 g to 627.1 ?? 15.9 g) in comparison to a third colony (gosling mass at 30.5 days ranged 640.0 ?? 8.3 g to 821.6 ?? 13.6 g) and to most previous estimates of age-adjusted mass of brant goslings. Thus, our results are consistent with the hypothesis that poor gosling growth is negatively influencing the brant population. There are 2 non-mutually exclusive explanations for the apparent growth rates we observed. First, the population decline may have been caused by density-independent factors and habitat capacity has declined along with the population as a consequence of the unique foraging feedback between brant and their grazing habitats. Alternatively, a reduction in habitat capacity, as a result of changes to the grazing system, may have negatively influenced gosling growth, which is contributing to the overall long-term population decline. We found support for both explanations. For colonies over habitat capacity we recommend management to enhance foraging habitat, whereas for colonies below habitat capacity we recommend management to increase nesting productivity. ?? 2010 The Wildlife Society.

  9. Density-dependent effects on growth, body size, and clutch size in Black Brant

    Science.gov (United States)

    Sedinger, James S.; Lindberg, Mark S.; Person, Brian T.; Eichholz, Michael W.; Herzog, Mark P.; Flint, Paul L.

    1998-01-01

    We documented gosling size in late summer, adult body size, and clutch size of known-age Black Brant (Branta bernicla nigricans) females nesting on the Tutakoke River colony between 1986 and 1995. During this period, the colony increased from 1,100 to >5,000 nesting pairs. Gosling mass at 30 days of age declined from 764 ± SE of 13 g and 723 ± 15 g for males and females, respectively, in the 1986 cohort, to 665 ± 18 g and 579 ± 18 g in the 1994 cohort. Gosling size was directly negatively correlated with number of Black Brant broods. We detected no trend in adult body size for individuals from these cohorts; in fact, adults from the 1992 and 1994 cohorts had the largest overall masses. Clutch size increased with age from 3.4 eggs for 2-year-old females to 4.4 eggs for 5-year-old females. Clutch size declined during the study by 0.20 (3-year-old females) to 0.45 (2-year-old females) eggs. Clutch size did not decline between the 1986 and 1990 cohorts for females that were >5 years old. Our results for clutch size and gosling size are similar to those recorded for Lesser Snow Geese (Chen caerulescens caerulescens). Our failure to detect a trend in adult body size, however, differs from the response of other geese to increasing population density. We interpret this difference in effects of density on adult size between Black Brant and other geese as an indication of stronger selection against the smallest individuals in Black Brant relative to other species of geese.

  10. Environmental influence on life-history traits: Growth, survival, and fecundity in Black Brant (Branta bernicla)

    Science.gov (United States)

    Sedinger, James S.; Flint, Paul L.; Lindberg, Mark S.

    1995-01-01

    We studied relationships between body size of female Black Brant goslings (Branta bernicla nigricans) late in their growth period and first year survival, eventual adult body size, breeding propensity, and size and volume of clutches they eventually produced to examine the relationship between growth and fitness in this population. We indexed body size by calculating PC1 scores based on either culmen and tarsus, or culmen, tarsus, and mass. Gosling (PC scores based on culmen and tarsus) size was positively correlated with resighting rate (P = 0.005), indicating that larger goslings survived at a higher rate than did smaller goslings. Gosling size was correlated with adult size of the same individuals (P = 0.0004). Larger goslings were more likely to breed as 2- or 3-yr-olds than were medium or small goslings (P = 0.008). Larger adult brant laid more eggs (P = 0.03) and produced clutches with greater total volume (P = 0.03) than did smaller brant. Given the important role of foraging environment in growth of goslings, these data suggest an important role of early environment in determining life-history traits.

  11. Long‐term trends in fall age ratios of black brant

    Science.gov (United States)

    Ward, David H.; Amundson, Courtney L.; Stehn, Robert A.; Dau, Christian P.

    2018-01-01

    Accurate estimates of the age composition of populations can inform past reproductive success and future population trajectories. We examined fall age ratios (juveniles:total birds) of black brant (Branta bernicla nigricans; brant) staging at Izembek National Wildlife Refuge near the tip of the Alaska Peninsula, southwest Alaska, USA, 1963 to 2015. We also investigated variation in fall age ratios associated with sampling location, an index of flock size, survey effort, day of season, observer, survey platform (boat‐ or land‐based) and tide stage. We analyzed data using logistic regression models implemented in a Bayesian framework. Mean predicted fall age ratio controlling for survey effort, day of year, and temporal and spatial variation was 0.24 (95% CL = 0.23, 0.25). Overall trend in age ratios was −0.6% per year (95% CL = −1.3%, 0.2%), resulting in an approximate 26% decline in the proportion of juveniles over the study period. We found evidence for variation across a range of variables implying that juveniles are not randomly distributed in space and time within Izembek Lagoon. Age ratios varied by location within the study area and were highly variable among years. They decreased with the number of birds aged (an index of flock size) and increased throughout September before leveling off in early October and declining in late October. Age ratios were similar among tide stages and observers and were lower during boat‐based (offshore) than land‐based (nearshore) surveys. Our results indicate surveys should be conducted annually during early to mid‐October to ensure the entire population is present and available for sampling, and throughout Izembek Lagoon to account for spatiotemporal variation in age ratios. Sampling should include a wide range of flock sizes representative of their distribution and occur in flocks located near and off shore. Further research evaluating the cause of declining age ratios in the fall population is necessary

  12. Mass dynamics of wintering Pacific Black Brant: Body, adipose tissue, organ, and muscle masses vary with location

    Science.gov (United States)

    Mason, D.D.; Barboza, P.S.; Ward, D.H.

    2007-01-01

    We compared body size and mass of the whole body, organs, adipose tissue, and muscles of adult Pacific Black Brant (Branta bernicla nigricans (Lawrence, 1846)) collected concurrently in Alaska and Baja California during the fall, winter, and spring of 2002–2003. Head and tarsal lengths of males were similar between sites and slightly larger for females in Alaska than in Baja California. Brant appear to operate under similar physiological bounds, but patterns of nutrient allocation differ between sites. Birds wintering in Alaska lost similar amounts of adipose tissue during early winter as birds in Baja California gained during late winter before migration. Masses of the body, adipose tissue, and flight muscles during mid-winter were similar between sites. Seasonal adipose tissue deposition may, therefore, equally favor winter residency or long-distance migration. Gonad and liver masses increased in late winter for birds in Alaska but not for those in Baja California, suggesting birds wintering in Baja may delay reproductive development in favor of allocating reserves needed for migration. Phenotypic flexibility allows Brant to use widely divergent wintering sites. The wintering location of Brant likely depends more upon changes in environmental conditions and food availability, than upon physiological differences between the two wintering populations.

  13. Carry-over effects of winter location contribute to variation in timing of nest initiation and clutch size in black brant (Branta bernicla nigricans)

    Science.gov (United States)

    Schamber, Jason L.; Sedinger, James S.; Ward, David H.

    2012-01-01

    We assessed carry-over effects from winter location on timing of nest initiation and clutch size of Black Brant (Branta bernicla nigricans) using observations of individually marked brant breeding at the Tutakoke River colony in Alaska, and wintering along a latitudinal gradient at three areas on the Pacific coast of Baja California: northernmost Bahia San Quintin (BSQ), Laguna Ojo de Liebre (LOL), and southernmost Laguna San Ignacio (LSI). Black Brant initiated nests according to a north—south trend in winter location, although year was a stronger predictor of initiation date than was wintering site. Female Black Brant that wintered at BSQ initiated nests 2.2 days earlier than females from LSI. Conversely, Black Brant showed only a weak south—north trend in clutch size; individuals from LSI laid slightly larger clutches than individuals from BSQ, probably because a smaller proportion of only high-quality females from the southernmost wintering area in Baja California were able to attain the nutritional condition necessary to breed. These results indicate that winter location can influence individual reproductive performance and, potentially, limit population growth of southern segments of the wintering Black Brant population.

  14. Growth rate is negatively correlated with hatch date in Black Brant

    Science.gov (United States)

    Sedinger, James S.; Flint, Paul L.

    1991-01-01

    Arctic geese nest in a highly seasonal environment in which ungrazed plants reach peak nitrogen concentrations when goslings hatch (Sedinger and Raveling 1986). Grazing by geese prolongs peak nutrient concentrations but reduces food availability. This should cause nutrient availability to decline seasonally. Here, we test the hypothesis that late-hatching goslings of Black Brant (Branta bernicla nigricans) grow more slowly than those hatching early. We substracted the sizes of wild goslings from those of captive-reared goslings of the same age and regressed the differences against hatch date. Differences between wild- and captive-reared goslings for body mass, tarsus length, and culmen length were significantly negatively related to hatch date; i.e., late-hatching wild goslings were smaller than those hatching early, after accounting for age. We detected no between-year difference in gosling size, but male goslings were larger than females of the same age for all measures. Egg size was only weakly associated with size of goslings 1 mo after hatching, but we detected no effect of other brood characteristics on growth. Seasonal variation in gosling growth rate may favor early nesting in arctic geese.

  15. Early environment and recruitment of black brant (Branta bernicla nigricans) into the breeding population

    Science.gov (United States)

    Sedinger, James S.; Herzog, Mark P.; Ward, David H.

    2004-01-01

    In geese, growth regulates survival in the first year. We examined whether early growth, which is primarily governed by environmental conditions, also affects the probability that individuals that survive their first year enter the breeding population. We used logistic regression on a sample of Black Brant (Branta bernicla nigricans) that were weighed at a known age in their first summer and observed during winter (indicating that they had survived the principal mortality period in their first year) to study whether early growth influenced the probability that those individuals would be recruited into the breeding population. We also examined the effects of cohort (1986-1996), sex, age when measured, and area where individuals were reared. The model with the lowest Akaike's Information Criterion score contained body mass, age (days) at measurement, cohort, sex, and brood-rearing area. Models that included variable mass had 85% of the cumulative model weight of the models we considered, indicating that gosling mass had a substantial effect on probability of them entering the breeding population. Females were more likely to be detected breeding than males, which is consistent with the differential fidelity of the sexes. Of individuals that survived the first year, larger goslings were more likely to become breeders. More recent cohorts were less likely to have been detected as breeders. Our findings indicate that environment during the growth period affects the ability of individuals to enter the breeding population, even after accounting for the effects of growth on survival.

  16. [Habitat use patterns of the Black Brant Branta bernicla nigricans (Anseriformes: Anatidae) in natural and artificial areas of Guerrero Negro, Baja California Sur, Mexico].

    Science.gov (United States)

    Cedillo, Israel Martínez; Carmona, Roberto; Ward, David H; Danemann, Gustavo D

    2013-06-01

    The Black Brant is a common inhabitant of the Western Artic American tundra, which migrates to Southern Pacific coasts during the winter season. Approximately, 31000 birds (31%) constitute the Mexican population of Brants at Guerrero Negro, Ojo de Liebre, and Exportadora de Sal lagoon complex; nevertheless, there is little information about the distribution patterns and zone usage. At Guerrero Negro Lagoon (GNL), Ojo de Liebre Lagoon (OLL, both natural sites), and at Exportadora de Sal (ESSA, artificial site) we determined by monthly censuses (from November 2006 to April 2007, 08:00-16:00h) and observed: (1) season and site effects on population structure (age groups), and (2) the tide level relationship with the abundance and proportion of feeding birds. Within a total of 150 observation hours and 98 birds, our results showed a general 0.68 proportion of adults, that was higher in winter than in spring. The statistics analysis showed no effects by site on the proportion of feeding birds, but we observed a temporal decrease at ESSA and at GNL. In contrast the proportion of feeding birds at OLL was constant. We observed an increase in the juveniles between winter and spring. This increase is related with the differential migration, which mentions that the juveniles are the last to leave the wintering area. In winter the relations of the tide level with the abundance of Brant were: direct at ESSA, inverse at OLL and no relation found at GNL. In spring, no relation was observed in the sites. The proportion of Brants feeding at OLL (the site with the higher abundance) was independent of the tide level. This is related with two possible behaviors of the geese: (1) they can move through the lagoon and take advantage of the tidal lag, which is up to four hours; and (2) they can modify their feeding strategies, more on floating eelgrass (Zostera marina).

  17. Predicted eelgrass response to sea level rise and its availability to foraging Black Brant in Pacific coast estuaries.

    Science.gov (United States)

    Shaughnessy, Frank J; Gilkerson, Whelan; Black, Jeffrey M; Ward, David H; Petrie, Mark

    2012-09-01

    Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers of eelgrass. Digital elevation models were developed for seven estuaries from Alaska, Washington, California (USA), and Mexico. Scenarios of future total eelgrass area were derived from combinations of estuarine specific sediment and tectonic rates (i.e., bottom change rate) with three rates of eustatic sea level rise (ESLR). Percentages of total eelgrass areas that were accessible to foraging Brant were determined for December when the birds overwinter at more southerly sites and in April as they move north to sites where they build body stores on their way to nesting areas in Alaska. The modeling showed that accessible eelgrass area could be lower than total area due to how daytime low-tide height, eelgrass shoot length, and the upper elevation of eelgrass determined Brant-reaching depth. Projections of future eelgrass area indicated that present-day ESLR (2.8 mm/yr) and bottom change rates should sustain the current pattern of estuarine use by Brant except in Morro Bay, where use should decrease because eelgrass is being ejected from this estuary by a positive bottom change rate. Higher ESLR rates (6.3 and 12.7 mm/yr) should result in less Brant use of estuaries at the northern and southern ends of the flyway, particularly during the winter, but more use of mid-latitude estuaries. The capacity of mid-latitude estuaries to function as Brant feeding refugia, or for these estuaries and Izembek Lagoon to provide drift rather than attached leaves, is eventually limited by the decrease in total eelgrass area, which is a result of a light extinction affect on the eelgrass, or the habitat being pushed out of the estuary by positive tectonic rates. Management

  18. Predicted eelgrass response to sea level rise and its availability to foraging Black Brant in Pacific coast estuaries

    Science.gov (United States)

    Shaughnessy, Frank J.; Gilkerson, Whelan; Black, Jeffrey M.; Ward, David H.; Petrie, Mark

    2012-01-01

    Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers of eelgrass. Digital elevation models were developed for seven estuaries from Alaska, Washington, California (USA), and Mexico. Scenarios of future total eelgrass area were derived from combinations of estuarine specific sediment and tectonic rates (i.e., bottom change rate) with three rates of eustatic sea level rise (ESLR). Percentages of total eelgrass areas that were accessible to foraging Brant were determined for December when the birds overwinter at more southerly sites and in April as they move north to sites where they build body stores on their way to nesting areas in Alaska. The modeling showed that accessible eelgrass area could be lower than total area due to how daytime low-tide height, eelgrass shoot length, and the upper elevation of eelgrass determined Brant-reaching depth. Projections of future eelgrass area indicated that present-day ESLR (2.8 mm/yr) and bottom change rates should sustain the current pattern of estuarine use by Brant except in Morro Bay, where use should decrease because eelgrass is being ejected from this estuary by a positive bottom change rate. Higher ESLR rates (6.3 and 12.7 mm/yr) should result in less Brant use of estuaries at the northern and southern ends of the flyway, particularly during the winter, but more use of mid-latitude estuaries. The capacity of mid-latitude estuaries to function as Brant feeding refugia, or for these estuaries and Izembek Lagoon to provide drift rather than attached leaves, is eventually limited by the decrease in total eelgrass area, which is a result of a light extinction affect on the eelgrass, or the habitat being pushed out of the estuary by positive tectonic rates. Management

  19. North American Brant: Effects of changes in habitat and climate on population dynamics

    Science.gov (United States)

    Ward, David H.; Reed, Austin; Sedinger, James S.; Black, Jeffrey M.; Derksen, Dirk V.; Castelli, Paul M.

    2005-01-01

    We describe the importance of key habitats used by four nesting populations of nearctic brant (Branta bernicla) and discuss the potential relationship between changes in these habitats and population dynamics of brant. Nearctic brant, in contrast to most geese, rely on marine habitats and native intertidal plants during the non-breeding season, particularly the seagrass, Zostera, and the macroalgae, Ulva. Atlantic and Eastern High Arctic brant have experienced the greatest degradation of their winter habitats (northeastern United States and Ireland, respectively) and have also shown the most plasticity in feeding behavior. Black and Western High Arctic brant of the Pacific Flyway are the most dependent on Zostera, and are undergoing a shift in winter distribution that is likely related to climate change and its associated effects on Zostera dynamics. Variation in breeding propensity of Black Brant associated with winter location and climate strongly suggests that food abundance on the wintering grounds directly affects reproductive performance in these geese. In summer, salt marshes, especially those containing Carex and Puccinellia, are key habitats for raising young, while lake shorelines with fine freshwater grasses and sedges are important for molting birds. Availability and abundance of salt marshes has a direct effect on growth and recruitment of goslings and ultimately, plays an important role in regulating size of local brant populations. ?? 2005 Blackwell Publishing Ltd.

  20. Electron microscopy study of an Old Russian (XII century) encolpion cross with black inlay

    Science.gov (United States)

    Kolobylina, N. N.; Greshnikov, E. A.; Vasiliev, A. L.; Tereschenko, E. Yu.; Zaytseva, I. E.; Makarov, N. A.; Kashkarov, P. K.; Yatsishina, E. B.; Kovalchuk, M. V.

    2017-07-01

    The phase compositions of the basic material (alloy) of a pre-Mongolian Old Russian encolpion cross found near Suzdal and its black inlay have been investigated by methods of scanning and transmission electron microscopy and energy-dispersive X-ray microanalysis. The cross material is lead-zinc-tin α-bronze, and the black is copper sulfide with lead inclusions. As a result of the corrosion, tin and copper oxides and zinc sulfides, which made the cross dark gray, were formed on its surface. It is shown that the corrosion depth is as large as 50 μm; thus, laps must be prepared to accurately determine the morphology and phase composition of the corrosion layer. Decoration with black was apparently performed by pouring with copper sulfide melt or melting a powder preliminarily placed in grooves forming an image on the surface.

  1. Estimating populations of nesting brant using aerial videography

    Science.gov (United States)

    Anthony, R. Michael; Anderson, W.H.; Sedinger, J.S.; McDonald, L.L.

    1995-01-01

    We mounted a video camcorder in a single-engine aircraft to estimate nesting density along 10-m wide strip transects in black brant colonies on the Yukon Delta National Wildlife Refuge, Alaska during 1990-1992. A global positioning system (GPS) receiver was connected to the video recorder and a laptop computer to locate transects and annotate video tape with time and latitude-longitude at 1-second intervals. About 4-5 hours of flight time were required to record 30-40 minutes of video tape needed to survey large (>5,000 nests in > 10 km2)colonies. We conducted ground searches along transects to locate and identify nests for determining detection rates of nests in video images. Counts of nests from video transects were correlated with actual numbers of nests. Resolution of images was sufficient to detect 81% of known nests (with and without incubating females). Of these, 68% were correctly identified as brant nests. The most common misidentification of known nests was failure of viewers to see the nest that the detected bird was incubating. Unattended nests with exposed eggs, down-covered nests, and nesting brant, cackling Canada geese, and emperor geese were identified in video images. Flushing of incubating geese by survey aircraft was not significant. About 10% of known nests were unoccupied in video images compared to 16% unoccupied nests observed from tower blinds during periods without aircraft disturbance.

  2. Patrones de uso de sitios naturales y artificiales por Branta bernicla nigricans (Anseriformes: Anatidae en Guerrero Negro, Baja California Sur, México Habitat use patterns of the Black Brant Branta bernicla nigricans (Anseriformes: Anatidae in natural and artificial areas of Guerrero Negro, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Israel Martínez Cedillo

    2013-06-01

    Full Text Available En el complejo lagunar Guerrero Negro-Ojo de Liebre-Exportadora de Sal inverna el 31% de la población de Ganso de collar (Branta bernicla nigricans que utiliza México (31 000 aves en promedio. Nosotros realizamos censos de punto mensuales (noviembre 2006 a abril 2007 en tres sitios para determinar: (1 los efectos de la época del año y del sitio en la estructura poblacional (grupos de edad y (2 la relación del nivel de marea con la abundan- cia y la proporción de aves alimentándose. La proporción general de adultos fue de 0.68. Esta proporción fue mayor en invierno que en primavera. Por sitio en LGN y ESSA disminuyó y en LOL se mantuvo constante. El incremento de aves inmaduras entre el invierno y la primavera se relaciona con su partida primaveral tardía. La alimentación del Ganso de collar en LOL (el sitio de mayor abundancia fue independiente del nivel de marea, lo que se puede relacionar con dos conductas: (1 que las aves se muevan a lo largo de la laguna, para aprovechar el desfase, de hasta cuatro horas en el nivel de marea o (2 que modifiquen sus estrategias de alimentación, para consumir el pasto flotante.The Black Brant is a common inhabitant of the Western Artic American tundra, which migrates to Southern Pacific coasts during the winter season. Approximately, 31 000 birds (31% constitute the Mexican population of Brants at Guerrero Negro, Ojo de Liebre, and Exportadora de Sal lagoon complex; nevertheless, there is little information about the distribution patterns and zone usage. At Guerrero Negro Lagoon (GNL, Ojo de Liebre Lagoon (OLL, both natural sites, and at Exportadora de Sal (ESSA, artificial site we determined by monthly censuses (from November 2006 to April 2007, 08:00-16:00h and observed: (1 season and site effects on population structure (age groups, and (2 the tide level relationship with the abundance and proportion of feeding birds. Within a total of 150 observation hours and 98 birds, our results showed a

  3. XII Elkonin Readings

    Directory of Open Access Journals (Sweden)

    Bugrimenko E.A.,

    2016-07-01

    Full Text Available The article introduces the reader the main content of report presented at the XII Elkonin Readings (4th March, 2016. Elkonin Readings takes place each 2 years in Psychological Institute, Russian Academy of education. This year they are focused on the problem of “Mediation and development”. Speakers from different institutions presented their approaches to solving these problems. The theoretical foundation of the new understanding of the relationship of functional genesis and ontogenesis, buildings mediation activities, proximal development areas have been disclosed in the articles of V.V. Rubtsov, D.B. Elkonin, P.G. Nezhnov. The new conditions for mediation were created on the basis of the different materials (games, reading, and spatial image of “self” according to an experimental practice of teaching and correction of self- development. Developing of creative ways of mediation were mentioned in the articles of L.I. Elkoninov, E.O. Smirnov, E.A. Abdulaeva, E.A. Bugrimenko, N.U. Mangutov, that meet actual problems for modern children.

  4. Factor XII Contact Activation.

    Science.gov (United States)

    Naudin, Clément; Burillo, Elena; Blankenberg, Stefan; Butler, Lynn; Renné, Thomas

    2017-11-01

    Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this contact to surfaces triggers a conformational change in the zymogen inducing autoactivation. Several surfaces that have the capacity for initiating FXII contact activation have been identified, including misfolded protein aggregates, collagen, nucleic acids, and platelet and microbial polyphosphate. Activated FXII initiates the proinflammatory kallikrein-kinin system and the intrinsic coagulation pathway, leading to formation of bradykinin and thrombin, respectively. FXII contact activation is well characterized in vitro and provides the mechanistic basis for the diagnostic clotting assay, activated partial thromboplastin time. However, only in the past decade has the critical role of FXII contact activation in pathological thrombosis been appreciated. While defective FXII contact activation provides thromboprotection, excess activation underlies the swelling disorder hereditary angioedema type III. This review provides an overview of the molecular basis of FXII contact activation and FXII contact activation-associated disease states. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Response of fall-staging brant and Canada geese to aircraft overflights in southwestern Alaska

    Science.gov (United States)

    Ward, D.H.; Stehn, R.A.; Erickson, W.P.; Derksen, D.V.

    1999-01-01

    Because much of the information concerning disturbance of waterfowl by aircraft is anecdotal, we examined behavioral responses of Pacific brant (Branta bernicla nigricans) and Canada geese (B. canadensis taverneri) to experimental overflights during fall staging at Izembek Lagoon, Alaska. These data were used to develop predictive models of brant and Canada goose response to aircraft altitude, type, noise, and lateral distance from flocks. Overall, 75% of brant flocks and 9% of Canada goose flocks flew in response to overflights. Mean flight and alert responses of both species were greater for rotary-wing than for fixed-wing aircraft and for high-noise than for low-noise aircraft. Increased lateral distance between an aircraft and a flock was the most consistent predictive parameter associated with lower probability of a response by geese. Altitude was a less reliable predictor because of interaction effects with aircraft type and noise. Although mean response of brant and Canada geese generally was inversely proportional to aircraft altitude, greatest response occurred at intermediate (305-760 m) altitudes. At Izembek Lagoon and other areas where there are large concentrations of waterfowl, managers should consider lateral distance from the birds as the primary criterion for establishing local flight restrictions, especially for helicopters.

  6. Cranial Nerves IX, X, XI, and XII.

    Science.gov (United States)

    Gillig, Paulette Marie; Sanders, Richard D

    2010-05-01

    This article concludes the series on cranial nerves, with review of the final four (IX-XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected by lesions in the basal ganglia. Vagus nerve funtion (craniel nerve X) can be compromised in schizophrenia, bulimia, obesity, and major depression. A cervical lesion to the nerve roots of the spinal accessory nerve (craniel nerve XI) can cause a cervical dystonia, which sometimes is misdiagnosed as a dyskinesia related to neuroleptic use. Finally, unilateral hypoglossal (craniel nerve XII) nerve palsy is one of the most common mononeuropathies caused by brain metastases. Supranuclear lesions of cranial nerve XII are involved in pseudobulbar palsy and ALS, and lower motor neuron lesions of cranial nerve XII can also be present in bulbar palsy and in ALS patients who also have lower motor neuron involvement. This article reviews these and other syndromes related to cranial nerves IX through XII that might be seen by psychiatry.

  7. Coagulation factor XII in thrombosis and inflammation.

    Science.gov (United States)

    Maas, Coen; Renné, Thomas

    2018-02-26

    Combinations of proinflammatory and procoagulant reactions are the unifying principle for a variety of disorders affecting the cardiovascular system. The factor XII-driven-contact system starts coagulation and inflammatory mechanisms via the intrinsic pathway of coagulation and the bradykinin-producing kallikrein-kinin system, respectively. The biochemistry of the contact system in vitro is well understood, however its in vivo functions are just beginning to emerge. Challenging the concept of the coagulation balance, targeting factor XII or its activator polyphosphate provides protection from thromboembolic diseases without interfering with hemostasis. This suggests that the polyphosphate/factor XII axis contributes to thrombus formation while being dispensable for hemostatic processes. In contrast to deficiency in factor XII providing safe thromboprotection, excessive FXII activity is associated with the life-threatening inflammatory disorder hereditary angioedema. The current review summarizes recent finding of the polyphosphate/factor XII-driven contact system at the intersection of procoagulant and proinflammatory disease states. Elucidating the contact system offers the exciting opportunity to develop strategies for safe interference with both thrombotic and inflammatory disorders. Copyright © 2018 American Society of Hematology.

  8. Migration patterns of Western High Arctic (Grey-belly) Brant Branta bernicla

    Science.gov (United States)

    Boyd, W. Sean; Ward, David H.; Kraege, Donald K.; Gerick, Alyssa A.

    2013-01-01

    This study describes the seasonal migration patterns of Western High Arctic Brant (WHA, or Grey-belly Brent Geese), Branta bernicla, an admixed population that breeds in the Canadian High Arctic and winters along the Pacific coast of North America. Adult WHA Brant were captured in family groups on Melville Island (75°23’N, 110°50’W) in 2002 and 2005 and marked with satellite platform transmitting terminal (PTT) transmitters or very high frequency (VHF) transmitters. During autumn migration, all PTT-tagged Brant followed a coastal route around Alaska and staged for variable lengths of time at the following sites on the north and west coasts of Alaska: Kasegaluk Lagoon (69°56’N, 162°40’W), Ikpek Lagoon (65°55’N, 167°03’W), and Izembek Lagoon (55°19’N, 162°50’W). Izembek Lagoon was the most important staging area in terms of length of stay (two months on average) and the majority (67–93%) of PTT and VHF detections occurred in Moffet Bay (55°24’N, 162°34’W). After departing Izembek Lagoon, the PTT-tagged geese followed a c. 2,900 km trans-oceanic route to overwinter in the southern part of the Salish Sea (i.e. from north Puget Sound, Washington to south Strait of Georgia, British Columbia; centred at c. 48°45’N, 122°40’W). Most (c. 45%) PTT detections in the southern Salish Sea occurred in Samish Bay (48°36’N, 122°30’W) followed by Padilla Bay (48°30’N, 122°31’W; c. 26%). Brant migrated north from the Salish Sea along the coast to southeast Alaska and then followed either an interior route across the Yukon or a coastal route around Alaska. The “interior” birds staged for c. four days at Liverpool Bay (69°20’N, 133°55’W) in the Northwest Territories before flying on to Melville Island. They also departed the Salish Sea two weeks later than the coastal migrants and arrived at Melville Island two weeks earlier. This study and previous research suggest that WHA Brant use similar migration routes each year and

  9. Superfund at work: Hazardous waste cleanup efforts nationwide, fall 1992. (Wide Beach section of Brant, New York)

    International Nuclear Information System (INIS)

    1992-01-01

    Wide-spread contamination of polychlorinated biphenyls (PCBs) threatened the Wide Beach section of Brant, New York, a popular vacation resort. EPA's Superfund program effectively completed a permanent cleanup of Wide Beach in the span of one year. Other highlights included: a new and innovative technology to remove PCB contamination; reduction of PCBs to one-fifth of acceptable levels; temporary relocation of residents who were concerned for their health while cleanup activities took place; newly paved roads and driveways, re-landscaped yards, and a new storm sewer system; and restoration of ecologically sensitive wetlands. EPA's achievements significantly reduced PCB risks at Wide Beach, and left a satisfied community in Brant

  10. Cranial Nerves IX, X, XI, and XII

    OpenAIRE

    Gillig, Paulette Marie; Sanders, Richard D.

    2010-01-01

    This article concludes the series on cranial nerves, with review of the final four (IX–XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected b...

  11. XII Tables for researchers on extraterrestrial intelligence

    Science.gov (United States)

    Cocca, Aldo Armando

    In the legal field, studies on extraterrestrial intelligence began four years before the leading article on interstellar communication was published. Even though discussion of the legal problems still lacks a juridical framework of universal acceptance, a few guidelines are suggested under the title of XII Tables (or Commandments). The XII Tables, which was the Romans' first code, also included provisions on international law and may be seen as a very important source of the law of nations. Their great merit was brevity, which allowed the progressive development of the law. These XII Tables have been divided into six to guide reactions in the event messages or signals are received, and six to determine the behavior of those responsible for answering if and when a communication attempt takes place. They were drafted on the basis of what is known as "ethics" and "law" in a way that any progress in this respect may be to the credit of our civilization and the human condition. For a wise and cautious analysis of the matter, the creation of a committee of representatives of governmental and non-governmental organizations is proposed.

  12. Collagen XII myopathy with rectus femoris atrophy and collagen XII retention in fibroblasts

    DEFF Research Database (Denmark)

    Witting, Nanna; Krag, Thomas; Werlauff, Ulla

    2018-01-01

    INTRODUCTION: Mutation in the collagen XII gene (COL12A1) was recently reported to induce Bethlem myopathy. We describe a family affected by collagen XII-related myopathy in 3 generations. METHODS: Systematic interview, clinical examination, skin biopsies, and MRI of muscle were used. RESULTS......: The phenotype was characterized by neonatal hypotonia, contractures, and delayed motor development followed by resolution of contractures and a motor performance limited by reduced endurance. DNA analyses revealed a novel donor splice-site mutation in COL12A1 (c.8100 + 2T>C), which segregated with clinical...... affection and abnormal collagen XII retention in fibroblasts. MRI disclosed a selective wasting of the rectus femoris muscle. DISCUSSION: COL12A1 mutations should be considered in patients with a mild Bethlem phenotype who present with selective wasting of the rectus femoris, absence of the outside...

  13. The Canadian space program from Black Brant to the International Space Station

    CERN Document Server

    Godefroy, Andrew B

    2017-01-01

    Canada’s space efforts from its origins towards the end of the Second World War through to its participation in the ISS today are revealed in full in this complete and carefully researched history. Employing recently declassified archives and many never previously used sources, author Andrew B. Godefroy explains the history of the program through its policy and many fascinating projects. He assesses its effectiveness as a major partner in both US and international space programs, examines its current national priorities and capabilities, and outlines the country’s plans for the future. Despite being the third nation to launch a satellite into space after the Soviet Union and the United States; being a major partner in the US space shuttle program with the iconic Canadarm; being an international leader in the development of space robotics; and acting as one of the five major partners in the ISS, the Canadian Space Program remains one of the least well-known national efforts of the space age. This book atte...

  14. [XII National Forum on Health Education].

    Science.gov (United States)

    Ramiro-H, Manuel

    2015-01-01

    In Guadalajara, on August 19, 20 and 21 was held the XII Foro Nacional de Educación en Salud, in line with the interest that both, the Dirección General and the Dirección de Prestaciones Médicas of the IMSS, have in training and updating the human resources for the care of the beneficiaries. The Unidad de Educación, Investigación y Políticas de Salud organized a meeting in which the actors of these tasks, the institutional staff and authorities from various universities worked together with the IMSS.

  15. Pius XII and the Jews: A Bibliographical Review.

    Science.gov (United States)

    Byers, Catherine

    1978-01-01

    Presents a brief biographical sketch of Pope Pius XII and samples literary treatment of Pius's actions with respect to Nazi atrocities against the Jewish people during World War II. Concludes that Pope Pius XII failed to show moral leadership. Materials reviewed include historical texts, studies of the Vatican, documents related to the war period,…

  16. Cinema and the Great War - Andrew Kelly, 1997. History by Hollywood. The use and abuse of the American past - Robert Brant Toplin, 1996

    NARCIS (Netherlands)

    Kester, Bernadette

    1998-01-01

    textabstractReview of: Cinema and the Great War. Andrew Kelly, Londen, New York (Routledge), 1997, 219 p.History by Hollywood. The use and abuse of the American past. Robert Brant Toplin, Chicago (Urbana), 1996, 267 p.

  17. "Her mouth is medicine": Beth Brant and Paula Gunn Allen's decolonizing queer erotics.

    Science.gov (United States)

    Burford, Arianne

    2013-01-01

    This article asserts the need to recognize the complexity of the theoretical work of more lesbian Native American writers, focusing specifically Beth Brant (Bay of Quinte Mohawk) and Paula Gunn Allen (Laguna Pueblo). Their poetry and short stories provide a theoretically nuanced analysis of how heteronormativity is intertwined in and dependent on colonialism, and thus a methodology for Queer Theory that requires an understanding of it in relation to colonialism. They reject heteronormative Pocahontas fantasies about Native women, offering a lesbian-based tactic for decolonization through the expression of erotic desire. This article demonstrates the endless possibilities for fierce queer resistance, revolutionary change, and healing from the trauma of genocide and the accompanying colonialist heteropatriarchal disciplining of Native women's bodies.

  18. La host (1998) Any XII. Núm. 7

    OpenAIRE

    Alè Revest, Josep Lluis; Agustí i Vicent, Joan; Belenguer, Emília; Sánchez-Pantoja Domínguez, Albert; Francisco, José Vicente; Trilles Font, Joan Josep; Gómez, Vicent; García Moliner, Federico; García, Agustín; Vicente, Ricardo; Alcón, Jaume; Gimeno, Vicent; Pallarés, Joan; Fernandez Jurado, Ramón; Lauterio, Amàlia

    1998-01-01

    SUMARI: Salutació.Crònica reial.La host.La torre dels Alçaments (i II).Casa i Cort dels reis d'Aragó (II).El bou en la cultura mediterrània.Joan Fuster,"in memoriam".Les illes columbretes.Bernat de Ventadorn, trobador d'ofici.Sant Antoni: Animals, dimonis i foc.III Capitol de l'arros i la taronja.Decàleg de promeses solemnes.Decàleg de promeses solemnes.Guijuelo:23-II-97 I capitol del jamón (XII jornadas de la matanza).Hernani: 23-III-97 II capítol de la sidra.Santander: 20-IV-97 XIII Capítol...

  19. Alates 13. XII on Vaala galeriis avatud "Talvesalong"

    Index Scriptorium Estoniae

    2004-01-01

    Väljas on Ellinor Aiki, Valdur Ohaka, Herman Talviku, Jaak Arro, Raoul Kurvitza, Andres Toltsi, Laurentsiuse, Lembit Saartsi, Rait Rosina, Merike Estna, Maarit Murka ning Aleksandr Breneri ja Barbara Schurzi tööd. 17. XII Anna Litvinova, Ilmar Kruusamäe ja Lembit Sarapuu ühised maaliseansid

  20. Comparision of analysis of the QTLMAS XII common dataset

    DEFF Research Database (Denmark)

    Lund, Mogens Sandø; Sahana, Goutam; de Koning, Dirk-Jan

    2009-01-01

    A dataset was simulated and distributed to participants of the QTLMAS XII workshop who were invited to develop genomic selection models. Each contributing group was asked to describe the model development and validation as well as to submit genomic predictions for three generations of individuals...

  1. Platonismo e Aristotelismo no século XII (II

    Directory of Open Access Journals (Sweden)

    Ruy Afonso da Costa Nunes

    1968-12-01

    Full Text Available Passo agora a examinar, à guisa de ilustração do platonismo no século XII, as concepções de alguns de seus pensadores a respeito da Alma do Mundo . Antes, porém, de efetuarmos tal exame, con-vém analisar a concepção original de Platão, bem como as que foram formuladas por Plotino e Macróbio.

  2. 48 CFR 715.370-2 - Title XII selection procedure-collaborative assistance.

    Science.gov (United States)

    2010-10-01

    ... Method for Title XII Activities for a more complete definition and discussion of the collaborative... procedure-collaborative assistance. 715.370-2 Section 715.370-2 Federal Acquisition Regulations System... Source Selection 715.370-2 Title XII selection procedure—collaborative assistance. (a) General. (48 CFR...

  3. Type XII and XIV collagens mediate interactions between banded collagen fibers in vitro and may modulate extracellular matrix deformability.

    Science.gov (United States)

    Nishiyama, T; McDonough, A M; Bruns, R R; Burgeson, R E

    1994-11-11

    Type XII and XIV collagens are very large molecules containing three extended globular domains derived from the amino terminus of each alpha chain and an interrupted triple helix. Both collagens are genetically and immunologically unique and have distinct distributions in many tissues. These collagens localize near the surface of banded collagen fibrils. The function of the molecules is unknown. We have prepared a mixture of native type XII and XIV collagens that is free of contaminating proteins by electrophoretic criteria. In addition, we have purified the collagenase-resistant globular domains of type XII or XIV collagens (XII-NC-3 or XIV-NC-3). In this study, we have investigated the effect of intact type XII and XIV and XII-NC-3 or XIV-NC-3 on the interactions between fibroblasts and type I collagen fibrils. We find that both type XII and XIV collagens promote collagen gel contraction mediated by fibroblasts, even in the absence of serum. The activity is present in the NC-3 domains. The effect is dose-dependent and is inhibited by denaturation. The effect of type XII NC-3 is inhibited by the addition of anti-XII antiserum. To elucidate the mechanism underlying this phenomenon, we examined the effect of XII-NC-3 or XIV-NC-3 on deformability of collagen gels by centrifugal force. XII-NC-3 or XIV-NC-3 markedly promotes gel compression after centrifugation. The effect is also inhibited by denaturation, and the activity of type XII-NC3 is inhibited by the addition of anti-XII antiserum. The results indicate that the effect of XII-NC-3 or XIV-NC-3 on collagen gel contraction by fibroblasts is not due to activation of cellular events but rather results from the increase in mobility of hydrated collagen fibrils within the gel. These studies suggest that collagen types XII and XIV may modulate the biomechanical properties of tissues.

  4. 40 CFR Appendix Xii to Part 266 - Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Nickel or Chromium-Bearing Materials that may be Processed in Exempt Nickel-Chromium Recovery Furnaces XII Appendix XII to Part 266... FACILITIES Pt. 266, App. XII Appendix XII to Part 266—Nickel or Chromium-Bearing Materials that may be...

  5. XII International Conference of the Italian Association on Artificial Intelligence

    CERN Document Server

    Semeraro, Giovanni; Vargiu, Eloisa; New Challenges in Distributed Information Filtering and Retrieval : DART 2011: Revised and Invited Papers

    2013-01-01

    This volume focuses on new challenges in distributed Information Filtering and Retrieval. It collects invited chapters and extended research contributions from the DART 2011 Workshop, held in Palermo (Italy), on September 2011, and co-located with the XII International Conference of the Italian Association on Artificial Intelligence. The main focus of DART was to discuss and compare suitable novel solutions based on intelligent techniques and applied to real-world applications. The chapters of this book present a comprehensive review of related works and state of the art. Authors, both practitioners and researchers, shared their results in several topics such as "Multi-Agent Systems", "Natural Language Processing", "Automatic Advertisement", "Customer Interaction Analytics", "Opinion Mining".

  6. XII International Conference on the Theory of Machines and Mechanisms

    CERN Document Server

    Bílek, Martin; Žabka, Petr

    2017-01-01

    This book presents the most recent advances in the research of machines and mechanisms. It collects 54 reviewed papers presented at the XII International Conference on the Theory of Machines and mechanisms (TMM 2016) held in Liberec, Czech Republic, September 6-8, 2016. This volume offers an international selection of the most important new results and developments, grouped in six different parts, representing a well-balanced overview, and spanning the general theory of machines and mechanisms, through analysis and synthesis of planar and spatial mechanisms, linkages and cams, robots and manipulators, dynamics of machines and mechanisms, rotor dynamics, computational mechanics, vibration and noise in machines, optimization of mechanisms and machines, mechanisms of textile machines, mechatronics to the control and monitoring systems of machines. This conference is traditionally organised every four year under the auspices of the international organisation IFToMM and the Czech Society for Mechanics.

  7. Agriculture in the new century: FY 2000 report to Congress on Title XII

    OpenAIRE

    United States Agency for International Development (USAID)

    2001-01-01

    Metadata only record This report summarizes the accomplishments of USAID and our public and private partners in FY 2000, the final year of implementation under Title XII as originally legislated in 1975. Available in SANREM office, FS

  8. Uudised : Gennadi Tanieli autorikontsert. Tallinna XII barokifestival. Tubina ühing koguneb / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2001-01-01

    21. jaan. toimus sarjas "Eesti heliloojad talveaias" G. Tanieli autorikontsert. 1.-11. veebr. toimuvast Tallinna XII Barokkfestivalist. 27. jaan. toimub EMAs Rahvusvahelise Eduard Tubina Ühingu esimene aastakoosolek, koosoleku päevakorrast

  9. Platonismo e Aristotelismo no século XII (III

    Directory of Open Access Journals (Sweden)

    Ruy Afonso da Costa Nunes

    1969-03-01

    No primeiro capítulo tive a oportunidade de focalizar a maneira como João de Salisbury considerava Aristóteles em relação a Platão. Vou proceder agora a uma análise de alguns passos do Metalogicus nos quais o autor se manifesta a propósito da questão dos Univer-sais e dos livros do Organon que vieram a constituir a Logica Nova. Com isso pretendo apresentar uma ilustração do aristotelismo no século XII, sem que seja minha intenção pôr em relêvo tôdas as re-ferências do Saresberiense à lógica e a Aristóteles . De início, acho conveniente acompanhar o autor em seu depoimento autobiográfico a respeito dos próprios estudos, pois isso permitir-nos-á apreciar o processo da formação aristotélica pelo qual êle passou sob a direção de vários mestres em Paris e em Chartres.

  10. Textos de compra-venta en el siglo XII

    Directory of Open Access Journals (Sweden)

    Marta Fernández Alcaide

    2008-06-01

    Full Text Available A partir del desarrollo del concepto de tradiciones discursivas, en los últimos años se ha realizado un estudio de textos del derecho del siglo XII, concretamente de unas actas de compra-venta. Estos documentos, aparentemente escritos en latín, ya presentan una sintaxis romance, muestra de la situación lingüística de la época, esa especie de bilingüismo diafásico entre el latín escrito y el romance hablado. Se empieza por un breve análisis fonológico, morfosintáctico y léxico, que ofrece una idea de las características lingüísticas del siglo. El objetivo del trabajo es el estudio de la estructura textual, facilitado por la escasa libertad de composición en este tipo de textos.---Based on the recent theoretical development of the discursive traditions, this article focuses on some law texts of the XIIth century, in particular, a few acts of purchase. These documents, apparently written in Latin, already display a Romance syntax. This depicts the linguistic situation of that time: some sort of dysphasic bilingualism between written Latin and spoken Romance. The article begins with phonological, morphological and lexical analyses that give a general idea of the characteristics of the language of the XIIth century. However, the objective of the present article is the study of the text structure, taking on consideration that there was not much room for creative display in this kind of documents.

  11. The lower cranial nerves: IX, X, XI, XII.

    Science.gov (United States)

    Sarrazin, J-L; Toulgoat, F; Benoudiba, F

    2013-10-01

    The lower cranial nerves innervate the pharynx and larynx by the glossopharyngeal (CN IX) and vagus (CN X) (mixed) nerves, and provide motor innervation of the muscles of the neck by the accessory nerve (CN XI) and the tongue by the hypoglossal nerve (CN XII). The symptomatology provoked by an anomaly is often discrete and rarely in the forefront. As with all cranial nerves, the context and clinical examinations, in case of suspicion of impairment of the lower cranial nerves, are determinant in guiding the imaging. In fact, the impairment may be located in the brain stem, in the peribulbar cisterns, in the foramens or even in the deep spaces of the face. The clinical localization of the probable seat of the lesion helps in choosing the adapted protocol in MRI and eventually completes it with a CT-scan. In the bulb, the intra-axial pathology is dominated by brain ischemia (in particular, with Wallenberg syndrome) and multiple sclerosis. Cisternal pathology is tumoral with two tumors, schwannoma and meningioma. The occurrence is much lower than in the cochleovestibular nerves as well as the leptomeningeal nerves (infectious, inflammatory or tumoral). Finally, foramen pathology is tumoral with, outside of the usual schwannomas and meningiomas, paragangliomas. For radiologists, fairly hesitant to explore these lower cranial pairs, it is necessary to be familiar with (or relearn) the anatomy, master the exploratory technique and be aware of the diagnostic possibilities. Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  12. Drug design studies of the novel antitumor targets carbonic anhydrase IX and XII.

    Science.gov (United States)

    Guler, O Ozensoy; De Simone, G; Supuran, C T

    2010-01-01

    The carbonic anhydrase (CA, EC 4.2.1.1) isozymes IX and XII are predominantly found in tumor cells and show a restricted expression in normal tissues. By efficiently hydrating carbon dioxide to protons and bicarbonate, these CAs contribute significantly to the extracellular acidification of solid tumors. CA IX and XII are overexpressed in many such tumors in response to the hypoxia inducible factor (HIF) pathway, and research on the involvement of these isozymes in cancer has progressed in recent years. The report of the X-ray crystal structure of CA IX, which is a dimeric protein with a quaternary structure not evidenced earlier for this family of enzymes, allows for structure-based drug design campaigns of inhibitors against this novel antitumor target. Indeed, it has been known for some time that aromatic/ heterocyclic sulfonamides and sulfamates have good affinity for this isoform, but generally they do not show specificity for the inhibition of the tumor-associated isoform versus the remaining CA isozymes (CA I-VII, and XII-XV) found in mammals. Recently, we reported several classes of compounds with good selectivity for the tumor-associated CAs, being shown that CA IX/XII inhibition reverses the effect of tumor acidification, leading to inhibition of the cancer cells growth. CA IX/XII are now proposed as novel therapeutic antitumor targets. Furthermore, as some types of CA inhibitors (CAIs), such as the fluorescent sulfonamides accumulate only in hypoxic tumor cells overexpressing these enzymes, CAIs may be also used as diagnostic tools for imaging of hypoxic cancer cells. Work from several laboratories recently reported the proof-of-concept studies for the use of CA IX/XII inhibitors as well as antibodies both in the therapy and imaging of hypoxic tumors.

  13. Factor XII-independent activation of the bradykinin-forming cascade

    DEFF Research Database (Denmark)

    Joseph, Kusumam; Tholanikunnel, Baby G; Bygum, Anette

    2013-01-01

    . Prolonged incubation of plasma deficient in both factor XII and C1-INH led to conversion of prekallikrein to kallikrein and cleavage of HK, as was seen in plasma from patients with hereditary angioedema but not plasma from healthy subjects. CONCLUSIONS: These results indicate that C1-INH stabilizes...... the prekallikrein-HK complex to prevent HK cleavage either by prekallikrein or by prekallikrein-HK autoactivation to generate kallikrein. In patients with hereditary angioedema, kallikrein and bradykinin formation can occur without invoking factor XII activation, although the kallikrein formed can rapidly activate...

  14. Activation of the contact system of coagulation by a monoclonal antibody directed against a neodeterminant in the heavy chain region of human coagulation factor XII (Hageman factor)

    NARCIS (Netherlands)

    Nuijens, J. H.; Huijbregts, C. C.; Eerenberg-Belmer, A. J.; Meijers, J. C.; Bouma, B. N.; Hack, C. E.

    1989-01-01

    We studied the characteristics of two monoclonal antibodies (mAbs), F1 and F3, against human coagulation factor XII (Hageman factor). Experiments with trypsin-digested 125I-factor XII revealed that the epitope for mAb F1 is located in the NH2-terminal Mr 40,100 portion of factor XII, whereas that

  15. 40 CFR Appendix Xii to Part 86 - Tables for Production Compliance Auditing of Heavy-Duty Engines and Heavy-Duty Vehicles...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Tables for Production Compliance Auditing of Heavy-Duty Engines and Heavy-Duty Vehicles, Including Light-Duty Trucks XII Appendix XII to... Appendix XII to Part 86—Tables for Production Compliance Auditing of Heavy-Duty Engines and Heavy-Duty...

  16. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as is hi...... suggested that appreciation of the highly personal motives of both Siouxsie Sioux and Janelle Monáe in wearing black may be achieved via analogies with the minimalist sublime of American artists Frank Stella’s and Ad Reinhardt’s black canvasses.......Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as...... is hinted by Rudyard Kipling’s illustration of ‘The [Black] Cat That Walked by Himself’ in his classic children’s tale). It was well understood by uniformed Anarchists, Fascists and the SS that there is an assertive presence connected with the black-clad figure. The paradox of black’s abstract elegance...

  17. Collagen XII Contributes to Epicardial and Connective Tissues in the Zebrafish Heart during Ontogenesis and Regeneration.

    Directory of Open Access Journals (Sweden)

    Jan Marro

    Full Text Available Zebrafish heart regeneration depends on cardiac cell proliferation, epicardium activation and transient reparative tissue deposition. The contribution and the regulation of specific collagen types during the regenerative process, however, remain poorly characterized. Here, we identified that the non-fibrillar type XII collagen, which serves as a matrix-bridging component, is expressed in the epicardium of the zebrafish heart, and is boosted after cryoinjury-induced ventricular damage. During heart regeneration, an intense deposition of Collagen XII covers the outer epicardial cap and the interstitial reparative tissue. Analysis of the activated epicardium and fibroblast markers revealed a heterogeneous cellular origin of Collagen XII. Interestingly, this matrix-bridging collagen co-localized with fibrillar type I collagen and several glycoproteins in the post-injury zone, suggesting its role in tissue cohesion. Using SB431542, a selective inhibitor of the TGF-β receptor, we showed that while the inhibitor treatment did not affect the expression of collagen 12 and collagen 1a2 in the epicardium, it completely suppressed the induction of both genes in the fibrotic tissue. This suggests that distinct mechanisms might regulate collagen expression in the outer heart layer and the inner injury zone. On the basis of this study, we postulate that the TGF-β signaling pathway induces and coordinates formation of a transient collagenous network that comprises fibril-forming Collagen I and fiber-associated Collagen XII, both of which contribute to the reparative matrix of the regenerating zebrafish heart.

  18. A Letter from Edmund Husserl to Franz Brentano from 29 XII 1889

    NARCIS (Netherlands)

    Ierna, Carlo

    2015-01-01

    Among the correspondence between Husserl and Brentano kept at the Houghton Library of Harvard University there is a letter from Husserl to Brentano from 29 XII 1889, whose contents were completely unknown until now. The letter is of some significance, both historically as well as systematically for

  19. Collagen XII: Protecting bone and muscle integrity by organizing collagen fibrils.

    Science.gov (United States)

    Chiquet, Matthias; Birk, David E; Bönnemann, Carsten G; Koch, Manuel

    2014-08-01

    Collagen XII, largest member of the fibril-associated collagens with interrupted triple helix (FACIT) family, assembles from three identical α-chains encoded by the COL12A1 gene. The molecule consists of three threadlike N-terminal noncollagenous NC3 domains, joined by disulfide bonds and a short interrupted collagen triple helix toward the C-terminus. Splice variants differ considerably in size and properties: "small" collagen XIIB (220 kDa subunit) is similar to collagen XIV, whereas collagen XIIA (350 kDa) has a much larger NC3 domain carrying glycosaminoglycan chains. Collagen XII binds to collagen I-containing fibrils via its collagenous domain, whereas its large noncollagenous arms interact with other matrix proteins such as tenascin-X. In dense connective tissues and bone, collagen XII is thought to regulate organization and mechanical properties of collagen fibril bundles. Accordingly, recent findings show that collagen XII mutations cause Ehlers-Danlos/myopathy overlap syndrome associated with skeletal abnormalities and muscle weakness in mice and humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Living in a physical world XII. Keeping up upward and down ...

    Indian Academy of Sciences (India)

    2007-08-18

    Aug 18, 2007 ... Home; Journals; Journal of Biosciences; Volume 32; Issue 6. Living in a physical world XII. Keeping up upward and down downward. Steven Vogel. Series Volume 32 Issue 6 September 2007 pp 1067-1081. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Transmembrane carbonic anhydrase isozymes IX and XII in the female mouse reproductive organs

    Directory of Open Access Journals (Sweden)

    Tomas Eija

    2004-10-01

    Full Text Available Abstract Background Carbonic anhydrase (CA classically catalyses the reversible hydration of dissolved CO2 to form bicarbonate ions and protons. The twelve active CA isozymes are thought to regulate a variety of cellular functions including several processes in the reproductive systems. Methods The present study was designed to investigate the expression of transmembrane CAs, CA IX and XII, in the mouse uterus, ovary and placenta. The expression of CA IX and XII was examined by immunoperoxidase staining method and western blotting. CA II and XIII served as positive controls since they are known to be present in the mouse reproductive tract. Results The data of our study indicated that CA XII is expressed in the mouse endometrium. Only very faint signal was observed in the corpus luteum of the ovary and the placenta remained mainly negative. CA IX showed weak reaction in the endometrial epithelium, while it was completely absent in the ovary and placenta. Conclusion The conservation of CA XII expression in both mouse and human endometrium suggests a role for this isozyme in reproductive physiology.

  2. RA-XII inhibits tumour growth and metastasis in breast tumour-bearing mice via reducing cell adhesion and invasion and promoting matrix degradation.

    Science.gov (United States)

    Leung, Hoi-Wing; Zhao, Si-Meng; Yue, Grace Gar-Lee; Lee, Julia Kin-Ming; Fung, Kwok-Pui; Leung, Ping-Chung; Tan, Ning-Hua; Lau, Clara Bik-San

    2015-11-23

    Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM) and migrate to adjacent tissues. This ultimately results metastasis. Hence, the present study investigated the in vitro effects of cyclopeptide glycoside, RA-XII on cell adhesion, invasion, proliferation and matrix degradation, and its underlying mechanism in murine breast tumour cells, 4T1. The effect of RA-XII on tumour growth and metastasis in 4T1-bearing mice was also investigated. Our results showed that RA-XII inhibited tumour cell adhesion to collagen, fibronectin and laminin, RA-XII also reduced the expressions of vascular cell adhesion molecule, intracellular adhesion molecule and integrins, and integrin binding. In addition, RA-XII significantly inhibited breast tumour cell migration via interfering cofilin signaling and chemokine receptors. The activities of matrix metalloproteinase-9 and urokinase-type of plasminogen activator, and the expressions of ECM-associated proteinases were attenuated significantly by RA-XII. Furthermore, RA-XII induced G1 phase arrest and inhibited the expressions of cyclins and cyclin-dependent kinases. RA-XII inhibited the expressions of molecules in PI3K/AKT, NF-kappaB, FAK/pSRC, MAPK and EGFR signaling. RA-XII was also shown to have anti-tumour, anti-angiogenic and anti-metastatic activities in metastatic breast tumour-bearing mice. These findings strongly suggested that RA-XII is a potential anti-metastatic agent for breast cancer.

  3. Multiplier Effect Industri Pariwisata Candi Muara Takus Terhadap Perekonomian Masyarakat Di Kecamatan XII Koto Kampar Kabupaten Kampar

    OpenAIRE

    Ikhsan, Muhammad; ', Mardiana; Setiawan, Deny

    2017-01-01

    The research was carried on in Kampar regency precisely in the District XII Koto Kampar. This study was conducted in Kampar regency located in District XII Koto Kampar. This study aims to (1) Identify the characteristics of visitors, businessmen and labor (2) To identify the perception of the condition of Tourism Muara Takus by visitors, businesses and workers in the tourist area (3) Measuring multiplier effet that caused by Muara Takus tourist activities on the economy of the community. The ...

  4. Prevalence of factor XII (Hageman factor) deficiency among 426 patients with coronary heart disease awaiting cardiac surgery.

    Science.gov (United States)

    Halbmayer, W M; Haushofer, A; Radek, J; Schön, R; Deutsch, M; Fischer, M

    1994-05-01

    Several case reports of myocardial infarction in patients with factor XII deficiency have been published. In the present study we investigated the prevalence of this condition. Factor XII activity (one-stage clotting assay), fibrinogen (derived method), and lipoprotein (a) (enzyme-linked immunosorbent assay) were measured in the plasma of 426 consecutive patients with coronary heart disease awaiting cardiac surgery. Among the 426 patients, 44 (10.3%) were found to be moderately deficient in factor XII (factor XII activity 17-50%, antigen 15-57%). The prevalence of factor XII deficiency was significantly higher (P < 0.0001) among patients with coronary heart disease than among 300 healthy blood donors (2.3%). Among coronary heart disease patients with this deficiency, elevated levels of fibrinogen, lipoprotein (a), and blood pressure were no more prevalent than in those without the deficiency; nor were cigarette smoking or a positive family history of thromboembolism more prevalent. Coronary heart disease patients showed a 10% prevalence of factor XII deficiency. However, the pattern of atherosclerotic risk factors did not differ between patients with or without the deficiency.

  5. Acquired factor XII deficiency in a woman with recurrent pregnancy loss: working on a differential diagnosis in a single case

    Directory of Open Access Journals (Sweden)

    Di Micco Pierpaolo

    2005-12-01

    Full Text Available Abstract Background Antiphospholipid syndrome (APS has been often associated to RPL since 1980 and some reports in the Literature rarely described antibodies to factor XII in patients with APS. Case history We report the case history of 34-year-old caucasian women with recurrent fetal loss and persistent prolonged activated partial thromboplastin time. Haemostatic tests revealed persistent light decrease of clotting factor XII with normal values of IgG and IgM anticardiolipin antibodies and transient positivity for lupus anticoagulant (LA. Few reports in the Literature described antibodies to factor XII in patient with antiphospholipid syndrome (APS and transient LA. So, once other causes of RPL were excluded, the patient was diagnosed an unusual form of APS associated to antibodies to factor XII, reduced factor XII plasma levels, transient LA and prolonged activated partial thromboplastin time. Discussion We suggest to consider also antibodies directed to clotting factors (e.g. factor XII in our case as second step of thrombophilia screening in RPL, in particular if a persistent prolonged aPTT is present without an apparent cause.

  6. Ludus de Antichristo e o drama da escatologia imperial no século XII

    Directory of Open Access Journals (Sweden)

    Vinicius Cesar Dreger de Araújo

    2013-09-01

    Full Text Available Buscamos neste texto analisar as imbricações entre o texto teatral germânico do século XII, o Ludus de Antichristo, e o seu contexto político-cultural, particularmente em relação às personagens do Anticristo e do Último Imperador Romano, seus protagonistas, com a Escatologia Imperial encontrada no período. Nosso artigo contém um detalhado resumo da peça, estudos relacionados às tradições e documentos que levaram à sua concepção e seu enquadramento nos debates políticos e religiosos do século XII.

  7. Collagen XII Contributes to Epicardial and Connective Tissues in the Zebrafish Heart during Ontogenesis and Regeneration

    OpenAIRE

    Marro, Jan; Pfefferli, Catherine; de Preux Charles, Anne-Sophie; Bise, Thomas; Ja?wi?ska, Anna

    2016-01-01

    Zebrafish heart regeneration depends on cardiac cell proliferation, epicardium activation and transient reparative tissue deposition. The contribution and the regulation of specific collagen types during the regenerative process, however, remain poorly characterized. Here, we identified that the non-fibrillar type XII collagen, which serves as a matrix-bridging component, is expressed in the epicardium of the zebrafish heart, and is boosted after cryoinjury-induced ventricular damage. Du...

  8. NPP safety and personnel training. XII International conference. Abstracts. Volume 2

    International Nuclear Information System (INIS)

    2011-01-01

    The XII International conference NPP Safety and Personnel Training took place in Obninsk, October 4-7 2011. The problems of personnel training for nuclear industry are discussed. The innovation nuclear systems and fuel cycle are considered. The much attention has been given to NPP radiation safety and radioecology issues. The recent high-speed computation and simulation methods used in reactor technology are presented [ru

  9. Comparision of analysis of the QTLMAS XII common dataset:I: Genomic selection

    OpenAIRE

    Lund, Mogens Sandø; Sahana, Goutam; de Koning, Dirk-Jan; Su, Guosheng; Carlborg, Örjan

    2009-01-01

    A dataset was simulated and distributed to participants of the QTLMAS XII workshop who were invited to develop genomic selection models. Each contributing group was asked to describe the model development and validation as well as to submit genomic predictions for three generations of individuals, for which they only knew the genotypes. The organisers used these genomic predictions to perform the final validation by comparison to the true breeding values, which were known only to the organise...

  10. Development of sulfonamides incorporating phenylacrylamido functionalities as carbonic anhydrase isoforms I, II, IX and XII inhibitors.

    Science.gov (United States)

    Angapelly, Srinivas; Ramya, P V Sri; Angeli, Andrea; Del Prete, Sonia; Capasso, Clemente; Arifuddin, Mohammed; Supuran, Claudiu T

    2017-10-15

    A series of novel sulfonamides incorporating phenylacrylamido functionalities were synthesized and investigated for the inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The physiologically and pharmacologically relevant human (h) isoforms hCA I and II (cytosolic isozymes), as well as the transmembrane tumor-associated hCA IX and XII were included in the study. These compounds showed low nanomolar or sub-nanomolar inhibition constants against hCA II (K I s in the range of 0.50-50.5nM), hCA IX (K I s of 1.8-228.5nM), and hCA XII (K I s of 3.5-96.2nM) being less effective as inhibitors of the off target isoform hCA I. A detailed structure-activity relationship study demonstrates that the nature and position of substituents present on the aromatic part of the scaffold strongly influence the inhibition of CA isoforms. As hCA II, IX and XII are involved in pathologies such as glaucoma and hypoxic, and metastatic tumors, compounds of the type reported in this work may be useful preclinical candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Use of Al XII and Mg XI lines as solar plasma diagnostics

    International Nuclear Information System (INIS)

    Bromage, B.J.I.; Phillips, K.J.H.; Keenan, F.P.; McCann, S.M.

    1989-09-01

    We present three sets of observations of n=1 to n=2 lines due to helium-like aluminium (Al XII), made during two solar flares (25 August, 1980 and 19 October, 1986), using the X-ray Polychromator on satellite. The observed temperature-sensitive line ratio G is shown to be consistent with previously observed close-coupling calculations, although the ratio R, which is both temperature and density-sensitive for lower-Z elements, is not sufficiently well determined from these data to say more than that the observed values of R are not inconsistent with the theoretical calculations. This region of the spectrum also includes the helium-like magnesium (Mg XI) 1 1 S-3 1 P line, and it is shown that the ratio of this line to the Al XII resonance (1 1 S-2 1 P) line is a more sensitive indicator of electron temperature than are the Al XII G and R ratios. We demonstrate that the three ratios may be used together in order to derive values of emission measure, electron temperature and electron density during these flares. (author)

  12. 2. XII möödus 20 aastat Adamson-Ericu muuseumi avamisest Eesti Kunstimuuseumi filiaalina ning 35 aastat Adamson-Ericu (1902-1968) surmast

    Index Scriptorium Estoniae

    2003-01-01

    Muuseumi ajaloost, põhikogust, Adamson-Ericu teoste põhiekspositsioonist, kunstinäitustest. 3. XII tutvustab Kersti Koll Adamson-Ericu ja läti kunstniku Ludolfs Libertsi näitust. 5. XII ekspositsioonis ringkäik "Meistri töövõtetest ning erinevatest materjalidest restauraatori pilgu läbi" Alar Nurkse juhtimisel, ekskursioon Ülle Kruusi juhtimisel. 10. XII algab projekti "Avatud muuseum" raames haridusprogramm "Noor kunstidetektiiv"

  13. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.

    1981-01-01

    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  14. Book of Proceedings of the XII Portuguese-Spanish Symposium on Plant Water Relations (2014)

    OpenAIRE

    R. P. Coelho, Renato; M. Vaz, Margarida

    2014-01-01

    This book contains the most relevant communications presented at the XII Portuguese-Spanish Symposium on Plant Water Relations which was held at the University of Évora, Portugal, organized by the Portuguese Society of Plant Physiology, the Spanish Society of Plant Physiology and the “Instituto de Ciências Agrárias e Ambientais Mediterrânicas” (ICAAM - University of Évora). The motto of the Symposium ― Water to Feed the World ― shows the clear purpose of investigators and academics in the...

  15. The GEKKO XII-HIPER (High Intensity Plasma Experimental Research) system relevant to ignition targets

    International Nuclear Information System (INIS)

    Miyanaga, N.; Nakatsuka, M.; Azechi, H.

    2001-01-01

    To test high gain targets surrogated in the planar geometry, we have constructed a new experimental system (HIPER) which provides the high ablation pressure with a uniform irradiance profile. These performances were achieved by bundling twelve beams of the existing GEKKO XII into a F/3 focus cone. The partially coherent light is introduced for the beam smoothing of a green foot pulse consisting of three beams, and the three-directional smoothing by spectral dispersion is utilized for residual nine beams delivering a blue main drive pulse. The detail of design concept and results of initial activation of this system are reported. (author)

  16. Black Alcoholism.

    Science.gov (United States)

    Watts, Thomas D.; Wright, Roosevelt

    1988-01-01

    Examines some aspects of the problem of alcoholism among Blacks, asserting that Black alcoholism can best be considered in an ecological, environmental, sociocultural, and public health context. Notes need for further research on alcoholism among Blacks and for action to reduce the problem of Black alcoholism. (NB)

  17. Black Culture

    Science.gov (United States)

    Brown, Angela Khristin

    2013-01-01

    The migration of blacks in North America through slavery became united. The population of blacks passed down a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape…

  18. PENGARUH PRESTASI PRAKTIK KERJA INDUSTRI DAN HASIL BELAJAR KEWIRAUSAHAAN TERHADAP MINAT BERWIRAUSAHAAN SISWA KELAS XII AKUNTANSI SMK NEGERI 25 JAKARTA

    Directory of Open Access Journals (Sweden)

    DESTA AMBARSARI

    2016-03-01

    Full Text Available This research purpose is to find out the influence of industrial practice and entrepreneurship learning achievement to entrepreneurship interest, XII Accounting Class in SMK Negeri 25 Jakarta. This type of research is survey, with quantitative approach. Data recording, interview and questionnaire are research technique. Sampling technique used proportional random sampling. Total population in this study were 77 students with a sample of 64 students of XII accounting class in SMK Negeri 25 Jakarta. The results showed that: there is a significant positive influence of industrial practice and entrepreneurship learning achievement to entrepreneurship interest, XII Accounting Class in SMK Negeri 25 Jakarta. Thus if industrial practice and entrepreneurship learning achievement increases, the entrepreneurship interest will also increase.

  19. New amide derivatives of Probenecid as selective inhibitors of carbonic anhydrase IX and XII: biological evaluation and molecular modelling studies.

    Science.gov (United States)

    Carradori, Simone; Mollica, Adriano; Ceruso, Mariangela; D'Ascenzio, Melissa; De Monte, Celeste; Chimenti, Paola; Sabia, Rocchina; Akdemir, Atilla; Supuran, Claudiu T

    2015-07-01

    Novel amide derivatives of Probenecid were synthesized and discovered to act as potent and selective inhibitors of the human carbonic anhydrase (hCA, EC 4.2.1.1) transmembrane isoforms hCA IX and XII. The proposed chemical transformation of the carboxylic acid into an amide group led to a complete loss of hCA I and II inhibition (Kis >10,000nM) and enhanced the inhibitory activity against hCA IX and XII, with respect to the parent compound (incorporating a COOH function). These promising biological results have been corroborated by molecular modelling studies within the active sites of the four studied human carbonic anhydrases, which enabled us to rationalize both the isoform selectivity and high activity against the tumor-associated isoforms hCA IX/XII. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Structure and function of transmembrane segment XII in osmosensor and osmoprotectant transporter ProP of Escherichia coli.

    Science.gov (United States)

    Liu, Feng; Culham, Doreen E; Vernikovska, Yaroslava I; Keates, Robert A B; Boggs, Joan M; Wood, Janet M

    2007-05-15

    Escherichia coli transporter ProP acts as both an osmosensor and an osmoregulator. As medium osmolality rises, ProP is activated and mediates H+-coupled uptake of osmolytes like proline. A homology model of ProP with 12-transmembrane (TM) helices and cytoplasmic termini was created, and the protein's topology was substantiated experimentally. Residues 468-497, at the end of the C-terminal domain and linked to TM XII, form an intermolecular, homodimeric alpha-helical coiled-coil that tunes the transporter's response to osmolality. We aim to further define the structure and function of ProP residues Q415-E440, predicted to include TM XII. Each residue was replaced with cysteine (Cys) in a histidine-tagged, Cys-less ProP variant (ProP*). Cys at positions 415-418 and 438-440 were most reactive with Oregon Green Maleimide (OGM), suggesting that residues 419 through 437 are in the membrane. Except for V429-I433, reactivity of those Cys varied with helical periodicity. Cys predicted to face the interior of ProP were more reactive than Cys predicted to face the lipid. The former may be exposed to hydrated polar residues in the protein interior, particularly on the periplasmic side. Intermolecular cross-links formed when ProP* variants with Cys at positions 419, 420, 422, and 439 were treated with DTME. Thus TM XII can participate, along its entire length, in the dimer interface of ProP. Cys substitution E440C rendered ProP* inactive. All other variants retained more than 30% of the proline uptake activity of ProP* at high osmolality. Most variants with Cys substitutions in the periplasmic half of TM XII activated at lower osmolalities than ProP*. Variants with Cys substitutions on one face of the cytoplasmic half of TM XII required a higher osmolality to activate. They included elements of a GXXXG motif that are predicted to form the interface of TM XII with TM VII. These studies define the position of ProP TM XII within the membrane, further support the predicted

  1. Progress in direct-drive laser fusion using GEKKO XII/PW facility

    International Nuclear Information System (INIS)

    Yamanaka, T.

    2002-01-01

    Extensive studies have been carried out for the fast-ignitor laser fusion which can provide one of the most feasible short tracks in the fusion energy development. We have upgraded the heating laser up to 1 PW(500 J/500 fs) and have started comprehensive studies on the transport of high current relativistic electron beam in the dense plasma. Substantial heating of the core plasma up to 1 keV is expected with implosion plasma produced by the Gekko XII laser. We have experimentally obtained for the first time all parameters to decide the growth rate of Rayleigh-Taylor instability using the HIPER irradiation system which can generate ablation pressure up to 60 Mbar and newly developed advanced x-ray diagnostic tools. We have proposed the FIREX (Fast Ignitor Realization Experiment) program for demonstrating the proof-of-principle of fast ignitor scheme. By the irradiation of ∼10 kJ/2-10 ps laser onto a DT core plasma formed by the GEKKO-XII, we are aiming at temperature of >8 keV and the fusion gain near unity. (author)

  2. Metallocene-based inhibitors of cancer-associated carbonic anhydrase enzymes IX and XII.

    Science.gov (United States)

    Salmon, Adam J; Williams, Michael L; Wu, Quoc K; Morizzi, Julia; Gregg, Daniel; Charman, Susan A; Vullo, Daniela; Supuran, Claudiu T; Poulsen, Sally-Ann

    2012-06-14

    In this study, 20 metallocene-based compounds comprising extensive structural diversity were synthesized and evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. These compounds proved moderate to good CA inhibitors in vitro, with several compounds displaying selectivity for cancer-associated isozymes CA IX and CA XII compared to off-target CA I and CA II. Compound 6 was the most potent ferrocene-based inhibitor with K(i)s of 5.9 and 6.8 nM at CA IX and XII, respectively. A selection of key drug-like parameters comprising Log P, Log D, solubility, and in vitro metabolic stability and permeability were measured for two of the ferrocene-based compounds, regioisomers 1 and 5. Compounds 1 and 5 were found to have characteristics consistent with lipophilic compounds, however, our findings show that the lipophilicity of the ferrocene moiety is not well modeled by replacement with either a naphthyl or a phenyl moiety in software prediction tools.

  3. Glycosaminoglycans affect the interaction of human plasma kallikrein with plasminogen, factor XII and inhibitors

    Directory of Open Access Journals (Sweden)

    Gozzo A.J.

    2003-01-01

    Full Text Available Human plasma kallikrein, a serine proteinase, plays a key role in intrinsic blood clotting, in the kallikrein-kinin system, and in fibrinolysis. The proteolytic enzymes involved in these processes are usually controlled by specific inhibitors and may be influenced by several factors including glycosaminoglycans, as recently demonstrated by our group. The aim of the present study was to investigate the effect of glycosaminoglycans (30 to 250 µg/ml on kallikrein activity on plasminogen and factor XII and on the inhibition of kallikrein by the plasma proteins C1-inhibitor and antithrombin. Almost all available glycosaminoglycans (heparin, heparan sulfate, bovine and tuna dermatan sulfate, chondroitin 4- and 6-sulfates reduced (1.2 to 3.0 times the catalytic efficiency of kallikrein (in a nanomolar range on the hydrolysis of plasminogen (0.3 to 1.8 µM and increased (1.9 to 7.7 times the enzyme efficiency in factor XII (0.1 to 10 µM activation. On the other hand, heparin, heparan sulfate, and bovine and tuna dermatan sulfate improved (1.2 to 3.4 times kallikrein inhibition by antithrombin (1.4 µM, while chondroitin 4- and 6-sulfates reduced it (1.3 times. Heparin and heparan sulfate increased (1.4 times the enzyme inhibition by the C1-inhibitor (150 nM.

  4. 76 FR 11191 - Hazardous Materials: Adoption of ASME Code Section XII and the National Board Inspection Code

    Science.gov (United States)

    2011-03-01

    ... Hazardous Materials: Adoption of ASME Code Section XII and the National Board Inspection Code AGENCY... the electronic availability of the American Society of Mechanical Engineers' (ASME) Boiler and... the ANPRM published on December 23, 2010 (ANPRM; 75 FR 80765). The ASME Boiler and Pressure Vessel...

  5. 75 FR 80765 - Hazardous Materials: Adoption of ASME Code Section XII and the National Board Inspection Code

    Science.gov (United States)

    2010-12-23

    ..., Ground Floor, Room W12-140, Routing Symbol M-30, 1200 New Jersey Avenue, SE., Washington, DC 20590. Hand... update current regulations in recognition of the technological enhancements referred to above, maintain... the requirements of Section XII for application of the appropriate Code Symbol stamp; (b) Knowledge of...

  6. Konstruksi Strain Haploid Saccharomyces cerevisiae Pembawa Kromosom XII yang Terpotong pada Sisi Kanan Lokus rDNA

    Directory of Open Access Journals (Sweden)

    TRIWIBOWO YUWONO

    2005-05-01

    Full Text Available Saccharomyces cerevisiae has a great potential for fermentation industry and molecular biology research. Many works have been conducted to increase S. cerevisiae growth rate. The objective of this research was to obtain a rDNA fragment of chromosome XII of S. cerevisiae with splitting at right region of rDNA locus. Chromosome XII was splitted by using a chromosome-splitting vector (pDW49 that carried a cloned DNA fragment of rDNA locus. An E. coli strain DH5α was used as a host for pDW49 amplification. The pDW49 plasmid was digested with BamHI to eliminate the HIS3 DNA stuffer. The larger BamHI fragment was isolated by agarose gel electrophoresis. The BamHI fragment was subsequently self-ligated, resulting in the Tr ends being joined head-to-head. The recircularized DNA molecule was linearized by cleavage at the homologous sequence (at the right region of rDNA locus using BglII. The linearized DNA molecule was introduced into S. cerevisiae strain W303-1A by lithium acetate method. Confirmation of chromosome XII splitting was analyzed by PFGE (Pulsed Field Gel Electrophoresis for 24 h with switching interval of 45 sec followed by 6 h run with switching interval of 15 sec. The result of PFGE showed an additional chromosomal band (611 kbp, suggesting that the chromosome XII has been splitted.

  7. 78 FR 79363 - Hazardous Materials: Adoption of ASME Code Section XII and the National Board Inspection Code

    Science.gov (United States)

    2013-12-30

    ... would reduce fuel costs. Entities that repair tanks and third-party inspectors would have to be trained... Transport Tanks, and Part 3, Supplement 6: Repair, Alteration, and Modification of DOT Transport Tanks go to... design, material, construction, repair and inspection of transport tanks. Incorporating Section XII and...

  8. Characterization and Sequencing of a Genotype XII Newcastle Disease Virus Isolated from a Peacock (Pavo cristatus) in Peru.

    Science.gov (United States)

    Chumbe, Ana; Izquierdo-Lara, Ray; Tataje-Lavanda, Luis; Figueroa, Aling; Segovia, Karen; Gonzalez, Rosa; Cribillero, Giovana; Montalvan, Angela; Fernández-Díaz, Manolo; Icochea, Eliana

    2015-07-30

    Here, we report the first complete sequence and biological characterization of a Newcastle disease virus (NDV) isolated from a peacock in South America (NDV/peacock/Peru/2011). This isolate, classified as genotype XII in class II, highlights the need for increased surveillance of noncommercial avian species. Copyright © 2015 Chumbe et al.

  9. Evaluation of177Lu-CHX-A″-DTPA-6A10 Fab as a radioimmunotherapy agent targeting carbonic anhydrase XII.

    Science.gov (United States)

    Fiedler, L; Kellner, M; Gosewisch, A; Oos, R; Böning, G; Lindner, S; Albert, N; Bartenstein, P; Reulen, H-J; Zeidler, R; Gildehaus, F J

    2018-03-04

    Due to their infiltrative growth behavior, gliomas have, even after surgical resection, a high recurrence tendency. The approach of intracavitary radioimmunotherapy (RIT) is aimed at inhibiting tumor re-growth by directly administering drugs into the resection cavity (RC). Direct application of the radioconjugate into the RC has the advantage of bypassing the blood-brain barrier, which allows the administration of higher radiation doses than systemic application. Carbonic anhydrase XII (CA XII) is highly expressed on glioma cells while being absent from normal brain and thus an attractive target molecule for RIT. We evaluated a CA XII-specific 6A10 Fab (fragment antigen binding) labelled with 177 Lu as an agent for RIT. 6A10 Fab fragment was modified and radiolabelled with 177 Lu and characterized by MALDI-TOF, flow cytometry and radio-TLC. In vitro stability was determined under physiological conditions. Biodistribution studies, autoradiography tumor examinations and planar scintigraphy imaging were performed on SCID-mice bearing human glioma xenografts. The in vitro CA XII binding capacity of the modified Fab was confirmed. Radiochemical purity was determined to be >90% after 72 h of incubation under physiological conditions. Autoradiography experiments proved the specific binding of the Fab to CA XII on tumor cells. Biodistribution studies revealed a tumor uptake of 3.0%ID/g after 6 h and no detectable brain uptake. The tumor-to-contralateral ratio of 10/1 was confirmed by quantitative planar scintigraphy. The radiochemical stability in combination with a successful in vivo tumor uptake shows the potential suitability for future RIT applications with the 6A10 Fab. Copyright © 2018. Published by Elsevier Inc.

  10. Le carte del monastero di S. Maria di Chiaravalle milanese. Additiones documentarie (secolo XII

    Directory of Open Access Journals (Sweden)

    Maria Cristina Piva

    2013-01-01

    Full Text Available Founded in 1135 in the immediate outskirts of Milan, Cistercian monastery of S. Maria di Chiaravalle was one of the most important ecclesiastical institutions in Lombardy. Since its foundation, it has played a prominent role in the political, religious, social and economic life of the city. In the Middle Ages the abbey distinguished itself with intensive production and preservation of documents, exemplified nowadays by the several hundreds of charterse preserved in the Archivio di Stato of Milan. This research aims to complete the organic reconstruction work, recently carried out by Anna Maria Rapetti and Ada Grossi regarding the XII century tabularium of Chiaravalle, with the critical edition of 28 unreleased documents dated between 1106 and 1164. In the introduction, in addition to the presentation of the documents, a paragraph will outline the historiographical balance of the studies conducted so far on the abbey.

  11. Manejo odontológico de paciente con Deficit de Factor XII: Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Hermida L

    2011-01-01

    Full Text Available El Servicio de Medicina Transfusional del Centro Hospitalario Pereira Rossell es el centro de referencia nacional en el área materno infantil. En el marco del convenio MSPFacultad de Odontología de la UDELAR, se atienden en este Servicio pacientes con diversas coagulopatías. El déficit de factor XII es una patología de baja prevalencia (1-1000000 y no existe evidencia científica que respalde protocolos clínicos de atención a nivel odontológico. Se presenta el caso clínico del paciente NT, portador de esta patología, de alto riesgo con alta actividad de caries, en dentición mixta, a quien se le realizó tratamiento odontológico integral con apoyo del equipo multidisciplinario que trabaja en el Servicio de Hemoterapia del CHPR.

  12. Saccharin Sulfonamides as Inhibitors of Carbonic Anhydrases I, II, VII, XII, and XIII

    Directory of Open Access Journals (Sweden)

    Vaida Morkūnaitė

    2014-01-01

    Full Text Available A series of modified saccharin sulfonamides have been designed as carbonic anhydrase (CA inhibitors and synthesized. Their binding to CA isoforms I, II, VII, XII, and XIII was measured by the fluorescent thermal shift assay (FTSA and isothermal titration calorimetry (ITC. Saccharin bound the CAs weakly, exhibiting the affinities of 1–10 mM for four CAs except CA I where binding could not be detected. Several sulfonamide-bearing saccharines exhibited strong affinities of 1–10 nM towards particular CA isoforms. The functional group binding Gibbs free energy additivity maps are presented which may provide insights into the design of compounds with increased affinity towards selected CAs.

  13. HUBUNGAN PENGALAMAN PRAKTIK KERJA INDUSTRI DAN PRESTASI BELAJAR KEJURUAN DENGAN MINAT BERWIRAUSAHA SISWA KELAS XII TKR SMK COKROAMINOTO 2 BANJARNEGARA TAHUN PELAJARAN 2015/2016

    Directory of Open Access Journals (Sweden)

    Bayu Sandhi Pamungkas

    2016-06-01

    Results of this research is: (1 Industry experience working practices positively and significantly related with interest in entreprenuership class XII TKR student of SMK Cokroaminoto 2 Banjarnegara academic year 2015/2016; (2 Vocational learning achievement positively and significantly related with interest in entrepreneurship class XII TKR student of SMK Cokroaminoto 2 Banjarnegara academic year 2015/2016; (3 Industry experience working practices and vocational learning achievement  together positively and significantly related with interest in entrepreunership class XII TKR student of SMK Cokroaminoto 2 Banjarnegara academic year 2015/2016

  14. ANALISIS PROSES PEMBELAJARAN POKOK BAHASAN ELEKTROKIMIA DI KELAS XII SMAN 1 PANTI

    Directory of Open Access Journals (Sweden)

    Indang Dewata

    2016-09-01

    Full Text Available The purpose of this research was to analyze the learning process of electrolysis cell matter which covered the planning, implementation, and evaluation; and analysis of theunderstanding of students’ concept (conception  as well as the finding of the cause of the misconceptions and not understanding in matter of electrolysis cell. The study used was descriptive analysis. It was used to answer the problem’s formulation in this study. The object of this research were the process of learning and students’ conceptions. The subjects of this study were students in grade XII IA I and IA II and chemistry teacher in grade XII IA at SMAN 1  Panti. Instruments in this study were the observation guide, a recorder (Handycam and two tier diagnostic test.Based on the data analysis, it is found that (1 learning process in the electrolysis cell matter in SMAN 1 Panti was not in accordance with the standards of process (2 Students IA I and IA II had misconceptions and did not understand the whole concept in electrolysis cell matter. (3 The cause of misconceptions and not understanding of students were mainly the teachers and students. The learning process should be conducted in accordance with the standards of process that has been established by government in order to ensure learning carried out effectively, so the quality of learning can be improved. Kata kunci: analisis, proses pembelajaran, elektrokimia

  15. KETERAMPILAN MENULIS KREATIF CERPEN MENGGUNAKAN MEDIA AUDIO SISWA KELAS XII SMAN 1 KECAMATAN PAYAKUMBUH

    Directory of Open Access Journals (Sweden)

    Wirda Linda

    2017-04-01

    Full Text Available Writing skills is activities of language serves to produce  written language. Writing can improve intelligence, develop initiative, creativity,, stimulate the willingness and ability to gather information. Students' skills in short stories writing activities is still lacking. This things because teachers use less attractive media. Thus, this study uses audio media to increase students' interest in writing. This study aimed to describe the shost story intrinsic elements and the use of capital letters in Creative Short Story Writing Skills Using Media Audio Class XII SMAN I Payakumbuh District.This research is a quantitative research using descriptive method. The study population class XII students totaling 217 consists of 8 classes. Writer to perform sampling with random random sampling techniques. The instrument of this study is to test performance. Data analysis  in the study: to check the results to write short stories, analyze the data and provide a score based on indicators, and put forward the test results to the classification skills by using a scale of 10.Results showed that  average value of 90.8 are in the range of 86-95% with good qualification. Creative writing skills are evaluated from two short stories specified indicators are: (1 short story creative writing skills in terms of the intrinsic elements of the short story is the 100 that are in the range of 96-100% with impeccable qualifications; (2 The short story creative writing skills in terms of capitalization was 80.8% are in the 76-85 range with good qualifications. Thus, we can conclude the students are already capable in writing short stories as well as the use of capital letters in writing.    

  16. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  17. Opisthorchiasis in infant remains from the medieval Zeleniy Yar burial ground of XII-XIII centuries AD

    Directory of Open Access Journals (Sweden)

    Sergey Mikhailovich Slepchenko

    2015-01-01

    Full Text Available We present a paleoparasitological analysis of the medieval Zeleniy Yar burial ground of the XII-XII centuries AD located in the northern part of Western Siberia. Parasite eggs, identified as eggs of Opisthorchis felineus, were found in the samples from the pelvic area of a one year old infant buried at the site. Presence of these eggs in the soil samples from the infant’s abdomen suggests that he/she was infected with opisthorchiasis and imply consumption of undercooked fish. Ethnographic records collected among the population of the northern part of Western Siberia reveal numerous cases of feeding raw fish to their children. Zeleniy Yar case of opisthorchiasis suggests that this dietary custom has persisted from at least medieval times.

  18. Opisthorchiasis in infant remains from the medieval Zeleniy Yar burial ground of XII-XIII centuries AD

    Science.gov (United States)

    Slepchenko, Sergey Mikhailovich; Gusev, Alexander Vasilevich; Ivanov, Sergey Nikolaevich; Svyatova, Evgenia Olegovna

    2015-01-01

    We present a paleoparasitological analysis of the medieval Zeleniy Yar burial ground of the XII-XII centuries AD located in the northern part of Western Siberia. Parasite eggs, identified as eggs of Opisthorchis felineus, were found in the samples from the pelvic area of a one year old infant buried at the site. Presence of these eggs in the soil samples from the infant’s abdomen suggests that he/she was infected with opisthorchiasis and imply consumption of undercooked fish. Ethnographic records collected among the population of the northern part of Western Siberia reveal numerous cases of feeding raw fish to their children. Zeleniy Yar case of opisthorchiasis suggests that this dietary custom has persisted from at least medieval times. PMID:26602874

  19. Opisthorchiasis in infant remains from the medieval Zeleniy Yar burial ground of XII-XIII centuries AD.

    Science.gov (United States)

    Slepchenko, Sergey Mikhailovich; Gusev, Alexander Vasilevich; Ivanov, Sergey Nikolaevich; Svyatova, Evgenia Olegovna

    2015-12-01

    We present a paleoparasitological analysis of the medieval Zeleniy Yar burial ground of the XII-XII centuries AD located in the northern part of Western Siberia. Parasite eggs, identified as eggs of Opisthorchis felineus, were found in the samples from the pelvic area of a one year old infant buried at the site. Presence of these eggs in the soil samples from the infant's abdomen suggests that he/she was infected with opisthorchiasis and imply consumption of undercooked fish. Ethnographic records collected among the population of the northern part of Western Siberia reveal numerous cases of feeding raw fish to their children. Zeleniy Yar case of opisthorchiasis suggests that this dietary custom has persisted from at least medieval times.

  20. XII ASSEMBLEIA GERAL ORDINÁRIA DO SÍNODO DOS BISPOS SOBRE A PALAVRA DE DEUS

    Directory of Open Access Journals (Sweden)

    Johan Konings

    2009-01-01

    Full Text Available Em outubro de 2008 transcorreu em Roma a XII Assembleia Geral Ordin ária do Sínodo dos Bispos, o qual é uma instituição permanente criada pelo Concílio Vaticano II para manter o diálogo dos pastores-bispos das Igrejas particulares. Nesta Assembleia, dedicada à Palavra de Deus na vida e na missão da Igreja, foi retomada praticamente a Constituição Dogmática Dei Verbum do Vaticano II. Depois de apresentar o tema da Palavra de Deus, traçamos um breve histórico focalizando os inícios da Tradição cristã e os tempos modernos desde Leão XIII até hoje. Em seguida descrevemos a XII Assembleia Geral, especialmente a Relatio post Disceptationem e as Propositiones. Concluímos com uma reflexão teológicopastoral sobre a Revelação e a leitura bíblica, e sugestões para a prática. ABSTRACT: In October of 2008 the XII Ordinary General Assembly of the Sinod of Bishops took place in Rome. The Sinod of Bishops is a permanent institution created by the II Vatican Council in order to maintain the dialogue of pastorsbishops of the particular Churches. This Assembly, dedicated to the Word of God in the life and in the mission of the Church, basically treated again the Dogmatic Constitution Dei Verbum of the II Vatican Council. After presenting the theme of the Word of God, we outline a brief history focusing on the beginnings of the Christian Tradition and the modern epoch since Leo XIII until today. Next we describe the XII General Assembly, especially the Relatio post Disceptationem and the Propostiones. We conclude with a theological-pastoral reflection on Revelation and the reading of the bible, and some practical suggestions.

  1. Comparision of analysis of the QTLMAS XII common dataset:II: genome-wide association and fine mapping

    OpenAIRE

    Crooks, Lucy; Sahana, Goutam; de Koning, Dirk-Jan; Lund, Mogens Sandø; Carlborg, Örjan

    2009-01-01

    As part of the QTLMAS XII workshop, a simulated dataset was distributed and participants were invited to submit analyses of the data based on genome-wide association, fine mapping and genomic selection. We have evaluated the findings from the groups that reported fine mapping and genome-wide association (GWA) efforts to map quantitative trait loci (QTL). Generally the power to detect QTL was high and the Type 1 error was low. Estimates of QTL locations were generally very accurate. Some metho...

  2. Black Cohosh

    Science.gov (United States)

    ... who have had hormone-sensitive conditions such as breast cancer or for pregnant women or nursing mothers. Black cohosh should not be confused with blue cohosh (Caulophyllum thalictroides) , which has different effects and may not be safe. Black cohosh has ...

  3. PREFACE: 12th Conference on Recent Developments in Gravity (NEB XII)

    Science.gov (United States)

    Christodoulakis, Theodosios; Vagenas, Elias C.

    2007-06-01

    Continuing the 24 year old tradition, one of the Greek relativistic groups, this time the Relativity Group of the Physics Department of the University of Athens, organized the 12th Conference of the series "Recent Developments in Gravity" (NEB XII). This time NEB took place at Nafplio, Greece, from Thursday 29 June to Sunday 2 July, 2006. The Conference was attended by more than 100 participants, more than 50% of whom were relativists from abroad (both Greek and other nationalities). This signifies a tendency of the last few Conferences to open up the Greek Relativity Conference to the international scientific community. Actually, many notable members of the relativistic community all over the globe showed particular interest in coming to Nafplio, and spend four relaxed days in a nice sunny and historical place, presenting the results of their more recent work and discussing it with colleagues and students from Greece. The NEB XII Conference covered various aspects of gravitational physics: Relativistic Astrophysics, Mathematical Relativity, Quantum Gravity, and Cosmology. Although the program was rather heavy and for the first time we had parallel sessions running in the afternoons, the wonderful weather (apart from the last afternoon when it rained heavily) and the beauty of Nafplio helped the organizers offer the participants a warm, pleasant, and creative time. According to most attendees, their impression was more than good, not only with respect to the hospitable environment, but with respect to the high level of talks as well. We hope the next Conference, which will be organized by the Relativity Group of the Aristotle University of Thessaloniki in the summer of 2008, will raise the standards of the Conference even higher, thus further establishing our Conference as a notable Conference in the Relativistic community all over the world. Finally, we would like to thank the Gravitational Physics Section of the European Physical Society (GPS/EPS), ILIAS

  4. PERKAWINAN BEDA AGAMA PASCA PUTUSAN MAHKAMAH KONSTITUSI NOMOR 68/ PUU-XII/2014 DALAM PERSPERKTIF HAM

    Directory of Open Access Journals (Sweden)

    Danu Aris Setiyanto

    2017-03-01

    Full Text Available Interfaith marriage, in fact, is a contentious issue in the family law. The arrangement of interfaith marriage in Indonesia is experiencing a change since before and after the establishment of the constitutional Law of R.I. No. 1 of 1974 regarding Marriage. Although there are changes in the regulations but some parties consider that arrangement of interfaith marriage is not firm, it is unclear / smuggling law in it. Regulation of interfaith marriage in Indonesia is considered to have reduced the freedom to choose a mate and find the happiness with a partner of different religions. This is considered by the applicant that Article 2, paragraph 1 does not comply with the principle of freedom of human rights. This paper focuses on studying the problems of the interfaith marriages after a Constitutional Court decision No. 68 / PUU-XII / 2014 in the perspective of human rights. Constitutional Court rejected entirely about judicial interfaith marriage, as it is considered unreasonable under the law and marriage in Indonesia is based on religion. Constitutional Court's decision contains the values of human rights with a particular meaning and is limited by the limited freedom of religion in Pancasila and the 1945 Constitution. [Perkawinan beda agama secara fakta merupakan persoalan yang menjadi perdebatan dalam hukum keluarga. Pengaturan perkawinan beda agama di Indonesia mengalami perubahan sejak sebelum dan setelah adanya UU R.I. Nomor 1 tahun 1974 tentang Perkawinan. Walaupun ada perubahan secara regulasi tetapi beberapa pihak menganggap bahwa pengaturan perkawinan beda agama tidak tegas, ada ketidakjelasan/penyelundupan hukum di dalamnya. Regulasi perkawinan beda agama di Indonesia dianggap telah mengurangi kebebasan untuk memilih jodoh dan menemukan kebahagiaan bersama pasangannya yang berbeda agama. Hal inilah yang dianggap oleh para pemohon bahwa Pasal 2 ayat 1 tidak sesuai dengan prinsip kebebasan dalam HAM. Tulisan ini difokuskan untuk mengkaji

  5. Collagen XII and XIV, New Partners of Cartilage Oligomeric Matrix Protein in the Skin Extracellular Matrix Suprastructure*

    Science.gov (United States)

    Agarwal, Pallavi; Zwolanek, Daniela; Keene, Douglas R.; Schulz, Jan-Niklas; Blumbach, Katrin; Heinegård, Dick; Zaucke, Frank; Paulsson, Mats; Krieg, Thomas; Koch, Manuel; Eckes, Beate

    2012-01-01

    The tensile and scaffolding properties of skin rely on the complex extracellular matrix (ECM) that surrounds cells, vasculature, nerves, and adnexus structures and supports the epidermis. In the skin, collagen I fibrils are the major structural component of the dermal ECM, decorated by proteoglycans and by fibril-associated collagens with interrupted triple helices such as collagens XII and XIV. Here we show that the cartilage oligomeric matrix protein (COMP), an abundant component of cartilage ECM, is expressed in healthy human skin. COMP expression is detected in the dermal compartment of skin and in cultured fibroblasts, whereas epidermis and HaCaT cells are negative. In addition to binding collagen I, COMP binds to collagens XII and XIV via their C-terminal collagenous domains. All three proteins codistribute in a characteristic narrow zone in the superficial papillary dermis of healthy human skin. Ultrastructural analysis by immunogold labeling confirmed colocalization and further revealed the presence of COMP along with collagens XII and XIV in anchoring plaques. On the basis of these observations, we postulate that COMP functions as an adapter protein in human skin, similar to its function in cartilage ECM, by organizing collagen I fibrils into a suprastructure, mainly in the vicinity of anchoring plaques that stabilize the cohesion between the upper dermis and the basement membrane zone. PMID:22573329

  6. A novel library of saccharin and acesulfame derivatives as potent and selective inhibitors of carbonic anhydrase IX and XII isoforms.

    Science.gov (United States)

    Carradori, Simone; Secci, Daniela; De Monte, Celeste; Mollica, Adriano; Ceruso, Mariangela; Akdemir, Atilla; Sobolev, Anatoly P; Codispoti, Rossella; De Cosmi, Federica; Guglielmi, Paolo; Supuran, Claudiu T

    2016-03-01

    Small libraries of N-substituted saccharin and N-/O-substituted acesulfame derivatives were synthesized and tested as atypical and selective inhibitors of four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). Most of them inhibited hCA XII in the low nanomolar range, hCA IX with KIs ranging between 19 and 2482nM, whereas they were poorly active against hCA II (KIs >10μM) and hCA I (KIs ranging between 318nM and 50μM). Since hCA I and II are ubiquitous off-target isoforms, whereas the cancer-related isoforms hCA IX and XII were recently validated as drug targets, these results represent an encouraging achievement in the development of new anticancer candidates. Moreover, the lack of a classical zinc binding group in the structure of these inhibitors opens innovative, yet unexplored scenarios for different mechanisms of inhibition that could explain the high inhibitory selectivity. A computational approach has been carried out to further rationalize the biological data and to characterize the binding mode of some of these inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Identidad de las hospitalarias en la corona de Aragón (siglos XII-XIII

    Directory of Open Access Journals (Sweden)

    Maria Bonet Donato

    2014-12-01

    Full Text Available La rama femenina del Hospital fue singular en el seno de la institución y logró una autonomía y una entidad diferenciadora que se manifestó y consolidó en la afirmación de elementos identitarios. La identidad de las hospitalarias se concretó en la reivindicación y el despliegue de funciones y actividades singulares, en la existencia de mujeres carismáticas que encarnaron dicha identidad y en el reconocimiento de ciertos espacios. Las comunidades de monjas hospitalarias de la corona de Aragón en los siglos XII y XIII se caracterizaron por una diferenciación entre ellas mayor que la que se dio entre las encomiendas masculinas, y a su vez tuvieron mayor individualización en el contexto institucional. Las hospitalarias expresaron su espiritualidad y lograron visibilidad y protagonismo social, conforme a la creación o recreación de la identidad hospitalaria. Dicha identidad femenina hospitalaria resultó de la combinación de aspectos concernientes a la identidad familiar, femenina, espiritual, religiosa, individual, política, y se acomodó a la “personalidad” de cada entidad conventual, e inclusive a la de algunas figuras con destacado liderazgo

  8. Defective glycosylation of coagulation factor XII underlies hereditary angioedema type III

    Science.gov (United States)

    Björkqvist, Jenny; de Maat, Steven; Lewandrowski, Urs; Di Gennaro, Antonio; Oschatz, Chris; Schönig, Kai; Nöthen, Markus M.; Drouet, Christian; Braley, Hal; Nolte, Marc W.; Sickmann, Albert; Panousis, Con; Maas, Coen; Renné, Thomas

    2015-01-01

    Hereditary angioedema type III (HAEIII) is a rare inherited swelling disorder that is associated with point mutations in the gene encoding the plasma protease factor XII (FXII). Here, we demonstrate that HAEIII-associated mutant FXII, derived either from HAEIII patients or recombinantly produced, is defective in mucin-type Thr309-linked glycosylation. Loss of glycosylation led to increased contact-mediated autoactivation of zymogen FXII, resulting in excessive activation of the bradykinin-forming kallikrein-kinin pathway. In contrast, both FXII-driven coagulation and the ability of C1-esterase inhibitor to bind and inhibit activated FXII were not affected by the mutation. Intravital laser-scanning microscopy revealed that, compared with control animals, both F12–/– mice reconstituted with recombinant mutant forms of FXII and humanized HAEIII mouse models with inducible liver-specific expression of Thr309Lys-mutated FXII exhibited increased contact-driven microvascular leakage. An FXII-neutralizing antibody abolished bradykinin generation in HAEIII patient plasma and blunted edema in HAEIII mice. Together, the results of this study characterize the mechanism of HAEIII and establish FXII inhibition as a potential therapeutic strategy to interfere with excessive vascular leakage in HAEIII and potentially alleviate edema due to other causes. PMID:26193639

  9. Gambaran Strategi Coping Stress Siswa Kelas XII Sman 42 Jakarta dalam Menghadapi Ujian Nasional

    Directory of Open Access Journals (Sweden)

    Muhamad Nanang Suprayogi

    2011-04-01

    Full Text Available This study intended to know the description of stress coping strategies of 12th grade students of Jakarta 42 State Senior High School in facing National Exam. This study stems from the interest of researchers towards the number of cases of high school students who do not pass the National Exam. Researchers seek to impart knowledge to students on how to cope with their stress effectively and to the school and parents for providing the proper approach for students to face the National Exam. This study is a quantitative study using questionnaires as a measurement to know the description of stress coping strategies of Jakarta 42 State Senior High School students. Research instruments are compiled based on the theory developed by Lahey. In this research, obtained results that the class XII students of SMAN 42 Jakarta have a more predominant use of effective coping to cope with their stress in facing the National Exam. The most widely used strategy is removing stress and managing stress reaction  

  10. Determinación del precio de las 25 pesetas de Alfonso XII comunes

    Directory of Open Access Journals (Sweden)

    Juan Luis Santos

    2016-12-01

    Full Text Available This article analyzes the data of seventy-eight auctions carried out between 2006 and 2016 and studies how often the coins of 25 peseta of Alfonso XII appear in relation to the total of the lots auctioned and the lots of the Centenary. Next it is studied if the frequency of appearance of each type of coin corresponds with the levels of minting. The correlation is also presented between the change in gold price and the percentage of common coins not sold and the change in gold price and the percentage of units sold by the mode of the price. Finally, a model to estimate the price is developed taking into account the price of the ounce of gold and its variation, the year of coinage, the state of conservation and the presence of all numbers in both stars. With this model, hat explains 87.2% of the price variation, it is estimated the price in the last auction to assess the accuracy of results.

  11. Factor XII and uPAR upregulate neutrophil functions to influence wound healing.

    Science.gov (United States)

    Stavrou, Evi X; Fang, Chao; Bane, Kara L; Long, Andy T; Naudin, Clément; Kucukal, Erdem; Gandhi, Agharnan; Brett-Morris, Adina; Mumaw, Michele M; Izadmehr, Sudeh; Merkulova, Alona; Reynolds, Cindy C; Alhalabi, Omar; Nayak, Lalitha; Yu, Wen-Mei; Qu, Cheng-Kui; Meyerson, Howard J; Dubyak, George R; Gurkan, Umut A; Nieman, Marvin T; Sen Gupta, Anirban; Renné, Thomas; Schmaier, Alvin H

    2018-01-29

    Coagulation factor XII (FXII) deficiency is associated with decreased neutrophil migration, but the mechanisms remain uncharacterized. Here, we examine how FXII contributes to the inflammatory response. In 2 models of sterile inflammation, FXII-deficient mice (F12-/-) had fewer neutrophils recruited than WT mice. We discovered that neutrophils produced a pool of FXII that is functionally distinct from hepatic-derived FXII and contributes to neutrophil trafficking at sites of inflammation. FXII signals in neutrophils through urokinase plasminogen activator receptor-mediated (uPAR-mediated) Akt2 phosphorylation at S474 (pAktS474). Downstream of pAkt2S474, FXII stimulation of neutrophils upregulated surface expression of αMβ2 integrin, increased intracellular calcium, and promoted extracellular DNA release. The sum of these activities contributed to neutrophil cell adhesion, migration, and release of neutrophil extracellular traps in a process called NETosis. Decreased neutrophil signaling in F12-/- mice resulted in less inflammation and faster wound healing. Targeting hepatic F12 with siRNA did not affect neutrophil migration, whereas WT BM transplanted into F12-/- hosts was sufficient to correct the neutrophil migration defect in F12-/- mice and restore wound inflammation. Importantly, these activities were a zymogen FXII function and independent of FXIIa and contact activation, highlighting that FXII has a sophisticated role in vivo that has not been previously appreciated.

  12. Development of Instructional Materials for Electrochemical Module Class XII Science High School Students with Guided Inquiry Learning Approach

    Directory of Open Access Journals (Sweden)

    Lilik Fatmawati

    2014-06-01

    Full Text Available Pengembangan Bahan Ajar Modul Elektrokimia untuk Siswa SMA Kelas XII IPA dengan Pendekatan Pembelajaran Inkuiri Terbimbing Abstract: The aim of this study was to determine the feasibility and effectiveness of the electrochemical module for high school students of class XII results of development. Electrochemical module of the development consists of two learning activities, ie to the material Volta cells and electrolysis cells for the material. Results of the assessment by two chemistry lecturer, State University of Malang and two chemistry teachers XII as an expert content / learning material for eligibility contents was 92.9%, for eligibility and completeness of presentation is 91.1%, and for the eligibility of language is 92.3% , which is classified as very feasible criteria. Overall the average value was 92.1 feasibility. Effectiveness module is indicated by the results of the development of perception and student learning outcomes. Students' perceptions obtained from student assessment results to module development. In the limited field trials obtained average value is 81.8 for all aspects of the maximum value of 100. Obtaining the average value of student learning outcomes for the cognitive aspect is 83.3, for the affective aspect is 82.3, and for the psychomotor aspect is 83.8 out of 100. The maximum value of the overall results of the study showed that the electrochemical module for high school students Class XII Science development results are very decent and very effectively used in the learning process. Key Words: guided inquiry, electrochemical module, model 4-D Abstrak: Tujuan penelitian ini adalah mengetahui kelayakan, dan keefektifan modul elektrokimia untuk siswa SMA kelas XII hasil pengembangan. Modul Elektrokimia hasil pengembangan terdiri dari dua kegiatan belajar, yaitu untuk materi sel Volta dan untuk materi sel elektrolisis. Hasil penilaian oleh dua dosen kimia Universitas Negeri Malang dan dua guru kimia kelas XII sebagai

  13. Black Tea

    Science.gov (United States)

    ... leaves of the same plant, has some different properties. Black tea is used for improving mental alertness ... that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen ( ...

  14. PENGARUH STRATEGI PEMBELAJARAN PRAKTIKUM SIFAT KOLIGATIF TERHADAP HASIL BELAJAR SISWA KELAS XII

    Directory of Open Access Journals (Sweden)

    Muhammad Hubbi

    2017-01-01

    belajar siswa kelas XII IPA Madrasah Aliyah Ma’arif 7 Lamongan pada materi sifat koligatif larutan. Hasil belajar berupa nilai yang berasal laporan hasil praktikum dan tes tulis. Subyek penelitian ini adalah 34 siswa kelas XII-E IPA Madrasah Aliyah Ma’arif 7 Lamongan tahun pelajaran 2015-2016. Rancangan penelitian yang digunakan adalah the one group pretest-posttest. Instrumen penelitian menggunakan tes tulis dan lembar observasi. Tes tulis untuk mengukur hasil belajar divalidasi sebelum digunakan dan memiliki reliabilitas 0,802. Data yang diperoleh selanjutnya dianalisis dengan analisis deskriptif dan uji beda. Uji beda menggunakan uji t-paired. Hasil uji-t berpasangan diperoleh sig 0,000 yang berarti lebih kecil dari 0,05 sehingga H0 ditolak dengan reliabilitas 95%. Berdasarkan hasil tersebut dapat disimpulkan bahwa terdapat peningkatan hasil belajar yang signifikan pada pembelajaran praktikum dengan menggunakan prosedur praktikum sifat koligatif larutan. Nilai rata-rata hasil belajar siswa meningkat dari 61,05 menjadi 81,44. Peningkatan ini menunjukkan pembelajaran praktikum berbasis inkuiri terbimbing memiliki tingkat efektivitas yang baik.

  15. The Procoagulant Activity of Apoptotic Cells Is Mediated by Interaction with Factor XII

    Directory of Open Access Journals (Sweden)

    Aizhen Yang

    2017-09-01

    Full Text Available Apoptotic cells, by externalizing phosphatidylserine (PS as a hallmark feature, are procoagulant. However, the mechanism by which apoptotic cells activate coagulation system remains unknown. Intrinsic coagulation pathway is initiated by coagulation factor XII (FXII of contact activation system. The purpose of this study was to determine whether FXII is involved in procoagulant activity of apoptotic cells. Using western blotting and chromogenic substrate assay, we found that incubation with apoptotic cells, but not with viable cells, resulted in rapid cleavage and activation of FXII in the presence of prekallikrein and high molecular weight kininogen (HK, other two components of contact activation system. As detected by flow cytometry, FXII bound to apoptotic cells in a concentration-dependent manner, which was inhibited by annexin V and PS liposome. Direct association of FXII with PS was confirmed in a surface plasmon resonance assay. Clotting time of FXII-deficient plasma induced by apoptotic cells was significantly prolonged, which was fully reversed by replenishment with FXII. Corn trypsin inhibitor, a FXII inhibitor, completely prevented apoptotic cells-induced intrinsic tenase complex formation. Consistently, apoptotic cells significantly increased thrombin production in normal plasma, which was not affected by an inhibitory anti-tissue factor antibody. However, blocking of PS by annexin V, inhibition of FXII, or the deficiency of FXII suppressed apoptotic cells-induced thrombin generation. Addition of purified FXII to FXII-deficient plasma recovered thrombin generation to the normal plasma level. In conclusion, FXII binds to apoptotic cells via PS and becomes activated, thereby constituting a novel mechanism mediating the procoagulant activity of apoptotic cells.

  16. Settlement, territory and notarial formulas: a verification (Verona, IX-XII century Insediamento, territorio e formule notarili: una verifica (Verona, IX-XII secolo

    Directory of Open Access Journals (Sweden)

    Andrea Brugnoli

    2011-10-01

    well as synchronous – allows instead to highlight their links with the different practices in the territory: not only through the presence of landlordship, but also the structure of habitat, the forms of solidarity and the access to common resources.

     

    L’organizzazione del territorio rurale nel medioevo e la sua conoscibilità attraverso le tecniche ubicatorie utilizzate dai notai costitiscono un tema classico nella storiografia italiana della seconda metà del Novecento. La documentazione prodotta nel territorio veronese ben si presta per una verifica delle ipotesi e la formulazione di alcune linee guida per l’interpretazione delle formule notarili per quanto attiene all’insediamento e alla territorialità di villaggio. Il numero di documenti prodotti e conservati nel Veronese per i secoli IX-XII, e la loro omogeneità quanto a istituzioni che ce li hanno conservati e tramandati, permette di affrontare una complessa analisi che deve considerare diverse variabili. Sul piano documentario si tratta di possibili varietà, al limite dell’individualità, di formulari e di usi notarili; a queste si uniscono differenze geografiche, di assetti proprietari, dello sviluppo di presenze signorili e di pratiche agrarie, oltre che di popolamento che caratterizzano questo territorio. In particolare la varietà del quadro geografico, equamente suddiviso tra una fascia collinare di non disprezzabile estensione, una fascia di pianura asciutta e irrigua e una di bassa pianura soggetta a esondazioni si prospettava come un elemento positivo per identificare i diversi fattori attivi nella costruzione dell’insediamento rurale, la sua organizzazione e rappresentazione. Il presupposto di partenza è che le formule ubicatorie siano articolate in schemi frutto di una dialettica tra cultura notarile da un lato e percezione dell’organizzazione dello spazio dall’altro; quest’ultima a sua volta risultato del rapporto che si instaura tra le comunità umane e il

  17. Geothermal Program Review XII: proceedings. Geothermal Energy and the President's Climate Change Action Plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-31

    Geothermal Program Review XII, sponsored by the Geothermal Division of US Department of Energy, was held April 25--28, 1994, in San Francisco, California. This annual conference is designed to promote effective technology transfer by bringing together DOE-sponsored researchers; utility representatives; geothermal energy developers; suppliers of geothermal goods and services; representatives from federal, state, and local agencies; and others with an interest in geothermal energy. In-depth reviews of the latest technological advancements and research results are presented during the conference with emphasis on those topics considered to have the greatest potential to impact the near-term commercial development of geothermal energy.

  18. Black Willow

    Science.gov (United States)

    R. M. Krinard

    1980-01-01

    Black willow and other species of Salix together comprise a majority of the stocking. Cottonwood is the chief associate, particularly in the early stages, but green ash, sycamore, pecan, persimmon, waterlocust, American elm, baldcypress, red maple, sugarberry, box-elder, and in some areas, silver maple are invaders preceding the next successional stage.

  19. Counseling Blacks

    Science.gov (United States)

    Vontress, Clemmont E.

    1970-01-01

    Blacks have developed unique environmental perceptions, values, and attitudes, making it difficult for counselors to establish and maintain positive rapport. This article examines attitudinal ingredients posited by Carl Rogers for relevance to this problem, and suggests in-service training to help counselors and other professionals relate…

  20. Black Psyllium

    Science.gov (United States)

    ... by mouth for up to 6 weeks reduces blood sugar in people with type 2 diabetes. Cancer. Diarrhea. Irritable bowel syndrome (IBS). Other conditions. ... with the dose. Diabetes: Black psyllium can lower blood sugar levels ... with type 2 diabetes by slowing down absorption of carbohydrates. Monitor blood ...

  1. XII Encuentro Científico “Desarrollo, innovación y salud”

    Directory of Open Access Journals (Sweden)

    Luis Alberto Gómez

    2011-08-01

    componentes complementarios de la totalidad de las evidencias que permiten entender los determinantes de un estado de salud o de enfermedad. Los progresos en la definición de la relación de un evento biológico, ambiental, nutricional o social con el riesgo de desarrollar una enfermedad, están orientados por los desarrollos científicos y tecnológicos, así como por su incorporación en los bienes y servicios. En este escenario tan complejo, y para enfrentar los problemas actuales y por venir, la investigación científica en salud es una de las áreas de desarrollo con una gran responsabilidad de generar conocimiento científico, que permita orientar y proponer diferentes estrategias para atender problemas nuevos y futuros. La generación y la gestión del conocimiento en salud, como un factor de desarrollo y transformación del mundo moderno, determina que el Instituto Nacional de Salud, esté asumiendo un papel de liderazgo en la producción de ciencia y tecnología e innovación para contribuir a resolver problemas de salud, en concordancia con la realidad y las necesidades nacionales e internacionales. El Instituto Nacional de Salud ocupa una posición especial para dirigir y coordinar los esfuerzos colectivos e impulsar los cambios necesarios para aumentar la capacidad de investigación en salud, entre otros procesos de desarrollo. Con el objetivo de proporcionar un espacio para difundir la producción científico-técnica reciente en el campo de la salud humana, así como de promover y orientar la cooperación y transferencia de ciencia, tecnología e innovación en salud, el Instituto Nacional de Salud realiza el XII Encuentro Científico. En este encuentro se presentan algunos de los avances de las líneas institucionales y de los proyectos de investigación, con la participación de investigadores del Instituto y de algunos invitados nacionales e internacionales. Entre las principales áreas temáticas que se desarrollan se incluyen: redes y desarrollo en salud

  2. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  3. Quantum black holes

    CERN Document Server

    Calmet, Xavier; Winstanley, Elizabeth

    2014-01-01

    Written by foremost experts, this short book gives a clear description of the physics of quantum black holes. The reader will learn about quantum black holes in four and higher dimensions, primordial black holes, the production of black holes in high energy particle collisions, Hawking radiation, black holes in models of low scale quantum gravity and quantum gravitational aspects of black holes.

  4. Espacio retroestíleo, punto de encuentros nerviosos: vii, ix, x, xi, xii pares craneales y el ganglio simpático cervical superior

    OpenAIRE

    Franco Castillo, Julio César; Santa María, Elsa Margarita

    2014-01-01

    Se propone una técnica para el abordaje, con fines de terapia neural, de los elementos contenidos en el espacio retroestíleo (pares craneanos VII, IX, X, XI y XII, y ganglio simpático cervical superior) que sea mínimamente invasiva y por lo tanto, presente menos riesgo de lesiones asociadas.

  5. Black holes

    International Nuclear Information System (INIS)

    Carter, B.

    1980-01-01

    In years 1920 as a result of quantum mechanics principles governing the structure of ordinary matter, a sudden importance for a problem raised a long time ago by Laplace: what happens when a massive body becomes so dense that even light cannot escape from its gravitational field. It is difficult to conceive how could be avoided in the actual universe the accumulation of important masses of cold matter having been submitted to gravitational breaking down followed by the formation of what is called to day a black hole [fr

  6. Manejo odontológico do paciente com Deficiência de Fator XII: Relato de caso

    Directory of Open Access Journals (Sweden)

    Hermida L

    2011-01-01

    Full Text Available El Servicio de Medicina Transfusional del Centro Hospitalario Pereira Rossell es el centro de referencia nacional en el área materno infantil. En el marco del convenio MSPFacultad de Odontología de la UDELAR, se atienden en este Servicio pacientes con diversas coagulopatías. El déficit de factor XII es una patología de baja prevalencia (1-1000000 y no existe evidencia científica que respalde protocolos clínicos de atención a nivel odontológico. Se presenta el caso clínico del paciente NT, portador de esta patología, de alto riesgo con alta actividad de caries, en dentición mixta, a quien se le realizó tratamiento odontológico integral con apoyo del equipo multidisciplinario que trabaja en el Servicio de Hemoterapia del CHPR.

  7. Voyages of a successful text. The Dialogi of Gregory the Great in Medieval Sicily (XII-XIV Century

    Directory of Open Access Journals (Sweden)

    Rossana Barcellona

    2013-10-01

    Full Text Available This essay reconstructs two “Sicilian chapters” of great success from the Dialogi by Gregorius Magnus which were enjoyed in the medieval era. These are the legend of Placido (Placido is a Benedict's young disciple mentioned in the Dialogi, which has Sicily as a background, as recounted by Pietro, Deacon of Montecassino between the XI and the XII centuries, and the Sicilian vulgarization of the work, carried out by Giovanni Campolo in the first half of the XIV century. The literary voyage of Placido and the work of Campolo are two excellent examples of the circulation and the fruition of an exemplary and authoritative text. Each highlights the complex intricacy of religion, culture and politics in the various systems of power and in the various historical settings that the medieval age explored.

  8. Influencia de la historia de España (del siglo XII al XIX en el periodismo especializado en ciencia

    Directory of Open Access Journals (Sweden)

    Dr. Carlos Elías

    2001-01-01

    Full Text Available El periodismo especializado en ciencia y tecnología en España no ha alcanzado los niveles de los países anglosajones. Ello se pone de manifiesto no sólo por la relativa ausencia de suplementos destinados a ciencia en los periódicos generalistas sino, sobre todo, por la ausencia de portales de Internet en los que se divulgue la ciencia en español así como los logros en este campo de la comunidad hispana. Pero esta circunstancia no es casual: es el producto de una historia, la de la ciencia en España, que siempre ha tenido muchos detractores, entre ellos la iglesia. En este artículo se analiza cómo influyó la historia de España desde el siglo XII hasta principios del XIX en el actual periodismo especializado en ciencia.

  9. Soft x-ray amplification in lithium-like Al XI (154 /angstrom/) and Si XII (129 /angstrom/)

    International Nuclear Information System (INIS)

    Kim, D.; Skinner, C.H.; Wouters, A.; Valeo, E.; Voorhees, D.; Suckewer, S.

    1988-03-01

    Recent experiments on soft x-ray amplification in lithium-like ions in a CO 2 laser-produced recombining plasma confined in a magnetic field are presented. The maximum gain-length products observed are GL ≅ 3 to 4 for the 154 /angstrom/, 4f-3d transition in Al XI and GL (approxreverse arrowequal/ 1 to 2 for the 129 /angstrom/, 4f-3d transition in Si XII, respectively. A one-dimensional hydrodynamic code with a collisional-radiative atomic model was used to model the plasma and the theoretical predictions of gain agree well with the observations. Descriptions of both hydrodynamic and atomic physics code are given. 36 refs., 10 figs

  10. Notas sobre la penetración del derecho común en Galicia (siglos XII-XV

    Directory of Open Access Journals (Sweden)

    Martínez Martínez, Faustino

    2001-12-01

    Full Text Available This work on the galician case places in a general thinking about the fenomena, comon to other territories of Iberian Peninsula, of the so-called Common Law reception. Our area was not an exception to this process fully developed from XII and XIII centuries. Across this paper we study the conditions that improve the arrival of this new legal conception (the so-called penetration. The penetration will lay the foundation for the later reception. We study the progressive assimilation of the common law looking into different documents that shows the legal practice (wills, contracts, sentences....

    El presente trabajo se enmarca dentro de una reflexión general sobre el fenómeno, común a otros territorios de la Península Ibérica, de la llamada recepción del Derecho Común, centrado por razones obvias en Galicia. Nuestra región no fue una excepción a este proceso que se desarrolla con plenitud a partir de los siglos XII y XIII. A través de las páginas de esta colaboración se estudian las condiciones que favorecieron la llegada de las primeras manifestaciones de esta nueva concepción del Derecho (la llamada propiamente «penetración» que sentará las bases para una posterior «recepción». Estudiamos la progresiva asimilación del derecho común mediante el examen de diferentes documentos que muestran la práctica jurídica (testamentos, contratos, sentencias, etc..

  11. Castillos, poder feudal y reorganización espacial en la Transierra madrileña (siglos XII-XIII

    Directory of Open Access Journals (Sweden)

    Iñaki Martín Viso

    2000-01-01

    Full Text Available Algunos castillos de la Transierra madrileña en los siglos xii y xiii son herederos de los husün musulmanes, pero se convierten en esa época en centros de poder señorial sobre unas débiles comunidades. No obstante, sólo su transformación en concejos permitirá la supervivencia de algunos de ellos, aunque se observa también un desplazamiento del habitat hacia el llano, resultado de la formación de un nuevo sistema productivo basado en la agricultura cerealfstica y la propiedad feudal, por lo que el papel de los castillos es limitado. En las zonas serranas su relevancia es aún menor y nunca estructuraron el paisaje, labor que ejercieran los sexmos de la Tierra de Segovia.Some castles of the Madrid's Transierra in the xii"" and xiif" centuries are inheritors of the muslim husün, but they viere converted during this age in centres of a lordship power which was imposed to the weak communities. However, only some of them could survive through their conversión In town counciis (concejos, although there is also an habitat's displacement to the plain, that is the result of the new producing system based on the grain agrículture and the feudal property, so the role of the castles was reduced. In the mountain áreas the landscape was never structured by castles, but by the rural distrícts (sexmos ofthe Segovia's Land.

  12. Making Blackness, Making Policy

    OpenAIRE

    Geller, Peter

    2012-01-01

    Too often the acknowledgment that race is a social construction ignores exactly how this construction occurs. By illuminating the way in which the category of blackness and black individuals are made, we can better see how race matters in America. Antidiscrimination policy, social science research, and the state's support of its citizens can all be improved by an accurate and concrete definition of blackness. Making Blackness, Making Policy argues that blackness and black people are literally...

  13. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Black holes; numerical relativity; nonlinear sigma. Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. ... Theoretical and Computational Studies Group, Southampton College, Long Island University, Southampton, NY 11968, USA ...

  14. PREFACE: XII Latin American workshop on plasma physics (17-21 September 2007, Caracas, Venezuela)

    Science.gov (United States)

    Puerta, Julio

    2008-10-01

    Some years ago a group of Latin American physicists took the initiative to consult about the viability of organizing a meeting on plasma physics for researchers and students of the region. The result was that it was not only a good idea, but a necessity in order to show and share everyone's work, and to keep updated on latest advances and technologies on plasma physics. It was decided that for new researchers as well as students of Physics, it would prove to be the best way to keep them posted on such matters. This was the birth of a series of meetings known as Latin American workshops on plasma physics that take place every two years in a different Latin American country. In Venezuela we have had the opportunity to organize two editions of this interesting and important reunion of physicists. The first of these Latin American workshops on plasma physics was held in Cambuquira (Brazil) in 1982. After organizing the first six editions of the workshop, the VII LAWPP meeting was realized in Caracas in January 1997. It was designed with a structure similar to the first edition. It developed in two stages, a first week devoted to short courses with lecturers in different fields of plasma physics and a second week for contributed and invited presentations. Participants from sixteen different countries were present, half of them from this continent and the other half from overseas, demonstrating the international character of this meeting. There have been four more editions of the workshop and once again, we have had the opportunity to organize this latest edition of the series: the XII Latin American workshop on plasma physics, which took place in Caracas, Venezuela from the 17th to the 21st of September 2007. The structure was modified, because contributed and review papers were together during the first stage, with short courses realized during the second one, called mini-courses, and given by several high level contributors such as José Boedo, Leopoldo Soto, Claude

  15. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-06-01

    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  16. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....

  17. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  18. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.

    1980-01-01

    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  19. Black Eye: First Aid

    Science.gov (United States)

    First aid Black eye Black eye: First aid By Mayo Clinic Staff A black eye is caused by bleeding under the skin around the eye. Most injuries that cause a ... 13, 2018 Original article: http://www.mayoclinic.org/first-aid/first-aid-black-eye/basics/ART-20056675 . Mayo ...

  20. The Effect of Industrial Work Performance Practice and Performance Automotive Electrical Prakti entrepreneurial n Against Interests Automotive Mechanics Class XII Smk Diponegoro Depok Sleman

    OpenAIRE

    Arif Mustofa; Pairun Roniwijaya

    2013-01-01

    The purpose of this study was to determine (1) the influence of the industrial working practices achievement entrepreneurial interests, (2) the effect of automotive electrical practice achievement against entrepreneurial interests, and (3) influence of achievement and accomplishment industry work practices automotive electrical practices to entrepreneurial interest Automotive Mechanics XII class students of SMK Diponegoro Depok Sleman school year 2012/2013.  The results showed that the test r...

  1. El castillo de Portilla (Zambrana, Álava: Origen y significado de una fortaleza plenomedieval en territorio alavés (siglos XI-XII

    Directory of Open Access Journals (Sweden)

    Jose Luis Solaun Bustinza, Agustín Azkarate Garai-Olaun

    2016-01-01

    Las recientes investigaciones arqueológicas efectuadas en esta fortaleza han permitido conocer mejor su origen y significado. Las evidencias apuntan a que la actual fortaleza, construida entre principios del siglo XI y mediados del siglo XII, estuvo bajo titularidad real, aunque fue gestionada por importantes aristocracias locales y regionales, siendo testigo de las complejas relaciones entre el poder público y privado y, obviamente, de la multiplicidad de funciones que esta fortaleza pudo desempeñar.

  2. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M

    2003-01-01

    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  3. PENGARUH PRAKTIK KERJA INDUSTRI DAN LINGKUNGAN KELUARGA TERHADAP MOTIVASI BERWIRAUSAHA SISWA KELAS XII PEMASARAN SMK NEGERI 2 SEMARANG

    Directory of Open Access Journals (Sweden)

    Sodikin

    2014-06-01

    Full Text Available Motivasi siswa untuk menjadi seorang wirausaha dipengaruhi oleh praktik kerja industri dan lingkungan keluarga. Permasalahan penelitian ini adalah: sebesar besar pengaruh praktik kerja industri dan lingkungan keluarga terhadap motivasi berwirausaha siswa baik secara parsial maupun simultan. Populasi dalam penelitian ini berjumlah 99 siswa yang terdiri dari kelas XII Pemasaran SMK Negeri 2 Semarang, karena merupakan penelitian populasi sehingga semua populasi dijadikan sampel penelitian. Variabel yang diteliti yaitu variabel praktik kerja industri, lingkungan keluarga dan motivasi berwirausaha. Metode pengumpulan data menggunakan angket dan dokumentasi. Analisis data menggunakan analisis deskripsi persentase dan analisis regresi berganda. Hasil penelitian uji regresi menunjukkan hasil uji parsial untuk praktik kerja industri diperoleh thitung sebesar 4,847 dengan signifikansi 0,000 dan lingkungan keluarga diperoleh thitung sebesar 3,182 dengan signifikansi 0,002 berarti H0 ditolak dan Ha1, Ha2, Ha3 diterima. Besarnya pengaruh secara parsial untuk variabel praktik kerja industri sebesar 19,62% dan lingkungan keluarga sebesar 9,55%, secara simultan sebesar 44%. Student motivation to become an entrepreneur is influenced by industry work practices and family environment. The problems of this research are: the influence of industry work practices and family environment against entrepreneurial motivation either partially or simultaneously. The population in this study is composed of 99 students of class XII SMK N 2 Semarang Marketing, as a research population so that all the population made research sample. The variables studied were industry work practices, family environment and entrepreneurial motivation. Methods of data collection using questionnaire and documentation. Data analysis using descriptive analysis and multiple regression analysis percentage. Results of regression studies showed partial test results obtained for industrial work practices

  4. PENINGKATAN KREATIVITAS BERWIRAUSAHA SISWA KELAS XII JASA BOGA 1 DALAM PENGOLAHAN LIMBAH BANDENG SEBAGAI PELUANG USAHA MELALUI UNIT PRODUKSI DI SMK NEGERI 3 PATI

    Directory of Open Access Journals (Sweden)

    Sri Puji Haryati

    2015-08-01

    Full Text Available The research aims are to: 1 increase students' creativity entrepreneurship Catering 1 Class XII in treating waste as a business opportunity thorns milkfish through the utilization of Production Unit of SMK Negeri 3 Pati and 2 determine the magnitude of the increase in Class XII student entrepreneurship creativity Catering 1 after using Production Unit of SMK Negeri 3 Pati. The method used is descriptive, the technique of classroom action research through qualitative and quantitative analysis. The pprinciples of recycling activity/procedures are: planning, acting, observing, and reflecting. Research held at SMK Negeri 3 Pati, with as many as 31 research subjects. Techniques of data collection are: observation, interviews, field notes, documentation. This study uses an interactive analysis that consists of data collection, data reduction, data presentation and conclusion. The research results showed that there is an increase in entrepreneurial creativity of each cycle, as seen in the first cycle the average value of creativity in entrepreneurship is 81% (the category of "creative" once held the second cycle to 94% (the category of "very creative", so that there is an increase in by 13%. In conclusion empowerment Production Unit Schools can improve the creativity of class XII student entrepreneurship Catering 1 in creating business opportunities through waste treatment milkfish.

  5. Open saccharin-based secondary sulfonamides as potent and selective inhibitors of cancer-related carbonic anhydrase IX and XII isoforms.

    Science.gov (United States)

    D'Ascenzio, Melissa; Guglielmi, Paolo; Carradori, Simone; Secci, Daniela; Florio, Rosalba; Mollica, Adriano; Ceruso, Mariangela; Akdemir, Atilla; Sobolev, Anatoly P; Supuran, Claudiu T

    2017-12-01

    A large number of novel secondary sulfonamides based on the open saccharin scaffold were synthesized and evaluated as selective inhibitors of four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). They were obtained by reductive ring opening of the newly synthesized N-alkylated saccharin derivatives and were shown to be inactive against the two cytosolic off-target hCA I and II (K i s > 10 µM). Interestingly, these compounds inhibited hCA IX in the low nanomolar range with K i s ranging between 20 and 298 nM and were extremely potent inhibitors of hCA XII isoenzyme (K i s ranging between 4.3 and 432 nM). Since hCA IX and XII are the cancer-related isoforms recently validated as drug targets, these results represent an important goal in the development of new anticancer candidates. Finally, a computational approach has been performed to better correlate the biological data to the binding mode of these inhibitors.

  6. Estrategias territoriales de un poder monástico en la Galicia medieval: Celanova (siglos X-XII

    Directory of Open Access Journals (Sweden)

    José Carlos SÁNCHEZ PARDO

    2011-02-01

    Full Text Available Se pretende afrontar un tema tradicional en la historiografía medieval española, como son los dominios monásticos, desde la perspectiva menos explorada de las estrategias espaciales que la reciente expansión del uso de los Sistemas de Información Geográfica ha facilitado. De esta manera, a través del caso gallego del monasterio de Celanova entre los siglos X y XII, observamos la complejidad que se esconde tras la planificación de la ubicación de uno de estos centros de poder así como la variedad y flexibilidad de tácticas empleadas en su proceso de crecimiento. Todo ello no solo enfatiza el conocido alto grado de conocimiento del entorno de los poderes señoriales entre finales de la Alta y Plena Edad Media, sino que también revela la importancia que dichos grupos daban a las estrategias espaciales en relación con la estructura preexistente de poblamiento y el papel que estas jugaron en el proceso de feudalización del noroeste peninsular.

  7. Measurements of density dependent intensity ratios of extreme ultraviolet line emission from Fe X, XI, and XII

    Science.gov (United States)

    Shimizu, Erina; Ali, Safdar; Tsuda, Takashi; Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi; Hara, Hirohisa; Watanabe, Tetsuya; Nakamura, Nobuyuki

    2017-05-01

    We report high-resolution density dependent intensity ratio measurements for middle charge states of iron in the extreme ultraviolet (EUV) spectral wavelength range of 160-200 Å. The measurements were performed at the Tokyo EBIT laboratory by employing a flat-field grazing incidence spectrometer installed on a low energy compact electron beam ion trap. The intensity ratios for several line pairs stemming from Fe X, Fe XI and Fe XII were extracted from spectra collected at the electron beam energies of 340 and 400 eV by varying the beam current between 7.5 and 12 mA at each energy. In addition, the effective electron densities were obtained experimentally by imaging the electron beam profile and ion cloud size with a pinhole camera and visible spectrometer, respectively. In this paper, the experimental results are compared with previous data from the literature and with the present calculations performed using a collisional-radiative model. Our experimental results show a rather good agreement with the calculations and previous reported results.

  8. Frontera y órdenes militares en la Edad Media castellano-leonesa (siglos XII-XIII

    Directory of Open Access Journals (Sweden)

    Carlos de AYALA MARTÍNEZ

    2009-12-01

    Full Text Available RESUMEN: El estudio presenta una breve panorámica del papel de las órdenes militares castellano-leonesas en la formación y consolidación de la frontera del reino con el Islam en los siglos XII y XIII. Ese papel tiene una triple dimensión –militar, colonizadora y estrictamente política– y sólo es posible constatar su eficacia a raíz del afianzamiento territorial e institucional de las órdenes militares, es decir, a partir del primer tercio del siglo XIII.ABSTRACT: The survey presents a brief view of the Castillian-Leonese military order’s role in the formation and consolidation of the kingdom’s border with the Islam in the twelfth and thirteenth centuries. This role has a triple dimension –military, settler and strictly political– and it is only possible to show its efficiency from the territorial and institutional strengthening of the military orders, that is, from the first third of the thirteenth century.

  9. New anticancer drug candidates sulfonamides as selective hCA IX or hCA XII inhibitors.

    Science.gov (United States)

    Gul, Halise Inci; Yamali, Cem; Sakagami, Hiroshi; Angeli, Andrea; Leitans, Janis; Kazaks, Andris; Tars, Kaspars; Ozgun, Dilan Ozmen; Supuran, Claudiu T

    2018-04-01

    In this study, new 4-[3-(aryl)-5-substitutedphenyl-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamides (19-36) were synthesized and evaluated their cytotoxic/anticancer and CA inhibitory effects. According to results obtained, the compounds 34 (4-[5-(2,3,4-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl] benzensulfonamide, Potency-Selectivity Expression (PSE) = 141) and 36 (4-[5-(3,4,5-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide, PSE = 54.5) were found the leader anticancer compounds with the highest PSE values. In CA inhibitory studies, the compounds 36 and 24 (4-[5-(3,4,5-trimethoxyphenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide) were found the leader CA inhibitors depending on selectivity ratios. The compound 36 was a selective inhibitor of hCA XII isoenzyme (hCA I/hCA XII = 1250 and hCA II/hCA XII = 224) while the compound 24 was a selective inhibitor of hCA IX isoenzyme (hCA I/hCA IX = 161 and hCA II/hCA IX = 177). The compounds 24, 34, and 36 can be considered to develop new anticancer drug candidates. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Brane world black rings

    International Nuclear Information System (INIS)

    Sahay, Anurag; Sengupta, Gautam

    2007-01-01

    Five dimensional neutral rotating black rings are described from a Randall-Sundrum brane world perspective in the bulk black string framework. To this end we consider a rotating black string extension of a five dimensional black ring into the bulk of a six dimensional Randall-Sundrum brane world with a single four brane. The bulk solution intercepts the four brane in a five dimensional black ring with the usual curvature singularity on the brane. The bulk geodesics restricted to the plane of rotation of the black ring are constructed and their projections on the four brane match with the usual black ring geodesics restricted to the same plane. The asymptotic nature of the bulk geodesics are elucidated with reference to a bulk singularity at the AdS horizon. We further discuss the description of a brane world black ring as a limit of a boosted bulk black 2 brane with periodic identification

  11. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  12. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  13. Black-Body Radiation

    Indian Academy of Sciences (India)

    Keywords. Black-body radiation; thermal radiation; heat; electromagnetic radiation; Stefan's Law; Stefan–Boltzmann Law; Wien's Law; Rayleigh–Jeans Law; black-body spectrum; ultraviolet catastrophe; zero point energy; photon.

  14. Dynamics of black holes

    OpenAIRE

    Hayward, Sean A.

    2008-01-01

    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  15. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.

    1976-01-01

    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  16. KORELASI BIMBINGAN PRAKTIK KERJA INDUSTRI DAN PRESTASI PRAKTIK KERJA INDUSTRI DENGAN MINAT BEKERJA PADA SISWA KELAS XII BIDANG KEAHLIAN TEKTIK MEKANIK OTOMOTIF SMK TAMANSISWA JETIS YOGYAKARTA TAHUN AJARAN 2013/2014

    Directory of Open Access Journals (Sweden)

    Lulut Setiya Priyanto

    2014-06-01

    This research is ex post facto research, data collection techniques using questionnaires and documentation. The population in this study were students of class XII Automotive Engineering Expertise at the SMK Yogyakarta Tamansiswa Jetis totaling 82 respondents as well as a sample in this study. Prior to the study, the instrument first tested on 29 students of class XII SMK Piri 1 Yogyakarta. Having piloted tested the validity and reliability to determine the item valid and reliable instrument. Engineering data analysts used in this study is hypothesis testing, prior to testing the hypothesis, first tested as a condition of a requirements analysis so that the analysis of the research actually has a high reliability. Test requirements analysis done by testing normality, linearity test and test intercorrelations. After test requirements are met analysis tested the hypothesis. Test this hypothesis using multiple regression and partial correlation. The results showed that: 1 the guidance of industry working practices (X1 and the achievements of the industry work practices (X2 are jointly positively correlated with interest in working on the student (Y class XII Expertise Automotive Engineering, 2 industry practice guidance ( X1 partially positively correlated with interest in working on the student (Y class XII Expertise Automotive Engineering, 3 achievement of industry working practices (X2 partially positively correlated with interest in working on the student (Y class XII Mechanical Engineering Expertise automotive.

  17. Monopole black hole skyrmions

    OpenAIRE

    Moss, I.G.; Shiiki, N.; Winstanley, E.

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  18. Alcoholism and Blacks.

    Science.gov (United States)

    Mosley, Bertha; And Others

    1988-01-01

    Notes that in America, knowledge base concerning alcoholism is concentrated on drinking patterns of Whites, and that Black Americans often differ in their drinking behavior, resulting in a need to clarify issues regarding alcoholism and Blacks. Provides theoretical information useful in better discerning drinking behavior of Blacks. (Author/NB)

  19. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  20. Genocide and Black Ecology

    Science.gov (United States)

    Sinnette, Calvin H.

    1972-01-01

    Contends that the survival of black people is in serious jeopardy as is evidenced in contemporary discussions on the worldwide plight of black people, and that an exhaustive study of the problem in its many dimensions is seriously lacking; the moral and ethical issues of genocide require examination from a black perspective. (JW)

  1. Esclavos musulmanes en los hospitales de cautivos de la Orden Militar de Santiago (siglos XII y XIII

    Directory of Open Access Journals (Sweden)

    Echevarría Arsuaga, Ana

    2007-12-01

    Full Text Available Military Orders had slave manpower in their lands since their foundation. However, the hospitals for ransoming captives owned by the Order of Santiago are the best example of how slavery worked in the kingdom of Leon-Castile during the twelfth and thirteenth centuries. These houses had enough room to provide lodging for captives while ransoms were being negotiated. They also helped to redistribute those Muslims who, lacking this possibility, became slaves of the order itself, or were sold in the slave markets of the kingdom. The scarce records kept in the Archivo Histórico Nacional, section Órdenes Militares, referring to slaves, help to understand the development of traffic, work and manumission of these people.

    Las órdenes militares dispusieron desde su fundación de mano de obra esclava en sus tierras, pero la institución que mejor sirve para estudiar la esclavitud en los siglos XII y XIII en los reinos de León y Castilla son los hospitales para la redención de cautivos de la Orden de Santiago. Estas instituciones disponían de espacio para alojar a los cautivos mientras se negociaban rescates con los poderes islámicos, y atendían a la redistribución de aquellos musulmanes que, por no haber sido redimidos, pasaban a ser esclavos de la propia orden o a ser vendidos en los mercados de los reinos cristianos. Los escasos documentos de la sección de Órdenes Militares del Archivo Histórico Nacional dedicados a esclavos ayudan a comprender el funcionamiento del tráfico, trabajo y liberación de este colectivo.

  2. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  3. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

  4. PENERAPAN SIMASET PADA MATERI LAPORAN PENERIMAAN DAN PENDISTRIBUSIAN SARANA DAN PRASARANA UNTUK MENINGKATKAN MOTIVASI BELAJAR SISWA KELAS XII ADMINISTRASI PERKANTORAN SMKN 1 MALANG

    Directory of Open Access Journals (Sweden)

    Novi Damayanti

    2017-11-01

    Full Text Available XII APK 1 class at SMKN 1 Malang have a problem on their learning motivation that showed by their attitude at the time of learning. The student’s motivation is relatively low. It is because the material, which is the report of facilities and infrastructure reception and distribution, requires a high concentration, therefore they need SIMAset as learning media that can help them to reach the goal of learning. The purpose of this research is to increase student’s motivation. This research is Classroom Action Research (CAR that was conducted in two cycles in which each cycle consist of planning, implementation, observation, and reflection. Data collection techniques in this study was done by using observation, interview, test, documentation, and questionnaire. This research using qualitative interactive techniques data analysis. The result of this study showed that SIMAset can increase student motivation. Abstrak: Kelas XII APK 1 SMKN 1 Malang memiliki permasalahan pada motivasi belajar yang ditunjukkan oleh sikap siswa pada saat proses pembelajaran berlangsung. Motivasi belajar siswa kelas XII APK 1 SMKN 1 Malang relatif rendah. Hal tersebut disebabkan karena materi yang dipelajari yaitu laporan penerimaan dan pendistribusian sarana dan prasarana membutuhkan konsentrasi yang tinggi, sehingga dibutuhkan media pembelajaran SIMAset yang dapat membantu siswa untuk mencapai tujuan pembelajaran dengan baik. Penelitian ini bertujuan untuk meningkatkan motivasi belajar siswa. Penelitian ini merupakan Penelitian Tindakan Kelas (PTK yang dilaksanakan dalam dua siklus, masing-masing siklus terdiri atas tahap perencanaan, pelaksanaan, pengamatan, dan refleksi. Teknik pengumpulan data yang digunakan yaitu observasi, wawancara, tes, dokumentasi, dan angket. Analisis data menggunakan teknik analisis data kualitatif interaktif. Hasil penelitian menunjukkan bahwa SIMAset dapat meningkatkan motivasi belajar siswa.

  5. Hegel y Aristóteles: Una lectura de Metafísica XII, 7,1072b 18-30

    Directory of Open Access Journals (Sweden)

    Luis Xavier López-Farjeat

    2013-11-01

    Full Text Available The author does a hegelian interpretation of Metaphysics XII, 7, 1072b 18-30, passage with which the Encyclopedia of the Philosophical Sciences concludes. Here are drawn the relations and similitudes that exist between Aristotle's Unmoved Mover and Hegel's Absolute. In order to understand in which points both thinkers coincide when describing divine thought, it is highly important to analyze the notions of thought, movement, power, act, concept, object, material substance, formal substance and suprasensible substance. The interpretative turn that Hegel does of Metaphysics and the comparative reading here offered, point towards a better understanding of the nature of the Unmoved Mover and the Absolute.

  6. CIÊNCIA, CIDADE E UTOPIA: XII SIMPOSIO NACIONAL DE GEOGRAFIA URBANA (SIMPURB, BELO HORIZONTE, 16 a 19 de NOVEMBRO de 2011

    Directory of Open Access Journals (Sweden)

    Eudes André Leopoldo de Souza

    2012-12-01

    Full Text Available O texto trata das principais discussões levantadas no XII Simpósio Nacional de Geografia Urbana (SIMPURB ocorrido ano passado. Dispõe sobre o meio frutífero propiciado no encontro para o avanço teórico-prático da problemática urbana e as estratégias de superação possíveis do modo de produção capitalista e da cidade encarcerada.

  7. Interacting black holes

    International Nuclear Information System (INIS)

    Costa, Miguel S.; Perry, Malcolm J.

    2000-01-01

    We revisit the geometry representing l collinear Schwarzschild black holes. It is seen that the black holes' horizons are deformed by their mutual gravitational attraction. The geometry has a string like conical singularity that connects the holes but has nevertheless a well defined action. Using standard gravitational thermodynamics techniques we determine the free energy for two black holes at fixed temperature and distance, their entropy and mutual force. When the black holes are far apart the results agree with Newtonian gravity expectations. This analyses is generalized to the case of charged black holes. Then we consider black holes embedded in string/M-theory as bound states of branes. Using the effective string description of these bound states and for large separation we reproduce exactly the semi-classical result for the entropy, including the correction associated with the interaction between the holes

  8. Black silicon integrated aperture

    Science.gov (United States)

    Liu, Tianbo; Dickensheets, David L.

    2017-10-01

    This paper describes the incorporation of nanotextured black silicon as an optical absorbing material into silicon-based micro-optoelectromechanical systems devices to reduce stray light and increase optical contrast during imaging. Black silicon is created through a maskless dry etch process and characterized for two different etch conditions, a cold etch performed at 0°C and a cryogenic etch performed at -110°C. We measure specular reflection at visible wavelengths to be black velvet paint used to coat optical baffles and compare favorably with other methods to produce black surfaces from nanotextured silicon or using carbon nanotubes. We illustrate the use of this material by integrating a black silicon aperture around the perimeter of a deformable focus-control mirror. Imaging results show a significant improvement in contrast and image fidelity due to the effective reduction in stray light achieved with the self-aligned black aperture.

  9. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  10. Franklin Roosevelt, Pius XII, Joseph Stalin and the Problem of the USSR’s Image and Reputation During the Second World War

    Directory of Open Access Journals (Sweden)

    Filippov Boris

    2016-08-01

    Full Text Available The aggression of Hitler’s Germany against the USSR made our country an ally of the United States and Great Britain. But the decision to help USSR with weapons and hardware (the lend-lease act faced opposition not only from the American isolationists but also from religious groups. Both Catholics and Protestants were against the very idea of helping the country in which churches were destroyed and the faithful were persecuted. They have considered such an idea to be immoral. To overcome the opposition in Congress, president F. D. Roosevelt and the US diplomats tried to convince Stalin to reject his policies of religious oppression. Roosevelt also asked pope Plus XII for help. At the same time German and Italian ambassadors were trying to convince the Pope to support their “crusade against the godless Bolshevik Russia”. The question of USSR’s image was an important issue throughout the course of war. The article tells the history of the most signifi cant efforts undertaken by the Western allies and Stalin to improve the international reputation of the USSR. First of all, it tells the story of the mysterious letter from Stalin to Plus XII (1942 and about even more mysterious visit of the American priest Stanislav Orlemansky to Moscow and his meeting with Stalin in 1944.

  11. MODEL PEMBELAJARAN ” WEB BASED EDUCATION ” UNTUK MENINGKATKAN PRESTASI BELAJAR PENDIDIKAN KEWARGANEGARAAN DI KELAS XII IPA SMA NEGERI 1 GANTUNG

    Directory of Open Access Journals (Sweden)

    Sabarudin Sabarudin

    2015-03-01

    Full Text Available This study is an action of teachers to improve student learning achievement Civics Class XII Science SMAN 1 Gantung in the Academic Year 2014/2015. This classroom action research conducted in three cycles and includes four phases, namely planning, action, observation and reflection. Each action consists of three activities, namely the preliminary (appersepsi, the core activity of carrying out the Learning Model "Web Based Education", and cover with giving about evaluation, motivation and reinforcement. To assess learning achievement Civics, researchers used tools test instrument. The results showed that the use of the learning model "Web Based Education" can improve student achievement in high school civics class. This is evident from the learning achievement test data also showed an increase in pre-cycle that is as much as 7 students (20.59% reached KKM with an average of 66.62, in the first cycle of students who achieve complete by 73.59% or 25 students with an average of 82.65 and the second cycle is equal to 88.24% or 30 students with an average of 90.24. After the whole cycle is done, it can be concluded that the use of Learning Model "Web Based Education" can improve learning achievement in civics class XII IPA SMAN 1 Gantung in the school year 2014/2015. Keywords: Web Based Education, Learning Achievement Civics

  12. National Library of Norway's new database of 22 manuscript maps concerning the Swedish King Charles XII's campaign in Norway in 1716 and 1718

    Directory of Open Access Journals (Sweden)

    Benedicte Gamborg Brisa

    2003-03-01

    Full Text Available The National Library of Norway is planning to digitise approximately 1,500 manuscript maps. Two years ago we started working on a pilot project, and for this purpose we chose 22 maps small enough to be photographed in one piece. We made slides 6 x 7 cm in size, converted the slides into PhotoCDs and used four different resolutions on JPEG-files. To avoid large file sizes, we had to divide the version with the biggest resolution into four pieces. The preliminary work was done in Photoshop, the database on the web is made in Oracle. You can click on the map to zoom. Norwegians and probably Swedes during the Great Northern War drew the 22 maps when the Swedish King Charles XII in 1716 and 1718 unsuccessfully attempted to conquer Norway. The database is now accessible on the National Library of Norway's web site. The database is in Norwegian, but we are working on an English version as well. The maps are searchable on different topics, countries, counties, geographical names, shelfmarks or a combination of these. We are planning to expand the database to other manuscript maps later. This is the reason why it is possible to search for obvious subjects as Charles XII and the Great Northern War.

  13. Factors Affecting Implementation of Decree of Ministry of Health No. 2562/ MENKES/ PER/ XII/2011 on Jampersal (Maternity Insurance Technical Guideline in Independet Midwifery Practice in Semarang Municipality

    Directory of Open Access Journals (Sweden)

    Fitriani Nur Damayanti

    2013-06-01

    Full Text Available Provide financial guarantees for service delivery (Jampersal, the government established the program with the Regulation of the Minister of Health Minister Regulation No. 2562/ Menkes/ Per/XII/2011 on Technical Guidelines for Delivery Guarantee. This study was conducted to determine the factors that affect the implementation Permenkes 2562/Menkes/Per/XII/2011 Number of Technical Guidance Delivery Guarantee in Semarang Independent Midwives Practice. The method approach used in this study is a qualitative sociological research juridical, Specifications. This is a descriptive research study. Technical factors such as health facilities are factors that affect the implementation of the labor warranty. Delivery Guarantee service is good and the maximum is influenced by many factors such as health workers. Health personnel especially midwives are the main factors in service delivery assurance. Provisions of medicines in service delivery assurance in Independent Practice Midwife Semarang are still having problems. Jampersal huge cost on hospitals and midwifery practices vary independently. Juridical factors, among others, have made the law of warranty service delivery as a midwife practice internal self- regulation, which includes service procedures, assignment of medical personnel. The scope of midwifery includes antenatal care, maternity (high risk, childbirth, newborns, family planning, and management of complications in obstetrics.

  14. EFFECT OF AUTOMOTIVE PERFORMANCE LEARNING WORK PRACTICES AND PERFORMANCE INDUSTRY OF interest in entrepreneurship LIGHT VEHICLE ENGINEERING XII SMK PIRI 1 YOGYAKARTA 2013/2014

    Directory of Open Access Journals (Sweden)

    Rachmat Udin

    2014-06-01

    Full Text Available The hypothesis of this study were (1 there is a positive influence on learning achievement automotive interest in entrepreneurship, (2 there is a positive influence on the industry work practices accomplishment interest in entrepreneurship, (3 there is a positive effect of learning achievement and achievement automotive industry work practices together to class XII student interest in entrepreneurship minor engineering vehicles SMK Piri 1 Yogyakarta Academic Year 2013/2014.  This research is a kind of ex - post facto research . The population in this study is a class XII student of SMK Piri 1Yogyakarta TKR which is 129 students, with a sample of 98 students. Data capture techniques using methods of documentation, test and questionnaire. The validity of the questionnaire instrument carried by grain analysis using Product Moment Correlation formula and reliability testing using Cronbach Alpha. Anlisis Analysis using partial correlation and multiple regression, which previously conducted test requirements analysis includes tests of normality, linearity and intercorrelations.  The results showed that (1 learning achievement and achievement automotive industry work practices together positive and significant effect on the interest in entrepreneurship. (2 The learning achievement of automotive positive and significant effect on the interest in entrepreneurship. (3 Achievement industry work practices and a significant positive effect on the interest in entrepreneurship. This shows that learning achievement automotive (X1 and the achievement of industrial work practices (X2 has the effect of interest in entrepreneurship (Y.

  15. PEMANFAATAN FACEBOOK DALAM KETERAMPILAN MEMPRODUKSI TEKS CERITA SEJARAH PADA SISWA KELAS XII IPS-1 SMA NEGERI 3 BOJONEGORO TAHUN PELAJARAN 2015/2016

    Directory of Open Access Journals (Sweden)

    Susanto Susanto

    2015-12-01

    Full Text Available Facebook already familiar among students, thus giving rise to problems in the form of formulation of the problem. How harness, effectiveness studies, and student learning outcomes associated with social media media (facebook in improving the learning skills to produce historical narrative text in class XII IPS 1SMAN 3 Bojonegoro academic year 2015/2016? The method in use is the method of data collection in the form of questionnaires and interviews, and observations during the study (good attitude, knowledge and skills. Results of the research in this paper indicate that Facebook utilize media based learning as e-learning will be developed along technology. The learned very look fabulous. Students of class XII IPS -1 amounted to 32 students. Students who scored above 79 to as many as 27 students or equal to 84.4%. This means that students experiencing learning completeness. While students who scored below 79 or 78 down as much as 5 students, equivalent to 15.6%. Means there are five students who did not complete the work TCS.Saran in this study should be a teacher, the use of FB as a learning medium based e-learning, especially in order to improve the achievement of learning outcomes.

  16. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  17. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  18. Nonextremal stringy black hole

    International Nuclear Information System (INIS)

    Suzuki, K.

    1997-01-01

    We construct a four-dimensional BPS saturated heterotic string solution from the Taub-NUT solution. It is a nonextremal black hole solution since its Euler number is nonzero. We evaluate its black hole entropy semiclassically. We discuss the relation between the black hole entropy and the degeneracy of string states. The entropy of our string solution can be understood as the microscopic entropy which counts the elementary string states without any complications. copyright 1997 The American Physical Society

  19. STUDI KOMPARASI SELF CONTROL SISWA YANG MEMILIKI KECERDASAN SPIRITUAL TINGGI DAN RENDAH DI KELAS XII SMAN I KOTA KEDIRI TAHUN PELAJARAN 2013/2014

    Directory of Open Access Journals (Sweden)

    Ady Alfan Mahmudinata

    2016-07-01

    Full Text Available Referring to the character of the Education Act in Indonesia listed in Act 20 of 2003 on National Education System Indonesia Article: 1 The purpose of national education to develop the potential of learners to have the intelligence, personality, and noble character; and article 3, paragraph 1: National education serves to develop the ability and shape the character and civilization of the nation's dignity in the context of national life as well as you view the proyeksitas Islamic religious education that is feeding religious spiritual student-related non- Islamic values are synergistic against strong self control gaining control himself strong for the students, for the writer interested to learn and find out about the intelligence level of spiritual and differences self Control students, among students who have spiritual intelligence of high and low class XII SMAN I Kediri, with the formulation of the problem 1 What is the level of intelligence spiritual students ? 2 How Self Control students who have high spiritual intelligence? 3 How Self Control students who have low spiritual intelligence? 4 Do Self Control students who have high spiritual intelligence is stronger than the Self Control students who have low spiritual intelligence?This study uses a mixed method approach. The data collection was conducted by questionnaire, documentation, interviews and observation. The population of this research is class XII student of SMAN I Kediri. Sampling starts with random sampling techniques on Muslim students in class XII and generalized according to the level of intelligence Spiritual owned. Statistical data analysis with independent t-test formula. The research sample for the group of students who have Spiritual intelligence is as many as 152 students were taken based on Table Krejcie for error rate ( of 0.05 of the total students totaling 250 students, from 152 students after given a rating based on spiritual intelligence instrument  then found the

  20. Editorial 2017/XII/2

    Directory of Open Access Journals (Sweden)

    Jana Dlouhá

    2018-01-01

    Pokusy o pravdu, nebo cestu k ní, nemusí být vítězné, stačí, když jsou soustavné. S pravdou není spojena moc, která vše změní, ale vnitřní síla být sám sebou, a taky pro druhé. O tom píše v tomto čísle Envigogiky Zuzana Svobodová v článku Pojetí bratrství u Jana Patočky a jeho výzva dnešku. Pravda se prosazuje skrytým pohybem, který v sobě zahrnuje všechno smysluplné snažení. Aby nebyla bezmocná, aby dokázala jednotlivce i lidské společenství vyvést z podřízenosti, je třeba jí v pravém čase důrazně přitakat. Čin¸ který osvobozuje od lži, může osvobodit i od nenávisti. Společenství naděje, lásky a pravdy fungují na stejných principech: jsou založeny na vzájemné důvěře, a ochotě si tuto víru navzájem projevovat. Něčemu věřit, něco pro to udělat a společně se radovat z výsledku přináší radost. Tu nyní přejeme i Vám, našim čtenářům, kterým patří na naší cestě důležité místo. Za redakční tým Jana Dlouhá

  1. El museo deslumbrante. XII

    Directory of Open Access Journals (Sweden)

    Fernando Arbeláez

    1965-04-01

    Full Text Available Más que de su majestuoso teatro, Epidauro será siempre un recuerdo del verde. Del verde en todas sus matices y en todas sus coloraciones. Los árboles, los pequeños bosques, los prados, con su temperatura delicada y con su atmósfera feliz. Para llegar a la gran baraja de piedra, cruzamos un sendero que nos acoge como una verde matriz plena de fragancia y me siento flotar en las aguas amnióticas del olvido.

  2. Black holes are warm

    International Nuclear Information System (INIS)

    Ravndal, F.

    1978-01-01

    Applying Einstein's theory of gravitation to black holes and their interactions with their surroundings leads to the conclusion that the sum of the surface areas of several black holes can never become less. This is shown to be analogous to entropy in thermodynamics, and the term entropy is also thus applied to black holes. Continuing, expressions are found for the temperature of a black hole and its luminosity. Thermal radiation is shown to lead to explosion of the black hole. Numerical examples are discussed involving the temperature, the mass, the luminosity and the lifetime of black mini-holes. It is pointed out that no explosions corresponding to the prediction have been observed. It is also shown that the principle of conservation of leptons and baryons is broken by hot black holes, but that this need not be a problem. The related concept of instantons is cited. It is thought that understanding of thermal radiation from black holes may be important for the development of a quantified gravitation theory. (JIW)

  3. Black Craftsmen Through History.

    Science.gov (United States)

    Myers, Robin

    This report traces the evolution of the black craftsmen from ancient Egypt to the present. Special attention is given to the restricted use of black craftsmen under slavery, and the added problems they faced after being freed. Business and union discimination is described, along with recent government and private efforts to achieve equal…

  4. Black hole candidates

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Black hole candidates. In the case of X-ray sources such as Cyg X-1, the mass of the compact object inferred from combined optical and X-ray data, suggest M_compact object > 3.4 M_sun => Black Hole! A remarkable discovery!! Thus X-ray emitting binary systems ...

  5. Black hole Berry phase

    NARCIS (Netherlands)

    de Boer, J.; Papadodimas, K.; Verlinde, E.

    2009-01-01

    Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry’s phase: under adiabatic variations of the

  6. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  7. Black hole levitron

    NARCIS (Netherlands)

    Arsiwalla, X.D.; Verlinde, E.P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.’s multicenter

  8. Protecting Black Girls

    Science.gov (United States)

    Morris, Monique W.

    2016-01-01

    Statistics show that black girls in U.S. K-12 public schools are overrepresented among students who face disciplinary approaches (such as suspensions) that exclude or even criminalize them. Morris explains how black girls face conditions that make them vulnerable to a phenomenon she calls "school to confinement pathways"--conditions like…

  9. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of ...

  10. Black Boycott: Gainsville, Florida

    Science.gov (United States)

    White, Arthur O.

    1975-01-01

    A case study of the events precipitating a black student boycott in 1969 in Gainesville, Flordia, when school board manuevering to avoid school integration led to the threatened closing of Lincoln High School, a reputable black community school. Also described are the subsequent transformations of Lincoln into a vocational-technical school and…

  11. Neoliberalism and Black Education.

    Science.gov (United States)

    Rich, John Martin

    1986-01-01

    In contrast to traditional liberals, neoliberals share a commitment to greater economic risk-taking, support for entrepreneurism, a new industrial policy, and a different Federal Role. While New Deal and Great Society liberalism may have been more favorable to blacks, perhaps more balanced and equitable policies for blacks could be developed if…

  12. Lifshitz topological black holes

    International Nuclear Information System (INIS)

    Mann, R.B.

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  13. Legitimizing Blacks in Philosophy

    Directory of Open Access Journals (Sweden)

    Jameliah Shorter-Bourhanou

    2017-12-01

    Full Text Available In its efforts toward improving diversity, the discipline of philosophy has tended to focus on increasing the number of black philosophers. One crucial issue that has received less attention is the extent to which black philosophers are delegitimized in the discipline because their philosophical contributions challenge the status quo. A systematic problem that bars black philosophers from equal and full participation, this delegitimization precludes the emergence of genuine diversity and reveals the importance of interrogating broader attitudes toward black philosophical contributions. In this essay, I argue for radical systematic changes to disciplinary hallmarks of professionalization such as pedagogy, mentoring, publishing, and hiring practices with the aim of legitimizing black philosophers and their contributions.

  14. Hospitalarios y obispos en Castilla durante los siglos XII y XIII = Hospitallers and Bishops in Castile During the Twelfth and Thirteenth Centuries

    Directory of Open Access Journals (Sweden)

    Carlos Barquero Goñi

    2017-05-01

    Full Text Available La Orden de San Juan disfrutó de periodos de buena sintonía con el episcopado en Castilla y León. Sin embargo, era irremediable que surgieran conflictos jurisdiccionales entre ambos poderes. En Castilla y León aparecen desde el último cuarto del siglo XII. A diferencia de otras órdenes militares, los hospitalarios castellano-leoneses tienden a llevar estos pleitos con poca violencia y buscan rápidamente un acuerdo con el obispo correspondiente. La solución fue la común y usual en todos los litigios que enfrentaron a las órdenes militares con el episcopado durante los siglos XII y XIII. La Orden de San Juan y el obispo correspondiente se dividieron los derechos eclesiásticos de las iglesias hospitalarias. El reparto variaba en cada diócesis en función de la correlación de fuerzas existente. Esta clase de avenencias comienzan a hacerse en Castilla y León a partir de finales del siglo XII. Por lo general, cada sede episcopal llegaba a un solo acuerdo con la Orden. Con todo, hubo algunas como Zamora, Astorga o Toledo, con las que el Hospital realizó varios acuerdos. Las concordias de este tipo representaron el más decisivo mecanismo de acomodación de la Orden de San Juan en las estructuras de la Iglesia castellano-leonesa.There were many periods in which good relations prevailed between the Order of Saint John and the bishops of Castile. However, it was inevitable that jurisdictional conflicts would eventually arise between the two powers. In Castile, they appear since the last quarter of the twelfth century. Unlike other military orders, the Castilian Hospitallers usually carried out this litigation with little violence and quickly sought an agreement with the concerned bishop. They often arrived at a standard solution to the disputes among the military orders and the bishops in the twelfth and thirteenth centuries. The ecclesiastical rights of Hospitaller churches were divided between the Order of Saint John and a specific bishop

  15. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    as a star or dispersing altogether. Were we engineers with advanced technology, we might attempt to find that critical amount of energy necessary to form a black hole. However, despite some fears to the contrary, such technology does not exist, so instead we investigate this critical regime numerically. The first step is to pick ...

  16. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    denotes the partial derivatives of . The construction of a numerical method with which ... which configurations form black holes and which disperse (the only two options in this model). The problem in picturing such a space is that it is infinite ..... 4.1 The future: Less symmetry. The work described above all assumes spherical ...

  17. ULTRAMASSIVE BLACK HOLE COALESCENCE

    International Nuclear Information System (INIS)

    Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter

    2015-01-01

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production

  18. "Black Like Me": Reframing Blackness for Decolonial Politics

    Science.gov (United States)

    Dei, George J. Sefa

    2018-01-01

    From a particular vantage point, as an African-born scholar with a politics to affirm my Black subjectivity and Indigeneity in a diasporic context, my article engages a (re)theorization of Blackness for decolonial politics. Building on existing works of how Black scholars, themselves, have theorized Blackness, and recognizing the fluid,…

  19. La muerte de Alfonso XII y la configuración de la práctica política de la Restauración

    Directory of Open Access Journals (Sweden)

    María Ángeles Lario González

    1993-01-01

    Full Text Available Para entender el derrunribamiento del régimen político que vio la luz tras la Restauración borbónica en 1874, derrumbamiento que se produjo bajo la monarquía de Alfonso XIII, es imprescindible analizar en profundidad no sólo la teoría constitucional elaborada al efecto en 1876, sino, a la vez, la práctica política que creó un determinado estilo de relación entre las instituciones, que es el que nos puede explicar la causa de la fluidez en el intercambio político y la buena imagen que en general ofrecen las dos situaciones monárquicas anteriores a la monarquía citada: la de Alfonso XII y la Regencia de Mª Cristina, frente a la controversia histórica que generó el último reinado.

  20. As transgressões da carne: o desejo homossexual no mundo islâmico e cristão (séculos XII-XX

    Directory of Open Access Journals (Sweden)

    Fabio Augusto Scarpim

    2016-10-01

    Full Text Available O livro resenhado, por meio de vários ensaios, procura compreender as interações e os encontros entre os mundos cristão e islâmico por meio da análise das relações homoeróticas e homossexuais.  Com um arco temporal que vai do século XII ao XX os autores propõem uma via de explicação segundo a qual as práticas sexuais entre pessoas do mesmo sexo (em muitos casos entre cristãos e muçulmanos, embora proibida por ambas as religiões, teriam se constituído em um específico terreno de troca e interação entre ambos.

  1. QSAR study of pyrazolo[4,3-e][1,2,4]triazine sulfonamides against tumor-associated human carbonic anhydrase isoforms IX and XII.

    Science.gov (United States)

    Matysiak, Joanna; Skrzypek, Alicja; Tarasiuk, Paweł; Mojzych, Mariusz

    2017-12-01

    The QSAR models for a set of pyrazolo[4,3-e][1,2,4]triazines incorporating benzenesulfonamide moiety combined directly with the heterocyclic ring or by NH linkage were generated. The inhibitory potency of compounds against human carbonic anhydrase isoforms IX and XII and antiproliferative activity against human MCF-7 cells were used as the dependent variables. The Codessa pro software was used for the descriptors calculation and the Best Multi-Linear Regression (BMLR) algorithm was employed to build the QSAR models. It was found that quantum descriptors are critical of the compounds activities. The selected models have good predictive accuracy confirmed by a set of the statistical quantities recommended by OECD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The Joint International Conference of the XII International Conference on Mechanisms and Mechanical Transmissions (MTM) and the XXIII International Conference on Robotics (Robotics ’16)

    CERN Document Server

    Lovasz, Erwin-Christian; Hüsing, Mathias; Maniu, Inocentiu; Gruescu, Corina

    2017-01-01

    This volume presents the proceedings of the Joint International Conference of the XII International Conference on Mechanisms and Mechanical Transmissions (MTM) and the XXIII International Conference on Robotics (Robotics ’16), that was held in Aachen, Germany, October 26th-27th, 2016. It contains applications of mechanisms and transmissions in several modern technical fields such as mechatronics, biomechanics, machines, micromachines, robotics and apparatus. In connection with these fields, the work combines the theoretical results with experimental testing. The book presents reviewed papers developed by researchers specialized in mechanisms analysis and synthesis, dynamics of mechanisms and machines, mechanical transmissions, biomechanics, precision mechanics, mechatronics, micromechanisms and microactuators, computational and experimental methods, CAD in mechanism and machine design, mechanical design of robot architecture, parallel robots, mobile robots, micro and nano robots, sensors and actuators in ro...

  3. Exophytic pilocytic astrocytoma of the brain stem in an adult with encasement of the caudal cranial nerve complex (IX-XII): presurgical anatomical neuroimaging using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yousry, Indra; Yousry, Tarek A. [Department of Neuroradiology, Klinikum Grosshadern, Ludwig-Maximilians University, Marchioninistr. 15, 81377, Munich (Germany); Muacevic, Alexander; Olteanu-Nerbe, Vlad [Department of Neurosurgery, Klinikum Grosshadern, Ludwig-Maximilians University, Munich (Germany); Naidich, Thomas P. [Department of Radiology, Section of Neuroradiology, Mount Sinai Hospital, New York (United States)

    2004-07-01

    We describe a rare case of adult pilocytic astrocytoma in which exophytic growth from the brain stem presented as a right cerebellopontine angle mass. An initial MRI examination using T2- and T1-weighted images without and with contrast suggested the diagnosis of schwannoma. Subsequent use of 3D CISS (three-dimensional constructive interference in steady state) and T1-weighted contrast-enhanced 3D MP-RAGE (three-dimensional magnetization prepared rapid acquisition gradient echo) sequences led to the diagnosis of an exophytic brain stem tumor, documented the precise relationships of the tumor to cranial nerve VIII, revealed encasement of cranial nerves IX-XII (later confirmed intraoperatively), and provided the proper basis for planning surgical management. (orig.)

  4. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  5. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)

    2015-05-11

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  6. COGNITIVE STRUCTURE STRENGTHENING STUDENTS OF SMK N 1 ARSE CLASS XII WITH LEARNING MODEL ADVANCE ORGANIZER BY GRANT STRUCTURED LKS BASED APOS THEORY

    Directory of Open Access Journals (Sweden)

    Abdul Rahman Hakim

    2013-06-01

    Full Text Available The purpose of this research: (1 Improving Students' Cognitive Structures through the Advance Organizer Model Learning by giving Structured Worksheets based on APOS Theory, (2 Improving student activity through the Advance Organizer Model Learning by giving Structured Worksheets based on APOS Theory. This research was a Classroom Action Research (CAR which was carried out at SMK Negeri 1 Arse South Tapanuli. The research subject was grade 12 students of academy year 2012/2013 consisting 31 students, namely 18 males and 13 females. Object on this research were the student activity and student learning outcomes through the Advance Organizer Model Learning by giving Structured Worksheets based on APOS Theory. The research consisted of two cycles, each cycle consisting of three meetings. Test of achievement conducted at the end of each cycle. Test of achievement consisting of 15 questions. The results of the research are: (1 There is an increased of student learning outcomes on class XII Agribusiness Crop/Horticulture SMK Negeri 1 Arse which showed an increase in cognitive structure indicated strengthening of: (a Outcomes of achievement test in the first cycle, namely: the average = 63.66; percentage of completeness = 41.94%, (b Outcomes of achievement test in the second cycle, namely: the average = 82.58; percentage of completeness 90.32%. The percentage of completeness 48.39%, and the index gain 0.51 or moderate improvement criteria. (2 There is an increased of student activity on class XII Agribusiness Crop/Horticulture SMK Negeri 1 Arse shown from: first cycle is only the average of 59.72 up to 74.47 in the second cycle.

  7. Pesca y trabajo en el reino de Toledo. La cuenca alta y media del Tajo en los siglos XII al XVI

    Directory of Open Access Journals (Sweden)

    Sánchez Quiñones, Julián

    2006-06-01

    Full Text Available

    This work treats about the professions related with the fishing in the Kingdom of Toledo, in the high and middle course of river Tagus, from XII-XVIth centuries. Along these pages we have seen many different kind of people, public servants, great merchants, workers of the fisheries, involved in the fishing, trading and delivering of fish in this time. So with this article, we break with the idea which identified the fishing only with fishing men and boats showing how the medieval society was interested in every economic activity which produced profits.



    Este trabajo trata acerca de las profesiones relacionadas con la pesca en el Reino de Toledo, en la cuenca alta y media del río Tajo, de los siglos XII al XVI. A lo largo de estas páginas hemos visto muchos tipos diferentes de personas, oficiales públicos, grandes mercaderes, trabajadores de las pesquerías, envueltos en la captura, comercio y distribución del pescado. Con este artículo, queremos romper con la idea que identifica la pesca sólo con los pescadores y los barcos, mostrando como la sociedad medieval se interesaba en cualquier actividad económica que produjese beneficios.

  8. Understanding the Black Aesthetic Experience.

    Science.gov (United States)

    Curtis, Marvin V.

    1988-01-01

    Discussing the importance of the Black aesthetic experience, Curtis examines Black cultural heritage and participatory style, the spiritual, and the creation and recreation of Black music. Advocating multicultural music education in teacher training, he suggests that Black music be studied for its value and contribution to society. Lists five ways…

  9. The Thermodynamics of Black Holes

    Directory of Open Access Journals (Sweden)

    Wald Robert M.

    2001-01-01

    Full Text Available We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  10. Black Writers' Views of America.

    Science.gov (United States)

    Hairston, Loyle

    1979-01-01

    This article argues that the stagnation, pessimism, and self-pity evident in recent Black writing results in part from the alienation of Black writers from the mainstream of Black life, and in part from the illusions that they share with other Blacks who have embraced the American value system. (Author/EB)

  11. Introducing the Black Hole

    Science.gov (United States)

    Ruffini, Remo; Wheeler, John A.

    1971-01-01

    discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

  12. Colliding black hole solution

    International Nuclear Information System (INIS)

    Ahmed, Mainuddin

    2005-01-01

    A new solution of Einstein equation in general relativity is found. This solution solves an outstanding problem of thermodynamics and black hole physics. Also this work appears to conclude the interpretation of NUT spacetime. (author)

  13. Black Sea aerosols

    International Nuclear Information System (INIS)

    Hacisalihoglu, G.; Eliyakut, F.; Anwari, M.A.; Ataman, O.Y.; Balkas, T.I.; Tuncel, G.; Olmez, I.

    1991-01-01

    Shipboard, high volume air particulate samples were collected from the Black Sea atmosphere and analyzed by instrumental neutron activation analysis, atomic absorption spectrophotometry and ion chromatography for about 40 elements and ions. Concentrations of elements in the eastern and western parts of the Black Sea are different at the 95% confidence level, with lower concentrations in the eastern Black Sea. Back-trajectories and concentrations of elements in trajectory groups show that Europe accounts for more than 70% of the anthropogenic elements in the atmosphere. The average sulfate concentration was 7 μg/m 3 , which is comparable with rural sulfate levels in western Europe. Fluxes of elements from the atmosphere to the Black Sea are in good agreement with the results of similar flux calculations for other regions

  14. Black Teenage Pregnancy

    Directory of Open Access Journals (Sweden)

    Loretta I. Winters

    2012-01-01

    Full Text Available This article examines the relative importance of race and socioeconomic status (SES in determining whether Black and White teenagers report having ever been pregnant. Data gathered from 1999 to 2006 by the National Center for Health Statistics of the Center for Disease Control and Prevention included 1,580 Black and White females aged 15 to 19 years. Results supported the effects of race and SES, with SES having the stronger effect. However, the effects of race and SES differ when controlling for the state of the economy. No difference between Blacks and Whites was found during better economic times. During 2003-2004, the period of greatest economic stress, race was determined to be the only predictor of teenage pregnancy. In particular, during 2005-2006, the reduction in pregnancy rates for Black minors (15-17 fell below those for White minors within their respective SES categories. Policy implications are discussed in light of these findings.

  15. Illuminating black holes

    Science.gov (United States)

    Barr, Ian A.; Bull, Anne; O'Brien, Eileen; Drillsma-Milgrom, Katy A.; Milgrom, Lionel R.

    2016-07-01

    Two-dimensional shadows formed by illuminating vortices are shown to be visually analogous to the gravitational action of black holes on light and surrounding matter. They could be useful teaching aids demonstrating some of the consequences of general relativity.

  16. Black holes with halos

    Science.gov (United States)

    Monten, Ruben; Toldo, Chiara

    2018-02-01

    We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

  17. Black Friday = Broget Branding?

    DEFF Research Database (Denmark)

    Hansen, Heidi

    2015-01-01

    Black Friday er et godt eksempel på, hvordan ikke kun produktbrands og corporate brands rejser på tværs af landegrænser, men også traditioner som Halloween, Valentines Day og i dette tilfælde den ultimative tilbuds-fredag, som i USA går under navnet Black Friday. Men hvad er Black Friday i Danmark......? Essensen ved Black Friday er lave priser, og det er der ved første øjekast ikke mange brandingmuligheder forbundet ved, hvis man forstår branding som en måde at skabe ekstra værdi omkring sit produkt eller sin virksomhed. Som brand bliver man dog alligevel nødt til at forholde sig til konceptet, da det er...

  18. Mobilizing Black America

    Science.gov (United States)

    1993-04-01

    and financially for childbirth or parenting. - Adolescent Pregnancy Black female teenagers 15 to 19 years old were 140 percent more likely to have a...on adolescent pregnancy teenage sexual activity, and federally funded programs prevention. NATIONAL INSTITUTE OF CHILD HEALTH AND HUMAN DEVELOPMENT...communities? o Access to Health Care: Does everyone have equal access? o Poverty o Racism o Health Insurance o Black Physicians o Summary o Infant Mortality

  19. Black chrome outgassing study

    International Nuclear Information System (INIS)

    Beat, T.

    1979-01-01

    This report covers why black chrome is of interest, why its outgassing is relevant, how the study was conducted, examples of resultant data, and a conclusion. Black chrome is of interest in several areas of activity. Vacuum outgassing characteristics must be known to establish the pumping speed requirements. How much gas is evolved determines the pump speed required. The species of gas evolved determines the type of pump. The outgassing characteristics must be known to determine needed precleaning steps

  20. Quantum black holes

    International Nuclear Information System (INIS)

    't Hooft, G.

    1987-01-01

    No particle theory can be complete without gravity. Einstein's theory of gravity is of the Euler-Lagrange form, but standard quantization procedure fails. In quantum gravity the higher order interactions have a dimensionality different form the fundamental ones, because Newton's constant G has dimensions and the renormalization procedure fails. Another problem with quantum gravity is even more mysterious. Suppose that we had regularized the gravitational forces at the small distance end in the way that the weak intermediate vector boson regularized the fundamental 4-fermion interaction vertex of the weak interactions. Then what we discover is that the gravitational forces are unstable. Given sufficiently large amount of matter, it can collapse under its own weight. Classical general relativity tells us what will happen: a black hole is formed. But how is this formulated in quantum theory. S. Hawking observed that when a field theory is quantized in the background metric of a black hole, the black hole actually emits particles in a completely random thermal way. Apparently black holes are just another form of matter unstable against Hawking decay. Unfortunately this picture cannot be complete. The problem is that the quantum version of black holes has infinite phase space, and other symptoms of a run-away solution. Black holes are the heaviest and most compact forms of matter that can be imagined. A complete particle theory can have nothing but a spectrum of black-hole like objects at it high-energy end. This is why it is believed that a resolution of the black hole problem will in time disclose the complete small-distance structure of our world. 6 references

  1. Charged Galileon black holes

    International Nuclear Information System (INIS)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar

    2015-01-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory

  2. STUDI KOMPARASI HASIL BELAJAR AKUNTANSI DENGAN PENERAPAN METODE PEMBELAJARAN TEAMS GAMES TOURNAMENT (TGT DENGAN METODE CERAMAH BERVARIASI PADA KOMPETENSI DASAR JURNAL KHUSUS SISWA KELAS XII IPS SMA MUHAMMADIYAH 01 PATI

    Directory of Open Access Journals (Sweden)

    Dian Susilowati

    2013-11-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui apakah metode pembelajaran TGT dapat meningkatkan hasil belajar siswa, ada perbedaan hasil belajar siswa dengan penerapan metode TGT dengan ceramah bervariasi dan lebih efektif dibandingkan metode ceramah bervariasi. Penelitian ini adalah penelitian quasi eksperimen yang diawali menentukan populasi dan memilih sampel dari populasi. Populasi dalam penelitian ini adalah seluruh siswa kelas XII IPS SMA Muhammadiyah 01 Pati, dan sampel penelitian ini yaitu kelas XII IPS 1 sebagai kelas eksperimen dan kelas XII IPS 3 sebagai kelas kontrol dengan menggunakan teknik simple random sampling. Pengujian hipotesis pertama dengan uji paired sample t-test menunjukan nilai sig sebesar 0.000, pengujian hipotesis kedua dan ketiga dengan uji independent sample t-test menunjukan nilai sig sebesar 0,023 yang artinya lebih kecil dari level of significant (α yaitu sebesar 0,05, sehingga terdapat peningkatan hasil belajar, perbedaan hasil belajar dan keefektifan metode TGT. Hasil penelitian menunjukkan bahwa metode pembelajaran TGT dapat meningkatkan hasil belajar siswa, menunjukkan adanya perbedaan hasil belajar dan lebih efektif meningkatkan hasil belajar siswa pada kompetensi dasar jurnal khusus. The purpose of this study was to determine whether the TGT learning methods can improve student learning outcomes, there is a difference in student learning outcomes with the adoption of IGT with lectures varied and more effective than the lecture method varies. This study is a quasi-experimental study that begins to determine the population and selecting a sample of the population. The population in this study were all students of class XII IPS SMA Muhammadiyah 01 Starch, and samples of this study are class XII IPS 1 as the experimental class and the class as a class XII IPS 3 control using simple random sampling technique. The first hypothesis test with paired samples t-test showed sig of 0000, the second and third

  3. PENGARUH PELAKSANAAN OJT (ON THE JOB TRAINING DAN PERAN ORANGTUA TERHADAP MINAT BERWIRAUSAHA PADA SISWA KELAS XII KOMPETENSI KEAHLIAN AKUNTANSI DI SMK NEGERI 2 SEMARANG TAHUN AJARAN 2013/2014

    Directory of Open Access Journals (Sweden)

    Siti Mutmainah

    2013-11-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh OJT (On The Job Training dan peran orangtua terhadap minat berwirausaha pada siswa kelas XII Kompetensi Keahlian Akuntansi di SMK Negeri 2 Semarang tahun ajaran 2013/2014. Populasi dalam penelitian adalah seluruh siswa kelas XII kompetensi keahlian akuntansi SMK Negeri 2 Semarang sebanyak 108 siswa dan sampel dalam penelitian adalah seluruh populasi yang berjumlah 108 siswa. Metode pengump ulan data yang digunakan adalah metode kuesioner. Metode analisis data yang digunakan yaitu analisis deskriptif dan analisis regresi linier berganda. Hasil penelitian menunjukkan bahwa ada pengaruh positif antara OJT dan peran orangtua terhadap minat berwi rausaha. Hasil penelitian diperoleh persamaan regresi linier berganda yaitu Y = 27,396+0,233X 1+0,892X2 +e. Kontribusi OJT dan peran orangtua terhadap minat berwirausaha secara silmutan sebesar 29,8%. Besarnya pengaruh secara parsial variabel OJT sebesar 4,54% dan besarnya pengaruh secara parsial variabel peran orangtua sebesar 16,08%. Berdasarkan hasil penelitian disimpulkan bahwa ada pengaruh OJT dan peran orangtua terhadap minat berwirausaha siswa kelas XII kompetensi keahlian akuntansi SMK Negeri 2 Semara ng tahun ajaran 2013/2014 baik secara simultan maupun parsial. This research has purpose for knowing effect of OJT (On The Job Training and parent’s fungtion toward interesting in entrepreneurship simultaneously and partially students class XII accounting skills competence in Vocational High School State 2 Semarang year 2013/2014. The population of this research is all students class XII accounting skills comp etence in Vocational High School State 2 Semarang as many as 108 students and sample of this research is all of population as many as 108 students. Data collection method was used a questionnaire method. Data collection method was used a questionnaire method. Method of data analysis is descriptive analysis and multiple regression analysis. The

  4. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  5. Surface geometry of 5D black holes and black rings

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Goswami, Rituparno

    2007-01-01

    We discuss geometrical properties of the horizon surface of five-dimensional rotating black holes and black rings. Geometrical invariants characterizing these 3D geometries are calculated. We obtain a global embedding of the 5D rotating black horizon surface into a flat space. We also describe the Kaluza-Klein reduction of the black ring solution (along the direction of its rotation) which, though it is nakedly singular, relates this solution to the 4D metric of a static black hole distorted by the presence of external scalar (dilaton) and vector ('electromagnetic') fields. The properties of the reduced black hole horizon and its embedding in E 3 are briefly discussed

  6. Merging Black Holes

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  7. Pulsation of black holes

    Science.gov (United States)

    Gao, Changjun; Lu, Youjun; Shen, You-Gen; Faraoni, Valerio

    2018-01-01

    The Hawking-Penrose singularity theorem states that a singularity forms inside a black hole in general relativity. To remove this singularity one must resort to a more fundamental theory. Using a corrected dynamical equation arising in loop quantum cosmology and braneworld models, we study the gravitational collapse of a perfect fluid sphere with a rather general equation of state. In the frame of an observer comoving with this fluid, the sphere pulsates between a maximum and a minimum size, avoiding the singularity. The exterior geometry is also constructed. There are usually an outer and an inner apparent horizon, resembling the Reissner-Nordström situation. For a distant observer the horizon crossing occurs in an infinite time and the pulsations of the black hole quantum "beating heart" are completely unobservable. However, it may be observable if the black hole is not spherical symmetric and radiates gravitational wave due to the quadrupole moment, if any.

  8. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  9. Bringing Black Holes Home

    Science.gov (United States)

    Furmann, John M.

    2003-03-01

    Black holes are difficult to study because they emit no light. To overcome this obstacle, scientists are trying to recreate a black hole in the laboratory. The article gives an overview of the theories of Einstein and Hawking as they pertain to the construction of the Large Hadron Collider (LHC) near Geneva, Switzerland, scheduled for completion in 2006. The LHC will create two beams of protons traveling in opposing directions that will collide and create a plethora of scattered elementary particles. Protons traveling in opposite directions at very high velocities may create particles that come close enough to each other to feel their compacted higher dimensions and create a mega force of gravity that can create tiny laboratory-sized black holes for fractions of a second. The experiments carried out with LHC will be used to test modern string theory and relativity.

  10. Coiffured black rings

    Science.gov (United States)

    Bena, Iosif; Ross, Simon F.; Warner, Nicholas P.

    2014-08-01

    We describe a new type of hair on supersymmetric black string and black ring solutions, which produces the largest known violation of black hole uniqueness, parameterized by an arbitrary function and hence an infinite number of continuous parameters. The new solutions can have non-trivial density profiles for the electric fields along the horizon, and yet have a geometry that is regular, although generically not infinitely differentiable, at the horizon. Both neutral and charged probes can cross the horizon without experiencing divergent forces. We also find restricted examples, parameterized by a few arbitrary continuous parameters, where the charge densities fluctuate but the metric does not and hence is completely differentiable. Our new class of solutions owes its existence to a mechanism reminiscent of the Q-ball: in the simplest examples the metric has more symmetry than the matter that supports it.

  11. Black hole gravitohydromagnetics

    CERN Document Server

    Punsly, Brian

    2008-01-01

    Black hole gravitohydromagnetics (GHM) is developed from the rudiments to the frontiers of research in this book. GHM describes plasma interactions that combine the effects of gravity and a strong magnetic field, in the vicinity (ergosphere) of a rapidly rotating black hole. This topic was created in response to the astrophysical quest to understand the central engines of radio loud extragalactic radio sources. The theory describes a "torsional tug of war" between rotating ergospheric plasma and the distant asymptotic plasma that extracts the rotational inertia of the black hole. The recoil from the struggle between electromagnetic and gravitational forces near the event horizon is manifested as a powerful pair of magnetized particle beams (jets) that are ejected at nearly the speed of light. These bipolar jets feed large-scale magnetized plasmoids on scales as large as millions of light years (the radio lobes of extragalactic radio sources). This interaction can initiate jets that transport energy fluxes exc...

  12. Slowly balding black holes

    International Nuclear Information System (INIS)

    Lyutikov, Maxim; McKinney, Jonathan C.

    2011-01-01

    The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes N B =eΦ ∞ /(πc(ℎ/2π)), where Φ ∞ ≅2π 2 B NS R NS 3 /(P NS c) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  13. Black widow spider envenomation.

    Science.gov (United States)

    Peterson, Michael E

    2006-11-01

    Black widow spiders are found throughout the continental United States and north into the southern Canadian provinces. Male black widow spiders are of little medical importance. Female black widow spiders can be 20 times larger than males. The female can be identified by the hourglass pattern, red or orange in color, on the ventral aspect of her shiny, globose black abdomen. Black widow spiders control the amount of venom they inject; an estimated 15% of bites to humans are non-envenomating. Cats are very sensitive to the venom and deaths are common. Dogs have severe clinical signs but are considered more resistant than cats. A single bite is capable of delivering a lethal dose of venom to companion animals. There are several toxic components consisting of five or six biologically active proteins. These include a potent mammalian neurotoxin called alpha-latrotoxin, which induces neurotransmitter release from nerve terminals. Acetylcholine, noradrenalin, dopamine, glutamate, and enkephalin systems are all susceptible to the toxin. Onset of clinical signs usually occurs during the first 8 hours post envenomation. The condition is extremely painful in moderate to severe envenomations. Abdominal rigidity without tenderness is a hallmark sign of Latrodectus envenomation. In cats, paralytic signs may occur early and are particularly marked. Hypertension is a significant threat. First aid is of no value in the treatment. The primary treatment for black widow spider envenomation is the administration of specific antivenin, which provides the most permanent and quickest relief of the envenomation syndrome, usually within 30 minutes of infusion. The prognosis of Latrodectus envenomation is uncertain of several days, and complete recovery may take weeks.

  14. Roma ante el cambio dinástico en la monarquía española. La consulta de Carlos II a Inocencio XII sobre la sucesión

    Directory of Open Access Journals (Sweden)

    David Martín Marcos

    2007-04-01

    Full Text Available The problems derivated from the lack of Charles II’descendants affected the whole Europe at the end of the seventeenth century. In Italy this crisis was lived with particular intensity because an important part of its territories were controlled by the Spanish Monarchy. This article studies the role of Rome, as temporal and spiritual power, in the query maded to Innocent XII by Charles II in 1700 about the Spanish sucession.

  15. IMPLEMENTASI MODEL PEMBELAJARAN MIND MAP (PETA PIKIRAN) UNTUK MENINGKATKAN PRESTASI BELAJAR SISWA KELAS XII PADA MATA PELAJARAN RIAS WAJAH KHUSUS PROGRAM KEAHLIAN KECANTIKAN DI SMK NEGERI 27 JAKARTA PUSAT

    OpenAIRE

    ARINDIKA, RUSY

    2017-01-01

    ABSTRACT   Rusy Arindika 2012. Implementation Of The Mind Map Learning For Improving Student Achievement Against Class XII On the Subject Special Makeup Courses Beauty Expertise at SMKN 27 Jakarta. Thesis. Jakarta : Makeup Course, Department of Family Welfare, Faculty of Engineering, State University of Jakarta. The research was conducted based on action research or action research, which consisted of two cycles, where the description on each cycle include: planning action, impl...

  16. EFEKTIVITAS METODE DRILL BERBANTUAN MODUL PEMBELAJARAN DALAM UPAYA MENINGKATKAN HASIL BELAJAR SISWA KOMPETENSI DASAR JURNAL KHUSUS PERUSAHAAN DAGANG PADA SISWA KELAS XII IPS SMA NEGERI 10 SEMARANG TAHUN AJARAN 2013/2014

    Directory of Open Access Journals (Sweden)

    Meta Aditya Handayani

    2013-11-01

    Full Text Available Tujuan penelitian untuk mengetahui penerapan metode drill berbantuan modul dapat meningkatkan hasil belajar akuntansi kompetensi dasar Jurnal Khusus kelas XII IPS SMA Negeri 10 Semarang tahun ajaran 2013/2014 . Penelitian ini menggunakan metode quasi eksperimen. Populasi dalam penelitian ini adalah seluruh kelas XII IPS SMA Negeri 10 Semarang Tahun Ajaran 2013/2014. Metode pengumpulan data yaitu dengan menggunakan tes dan observasi. Pengujian hipotesis menggunakan uji paired sample t-tets dan independent sample t-test. Hasil penelitian menunjukkan peningkatan hasil belajar pada kelas eksperimen dilihat dari 61,16 meningkat mencapai 80,89. Selain itu menunjukkan hasil rata-rata nilai post-test sebesar 80,89 pada kelas eksperimen lebih tinggi dibandingkan nilai post-test sebesar 77,29 pada kelas kontrol. Berdasarkan hasil penelitian dapat disimpulkan bahwa pembelajaran dengan menggunakan metode pembelajaran drill berbantuan modul dapat meningkatkan hasil belajar serta efektif dalam meningkatkan hasil belajar siswa k ompetensi dasar jurnal khusus. Research purposes to determine the application of assisted modules drill method to improve learning outcomes of accounting competence base class XII IPS Special Journal SMA Negeri 10 Semarang school year 2013/2014. This study uses a quasi-experimental methods. The population in this study were all class XII IPS SMA Negeri 10 Semarang Academic Year 2013/2014. Data collection method is by using tests and observation. Hypothesis testing using paired sample t-tets and independent sample t-test. Results showed improved learning outcomes seen in the experimental classes increased to 80.89 from 61.16. In addition it shows the results of the average post-test score of 80.89 in the experimental class higher than the post -test score of 77.29 in the control class. Based on the results of this study concluded that learning by using drill -assisted learning modules to improve learning outcomes and effective in imp

  17. As formas da história: a doutrina agostiniana das seis idades do mundo e algumas de suas visualizações no século XII

    Directory of Open Access Journals (Sweden)

    Elisa Brilli

    2011-12-01

    Full Text Available Este artigo estuda a doutrina das seis idades do mundo, concebida por Santo Agostinho e amplamente difundida no Ocidente medieval. Após analisar a teorização de Agostinho, com base em fontes diversas, passa-se ao exame das iluminuras de três manuscritos que buscaram dar forma visual a essa concepção da história no século XII.

  18. Characterizing Black Hole Mergers

    Science.gov (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard

    2010-01-01

    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  19. Superfluid Black Holes.

    Science.gov (United States)

    Hennigar, Robie A; Mann, Robert B; Tjoa, Erickson

    2017-01-13

    We present what we believe is the first example of a "λ-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid ^{4}He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically anti-de Sitter hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  20. Are black holes springlike?

    Science.gov (United States)

    Good, Michael R. R.; Ong, Yen Chin

    2015-02-01

    A (3 +1 )-dimensional asymptotically flat Kerr black hole angular speed Ω+ can be used to define an effective spring constant, k =m Ω+2. Its maximum value is the Schwarzschild surface gravity, k =κ , which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: 2 π T =κ -k . Hooke's law, in the extremal limit, provides the force F =1 /4 , which is consistent with the conjecture of maximum force in general relativity.

  1. Bulletproof Black Man

    DEFF Research Database (Denmark)

    Højer, Henrik

    2016-01-01

    Netflix’ kommende serie om den sorte Marvel-helt Luke Cage lander snart – midt i de aktuelle racekonflikter i USA. I GIF-anatomien "Bulletproof Black Man" sætter Henrik Højer serien ind i dens amerikanske kontekst.......Netflix’ kommende serie om den sorte Marvel-helt Luke Cage lander snart – midt i de aktuelle racekonflikter i USA. I GIF-anatomien "Bulletproof Black Man" sætter Henrik Højer serien ind i dens amerikanske kontekst....

  2. Virtual Black Holes

    OpenAIRE

    Hawking, Stephen W.

    1995-01-01

    One would expect spacetime to have a foam-like structure on the Planck scale with a very high topology. If spacetime is simply connected (which is assumed in this paper), the non-trivial homology occurs in dimension two, and spacetime can be regarded as being essentially the topological sum of $S^2\\times S^2$ and $K3$ bubbles. Comparison with the instantons for pair creation of black holes shows that the $S^2\\times S^2$ bubbles can be interpreted as closed loops of virtual black holes. It is ...

  3. Better Physician's 'Black Bags'

    Science.gov (United States)

    1976-01-01

    The "black bag" is outgrowth of astronaut monitoring technology from NASA's Johnson Space Center. Technically known as the portable medical status system, a highly advanced physician's "black bag" weighs less than 30 pounds, yet contains equipment for monitoring and recording vital signs, electrocardiograms, and electroencephalograms. Liquid crystal displays are used to present 15 digits of data simultaneously for long periods of time without excessive use of battery power. Single printed circuit card contains all circuitry required to measure and display vital signs such as heart and respiration rate, temperature, and blood pressure.

  4. Partons and black holes

    International Nuclear Information System (INIS)

    Susskind, L.; Griffin, P.

    1994-01-01

    A light-front renormalization group analysis is applied to study matter which falls into massive black holes, and the related problem of matter with transplankian energies. One finds that the rate of matter spreading over the black hole's horizon unexpectedly saturates the causality bound. This is related to the transverse growth behavior of transplankian particles as their longitudinal momentum increases. This growth behavior suggests a natural mechanism to implement 't Hooft's scenario that the universe is an image of data stored on a 2 + 1 dimensional hologram-like projection

  5. Hubungan Asupan Energi Sarapan terhadap Tingkat Konsentrasi pada Siswa-Siswi Kelas XII SMA Negeri 1 Padang Tahun Ajaran 2013/2014

    Directory of Open Access Journals (Sweden)

    Kurnia Maidarmi Handayani

    2014-09-01

    Full Text Available AbstrakIndonesia menduduki peringkat terakhir dalam cognitive skills dan pencapaian pendidikan menurut penelitian yang dilakukan oleh Economist Intelligence Unit. Cognitive skills memerlukan fungsi otak yang adekuat yang dipertahankan oleh nutrisi berupa konsumsi pangan yang baik dan beragam, terutama sarapan. Penelitian di Amerika Serikat pada anak usia sekolah remaja (15-18 tahun menunjukkan bahwa sebesar 30% remaja tidak biasa sarapan. Penelitian ini bertujuan untuk mengetahui hubungan antara asupan energi sarapan dan tingkat konsentrasi pada siswa SMAN 1 Padang. Studi dilakukan di SMAN 1 Padang pada bulan November 2013 terhadap 116 siswa kelas XII. Desain penelitian bersifat analitik dengan desain cross sectional. Pengolahan data dilakukan dengan uji chi-square menggunakan sistem komputerisasi. Hasil penelitian menunjukkan terdapat perbedaan tingkat konsentrasi menggunakan digit symbol test antara siswa dengan asupan energi sarapan baik, kurang, dan sangat kurang (p=0,001 dan tidak terdapat perbedaan tingkat konsentrasi menggunakan digit span test antara siswa dengan asupan energi sarapan baik, kurang, dan sangat kurang (p=0,345. Terdapat hubungan yang bermakna antara asupan energi sarapan dengan tingkat konsentrasi menggunakan digit symbol test (p<0,05.Kata kunci: sarapan, asupan energi, konsentrasi, digit symbol test, digit span testAbstractIndonesia was ranked last in the cognitive skills and educational attainment according to research conducted by the Economist Intelligence Unit.Cognitive skills require brain function is maintained by adequate intake of nutrients such as good and varied food, especially breakfast. Research in the United States in children of school age youth (15-18 years showed that 30% of teenagers are not usually did breakfast.This study aimed to determine the relationship between energy intake at breakfast and the level of concentration of students of SMAN 1 Padang. The study was conducted at SMAN 1 Padang in

  6. PENGARUH BIMBINGAN KARIR DAN LINGKUNGAN SEKOLAH MELALUI MOTIVASI KERJA TERHADAP KESIAPAN KERJA SISWA KELAS XII KOMPETENSI KEAHLIAN AKUNTANSI SMK NEGERI 2 MAGELANG

    Directory of Open Access Journals (Sweden)

    Muhammad Zachim Alfan

    2013-02-01

    Full Text Available Kesiapan kerja merupakan keseluruhan kondisi individu yang meliputi kematangan fisik, mental dan pengalaman serta adanya kemauan dan kemampuan untuk melaksanakan suatu pekerjaan atau kegiatan. Tujuan dari penelitian ini adalah untuk mengetahui ada tidaknya pengaruh bimbingan karir dan lingkungan sekolah melalui motivasi terhadap kesiapan kerja siswa kelas XII SMK Negeri 2 Magelang. Populasi penelitian ini adalah siswa kelas XII Kompetensi Keahlian Akuntansi SMK Negeri 2 Magelang Tahun Ajaran 2013/2014. Jumlah sampel sebanyak 84 siswa yang diambil dengan menggunakan rumus Isaac. Pengambilan sampel tiap kelas menggunakan proporsional random sampling. Metode pengumpulan data adalah angket. Metode analisis data menggunakan teknik analisis deskriptif, regresi linear berganda dan analisis jalur. Hasil penelitian menunjukkan bahwa terdapat pengaruh bimbingan karir terhadap kesiapan kerja siswa (48,1%, lingkungan sekolah berpengaruh terhadap kesiapan kerja siswa (33,5%, bimbingan karir berpengaruh terhadap motivasi kerja siswa (30,5%, ada pengaruh lingkungan sekolah terhadap motivasi kerja siswa (27%, bimbingan karir melalui motivasi kerja berpengaruh terhadap kesiapan kerja siswa (50,8%, dan lingkungan sekolah melalui motivasi kerja berpengaruh terhadap kesiapan kerja siswa (35,9%. The working readiness is the entire condition of an individual including physical maturity, mental maturity, experiential maturity, the existence of willingness and capability to do a job or activity. The purpose of this study is to know whether there is influence of career guidance and environmental school through motivation toward the working readiness of the twelfth graders who are taking accountancy program at State Vocational High School 2 Magelang. In this research, the population was the twelfth graders with year of education 2013/2014 who are taking accountancy program at State Vocational High School 2 Magelang. The population was the twelfth graders with year of

  7. Black Elite: The New Market for Highly Educated Black Americans.

    Science.gov (United States)

    Freeman, Richard B.

    This examination of the collapse in traditional discriminatory patterns in the market for highly qualified black Americans documents the World War II gain of college trained and related high level black workers, investigates the response of black college students and qualified personnel to the new market setting, and explores the factors that…

  8. Black strings ending on horizons

    Science.gov (United States)

    Haddad, Nidal

    2012-12-01

    We construct an approximate static gravitational solution of the Einstein equations, with negative cosmological constant, describing a test black string stretching from the boundary of the Schwarzschild-AdS5 black brane toward the horizon. The construction builds on a derivative expansion method, assuming that the black brane metric changes slowly along the black string direction. We provide a solution up to second order in derivatives, and it implies, in particular, that the black string must shrink to zero size at the horizon of the black brane. In the near-horizon region of the black brane, where the two horizons intersect, we provide an exact solution of a cone that describes two intersecting horizons at different temperatures. Moreover, we show that this solution equally describes a thin and long black droplet.

  9. Reflections on a Black Mirror

    OpenAIRE

    Good, Michael R. R.

    2016-01-01

    A black mirror is an accelerated boundary that produces particles in an exact correspondence to an evaporating black hole. We investigate the spectral dynamics of the particle creation during the formation process.

  10. Black Musicians Leading the Way.

    Science.gov (United States)

    Music Educators Journal, 1982

    1982-01-01

    Describes the careers and musical achievements of Blacks who were forerunners in jazz, blues, gospel, music, spirituals, band music, classical music, ragtime, and opera. The list was compiled to provide teachers with historical background information for "Black History Month." (AM)

  11. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  12. Black Sea Bass genetic connectivity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microsatellite analysis of black sea bass was undertaken to determine magnitude and direction of mixing of black seabass across the Hatteras boundary, as well as...

  13. Meer bekend over Black Mold

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Kohrman, E.

    2008-01-01

    In de vollegrondsrozenteelt zorgde Black Mold in 2007 voor een groot aantal mislukte oculaties. In 2008 waren er aanzienlijk minder problemen. Uit onderzoek is meer bekend over de oorzaak en bestrijding van Black Mold.

  14. Aspects of hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Anabalón, Andrés, E-mail: andres.anabalon-at@uai.cl [Departamento de Ciencias, Facultad de Artes Liberales y Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar (Chile); Astefanesei, Dumitru [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)

    2015-03-26

    We review the existence of exact hairy black holes in asymptotically flat, anti-de Sitter and de Sitter space-times. We briefly discuss the issue of stability and the charging of the black holes with a Maxwell field.

  15. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.

    2008-09-01

    Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.

  16. Newborn Black Holes

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence. The holes are consuming material falling into them while somehow propelling other material away at great speeds. "First comes a blast of gamma rays followed by intense pulses of x-rays. The energies involved are much…

  17. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  18. Scholarly Black Market.

    Science.gov (United States)

    Sorooshian, Shahryar

    2017-04-01

    Fake and unethical publishers' activities are known by most of the readers of Science and Engineering Ethics. This letter tries to draw the readers' attention to the hidden side of some of these publishers' business. Here the black market of scholarly articles, which negatively affects the validity and reliability of research in higher education, as well as science and engineering, will be introduced.

  19. Twistors and Black Holes

    NARCIS (Netherlands)

    Neitzke, A.; Pioline, B.; Vandoren, S.

    2007-01-01

    Motivated by black hole physics in N = 2,D = 4 supergravity, we study the geometry of quaternionic-K¨ahler manifolds Mobtained by the c-map construction from projective special Kähler manifolds Ms. Improving on earlier treatments, we compute the Käahler potentials on the twistor space Z and Swann

  20. on black ironbark (Eucalyptus

    African Journals Online (AJOL)

    (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 honeybees started foraging in the ...

  1. Trichomicosis pubis: black variety.

    OpenAIRE

    Neri, I; Frassetto, A; Pasquinelli, G; Patrizi, A

    1994-01-01

    A case of a 25 year old man with the black variety of trichomicosis pubis is presented on account of its extreme rareity. Scanning electron microscopy confirms that trichomicosis pubis is caused by bacterial colonisation of the pubic hair and shows that bacteria are able to penetrate cuticular horny cells directly through their free plasma membrane.

  2. Suburban Black Lives Matter

    Science.gov (United States)

    Lewis-McCoy, R. L'Heureux

    2018-01-01

    This article explores the range of experiences and meanings of Black life in suburban space. Drawing from educational, historical, and sociological literatures, I argue that an underconsideration of suburban space has left many portraits of educational inequality incomplete. The article outlines the emergence of American suburbs and the formation…

  3. Black Psychology. Third Edition.

    Science.gov (United States)

    Jones, Reginald L., Ed.

    This book is the third edition of a resource for advanced students and professionals in black psychology in the form of 41 papers organized under 5 subheadings. The "overview" section includes one classic article and offers a new, world view paper. A "perspectives" section treats Afrocentric, humanistic, historical,…

  4. [Reinvesting in Black Communities].

    Science.gov (United States)

    Shipp, James

    Some of the issues involved in promoting home ownership among blacks and investment in inner city communities are discussed in this paper. The experiences of the Bedford Stuyvesant Restoration Corporation in revitalizing Bedford Stuyvesant are described. Economic barriers to prospective home ownership are identified and strategies and programs…

  5. Black Holes and Entanglement

    International Nuclear Information System (INIS)

    Borsten, L.

    2011-01-01

    An unexpected interplay between the seemingly disparate fields of M-theory and Quantum Information has recently come to light. We summarise these developments, culminating in a classification of 4-qubit entanglement from the physics of STU black holes. Based on work done in collaboration with D. Dahanayake, M. J. Duff, H. Ebrahim, A. Marrani and W. Rubens.

  6. Black Holes and Entanglement

    Science.gov (United States)

    Borsten, L.

    2011-07-01

    An unexpected interplay between the seemingly disparate fields of M-theory and Quantum Information has recently come to light. We summarise these developments, culminating in a classification of 4-qubit entanglement from the physics of STU black holes. Based on work done in collaboration with D. Dahanayake, M. J. Duff, H. Ebrahim, A. Marrani and W. Rubens.

  7. Watchable Wildlife: The Black Bear

    Science.gov (United States)

    Lynn L. Rogers

    1992-01-01

    Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

  8. Health Issues Facing Black Women.

    Science.gov (United States)

    Reid, Inez Smith

    Black women in the United States experience a high incidence of serious health problems and, as a group, receive insufficient and inadequate medical care. The death rate for black women suffering from breast cancer has increased substantially since 1950. Also of great concern is the high incidence of cervical cancer in low income black women…

  9. Uncovering Black Womanhood in Engineering

    Science.gov (United States)

    Gibson, Sheree L.; Espino, Michelle M.

    2016-01-01

    Despite the growing research that outlines the experiences of Blacks and women undergraduates in engineering, little is known about Black women in this field. The purpose of this qualitative study was to uncover how eight Black undergraduate women in engineering understood their race and gender identities in a culture that can be oppressive to…

  10. Warped products and black holes

    International Nuclear Information System (INIS)

    Hong, Soon-Tae

    2005-01-01

    We apply the warped product space-time scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstroem-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizons of these black holes

  11. Reading Black Literature With Understanding.

    Science.gov (United States)

    Alexander, Jean A.

    This paper is a broad study of the field of black American Literature which outlines the important movements, stereotypes, and trends that have had significant influence upon the literature. The changing stereotypes and archetypes of blacks depicted in American literature from the early concept of blacks as "chattels" to the contemporary concept…

  12. Queering Black Racial Identity Development

    Science.gov (United States)

    Johnson, Alandis A.; Quaye, Stephen John

    2017-01-01

    We used queer theory to encourage readers to think differently about previous theories about Black racial identity development. Queer theory facilitates new and deeper understandings of how Black people develop their racial identities, prompting more fluidity and nuance. Specifically, we present a queered model of Black racial identity development…

  13. Black silicon with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by mask-less reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Black bus-bars were realized by oxidized copper resulting in reflectance below 3% in the entire visible wavelength range. The combination of these two technologies may result in aesthetic, all-black panels based on conventional, front-contacted solar cells...

  14. Looking for the invisible universe - Black matter, black energy, black holes

    International Nuclear Information System (INIS)

    Elbaz, David

    2016-01-01

    As the discovery of the expansion of the universe and of black holes put the study of cosmology into question again because it now refers to invisible things such as black holes, black energy and black matter, the author proposes an other view on the universe within such a context. He first discusses these three enigmas of black matter, black energy and black holes. In a second part, he addresses, discusses and comments five illusions: the Uranian illusion (questions of the existence of an anti-world, of black matter temperature), the Mercurian illusion (quantum gravity, the string theory), the Martian illusion (a patchwork universe, the illusion of the infinite), the cosmic Maya (the John Wheeler's cup, the holographic universe), and the narcissistic illusion

  15. Black Strings, Black Rings and State-space Manifold

    CERN Document Server

    Bellucci, Stefano

    2011-01-01

    State-space geometry is considered, for diverse three and four parameter non-spherical horizon rotating black brane configurations, in string theory and $M$-theory. We have explicitly examined the case of unit Kaluza-Klein momentum $D_1D_5P$ black strings, circular strings, small black rings and black supertubes. An investigation of the state-space pair correlation functions shows that there exist two classes of brane statistical configurations, {\\it viz.}, the first category divulges a degenerate intrinsic equilibrium basis, while the second yields a non-degenerate, curved, intrinsic Riemannian geometry. Specifically, the solutions with finitely many branes expose that the two charged rotating $D_1D_5$ black strings and three charged rotating small black rings consort real degenerate state-space manifolds. Interestingly, arbitrary valued $M_5$-dipole charged rotating circular strings and Maldacena Strominger Witten black rings exhibit non-degenerate, positively curved, comprehensively regular state-space con...

  16. Escribiendo la reconquista: la consolidación de la memoria histórica en el Portugal del siglo XII

    Directory of Open Access Journals (Sweden)

    Stephen LAY

    2012-03-01

    Full Text Available Durante el siglo XII los portugueses experimentaron un alto nivel de agitación política y social, así como la amenaza militar planteada por los estados vecinos fue agravada por un reto cultural que provenía de la Europa latino-cristiana. En un esfuerzo por darle a su propia sociedad un contexto, los portugueses dirigieron sus miradas a un pasado lejano. Una serie de autores que trabajaron en Portugal durante este periodo nos han dado su visión particular de la invasión islámica del siglo VIII, de la consiguiente Reconquista y de la evolución de la relación entre cristianos y musulmanes en la Península Ibérica. En ese esfuerzo por contextualizar su propio mundo, estos autores han proporcionado al lector moderno una visión excepcional de una sociedad medieval de frontera que estaba inmersa en un proceso de rápidos cambios.

  17. Estrategias de subsistencia en los momentos finales del Pleistoceno medio: el nivel XII de la Cova del Bolomor (La Valldigna, Valencia

    Directory of Open Access Journals (Sweden)

    Ruth BLASCO

    2009-08-01

    Full Text Available RESUMEN: La Cova del Bolomor, situada en Tavernes de la Valldigna (Valencia, ofrece uno de los mejores registros faunísticos de la segunda mitad del Pleistoceno medio de la Península Ibérica. La cavidad contiene un relleno sedimentario formado por diecisiete niveles estratigráficos que abarcan desde el OIS 9 al OIS 5e. Esta amplia secuencia cronológica permite abordar diferentes cuestiones relacionadas con los grupos humanos de este periodo y sus relaciones con el medio ambiente. Concretamente, a partir del estudio zooarqueológico del nivel XII (OIS 6, se ha reconstruido la secuencia antrópica de obtención y procesamiento de los recursos faunísticos. De este modo, se han identificado diferentes estrategias de subsistencia llevadas a cabo por los homínidos para la obtención de los animales. Estas técnicas van desde el carroñeo hasta la caza e incluyen el aprovisionamiento de pequeñas presas como las aves (Cygnus olor o los lepóridos (Oryctolagus cuniculus. Esta variabilidad de estrategias podría interpretarse como la gran capacidad de adaptación que poseen estos grupos humanos para aprovechar las oportunidades que el medio les ofrece. También se ha observado la existencia de patrones bien sistematizados tanto en el aprovechamiento de los recursos faunísticos externos (piel, carne, tendones como en la obtención de los recursos internos (médula. Muchos de los elementos diagnósticos que evidencian la fracturación antrópica en el nivel XII presentan cierta sistematización en zonas y partes anatómicas concretas. La existencia de morfologías repetidas en algunos elementos esqueléticos indica una cierta estandarización a la hora de fracturar los huesos. Esta reiteración podría implicar la existencia de mecanismos de aprendizaje o de transmisión de información intergrupal por parte de los grupos humanos del Pleistoceno medio final. En general, este estudio pretende aportar datos sobre las estrategias de subsistencia de

  18. Genetic analysis of a novel missense mutation (Gly542Ser) with factor XII deficiency in a Chinese patient of consanguineous marriage.

    Science.gov (United States)

    Zou, Anqing; Wang, Mingshan; Jin, Yanhui; Cheng, Xiaoli; Su, Kankan; Yang, Lihong

    2018-04-01

    Coagulation factor XII deficiency is a rare autosomal recessive disorder, which could be found in a consanguineous family. We studied a Chinese family in which the activated partial thromboplastin time (APTT) of the proband had clearly prolonged up to 101.7 s, associated with low FXII activity of 3% and FXII antigen software services were used to study the conservatism and effects of the mutation. A transient in vitro expression study was performed to elucidate the possible pathological mechanism. Sequence analysis revealed a homozygous c.1681 G > A point mutation in exon 14, causing a novel Gly542Ser mutation in the catalytic domain. The results of the conservatism and bioinformatics analyses both indicated that the mutation likely affects the function of the protein. Additional expression studies in COS-7 cells showed that the antigen level of mutant FXII (FXII-Gly542Ser) was lower than wild type in culture medium, whereas the corresponding level of FXII antigen in cell lysates was equivalent. These results suggest that the Gly542Ser mutation causes FXII deficiency through intracellular degradation.

  19. PEMBELAJARAN KIMIA UNSUR MENGGUNAKAN KONTEKS KEUNGGULAN LOKAL TAMBANG TIMAH DI PULAU BANGKA DAN PENGARUHNYA PADA LITERASI SAINS SISWA SMA KELAS XII

    Directory of Open Access Journals (Sweden)

    Yunisfu Yunisfu

    2014-10-01

    Full Text Available Penelitian ini bertujuan untuk mengembangkan pembelajaran kontekstual berbasis masalah menggunakan konteks keunggulan lokal tambang timah di Bangka pada materi kimia unsur, serta pengaruhnya terhadap literasi sains pada aspek konten, konteks aplikasi, proses, dan sikap sains siswa SMA. Metode yang digunakan dalam penelitian ini adalah kuasi eksperimen dengan “one group pretest-posttest design”. Subyek penelitian adalah 29 orang siswa kelas XII dari salah satu SMA di Kabupaten Bangka Tengah. Pengumpulan data dilakukan melalui tes pilihan ganda untuk mengukur kemampuan literasi sains siswa. Selain itu, penyebaran angket, lembar observasi, dan LKS juga dilakukan untuk mengukur keterlaksanaan pembelajaran. Hasil pengumpulan data tes selanjutnya dihitung dan dianalisis berdasarkan nilai N-Gain (%, sedangkan data non tes dianalisis secara deskriptif.  Hasil penelitian menunjukkan secara keseluruhan pembelajaran dapat meningkatkan literasi sains siswa dengan N-Gain (% sebesar 59,72% (kategori sedang, begitu juga pada tiap aspek literasi sains pada aspek konten (60,97%, aspek konteks aplikasi (58,83%, aspek proses (63,49% dan aspek sikap (62,65%, yang mengalami peningkatan pada kategori sedang. Secara umum siswa memberikan tanggapan positif terhadap pembelajaran kontekstual berbasis masalah. Kata kunci:   keunggulan lokal tambang timah, literasi sains, pembelajaran  berbasis  masalah, pembelajaran kontekstual

  20. PENERAPAN MODEL PEMBELAJARAN THINK PAIR SHARE DENGAN PENDEKATAN INKUIRI UNTUK MENINGKATKAN MOTIVASI DAN HASIL BELAJAR IPA PADA SISWA KELAS XII SMK

    Directory of Open Access Journals (Sweden)

    Beny Yulianingsih

    2017-01-01

    Penelitian ini bertujuan untuk meningkatkan motivasi dan hasil belajar siswa yang menggunakan model pembelajaran Think Pair Share (TPS dengan pendekatan inkuiri. Penelitian ini termasuk penelitian tindakan kelas yang dilaksanakan dalam dua siklus. Subjek penelitian adalah siswa kelas XII SMK NU Tenggarang Bondowoso tahun ajaran 2016/2017. Data penelitian diperoleh melalui observasi dan tes. Hasil penelitian menunjukkan terjadi peningkatan motivasi siswa dari siklus I ke siklus II sebesar 69,69% dengan rincian pada aspek attention sebesar 73,16% pada siklus I menjadi 92,53% pada siklus II, pada aspek relevance sebesar 79,20% pada siklus I menjadi 95,07% pada siklus II, pada aspek confidence sebesar 73,70% pada siklus I menjadi 89,40% pada siklus II, dan pada aspek satisfaction sebesar 72,69% pada siklus I menjadi 91,43% pada siklus II. Begitupula hasil belajar afektif yang diperoleh selama proses pembelajaran berlangsung juga mengalami peningkatan persentase yaitu 76,22% pada siklus I dan 83,67% pada siklus II. Untuk keterlaksanaan proses pembelajaran juga menunjukkan peningkatan dari 92,22% pada siklus 1 dan 95,66% pada siklus II. Dengan demikian, hasil ini menunjukkan bahwa model pembelajaran kooperatif TPS dengan pendekatan inkuiri dapat meningkatkan motivasi dan hasil belajar siswa.

  1. Preliminary report on AED deployment on the entire Air France commercial fleet: a joint venture with Paris XII University Training Programme.

    Science.gov (United States)

    Bertrand, C; Rodriguez Redington, P; Lecarpentier, E; Bellaiche, G; Michel, D; Teiger, E; Morris, W; Le Bourgeois, J P; Barthout, M

    2004-11-01

    The positive effect of early defibrillation on survival from cardiac arrest has been demonstrated. We describe the use of AEDs over 1 year following the training of flight attendants. Air France and the University of Paris XII together designed a 1 year training programme for 14000 flight attendants. The university emergency departments (SAMU) provided 250 instructors. AEDs training and certification was conducted for crew members between November 2001 and November 2002. By January 2003, all aircraft were fully equipped with AEDs. All cases of cardiac arrest that occurred during the study were reviewed comprehensively. Comments from the crew were collected. Twelve cardiac arrests were reported between November 2002 and November 2003 out of 4194 cases of emergency care delivered to passengers. Shock treatment was advised initially in 5/12 cases. The survival rate after in-flight cardiac arrest was 3/12. The survival rate at discharge from hospital following in flight shock was 2/5. No complications arose from the use of AEDs. Training by professionals gave the flight attendants confidence and allowed for the survival of two young passengers. Our study highlights the ability of flight attendants to give better onboard care for the future. The next step is to consolidate the network between in-flight care and the medical dispatch centre in Paris.

  2. Statistical mechanics of black holes

    International Nuclear Information System (INIS)

    Harms, B.; Leblanc, Y.

    1992-01-01

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black-hole decay and of quantum coherence are also addressed

  3. Over spinning a black hole?

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam; Cardoso, Vitor; Nerozzi, Andrea; Rocha, Jorge V, E-mail: mariam.bouhmadi@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt, E-mail: andrea.nerozzi@ist.utl.pt, E-mail: jorge.v.rocha@ist.utl.pt [CENTRA, Department de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

    2011-09-22

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for black holes in higher dimensions. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.

  4. Growth of Primordial Black Holes

    Science.gov (United States)

    Harada, Tomohiro

    Primordial black holes have important observational implications through Hawking evaporation and gravitational radiation as well as being a candidate for cold dark matter. Those black holes are assumed to have formed in the early universe typically with the mass scale contained within the Hubble horizon at the formation epoch and subsequently accreted mass surrounding them. Numerical relativity simulation shows that primordial black holes of different masses do not accrete much, which contrasts with a simplistic Newtonian argument. We see that primordial black holes larger than the 'super-horizon' primordial black holes have decreasing energy and worm-hole like struture, suggesting the formation through quamtum processes.

  5. BlackBerry For Dummies

    CERN Document Server

    Kao, Robert

    2010-01-01

    Get the most juice out of your BlackBerry handheld!. Feature-rich and complex, the BlackBerry is the number one smartphone in the corporate world is among the most popular handhelds for business users. This new and updated edition includes all the latest and greatest information on new and current BlackBerry mobile devices. Covering a range of valuable how-to topics, this helpful guide explores the BlackBerry's most useful features, techniques for getting the most out of your BlackBerry, and practical information about power usage.: Covers all aspects of the number one smartphone in the corpor

  6. f(R) Black holes

    OpenAIRE

    Moon, Taeyoon; Myung, Yun Soo; Son, Edwin J.

    2011-01-01

    We study the $f(R)$-Maxwell black hole imposed by constant curvature and its all thermodynamic quantities, which may lead to the Reissner-Nordstr\\"om-AdS black hole by redefining Newtonian constant and charge. Further, we obtain the $f(R)$-Yang-Mills black hole imposed by constant curvature, which is related to the Einstein-Yang-Mills black hole in AdS space. Since there is no analytic black hole solution in the presence of Yang-Mills field, we obtain asymptotic solutions. Then, we confirm th...

  7. Rotating black hole and quintessence

    International Nuclear Information System (INIS)

    Ghosh, Sushant G.

    2016-01-01

    We discuss spherically symmetric exact solutions of the Einstein equations for quintessential matter surrounding a black hole, which has an additional parameter (ω) due to the quintessential matter, apart from the mass (M). In turn, we employ the Newman-Janis complex transformation to this spherical quintessence black hole solution and present a rotating counterpart that is identified, for α = -e 2 ≠ 0 and ω = 1/3, exactly as the Kerr-Newman black hole, and as the Kerr black hole when α = 0. Interestingly, for a given value of parameter ω, there exists a critical rotation parameter (a = a E ), which corresponds to an extremal black hole with degenerate horizons, while for a < a E , it describes a nonextremal black hole with Cauchy and event horizons, and no black hole for a > a E . We find that the extremal value a E is also influenced by the parameter ω and so is the ergoregion. (orig.)

  8. Internal structure of black holes

    International Nuclear Information System (INIS)

    Cvetic, Mirjam

    2013-01-01

    Full text: We review recent progress that sheds light on the internal structure of general black holes. We first summarize properties of general multi-charged rotating black holes both in four and five dimensions. We show that the asymptotic boundary conditions of these general asymptotically flat black holes can be modified such that a conformal symmetry emerges. These subtracted geometries preserve the thermodynamic properties of the original black holes and are of the Lifshitz type, thus describing 'a black hole in the asymptotically conical box'. Recent efforts employ solution generating techniques to construct interpolating geometries between the original black hole and their subtracted geometries. Upon lift to one dimension higher, these geometries lift to AdS 3 times a sphere, and thus provide a microscopic interpretation of the black hole entropy in terms of dual two-dimensional conformal field theory. (author)

  9. The transillumination technique as a method for the assessment of spermatogenesis using medicinal plants: the effect of extracts of black maca (Lepidium meyenii) and camu camu (Myrciaria dubia) on stages of the spermatogenic cycle in male rats.

    Science.gov (United States)

    Gonzales, Gustavo F; Vasquez, Vanessa Bertha; Gasco, Manuel

    2013-10-01

    Transillumination technique for assessment of stages of spermatogenic cycle is a useful tool for toxicological studies. This study was designed to determine the effect of two medicinal plants on spermatogenesis in male rats using the transillumination technique. For this, the effect of the combination of a fruit with highest content of ascorbic acid (Myrciaria dubia, camu camu) and extract of black maca (Lepidium meyenii) on seminiferous tubule stages scored by transillumination on intact tubules in adult male rats was assessed. Animals were treated during seven days with vehicle, black maca, camu camu or a mixture of black maca + camu camu and assessed for daily sperm production (DSP), stages of spermatogenic cycle as well as antioxidant activity and levels of flavonoids and polyphenols. Black maca increased stages of spermiation (VII-VIII) and mitosis of germ cells (IX-XI), whereas camu camu increased stages of mitosis (IX-XI) and meiosis (XII). Mixture of maca + camu camu increased stages of spermiation, mitosis and meiosis. All treatments increased DSP (p<0.05) and epididymal sperm count (p<0.05). Total polyphenols, flavonoids levels and antioxidant activity were higher in camu camu (p<0.001) than in black maca. In conclusion, M. dubia (camu camu) has potential effects improving spermatogenesis and co-administered with maca increase stages of mitosis, meiosis and spermiation of the spermatogenic cycle as assessed by the transillumination technique. This technique is becoming increasingly a useful tool for assessment spermatogenesis.

  10. Caged black holes: Black holes in compactified spacetimes. I. Theory

    International Nuclear Information System (INIS)

    Kol, Barak; Sorkin, Evgeny; Piran, Tsvi

    2004-01-01

    In backgrounds with compact dimensions there may exist several phases of black objects including a black hole and a black string. The phase transition between them raises questions and touches on fundamental issues such as topology change, uniqueness, and cosmic censorship. No analytic solution is known for the black hole, and moreover one can expect approximate solutions only for very small black holes, while phase transition physics happens when the black hole is large. Hence we turn to numerical solutions. Here some theoretical background to the numerical analysis is given, while the results will appear in a subsequent paper. The goals for a numerical analysis are set. The scalar charge and tension along the compact dimension are defined and used as improved order parameters which put both the black hole and the black string at finite values on the phase diagram. The predictions for small black holes are presented. The differential and the integrated forms of the first law are derived, and the latter (Smarr's formula) can be used to estimate the 'overall numerical error'. Field asymptotics and expressions for physical quantities in terms of the numerical values are supplied. The techniques include the 'method of equivalent charges', free energy, dimensional reduction, and analytic perturbation for small black holes

  11. Asymmetric black dyonic holes

    Directory of Open Access Journals (Sweden)

    I. Cabrera-Munguia

    2015-04-01

    Full Text Available A 6-parametric asymptotically flat exact solution, describing a two-body system of asymmetric black dyons, is studied. The system consists of two unequal counterrotating Kerr–Newman black holes, endowed with electric and magnetic charges which are equal but opposite in sign, separated by a massless strut. The Smarr formula is generalized in order to take into account their contribution to the mass. The expressions for the horizon half-length parameters σ1 and σ2, as functions of the Komar parameters and of the coordinate distance, are displayed, and the thermodynamic properties of the two-body system are studied. Furthermore, the seven physical parameters satisfy a simple algebraic relation which can be understood as a dynamical scenario, in which the physical properties of one body are affected by the ones of the other body.

  12. Forging a Black identity

    Directory of Open Access Journals (Sweden)

    Barry Chevannes

    1992-07-01

    Full Text Available [First paragraph] The Rastafarians: sounds of cultural dissonance [revised and updated editionj. LEONARD E. BARRETT, SR. Boston: Beacon Press, 1988. xviii + 302 pp. (Paper US$ 11.95 Rasta and resistance: from Marcus Garvey to Walter Rodney. HORACE CAMPBELL. Trenton NJ: Africa World Press, 1987. xiii + 236 pp. (Cloth US$32.95, Paper US$ 10.95 Garvey's children: the legacy of Marcus Garvey. TONY SEWELL. London: Macmillan Caribbean, 1990. 128 pp. (Paper £ 17.95 The central theme linking these three titles is the evolution of a black identity among English-speaking Caribbean peoples, in particular Jamaicans. Consequently all three authors cover the two most important historical phenomena in Caribbean black nationalism, namely Garveyism and Rastafari, one focusing on the former and the other two focusing on the latter.

  13. Black Holes and Firewalls

    Science.gov (United States)

    Polchinski, Joseph

    2015-04-01

    Our modern understanding of space, time, matter, and even reality itself arose from the three great revolutions of the early twentieth century: special relativity, general relativity, and quantum mechanics. But a century later, this work is unfinished. Many deep connections have been discovered, but the full form of a unified theory incorporating all three principles is not known. Thought experiments and paradoxes have often played a key role in figuring out how to fit theories together. For the unification of general relativity and quantum mechanics, black holes have been an important arena. I will talk about the quantum mechanics of black holes, the information paradox, and the latest version of this paradox, the firewall. The firewall points to a conflict between our current theories of spacetime and of quantum mechanics. It may lead to a new understanding of how these are connected, perhaps based on quantum entanglement.

  14. Mobilizing Black America

    Science.gov (United States)

    1992-04-01

    or just for a walk in the park. They offer an ear if the youngster simply needs someone to talk to. When it comes to a discussion of economic...neighborhoods and making it unsafe for decent people to walk the streets. One method that several schools have used to support the community in this...children with their studies. By their very presence these men show that education is not sissy .’ 3 6 Once we have succeeded in keeping black Americans

  15. Beyond the black hole

    International Nuclear Information System (INIS)

    Boslough, J.

    1985-01-01

    This book is about the life and work of Stephen Hawking. It traces the development of his theories about the universe and particularly black holes, in a biographical context. Hawking's lecture 'Is the end in sight for theoretical physics' is presented as an appendix. In this, he discusses the possibility of achieving a complete, consistent and unified theory of the physical interactions which would describe all possible observations. (U.K.)

  16. Black Sea challenges

    International Nuclear Information System (INIS)

    Drevet, J.F.

    2008-01-01

    In this month's European column, Jean-Francois Drevet examines the issues that arise for Europe from the Black Sea region. The Black Sea is increasingly becoming a crucial place of transit for hydrocarbon imports from the Caspian and Russia into the European Union. The considerable increase in this traffic raises both environmental problems (the risk of oil slicks) and issues of security of supply, on account of the economic and political fragility of some of the bordering or neighbouring states (Ukraine, Georgia, Armenia, Azerbaijan, Russia/Chechnya etc.). This is why, as Jean-Francois Drevet stresses, the European Union has been trying since the mid-1990's to claim a role in the management of the affairs of the region. With two bordering states (Rumania and Bulgaria) joining the EU in 2007, cooperation in the Black Sea has become a priority within the framework of the European Neighbourhood Policy, and this column delineates a number of the obstacles that still have to be surmounted. (author)

  17. Black silicon solar cells with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by maskless reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Four different methods to obtain blackened bus-bar strings were compared with respect to reflectance, and two of these methods (i.e., oxidized copper and etched solder) were used to fabricate functional allblack solar 9-cell panels. The black bus-bars (e.......g., by oxidized copper) have a reflectance below 3% in the entire visible wavelength range. The combination of black silicon cells and blackened bus-bars results in aesthetic, all-black panels based on conventional, front-contacted solar cells without compromising efficiency....

  18. Black Swan Tropical Cyclones

    Science.gov (United States)

    Emanuel, K.; Lin, N.

    2012-12-01

    Virtually all assessments of tropical cyclone risk are based on historical records, which are limited to a few hundred years at most. Yet stronger TCs may occur in the future and at places that have not been affected historically. Such events lie outside the realm of historically based expectations and may have extreme impacts. Their occurrences are also often made explainable after the fact (e.g., Hurricane Katrina). We nickname such potential future TCs, characterized by rarity, extreme impact, and retrospective predictability, "black swans" (Nassim Nicholas Taleb, 2007). As, by definition, black swan TCs have yet to happen, statistical methods that solely rely on historical track data cannot predict their occurrence. Global climate models lack the capability to predict intense storms, even with a resolution as high as 14 km (Emanuel et al. 2010). Also, most dynamic downscaling methods (e.g., Bender et al. 2010) are still limited in horizontal resolution and are too expensive to implement to generate enough events to include rare ones. In this study, we apply a simpler statistical/deterministic hurricane model (Emanuel et al. 2006) to simulate large numbers of synthetic storms under a given (observed or projected) climate condition. The method has been shown to generate realistic extremes in various basins (Emanuel et al. 2008 and 2010). We also apply a hydrodynamic model (ADCIRC; Luettich et al. 1992) to simulate the storm surges generated by these storms. We then search for black swan TCs, in terms of the joint wind and surge damage potential, in the generated large databases. Heavy rainfall is another important TC hazard and will be considered in a future study. We focus on three areas: Tampa Bay in the U.S., the Persian Gulf, and Darwin in Australia. Tampa Bay is highly vulnerable to storm surge as it is surrounded by shallow water and low-lying lands, much of which may be inundated by a storm tide of 6 m. High surges are generated by storms with a broad

  19. Black holes in realistic branes: Black string-like objects?

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Instituto de Física, Universidade de São Paulo, 05314-970, São Paulo, SP (Brazil); Departamento de Física, Universidade Federal da Paraíba, 58051-970, João Pessoa, PB (Brazil); Hoff da Silva, J.M., E-mail: hoff@feg.unesp.br [Departamento de Física e Química, Universidade Estadual Paulista, Av. Dr. Ariberto Pereira da Cunha, 333, Guaratinguetá, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC (UFABC), 09210-170, Santo André, SP (Brazil)

    2013-04-25

    A realistic model describing a black string-like object in an expanding Universe is analyzed in the context of the McVittie's solution of the Einstein field equations. The bulk metric near the brane is provided analogously to previous solutions for black strings. In particular, we show that at least when the Hubble parameter on the brane is positive, a black string-like object seems to play a fundamental role in the braneworld scenario, generalizing the standard black strings in the context of a dynamical brane.

  20. L'autografia d'autore Cambiamenti nella realizzazione e nella concezione del libro dal XII secolo all'invenzione della stampa

    Directory of Open Access Journals (Sweden)

    Micol Long

    2012-06-01

    Full Text Available Si ritiene a volte che l'invenzione della stampa abbia innescato il cambiamento nel modo di concepire l'oggetto libro, segnando il passaggio dall'idea medievale a quella moderna. Occorre però tenere presente che esiste un'importante evoluzione interna al medioevo e che l'invenzione della stampa, per quanto fondamentale, è da inserire all'interno di questo processo più ampio, che a partire dal XII secolo circa trasforma l'uso e la funzione stessa della scrittura, rivoluziona il modo di leggere e di conseguenza il libro stesso, sia concettualmente sia come oggetto fisico. L'approccio scelto per questo studio mira a risalire alle radici culturali dei cambiamenti nelle pratiche del lavoro intellettuale e, viceversa, a indagare se e come tali cambiamenti abbiano potuto influenzare, attraverso le opere stesse, la cultura dell'epoca. Il fenomeno oggetto specifico dell'indagine è l'autografia letteraria d'autore che, eccezionale nell'alto medioevo, è testimoniata da una nuova e ininterrotta serie di casi a partire dall'XI-XII secolo, per poi diffondersi nei secoli successivi. Il panorama culturale della fine del medioevo appare dunque caratterizzato dalla tensione tra una ricorrente aspirazione all'individualizzazione del rapporto tra l'autore e il suo testo, che si realizzava in un modello di produzione libraria basato su uno stretto controllo dell'autore sul prodotto finale, dal punto di vista sia filologico-testuale sia grafico e materiale, e l'opposta tendenza all'allentamento del controllo dell'autore sulla propria opera, come naturale conseguenza di una sempre più vasta circolazione dei testi ma anche di una diversa concezione del ruolo autoriale. It is generally believed that the invention of printing triggered a cultural change, marking the passage between the medieval idea of the book and the modern one. It should be noted, though, that there was an important evolution through the Late Middle Ages, and that the printing revolution

  1. 77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

    Science.gov (United States)

    2012-11-26

    ... Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of..., 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor) and Black Bear Development Holdings, LLC and Black Bear SO, LLC (transferees) filed an application for the partial the transfer of licenses...

  2. Black Father Involvement in Gifted Education: Thoughts from Black Fathers on Increasing/Improving Black Father-Gifted Teacher Partnerships

    Science.gov (United States)

    Grantham, Tarek C.; Henfield, Malik S.

    2011-01-01

    Black fathers are important advocates in addressing the underrepresentation of Black students in gifted programs, as well as the achievement gaps between Black and White students. Black fathers increasingly understand the important role that Black mothers have traditionally played in supporting their gifted children's school experiences. As a…

  3. Las mujeres nobles y el poder en los reinos de León y Castilla en el siglo XII: un estudio preliminar

    Directory of Open Access Journals (Sweden)

    Simon BARTON

    2012-03-01

    Full Text Available El presente artículo analiza hasta qué punto las mujeres pertenecientes a la aristocracia eran capaces de ostentar el poder y ejercer su influencia en el ámbito de los reinos de León y Castilla durante el siglo XII. Pese a ser cierto que el acceso de las mujeres nobles al poder y al ejercicio de influencias se encontraba limitado por cuestiones de género, lo cual implicaba que se encontraban prácticamente excluidas de determinadas esferas de actividad relevantes, tales como la pertenencia a la curia real, estas mujeres estaban lejos de ser meras víctimas pasivas del dominio masculino, como a menudo se ha supuesto. Gracias a sus considerables recursos económicos, que administraban a través de las instituciones entrelazadas del señorío y la familia, y a su estrecha relación con la Iglesia, dichas mujeres estaban capacitadas para desempeñar papeles destacados en el ámbito público y ejercer un grado importante de poder y autoridad en su paso por el ciclo vital que iba desde el matrimonio hasta la viudedad. Dicho papel público no necesariamente se volvía más limitado tras la muerte del marido; si acaso, ganaba importancia, ya que las madres continuaban ofreciendo su apoyo a sus hijos y ejercían el mecenazgo, especialmente el religioso, a una escala sin precedentes.

  4. Black Hole's 1/N Hair

    CERN Document Server

    Dvali, Gia

    2013-01-01

    According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

  5. Quantum effects in black holes

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1979-01-01

    A strict definition of black holes is presented and some properties with regard to their mass are enumerated. The Hawking quantum effect - the effect of vacuum instability in the black hole gravitational field, as a result of shich the black hole radiates as a heated body is analyzed. It is shown that in order to obtain results on the black hole radiation it is sufficient to predetermine the in-vacuum state at a time moment in the past, when the collapsing body has a large size, and its gravitational field can be neglected. The causes and the place of particle production by the black hole, and also the space-time inside the black hole, are considered

  6. Particle creation by black holes

    International Nuclear Information System (INIS)

    Hawking, S.W.

    1975-01-01

    In the classical theory black holes can only absorb and not emit particles. However it is shown that quantum mechanical effects cause black holes to create and emit particles. This thermal emission leads to a slow decrease in the mass of the black hole and to its eventual disappearance: any primordial black hole of mass less than about 10 15 g would have evaporated by now. Although these quantum effects violate the classical law that the area of the event horizon of a black hole cannot decrease, there remains a Generalized Second Law: S + 1/4 A never decreases where S is the entropy of matter outside black holes and A is the sum of the surface areas of the event horizons. This shows that gravitational collapse converts the baryons and leptons in the collapsing body into entropy. It is tempting to speculate that this might be the reason why the Universe contains so much entropy per baryon. (orig.) [de

  7. Origin of supermassive black holes

    OpenAIRE

    Dokuchaev, V. I.; Eroshenko, Yu. N.; Rubin, S. G.

    2007-01-01

    The origin of supermassive black holes in the galactic nuclei is quite uncertain in spite of extensive set of observational data. We review the known scenarios of galactic and cosmological formation of supermassive black holes. The common drawback of galactic scenarios is a lack of time and shortage of matter supply for building the supermassive black holes in all galaxies by means of accretion and merging. The cosmological scenarios are only fragmentarily developed but propose and pretend to...

  8. Destroying extremal magnetized black holes

    Science.gov (United States)

    Siahaan, Haryanto M.

    2017-07-01

    The gedanken experiment by Wald to destroy a black hole using a test particle in the equatorial plane is adapted to the case of extremal magnetized black holes. We find that the presence of external magnetic fields resulting from the "Ernst magnetization" permits a test particle to have strong enough energy to destroy the black hole. However, the corresponding effective potentials show that such particles would never reach the horizon.

  9. A Tale of Two O's: Odysseus and Oedipus in the Black Atlantic

    Directory of Open Access Journals (Sweden)

    Emily Greenwood

    2009-12-01

    Full Text Available [First paragraphs] Crossroads in the Black Aegean: Oedipus, Antigone, and Dramas of the African Diaspora. Barbara Goff & Michael Simpson. Oxford: Oxford University Press, 2007. xii + 401 pp. (Cloth US$ 150.00 Romare Bearden: A Black Odyssey. Robert G. O’Meally. New York: DC Moore Gallery, 2007. 116 pp. (Cloth$ 45.00 Commenting on cultural imperialism under European colonialism, Frantz Fanon (1990:39 remarked that “The settler makes history; his life is an epoch, an Odyssey.” In Fanon’s analysis the settler’s sense of history derived from the history of the “mother country,” rather than the history of the colony that he or she inhabited. But history did not stop here: the reference to the Odyssey reminds us that behind the modern colonial metropolis was a fictional line of descent reaching back to a Greco-Roman cradle, such that the European settler could lay claim to an even more ancient cultural inheritance. The two books examined here make short work of these classical imperial fictions; O’Meally demonstrates how Romare Bearden’s collages of the Odyssey collaborate with Homer, jazz style, to produce an epic that Black America can recognize as its own. If the voyage of Odysseus is sometimes taken to symbolize the migration of ancient Greek civilization toward the West, Barbara Goff and Michael Simpson interject the troubled figure of Oedipus, who plays Poseidon to the settler’s Odyssey, disrupting the voyage and confusing the trajectory (p. 268. Both studies are timely and speak to a wave of recent research on Black Classicism – an examination of the work to which the classical tradition has been put in Africa and the African diaspora, ranging from the hegemonic appropriation of Classics by colonizers and slave-owners to the use of Classics as an ironic counterdiscourse that writes back to racism and imperialism, or as a source of mythopoiesis in the formation of modern black identity.

  10. Statistical Hair on Black Holes

    International Nuclear Information System (INIS)

    Strominger, A.

    1996-01-01

    The Bekenstein-Hawking entropy for certain BPS-saturated black holes in string theory has recently been derived by counting internal black hole microstates at weak coupling. We argue that the black hole microstate can be measured by interference experiments even in the strong coupling region where there is clearly an event horizon. Extracting information which is naively behind the event horizon is possible due to the existence of statistical quantum hair carried by the black hole. This quantum hair arises from the arbitrarily large number of discrete gauge symmetries present in string theory. copyright 1996 The American Physical Society

  11. On black hole horizon fluctuations

    International Nuclear Information System (INIS)

    Tuchin, K.L.

    1999-01-01

    A study of the high angular momentum particles 'atmosphere' near the Schwarzschild black hole horizon suggested that strong gravitational interactions occur at invariant distance of the order of 3 √M [2]. We present a generalization of this result to the Kerr-Newman black hole case. It is shown that the larger charge and angular momentum black hole bears, the larger invariant distance at which strong gravitational interactions occur becomes. This invariant distance is of order 3 √((r + 2 )/((r + - r - ))). This implies that the Planckian structure of the Hawking radiation of extreme black holes is completely broken

  12. Black holes and the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Garriga, Jaume [Departament de Fisica Fonamental i Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti i Franques, 1, Barcelona, 08028 Spain (Spain); Vilenkin, Alexander; Zhang, Jun, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: jun.zhang@tufts.edu [Institute of Cosmology, Tufts University, 574 Boston Ave, Medford, MA, 02155 (United States)

    2016-02-01

    Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleating during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse.

  13. Thermodynamics of Accelerating Black Holes.

    Science.gov (United States)

    Appels, Michael; Gregory, Ruth; Kubizňák, David

    2016-09-23

    We address a long-standing problem of describing the thermodynamics of an accelerating black hole. We derive a standard first law of black hole thermodynamics, with the usual identification of entropy proportional to the area of the event horizon-even though the event horizon contains a conical singularity. This result not only extends the applicability of black hole thermodynamics to realms previously not anticipated, it also opens a possibility for studying novel properties of an important class of exact radiative solutions of Einstein equations describing accelerated objects. We discuss the thermodynamic volume, stability, and phase structure of these black holes.

  14. Braneworld Black Hole Gravitational Lensing

    International Nuclear Information System (INIS)

    Liang Jun

    2017-01-01

    A class of braneworld black holes, which I called as Bronnikov–Melnikov–Dehen (BMD) black holes, are studied as gravitational lenses. I obtain the deflection angle in the strong deflection limit, and further calculate the angular positions and magnifications of relativistic images as well as the time delay between different relativistic images. I also compare the results with those obtained for Schwarzschild and two braneworld black holes, i.e., the tidal Reissner-Nordström (R-N) and the Casadio–Fabbri–Mazzacurati (CFM) black holes. (paper)

  15. Black report up-date

    International Nuclear Information System (INIS)

    1988-12-01

    In 1984, the Black Report published its results on the incidence of cancer and leukaemia in under 25-year olds in the village of Seascale and the surrounding area near the Sellafield nuclear reprocessing plant. Since then the pressure group core, as a result of their own independent research, has discovered ten additional cases of childhood cancer which should have been included in the Black Report and a Further two cases since the Black Report was written. This represents an additional 31% over the initial numbers considered and a review of the Black Report is sought. (UK)

  16. How black holes saved relativity

    Science.gov (United States)

    Prescod-Weinstein, Chanda

    2016-02-01

    While there have been many popular-science books on the historical and scientific legacy of Albert Einstein's general theory of relativity, a gap exists in the literature for a definitive, accessible history of the theory's most famous offshoot: black holes. In Black Hole, the science writer Marcia Bartusiak aims for a discursive middle ground, writing solely about black holes at a level suitable for both high-school students and more mature readers while also giving some broader scientific context for black-hole research.

  17. Nariai black holes with quintessence

    OpenAIRE

    Fernando, Sharmanthie

    2014-01-01

    In this paper we study the properties of Schwarzschild black hole surrounded by quintessence matter. The main objective of the paper is to show the existence of Nariai type black hole for special values of the parameters in the theory. The Nariai black hole with the quintessence has the topology $dS_2 \\times S_2$ with $dS_2$ with a different scalar curvature than what would be expected for the Schwarzschild-de Sitter degenerate black hole. Temperature and the entropy for the Schwarzschild-de ...

  18. Children's Reactions to T.V. Blacks

    Science.gov (United States)

    Greenberg, Bradley S.

    1972-01-01

    An assessment of the frequency of exposure of young children, both black and white, to TV series which regularly featured blacks, degree of identification with black performers, attitudes towards blacks on TV and blacks outside of television, among other behaviors. (Author/JM)

  19. Artificial black holes

    CERN Document Server

    Visser, Matt; Volovik, Grigory E

    2009-01-01

    Physicists are pondering on the possibility of simulating black holes in the laboratory by means of various "analog models". These analog models, typically based on condensed matter physics, can be used to help us understand general relativity (Einstein's gravity); conversely, abstract techniques developed in general relativity can sometimes be used to help us understand certain aspects of condensed matter physics. This book contains 13 chapters - written by experts in general relativity, particle physics, and condensed matter physics - that explore various aspects of this two-way traffic.

  20. Magnonic Black Holes.

    Science.gov (United States)

    Roldán-Molina, A; Nunez, Alvaro S; Duine, R A

    2017-02-10

    We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons-the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.

  1. Thermal BEC Black Holes

    Directory of Open Access Journals (Sweden)

    Roberto Casadio

    2015-10-01

    Full Text Available We review some features of Bose–Einstein condensate (BEC models of black holes obtained by means of the horizon wave function formalism. We consider the Klein–Gordon equation for a toy graviton field coupled to a static matter current in a spherically-symmetric setup. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with a continuous occupation number. An attractive self-interaction is needed for bound states to form, the case in which one finds that (approximately one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The horizon wave function formalism is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons, resulting in agreement with the semiclassical calculations and which does not hold for a single very massive particle. The spectrum of these systems has two components: a discrete ground state of energy m (the bosons forming the black hole and a continuous spectrum with energy ω > m (representing the Hawking radiation and modeled with a Planckian distribution at the expected Hawking temperature. Assuming the main effect of the internal scatterings is the Hawking radiation, the N-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy M = Nm and Entropy 2015, 17 6894 a Planckian distribution for E > M at the same Hawking temperature. This can be used to compute the partition function and to find the usual area law for the entropy, with a logarithmic correction related to the Hawking component. The backreaction of modes with ω > m is also shown to reduce

  2. Drifting black aurorae?

    International Nuclear Information System (INIS)

    Schoute-Vanneck, H.; Scourfield, M.W.J.; Nielsen, E.

    1990-01-01

    Characteristics of eastward drifting forms, previously described in the literature as black aurorae, have been identified in low-light level TV camera data. The TV field of view was within the field of view of STARE and that of an all-sky camera. On the basis of these observations the authors propose that these auroral forms are a manifestation of folds or waves on the borders of auroral bands propagating along the dark regions between neighboring auroral bands. Conditions under which the folds or waves occur are compatible with their formation by the Kelvin-Helmholtz electrostatic instability

  3. Black lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Ramani, R.V.; Frantz, R.L. [Pennsylvania State University, University Park, PA (United States)

    1995-12-31

    Coal workers` pneumoconiosis (CWP), often called Black Lung Disease is a occupational disease which results from inhalation of coal mine dust which usually contains small amounts of free crystalline silica. This chapter reviews the current knowledge of the epidemiology and clinical aspects of CWP and how it has been controlled in the USA through the 1969 Coal Mine Act and dust level standards. It describes the sampling methods used. Medical control methods and engineering control of the disease is discussed. Work of the Generic Mineral Technology Center for Respirable Dust is described. 28 refs., 6 figs.

  4. CORRELATION OF INTEREST TO LEARN AND USE TIME LEARNING WITH LEARNING ACHIEVEMENT AUTOMOTIVE ELECTRICAL IN CLASS XII LIGHT VEHICLE ENGINEERING SMK PIRI I YOGYAKARTA ACADEMIC YEAR 2013/2014

    Directory of Open Access Journals (Sweden)

    Ari Pujiatmoko

    2014-06-01

    Full Text Available The purpose of this study were: 1 to determine whether there is a correlation between students' interest in learning and the learning achievement of automotive electrical, 2 to determine whether there is a correlation between the use of time studying the learning achievement of automotive electrical, 3 to determine whether there is a correlation between student interest and use the time to learn and the learning achievement of students of class XII automotive electrical TKR SMK PIRI 1 Yogyakarta academic year 2013/2014.  This research was conducted in class XII TKR SMK PIRI 1 Yogyakarta academic year 2013/2014. This study is an ex-post facto. This study used two independent variables and the interest in learning the use of learning time, while the dependent variable is the electrical automotive learning achievement. This study is a population study by the respondent amounted to 100 students. Techniques of data collection using questionnaire techniques and engineering documentation. Research instrument in this study is a questionnaire interest in learning, inquiry learning time management and documentation of student achievement. Trials using the instrument validity and reliability test. The analysis technique used is the prerequisite test for normality, linearity, and multicollinearity. Then test hypotheses using partial correlation analysis techniques and correlation.  The results showed that: 1 students' interest to have a strong positive correlation with school performance automotive electrical ρ value of 0.737; 2 the use of learning time have a low positive correlation with school performance automotive electrical ρ value of 0.275; 3 interest student learning and the use of study time has a very strong positive correlation with learning achievement of students of class XII automotive electrical TKR SMK PIRI I Yogyakarta academic year 2013/2014 as evidenced by the value of R = 0.811.

  5. ESTUDIOS METODOLÓGICOS DEL EFECTO DEL REGADÍO SOBRE LA CALIDAD DE LAS AGUAS DE LAS MASAS ASOCIADAS A UNA ZONA REGABLE: EL CASO DEL SECTOR B-XII DE LA ZONA REGABLE DEL BAJO GADALQUIVIR

    OpenAIRE

    Martínez Beltrán, J.

    2015-01-01

    [ES] El objeto del estudio ha sido determinar los efectos de la agricultura de regadío del Sector B-XII en la detracción de agua del Guadalquivir y en los contenidos de sales y nitratos de sus aguas en el tramo asociado a este sector, así como en el agua subterránea subyacente. La dotación de agua asignada en la campaña 2012-2013 ha sido inferior a la calculada para satisfacer las necesidades de agua de riego de los cultivos y el control de la salinidad de los suelos. La detrac...

  6. AN ANALYSIS OF STUDENTS’ ABILITY IN USING SUB-ORDINATE CONJUNCTION IN SENTENCE WRITING OF THE GRADE XII STUDENTS OF SMA N 2 METRO ACADEMIC YEAR 2013/2014

    OpenAIRE

    Bambang Eko Siagianto

    2017-01-01

    Abstracts: Sub-ordinate conjunction is very confusing to comprehend by students. In using sub-ordinate conjunction, students usually had errors. The purpose of this research to analyze whether or not the students are able to use sub-ordinate conjunction in sentence writing, to classify kinds of sub-ordinate conjunction that was often misused by students in sentence writing The research was done at the grade XII of SMA N 2 Metro in second semester of the academic year 2013/2014. The predicted ...

  7. Estado nutricional y rendimiento académico en estudiantes de educación media de los colegios IPARM (Universidad Nacional de Colombia-sede Bogotá) y Pío XII (Municipio de Guatavita)

    OpenAIRE

    Ramírez de Peña, Doris Amanda

    2014-01-01

    El objetivo fue establecer la relación entre el estado nutricional y el rendimiento académico de estudiantes de educación media (15 a 17 años) de los colegios IPARM de Bogotá, Universidad Nacional, y Departamental Pio XII de Guatavita. El diseño del estudio es descriptivo transeccional correlacional. Se tomaron mediciones de peso, talla, grasa corporal, masa muscular y los datos de las calificaciones de matemáticas y lenguaje, así como los puntajes de las pruebas SABER. Los estudiantes con gr...

  8. Black American and Nigerian Pentecostalism: A Black Religious ...

    African Journals Online (AJOL)

    Black American and Nigerian Pentecostalism: A Black Religious Schizophrenia, 1910-2010. ... in American and African Pentecostalism as is related to social crisis, the dislocation of masses brought on by economic deprivation, urbanization, the break up of traditional society and consequence loss of traditional values.

  9. Black Interpretation, Black American Literature, and Grey Audiences.

    Science.gov (United States)

    Washington, Earl M.

    1981-01-01

    Defines and illustrates language techniques used by Black authors writing to and for Blacks in the 1960s and 1970s. Suggests how language and theme barriers of such literature might be overcome in a contemporary integrated oral interpretation classroom. (PD)

  10. Black holes and holography

    International Nuclear Information System (INIS)

    Mathur, Samir D

    2012-01-01

    The idea of holography in gravity arose from the fact that the entropy of black holes is given by their surface area. The holography encountered in gauge/gravity duality has no such relation however; the boundary surface can be placed at an arbitrary location in AdS space and its area does not give the entropy of the bulk. The essential issues are also different between the two cases: in black holes we get Hawking radiation from the 'holographic surface' which leads to the information issue, while in gauge/gravity duality there is no such radiation. To resolve the information paradox we need to show that there are real degrees of freedom at the horizon of the hole; this is achieved by the fuzzball construction. In gauge/gravity duality we have instead a field theory defined on an abstract dual space; there are no gravitational degrees of freedom at the holographic boundary. It is important to understand the relations and differences between these two notions of holography to get a full understanding of the lessons from the information paradox.

  11. Area spectrum of slowly rotating black holes

    OpenAIRE

    Myung, Yun Soo

    2010-01-01

    We investigate the area spectrum for rotating black holes which are Kerr and BTZ black holes. For slowly rotating black holes, we use the Maggiore's idea combined with Kunstatter's method to derive their area spectra, which are equally spaced.

  12. Teaching Black History after Obama

    Science.gov (United States)

    Sotiropoulos, Karen

    2017-01-01

    This article is a reflection on the teaching of black history after the Obama presidency and at the dawn of the Trump era. It is both an analysis of the state of the academic field and a primer on how to integrate the past few decades of scholarship in black history broadly across standard K-12 curriculum. It demonstrates the importance of…

  13. Black Holes in Our Universe

    Indian Academy of Sciences (India)

    most sensitive scientific instrument ever ... sion, expelling a lot of the mass, but leaving behind a black hole that is at least ... hole, and indeed such a phenomenon may explain the disappear- ance of a star in the galaxy N6946 [21]. The collapse of stars into black holes might account for some of the extraordinarily powerful ...

  14. COMPOSITION OF BLACK BEAR MILK.

    Science.gov (United States)

    An analysis of black bear ( Ursus americanus Pallas) milk showed that the total solids, fat and protein were much higher and the lactose lower than...either cow or human milk. In comparison with polar bear (Thalarcotos maritimus ), the black bear milk was lower in fat, protein and total calories. (Author)

  15. Black Component of Dark Matter

    Directory of Open Access Journals (Sweden)

    A. V. Grobov

    2014-01-01

    Full Text Available A mechanism of primordial black hole formation with specific mass spectrum is discussed. It is shown that these black holes could contribute to the energy density of dark matter. Our approach is elaborated in the framework of universal extra dimensions.

  16. Black Holes in Our Universe

    Indian Academy of Sciences (India)

    was discovered in the constellation Cygnus; a bright X-ray emit- ter associated with a twin-star system, and christened Cygnus X-. 1. It has a massive star and a black hole orbiting each other. With an optical telescope it is the companion star of the black hole which is visible, which produces stellar winds blowing away from.

  17. Black holes and quantum mechanics

    NARCIS (Netherlands)

    t Hooft, G.|info:eu-repo/dai/nl/074127888

    2010-01-01

    After a brief review of quantum black hole physics, it is shown how the dynamical properties of a quantum black hole may be deduced to a large extent from Standard Model Physics, extended to scales near the Planck length, and combined with results from perturbative quantum gravity. Together, these

  18. Black-Hole Mass Measurements

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2004-01-01

    The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized.......The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized....

  19. ATLAS simulated black hole event

    CERN Multimedia

    Pequenão, J

    2008-01-01

    The simulated collision event shown is viewed along the beampipe. The event is one in which a microscopic-black-hole was produced in the collision of two protons (not shown). The microscopic-black-hole decayed immediately into many particles. The colors of the tracks show different types of particles emerging from the collision (at the center).

  20. Motor neuron disease in blacks

    African Journals Online (AJOL)

    1989-08-19

    Aug 19, 1989 ... A series of 86 black, Indian and white patients with motor neuron disease were analysed retrospectively. Although the material does not allow statistically valid conclusions, there are sufficient cases among blacks to allow two prima facie observations in this population group: (~ motor neuron disease.

  1. Black Music: A Financial Perspective.

    Science.gov (United States)

    Ashburne, Michael R.

    1977-01-01

    The financial relationships among artists, record companies, and music publishers in the recording industry are examined. It is shown that, although Black talent in the recording field has produced millions of dollars annually since the turn of the century, Black artists have been grossly underpaid. (Author/GC)

  2. Resource recovery from black water

    NARCIS (Netherlands)

    Graaff, de M.S.

    2010-01-01

    New sanitation systems based on separation at source offer a large potential for resource recovery from wastewater, e.g. energy and nutrients from black water and irrigation water from grey water. This review focuses on the components in source separated black water. The treatment options for the

  3. Black Youths and Illegal Drugs.

    Science.gov (United States)

    Joseph, Janice; Pearson, Patricia G.

    2002-01-01

    Examines the effect of drugs on black youths, discussing different types of drug involvement, reasons for drug involvement, extent and nature of involvement, drugs and crime, drugs and health issues, drug control strategies, and prevention. Policy implications include prioritizing drug prevention among black youths, providing alternatives to drug…

  4. What, no black hole evaporation

    International Nuclear Information System (INIS)

    Hajicek, P.; Israel, W.

    1980-01-01

    Tipler has claimed that the inward flux of negative energy across the horizon which (according to the semi-classical approximation) accompanies the evaporation of a black hole would cause a solar mass black hole to evaporate in less than a second. It is shown that this claim is in error. (orig.)

  5. Statistical black-hole thermodynamics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1975-01-01

    Traditional methods from statistical thermodynamics, with appropriate modifications, are used to study several problems in black-hole thermodynamics. Jaynes's maximum-uncertainty method for computing probabilities is used to show that the earlier-formulated generalized second law is respected in statistically averaged form in the process of spontaneous radiation by a Kerr black hole discovered by Hawking, and also in the case of a Schwarzschild hole immersed in a bath of black-body radiation, however cold. The generalized second law is used to motivate a maximum-entropy principle for determining the equilibrium probability distribution for a system containing a black hole. As an application we derive the distribution for the radiation in equilibrium with a Kerr hole (it is found to agree with what would be expected from Hawking's results) and the form of the associated distribution among Kerr black-hole solution states of definite mass. The same results are shown to follow from a statistical interpretation of the concept of black-hole entropy as the natural logarithm of the number of possible interior configurations that are compatible with the given exterior black-hole state. We also formulate a Jaynes-type maximum-uncertainty principle for black holes, and apply it to obtain the probability distribution among Kerr solution states for an isolated radiating Kerr hole

  6. Marital Happiness of Black Women.

    Science.gov (United States)

    Rutledge, Essie M.

    According to a study of 256 black married women between the ages of 26 and 60 living with their spouses, marital happiness is more common among black women than marital unhappiness. This finding is based on the secondary analysis of a sample of data collected in Detroit in 1968-1969. Variables statistically significant to the marital happiness of…

  7. Black raspberry: Korean vs. American

    Science.gov (United States)

    This fact sheet shows Korean black raspberry (Rubus coreanus) fruit, flower, and leaf features that distinguish them from their Rubus relatives, black raspberry (R. occidentalis) native to America. Common names with fruit characteristics, including berry size and pigment fingerprints, are summarized...

  8. Black hole decay as geodesic motion

    International Nuclear Information System (INIS)

    Gupta, Kumar S.; Sen, Siddhartha

    2003-01-01

    We show that a formalism for analyzing the near-horizon conformal symmetry of Schwarzschild black holes using a scalar field probe is capable of describing black hole decay. The equation governing black hole decay can be identified as the geodesic equation in the space of black hole masses. This provides a novel geometric interpretation for the decay of black holes. Moreover, this approach predicts a precise correction term to the usual expression for the decay rate of black holes

  9. Black holes and quantum processes in them

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1976-01-01

    The latest achievements in the physics of black holes are reviewed. The problem of quantum production in a strong gravitational field of black holes is considered. Another parallel discovered during investigation of interactions between black holes and between black holes and surrounding media, is also drawn with thermodynamics. A gravitational field of rotating black holes is considered. Some cosmological aspects of evaporation of small black holes are discussed as well as possibilities to observe them

  10. String-Corrected Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, V.

    2005-01-12

    We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically alter the causal structure of the solution, converting seemingly pathological null singularities into timelike singularities hidden behind a finite area horizon. We establish, analytically and numerically, that the string-corrected two-charge black hole metric has the same Penrose diagram as the extremal four-charge black hole. The higher derivative terms lead to another dramatic effect--the gravitational force exerted by a black hole on an inertial observer is no longer purely attractive. The magnitude of this effect is related to the size of the compactification manifold.

  11. The search for black holes

    International Nuclear Information System (INIS)

    Torn, K.

    1976-01-01

    Conceivable experimental investigations to prove the existence of black holes are discussed. Double system with a black hole turning around a star-satellite are in the spotlight. X-radiation emmited by such systems and resulting from accretion of the stellar gas by a black hole, and the gas heating when falling on the black hole might prove the model suggested. A source of strong X-radiation observed in the Cygnus star cluster and referred to as Cygnus X-1 may be thus identified as a black hole. Direct registration of short X-ray pulses with msec intervals might prove the suggestion. The lack of appropriate astrophysic facilities is pointed out to be the major difficulty on the way of experimental verifications

  12. Compressibility of rotating black holes

    International Nuclear Information System (INIS)

    Dolan, Brian P.

    2011-01-01

    Interpreting the cosmological constant as a pressure, whose thermodynamically conjugate variable is a volume, modifies the first law of black hole thermodynamics. Properties of the resulting thermodynamic volume are investigated: the compressibility and the speed of sound of the black hole are derived in the case of nonpositive cosmological constant. The adiabatic compressibility vanishes for a nonrotating black hole and is maximal in the extremal case--comparable with, but still less than, that of a cold neutron star. A speed of sound v s is associated with the adiabatic compressibility, which is equal to c for a nonrotating black hole and decreases as the angular momentum is increased. An extremal black hole has v s 2 =0.9 c 2 when the cosmological constant vanishes, and more generally v s is bounded below by c/√(2).

  13. Are LIGO's Black Holes Made From Smaller Black Holes?

    Science.gov (United States)

    Kohler, Susanna

    2017-05-01

    The recent successes of the Laser Interferometer Gravitational-Wave Observatory (LIGO) has raised hopes that several long-standing questions in black-hole physics will soon be answerable. Besides revealing how the black-hole binary pairs are built, could detections with LIGO also reveal how the black holes themselves form?Isolation or HierarchyThe first detection of gravitational waves, GW150914, was surprising for a number of reasons. One unexpected result was the mass of the two black holes that LIGO saw merging: they were a whopping 29 and 36 solar masses.On the left of this schematic, two first-generation (direct-collapse) black holes form a merging binary. The right illustrates a second-generation hierarchical merger: each black hole in the final merging binary was formed by the merger of two smaller black holes. [Adapted fromGerosa et al., a simultaneously published paper that also explores the problem of hierarchical mergers and reaches similar conclusions]How do black holes of this size form? One possibility is that they form in isolation from the collapse of a single massive star. In an alternative model, they are created through the hierarchical merger of smaller black holes, gradually building up to the size we observed.A team of scientists led by Maya Fishbach (University of Chicago) suggests that we may soon be able to tell whether or not black holes observed by LIGO formed hierarchically. Fishbach and collaborators argue that hierarchical formation leaves a distinctive signature on the spins of the final black holes and that as soon as we have enough merger detections from LIGO, we can use spin measurements to statistically determine if LIGO black holes were formed hierarchically.Spins from Major MergersWhen two black holes merge, both their original spins and the angular momentum of the pair contribute to the spin of the final black hole that results. Fishbach and collaborators calculate the expected distribution of these final spins assuming that

  14. Regular phantom black holes.

    Science.gov (United States)

    Bronnikov, K A; Fabris, J C

    2006-06-30

    We study self-gravitating, static, spherically symmetric phantom scalar fields with arbitrary potentials (favored by cosmological observations) and single out 16 classes of possible regular configurations with flat, de Sitter, and anti-de Sitter asymptotics. Among them are traversable wormholes, bouncing Kantowski-Sachs (KS) cosmologies, and asymptotically flat black holes (BHs). A regular BH has a Schwarzschild-like causal structure, but the singularity is replaced by a de Sitter infinity, giving a hypothetic BH explorer a chance to survive. It also looks possible that our Universe has originated in a phantom-dominated collapse in another universe, with KS expansion and isotropization after crossing the horizon. Explicit examples of regular solutions are built and discussed. Possible generalizations include k-essence type scalar fields (with a potential) and scalar-tensor gravity.

  15. UPAYA MENINGKATKAN MOTIVASI DAN HASIL BELAJAR MEMPERBAIKI SISTEM STARTER MELALUI METODE DEMONSTRASI PADA SISWA KELAS XII TKR SMK N 1 GABUSWETAN INDRAMAYU TAHUN AJARAN 2013/2014

    Directory of Open Access Journals (Sweden)

    Dwi Nurviyanto

    2014-06-01

    Full Text Available The purpose of this study was to determine the increase in student motivation and student learning outcomes by applying the learning method demonstration on learning fix a starter system in SMK N 1 Gabuswetan Indramayu academic year 2013/2014. The main focus of this study is the difference in student motivation and student learning outcomes of students before and after implementing the learning demonstration method in a class.             This research is classroom action research. The subjects in this study were students of class XII TKR B SMK N 1 Gabuswetan Indramayu academic year 2013/2014, amounting to 35 students. Objects in this study is based on an increase in motivation and learning outcomes through the demonstration method of fixing the starter system. The research was conducted in three cycles with four stages of classroom action research, namely: planning, implementation, observation, and reflection on each cycle. Data collection techniques obtained through the use of multiple choice questions (pre-test and post-test, observation of student activity sheets and motivation questionnaire (before and after the demonstration methods implemented. The analysis used is the analysis of quantitative data with descriptive statistics.             Results of research show that after the implemented demonstration method of motivation and learning outcomes showed improvement. Learning motivation increased from 49% pre-cycle (less motivated category to 74.6% (medium motivation category. Learning outcomes produce an average yield of pretest and post-test on the first cycle is 37 to 70.71 of 35 students, the average value of the class on the second cycle of the pre-test value of 40.29 into a post-test value 66.85 and the third cycle value average class in the third cycle is increased from pre-test value of 38.65 and post-test value to 76. After all the activities that students end up achieving completeness criteria or achieve

  16. Complicated Contradictions Amid Black Feminism and Millennial Black Women Teachers Creating Curriculum for Black Girls

    Science.gov (United States)

    Nyachae, Tiffany M.

    2016-01-01

    Millennial Black women teachers wrestle with two simultaneous burdens: disrupting the racist and sexist status quo of schooling through curriculum, and employing tactics to survive school politics among their majority White women colleagues. This article describes how the "Sisters of Promise" (SOP) curriculum aligned with Black feminism…

  17. Black Lives Matter of Black Identity Extremist? : The FBI, Black Activists and the Struggle for Victimhood

    NARCIS (Netherlands)

    Mutsaers, Paul

    2017-01-01

    The question 'who is the victim?' is an important social directive that shapes the struggles for victimhood in which Black Lives Matters, U.S. police forces and their various (counter)publics are currently engaging. This column begins with a controversial FBI report on so-called Black Identity

  18. Magnetic fields around black holes

    Science.gov (United States)

    Garofalo, David A. G.

    Active Galactic Nuclei are the most powerful long-lived objects in the universe. They are thought to harbor supermassive black holes that range from 1 million solar masses to 1000 times that value and possibly greater. Theory and observation are converging on a model for these objects that involves the conversion of gravitational potential energy of accreting gas to radiation as well as Poynting flux produced by the interaction of the rotating spacetime and the electromagnetic fields originating in the ionized accretion flow. The presence of black holes in astrophysics is taking center stage, with the output from AGN in various forms such as winds and jets influencing the formation and evolution of the host galaxy. This dissertation addresses some of the basic unanswered questions that plague our current understanding of how rotating black holes interact with their surrounding magnetized accretion disks to produce the enormous observed energy. Two magnetic configurations are examined. The first involves magnetic fields connecting the black hole with the inner accretion disk and the other involves large scale magnetic fields threading the disk and the hole. We study the effects of the former type by establishing the consequences that magnetic torques between the black hole and the inner accretion disk have on the energy dissipation profile. We attempt a plausible explanation to the observed "Deep Minimum" state in the Seyfert galaxy MCG-6- 30-15. For the latter type of magnetic geometry, we study the effects of the strength of the magnetic field threading the black hole within the context of the cherished Blandford & Znajek mechanism for black hole spin energy extraction. We begin by addressing the problem in the non-relativistic regime where we find that the black hole-threading magnetic field is stronger for greater disk thickness, larger magnetic Prandtl number, and for a larger accretion disk. We then study the problem in full relativity where we show that our

  19. A nonsingular rotating black hole

    International Nuclear Information System (INIS)

    Ghosh, Sushant G.

    2015-01-01

    The spacetime singularities in classical general relativity are inevitable, as predicated by the celebrated singularity theorems. However, it is a general belief that singularities do not exist in Nature and that they are the limitations of the general relativity. In the absence of a welldefined quantum gravity, models of regular black holes have been studied. We employ a probability distribution inspired mass function m(r) to replace the Kerr black hole mass M to represent a nonsingular rotating black hole that is identified asymptotically (r >> k, k > 0 constant) exactly as the Kerr-Newman black hole, and as the Kerr black hole when k = 0. The radiating counterpart renders a nonsingular generalization of Carmeli's spacetime as well as Vaidya's spacetime, in the appropriate limits. The exponential correction factor changing the geometry of the classical black hole to remove the curvature singularity can also be motivated by quantum arguments. The regular rotating spacetime can also be understood as a black hole of general relativity coupled to nonlinear electrodynamics. (orig.)

  20. The renaissance of black phosphorus.

    Science.gov (United States)

    Ling, Xi; Wang, Han; Huang, Shengxi; Xia, Fengnian; Dresselhaus, Mildred S

    2015-04-14

    One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from condensed matter physicists, chemists, semiconductor device engineers, and material scientists. Similar to graphite and transition metal dichalcogenides (TMDs), black P has a layered structure but with a unique puckered single-layer geometry. Because the direct electronic band gap of thin film black P can be varied from 0.3 eV to around 2 eV, depending on its film thickness, and because of its high carrier mobility and anisotropic in-plane properties, black P is promising for novel applications in nanoelectronics and nanophotonics different from graphene and TMDs. Black P as a nanomaterial has already attracted much attention from researchers within the past year. Here, we offer our opinions on this emerging material with the goal of motivating and inspiring fellow researchers in the 2D materials community and the broad readership of PNAS to discuss and contribute to this exciting new field. We also give our perspectives on future 2D and thin film black P research directions, aiming to assist researchers coming from a variety of disciplines who are desirous of working in this exciting research field.

  1. A Lovelock black hole bestiary

    International Nuclear Information System (INIS)

    Camanho, Xián O; Edelstein, José D

    2013-01-01

    We revisit the study of (A)dS black holes in Lovelock theories. We present a new tool that allows to attack this problem in full generality. In analyzing maximally symmetric Lovelock black holes with non-planar horizon topologies, many distinctive and interesting features are observed. Among them, the existence of maximally symmetric vacua does not support black holes in vast regions of the space of gravitational couplings, multi-horizon black holes and branches of solutions that suggest the existence of a rich diagram of phase transitions. The appearance of naked singularities seems unavoidable in some cases, raising the question about the fate of the cosmic censorship conjecture in these theories. There is a preferred branch of solutions for planar black holes, as well as for non-planar black holes with high enough mass or temperature. Our study clarifies the role of all branches of solutions, including asymptotically dS black holes, and whether they should be considered when studying these theories in the context of AdS/CFT. (paper)

  2. Phase transition for black holes with scalar hair and topological black holes

    OpenAIRE

    Myung, Yun Soo

    2008-01-01

    We study phase transitions between black holes with scalar hair and topological black holes in asymptotically anti-de Sitter spacetimes. As the ground state solutions, we introduce the non-rotating BTZ black hole in three dimensions and topological black hole with hyperbolic horizon in four dimensions. For the temperature matching only, we show that the phase transition between black hole with scalar hair (Martinez-Troncoso-Zanelli black hole) and topological black hole is second-order by usi...

  3. Quantum Mechanics of Black Holes

    Science.gov (United States)

    Witten, Edward

    2012-08-01

    The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general relativity. These objects swallow up whatever comes near and emit nothing. Physicists who have tried to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived at quite a different picture. The difference is analogous to the difference between thermodynamics and statistical mechanics. The thermodynamic description is a good approximation for a macroscopic system, but statistical mechanics describes what one will see if one looks more closely.

  4. Tunnelling from Goedel black holes

    International Nuclear Information System (INIS)

    Kerner, Ryan; Mann, R. B.

    2007-01-01

    We consider the spacetime structure of Kerr-Goedel black holes, analyzing their parameter space in detail. We apply the tunnelling method to compute their temperature and compare the results to previous calculations obtained via other methods. We claim that it is not possible to have the closed timelike curve (CTC) horizon in between the two black hole horizons and include a discussion of issues that occur when the radius of the CTC horizon is smaller than the radius of both black hole horizons

  5. Black Holes: A Traveler's Guide

    Science.gov (United States)

    Pickover, Clifford A.

    1998-03-01

    BLACK HOLES A TRAVELER'S GUIDE Clifford Pickover's inventive and entertaining excursion beyond the curves of space and time. "I've enjoyed Clifford Pickover's earlier books . . . now he has ventured into the exploration of black holes. All would-be tourists are strongly advised to read his traveler's guide." -Arthur C. Clarke. "Many books have been written about black holes, but none surpass this one in arousing emotions of awe and wonder towards the mysterious structure of the universe." -Martin Gardner. "Bucky Fuller thought big. Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." -Wired. "The book is fun, zany, in-your-face, and refreshingly addictive." -Times Higher Education Supplement.

  6. Orbital resonances around black holes.

    Science.gov (United States)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

  7. Quantum mechanics of black holes.

    Science.gov (United States)

    Witten, Edward

    2012-08-03

    The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general relativity. These objects swallow up whatever comes near and emit nothing. Physicists who have tried to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived at quite a different picture. The difference is analogous to the difference between thermodynamics and statistical mechanics. The thermodynamic description is a good approximation for a macroscopic system, but statistical mechanics describes what one will see if one looks more closely.

  8. Vacuum metastability with black holes

    International Nuclear Information System (INIS)

    Burda, Philipp; Gregory, Ruth; Moss, Ian G. annd

    2015-01-01

    We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evaporation process. Finally, we comment on the application of these results to vacuum decay seeded by black holes produced in particle collisions.

  9. Black holes from fluid mechanics

    Science.gov (United States)

    Lahiri, Subhaneil

    2009-12-01

    We use the AdS/CFT correspondence in a regime where the field theory is well described by fluid mechanics to study large black holes in asymptotically locally anti de Sitter spaces. In particular, we use the fluid description to study the thermodynamics of the black holes and the existence of exotic horizon topologies in higher dimensions. First we test this method by comparing large rotating black holes in global AdSD spaces to stationary solutions of the relativistic Navier-Stokes equations on SD-2. Reading off the equation of state of this fluid from the thermodynamics of non-rotating black holes, we proceed to construct the nonlinear spinning solutions of fluid mechanics that are dual to rotating black holes. In all known examples, the thermodynamics and the local stress tensor of our solutions are in precise agreement with the thermodynamics and boundary stress tensor of the spinning black holes. Our results yield predictions for the thermodynamics of all large black holes in all theories of gravity on AdS spaces, for example, IIB string theory on AdS5 x S 5 and M theory on AdS4 x S7 and AdS7 x S 4. We then construct solutions to the relativistic Navier-Stokes equations that describe the long wavelength collective dynamics of the deconfined plasma phase of N = 4 Yang Mills theory compactified down to d = 3 on a Scherk-Schwarz circle. Our solutions are stationary, axially symmetric spinning balls and rings of plasma. These solutions, which are dual to (yet to be constructed) rotating black holes and black rings in Scherk-Schwarz compactified AdS 5, and have properties that are qualitatively similar to those of black holes and black rings in flat five dimensional gravity. We also study the stability of these solutions to small fluctuations, which provides an indirect method for studying Gregory-Laflamme instabilities. We also extend the construction to higher dimensions, allowing one to study the existence of new black hole topologies and their phase diagram.

  10. Can Black Hole Relax Unitarily?

    Science.gov (United States)

    Solodukhin, S. N.

    2005-03-01

    We review the way the BTZ black hole relaxes back to thermal equilibrium after a small perturbation and how it is seen in the boundary (finite volume) CFT. The unitarity requires the relaxation to be quasi-periodic. It is preserved in the CFT but is not obvious in the case of the semiclassical black hole the relaxation of which is driven by complex quasi-normal modes. We discuss two ways of modifying the semiclassical black hole geometry to maintain unitarity: the (fractal) brick wall and the worm-hole modification. In the latter case the entropy comes out correctly as well.

  11. Gravitational polarizability of black holes

    International Nuclear Information System (INIS)

    Damour, Thibault; Lecian, Orchidea Maria

    2009-01-01

    The gravitational polarizability properties of black holes are compared and contrasted with their electromagnetic polarizability properties. The 'shape' or 'height' multipolar Love numbers h l of a black hole are defined and computed. They are then compared to their electromagnetic analogs h l EM . The Love numbers h l give the height of the lth multipolar 'tidal bulge' raised on the horizon of a black hole by faraway masses. We also discuss the shape of the tidal bulge raised by a test-mass m, in the limit where m gets very close to the horizon.

  12. Black holes and Higgs stability

    CERN Document Server

    Tetradis, Nikolaos

    2016-09-20

    We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum. We find that the energy barrier for transitions to the new vacuum, which characterizes the exponential suppression of the nucleation rate, can be reduced significantly in the black-hole background. A precise analysis is required in order to determine whether the the existence of primordial black holes is compatible with the form of the Higgs potential at high temperature or density in the Standard Model or its extensions.

  13. Black layers on historical architecture.

    Science.gov (United States)

    Toniolo, Lucia; Zerbi, Carlotta M; Bugini, Roberto

    2009-03-01

    The external surface of any building in urban polluted environment is unavoidably destined to be covered with layers that assume a grey to black colour and are generally called 'black crusts'. These, according to standard protocols and glossary, are deteriorated surface layers of stone material; they can have variable thickness, are hard and fragile and can detach spontaneously from the substrate, which, in general, is quite decayed. Plain visual examination may lead to consider 'black crusts' all similar, whilst only a careful diagnostic investigation can distinguish 'black crusts' and the consequences of their formation on stone substrates. In this paper, various black layers on marble are studied and compared and the morphological and compositional characteristics discussed according to the related mechanisms of formation. Differences between old (hundred years) and recent crusts (30 years) are investigated and pointed out. Samples of black crusts collected from the Milan Cathedral façade (Candoglia Marble) have been studied and compared with the careful and synergic employ of traditional techniques: optical (transmission and reflected VIS light) and electron microscopy, X-ray spectrometry and micro-Fourier transform infrared spectroscopy. Visual examination of loose fragments does not allow to point out outstanding differences amongst the various samples; black layers have similar main mineral components, gypsum and airborne particles, with different spatial distribution. The microscopic studies allowed to point out the porosity differences, the gypsum crystallisation habit, different amount of embedded particles, level and progress of marble decay. The observations lead to define three main types of black crusts: black crust deriving from marble sulphation, compact deposit and encrustation due to exogenic materials deposition. Black crusts show evidence of sulphation in progress, without a clear continuity solution between crust and marble; the lack of

  14. Cryo-Etched Black Silicon for Use as Optical Black

    Science.gov (United States)

    Yee, Karl Y.; White, Victor E.; Mouroulis, Pantazis; Eastwood, Michael L.

    2011-01-01

    Stray light reflected from the surface of imaging spectrometer components in particular, the spectrometer slit degrade the image quality. A technique has been developed for rapid, uniform, and cost-effective black silicon formation based on inductively coupled plasma (ICP) etching at cryogenic temperatures. Recent measurements show less than 1-percent total reflectance from 350 2,500 nm of doped black silicon formed in this way, making it an excellent option for texturing of component surfaces for reduction of stray light. Oxygen combines with SF6 + Si etch byproducts to form a passivation layer atop the Si when the etch is performed at cryogenic temperatures. Excess flow of oxygen results in micromasking and the formation of black silicon. The process is repeatable and reliable, and provides control over etch depth and sidewall profile. Density of the needles can be controlled to some extent. Regions to be textured can be patterned lithographically. Adhesion is not an issue as the nanotips are part of the underlying substrate. This is in contrast to surface growth/deposition techniques such as carbon nanotubes (CNTs). The black Si surface is compatible with wet processing, including processing with solvents, the textured surface is completely inorganic, and it does not outgas. In radiometry applications, optical absorbers are often constructed using gold black or CNTs. This black silicon technology is an improvement for these types of applications.

  15. Erratic Black Hole Regulates Itself

    Science.gov (United States)

    2009-03-01

    New results from NASA's Chandra X-ray Observatory have made a major advance in explaining how a special class of black holes may shut off the high-speed jets they produce. These results suggest that these black holes have a mechanism for regulating the rate at which they grow. Black holes come in many sizes: the supermassive ones, including those in quasars, which weigh in at millions to billions of times the mass of the Sun, and the much smaller stellar-mass black holes which have measured masses in the range of about 7 to 25 times the Sun's mass. Some stellar-mass black holes launch powerful jets of particles and radiation, like seen in quasars, and are called "micro-quasars". The new study looks at a famous micro-quasar in our own Galaxy, and regions close to its event horizon, or point of no return. This system, GRS 1915+105 (GRS 1915 for short), contains a black hole about 14 times the mass of the Sun that is feeding off material from a nearby companion star. As the material swirls toward the black hole, an accretion disk forms. This system shows remarkably unpredictable and complicated variability ranging from timescales of seconds to months, including 14 different patterns of variation. These variations are caused by a poorly understood connection between the disk and the radio jet seen in GRS 1915. Chandra, with its spectrograph, has observed GRS 1915 eleven times since its launch in 1999. These studies reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole. The wind is believed to shut down the jet by depriving it of matter that would have otherwise fueled it. Conversely, once the wind dies down, the jet can re-emerge. "We think the jet and wind around this black hole are in a sort of tug of war," said Joseph Neilsen, Harvard graduate student and lead author of the paper appearing in the journal Nature. "Sometimes one is winning and then, for reasons we don

  16. Laser Spectroscopy : XII International Conference

    CERN Document Server

    Allegrini, Maria; Sasso, Antonio

    1996-01-01

    This text includes all the recent advances in the field of laser spectroscopy. Major results span from the control of matter by electromagnetic fields (trapping and coding) to high precision measurements on simple atomic systems and to quantum optics with single atoms. It includes a report of the Bose-Einstein condensation achieved by laser-cooling of rubidium atoms. Achievements in the technology of tunable sources, in particular of miniaturized solid state devices, are also reported. Most recent advances in molecular spectroscopy are illustrated with emphasis on "cooled" spectra, clusters and high accuracy frequency references. Topics such as atomic interferometry and microcavity quantum optics are also covered.

  17. Radiation Effects on Polymers - XII

    DEFF Research Database (Denmark)

    El-Awady, N. I.; Ghanem, N. A.; Pedersen, Walther Batsberg

    1979-01-01

    Calibration of gel permeation chromatography was carried out to determine molecular weight and molecular weight distribution of the side-chains and homopolymer formed during grafting of cellulose acetate with acrylamide monomer using accelerated electrons. Polyacrylamide in side-chains and in hom...

  18. International Congress on Glass XII

    Energy Technology Data Exchange (ETDEWEB)

    Doremus, R H; LaCourse, W C; Mackenzie, J D; Varner, J R; Wolf, W W [eds.

    1980-01-01

    A total of 158 papers are included under nine headings: structure and glass formation; optical properties; electrical and magnetic properties; mechanical properties and relaxation; mass transport; chemical durability and surfaces; nucleation; crystallization; and glass ceramics; processing; and automatic controls. Separate abstracts were prepared for eight papers; four of the remaining papers had been processed previously for the data base. (DLC)

  19. The Black Man in American Society.

    Science.gov (United States)

    Framingham Public Schools, MA.

    GRADE OR AGES: Junior high school. SUBJECT MATTER: The black man in American society. ORGANIZATION AND PHYSICAL APPEARANCE: There are four major parts each with an overview. The four parts concern a) the African heritage of the black man, b) the American exploitation of the black man, c) the black man's contribution to American society, d) the…

  20. Black Hole Complementary Principle and Noncommutative Membrane

    International Nuclear Information System (INIS)

    Wei Ren

    2006-01-01

    In the spirit of black hole complementary principle, we have found the noncommutative membrane of Scharzchild black holes. In this paper we extend our results to Kerr black hole and see the same story. Also we make a conjecture that spacetimes are noncommutative on the stretched membrane of the more general Kerr-Newman black hole.

  1. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the conjecture that the primordial black holes ...

  2. The Black Journalist in South Africa.

    Science.gov (United States)

    Hachten, William A.

    The role of the black journalist in South Africa is contradictory, precarious, and permeated with politics. There is little freedom of expression for blacks in South Africa, yet white-owned newspapers have expanded their coverage of black news, and some have special editions for black readers. As a result, the English language press is using more…

  3. The Core Journal Concept in Black Studies

    Science.gov (United States)

    Weissinger, Thomas

    2010-01-01

    Black Studies scholars have shown interest in the core journal concept. Indeed, the idea of core journals for the study of the Black experience has changed several times since 1940. While Black Studies scholars are citing Black Studies journals with frequency, they also cite traditional disciplinary journals a great deal of the time. However,…

  4. Then and Now: Black Boycott in Waterloo.

    Science.gov (United States)

    Anderson, Ruth B.

    1983-01-01

    Discusses events following the desegregation of Waterloo, Iowa, schools. Describes the 1978 Black boycott of Hoover Junior High, which led to improvements in the treatment of Black students. Lists administrative responses to each Black grievance, and presents interviews with ten Black students three years after the boycott. (KH)

  5. Black Sprayable Molecular Adsorber Coating

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  6. Black holes and quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Hooft, G. ' t, E-mail: g.thooft@uu.n [Institute for Theoretical Physics, Utrecht University and Spinoza Institute, P.O. Box 80.195, 3508 TD Utrecht (Netherlands)

    2010-07-15

    After a brief review of quantum black hole physics, it is shown how the dynamical properties of a quantum black hole may be deduced to a large extent from Standard Model Physics, extended to scales near the Planck length, and combined with results from perturbative quantum gravity. Together, these interactions generate a Hilbert space of states on the black hole horizon, which can be investigated, displaying interesting systematics by themselves. To make such approaches more powerful, a study is made of the black hole complementarity principle, from which one may deduce the existence of a hidden form of local conformal invariance. Finally, the question is raised whether the principles underlying Quantum Mechanics are to be sharpened in this domain of physics as well. There are intriguing possibilities.

  7. Black hole evaporation: a paradigm

    International Nuclear Information System (INIS)

    Ashtekar, Abhay; Bojowald, Martin

    2005-01-01

    A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on spacetime geometry and structure of quantum theory would be resolved

  8. Homophobia, hypermasculinity and the US black church.

    Science.gov (United States)

    Ward, Elijah G

    2005-01-01

    Black churches in the USA constitute a significant source of the homophobia that pervades black communities. This theologically-driven homophobia is reinforced by the anti-homosexual rhetoric of black nationalism. Drawing on a variety of sources, this paper discusses the sources of homophobia within black communities, and its impact upon self-esteem, social relationships and physical health. Religion-based homophobia and black nationalism point to wider structures which have influenced their emergence, including racism, patriarchy and capitalism. It is vital for US black churches and communities to understand and transcend their longstanding resistance to openly addressing complex, painful issues of sexuality and embrace healthier definitions of black manhood.

  9. "Be Real Black for Me": Imagining BlackCrit in Education

    Science.gov (United States)

    Dumas, Michael J.; ross, kihana miraya

    2016-01-01

    The authors put forward a theorization of a Black Critical Theory, or what might be called BlackCrit, within, and in response to, Critical Race Theory, and then outline ways that BlackCrit in education helps us to more incisively analyze how the specificity of (anti)blackness matters in explaining how Black bodies become marginalized, disregarded,…

  10. A radiant black market

    International Nuclear Information System (INIS)

    Roser, T.

    1993-01-01

    On the 13 October the Bavarian police seized 2.2kg of uranium and arrested a group of seven people who had offered to sell it for $500.000. The existence of a black market for uranium may be a proliferation risk but it is not a serious health hazard - even if the material is negligently packed, as it seems to have been in all the recent cases. The situation is quite different when it comes to dealing with highly radioactive materials such as fission productions. Two such cases have been reported this summer involving Cs-137 and Sr-90, both emitters of hard beta rays. Little is known about the provenance of the radioactive and fissile material discovered. Obviously it originates from the ex-USSR, and the absence of highly enriched material suggests a civil rather than a military source. The governments of ex-Soviet states have apparently tried to intercept smugglers at their western frontiers, but have so far been unable to pinpoint the breaches in their security. It is also uncertain whether the occurrences discovered and reported are merely the tip of an iceberg. (author)

  11. Black holes in astrophysics

    International Nuclear Information System (INIS)

    Narayan, Ramesh

    2005-01-01

    This paper reviews the current status of black hole (BH) astrophysics, focusing on topics of interest to a physics audience. Astronomers have discovered dozens of compact objects with masses greater than 3M o-dot , the likely maximum mass of a neutron star. These objects are identified as BH candidates. Some of the candidates have masses ∼5M o-dot -20M o-dot and are found in x-ray binaries, while the rest have masses ∼10 6 M o-dot -10 9.5 M o-dot and are found in galactic nuclei. A variety of methods are being tried to estimate the spin parameters of the candidate BHs. There is strong circumstantial evidence that many of the objects have event horizons, so there is good reason to believe that the candidates are true BHs. Recent MHD simulations of magnetized plasma accreting on rotating BHs seem to hint that relativistic jets may be produced by a magnetic analogue of the Penrose process

  12. Black coal. Annual report 1997

    International Nuclear Information System (INIS)

    1997-01-01

    An overview is given of the situation of the world energy industry with regard to all energy carriers. Then energy-political conclusions are drawn for German black coal and the resulting prospects are detailed. Finally, some socio-political aspects are considered with regard to German black-coal mining: Workforce policy, tariff policy, social security and social safeguards for the adaptation process. (orig.) [de

  13. Black strings and classical hair

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Yang, H.

    1997-01-01

    We examine the geometry near the event horizon of a family of black string solutions with traveling waves. It has previously been shown that the metric is continuous there. Contrary to expectations, we find that the geometry is not smooth, and the horizon becomes singular whenever a wave is present. Both five-dimensional and six-dimensional black strings are considered with similar results. copyright 1997 The American Physical Society

  14. Black holes from extended inflation

    International Nuclear Information System (INIS)

    Hsu, S.D.H.; Lawrence Berkeley Lab., CA

    1990-01-01

    It is argued that models of extended inflation, in which modified Einstein gravity allows a graceful exit from the false vacuum, lead to copious production of black holes. The critical temperature of the inflationary phase transition must be >10 8 GeV in order to avoid severe cosmological problems in a universe dominated by black holes. We speculate on the possibility that the interiors of false vacuum regions evolve into baby universes. (orig.)

  15. Black Holes as Dark Matter

    OpenAIRE

    Frampton, Paul H.

    2009-01-01

    While the energy of the universe has been established to be about 0.04 baryons, 0.24 dark matter and 0.72 dark energy, the cosmological entropy is almost entirely, about $(1 - 10^{-15})$, from black holes and only $10^{-15}$ from everything else. This identification of all dark matter as black holes is natural in statistical mechanics. Cosmological history of dark matter is discussed.

  16. Behaviour of the Vlei Rat, Otomys Irroratus (Brants, 1827) | Davis ...

    African Journals Online (AJOL)

    Interactions of adults were tested and they were found to be very antisocial, with intrasexual aggression occurring when caged. Complex threat and communication patterns exist, a feature of asocial behaviour. Mating failed to occur in captivity, probably also a result of their antisocial nature. Marking behaviour is very ...

  17. behaviour of the vlei rat, otomys irroratus (brants, 1827)

    African Journals Online (AJOL)

    nocturnal (Hewitt 1931; Shortridge 1934). The vlei rat has been found to breed nearly throughout the year in the study area, June and. July being the exceptions. Asdell (I964) reports it as being polyoestrous, breeding about three times per year, and for the first time at about four months of age. Data from the study area.

  18. Black holes in the universe

    International Nuclear Information System (INIS)

    Camenzind, M.

    2005-01-01

    While physicists have been grappling with the theory of black holes (BH), as shown by the many contributions to the Einstein year, astronomers have been successfully searching for real black holes in the Universe. Black hole astrophysics began in the 1960s with the discovery of quasars and other active galactic nuclei (AGN) in distant galaxies. Already in the 1960s it became clear that the most natural explanation for the quasar activity is the release of gravitational energy through accretion of gas onto supermassive black holes. The remnants of this activity have now been found in the centers of about 50 nearby galaxies. BH astrophysics received a new twist in the 1970s with the discovery of the X-ray binary (XRB) Cygnus X-1. The X-ray emitting compact object was too massive to be explained by a neutron star. Today, about 20 excellent BH candidates are known in XRBs. On the extragalactic scale, more than 100.000 quasars have been found in large galaxy surveys. At the redshift of the most distant ones, the Universe was younger than one billion year. The most enigmatic black hole candidates identified in the last years are the compact objects behind the Gamma-Ray Bursters. The formation of all these types of black holes is accompanied by extensive emission of gravitational waves. The detection of these strong gravity events is one of the biggest challenges for physicists in the near future. (author)

  19. Black Hole Spin Measurement Uncertainty

    Science.gov (United States)

    Salvesen, Greg; Begelman, Mitchell C.

    2018-01-01

    Angular momentum, or spin, is one of only two fundamental properties of astrophysical black holes, and measuring its value has numerous applications. For instance, obtaining reliable spin measurements could constrain the growth history of supermassive black holes and reveal whether relativistic jets are powered by tapping into the black hole spin reservoir. The two well-established techniques for measuring black hole spin can both be applied to X-ray binaries, but are in disagreement for cases of non-maximal spin. This discrepancy must be resolved if either technique is to be deemed robust. We show that the technique based on disc continuum fitting is sensitive to uncertainties regarding the disc atmosphere, which are observationally unconstrained. By incorporating reasonable uncertainties into black hole spin probability density functions, we demonstrate that the spin measured by disc continuum fitting can become highly uncertain. Future work toward understanding how the observed disc continuum is altered by atmospheric physics, particularly magnetic fields, will further strengthen black hole spin measurement techniques.

  20. Atomic structure in black hole

    International Nuclear Information System (INIS)

    Nagatani, Yukinori

    2006-01-01

    We propose that any black hole has atomic structure in its inside and has no horizon as a model of black holes. Our proposal is founded on a mean field approximation of gravity. The structure of our model consists of a (charged) singularity at the center and quantum fluctuations of fields around the singularity, namely, it is quite similar to that of atoms. Any properties of black holes, e.g. entropy, can be explained by the model. The model naturally quantizes black holes. In particular, we find the minimum black hole, whose structure is similar to that of the hydrogen atom and whose Schwarzschild radius is approximately 1.1287 times the Planck length. Our approach is conceptually similar to Bohr's model of the atomic structure, and the concept of the minimum Schwarzschild radius is similar to that of the Bohr radius. The model predicts that black holes carry baryon number, and the baryon number is rapidly violated. This baryon number violation can be used as verification of the model. (author)

  1. Regular black hole in three dimensions

    OpenAIRE

    Myung, Yun Soo; Yoon, Myungseok

    2008-01-01

    We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.

  2. Thermodynamics of Horava-Lifshitz black holes

    International Nuclear Information System (INIS)

    Myung, Yun Soo; Kim, Yong-Wan

    2010-01-01

    We study black holes in the Horava-Lifshitz gravity with a parameter λ. For 1/3≤λ 3, the black holes behave the Reissner-Nordstroem type black hole in asymptotically flat spacetimes. Hence, these all are quite different from the Schwarzschild-AdS black hole of Einstein gravity. The temperature, mass, entropy, and heat capacity are derived for investigating thermodynamic properties of these black holes. (orig.)

  3. Detecting Black Hole Binaries by Gaia

    OpenAIRE

    Yamaguchi, Masaki S.; Kawanaka, Norita; Bulik, Tomasz; Piran, Tsvi

    2017-01-01

    We study the prospect of the Gaia satellite to identify black hole binary systems by detecting the orbital motion of the companion stars. Taking into account the initial mass function, mass transfer, common envelope phase, interstellar absorption and identifiability of black holes, we estimate the number of black hole binaries detected by Gaia and their distributions with respect to the black hole mass for several models with different parameters. We find that $\\sim 300-6000$ black hole binar...

  4. Black holes, qubits and octonions

    International Nuclear Information System (INIS)

    Borsten, L.; Dahanayake, D.; Duff, M.J.; Ebrahim, H.; Rubens, W.

    2009-01-01

    We review the recently established relationships between black hole entropy in string theory and the quantum entanglement of qubits and qutrits in quantum information theory. The first example is provided by the measure of the tripartite entanglement of three qubits (Alice, Bob and Charlie), known as the 3-tangle, and the entropy of the 8-charge STU black hole of N=2 supergravity, both of which are given by the [SL(2)] 3 invariant hyperdeterminant, a quantity first introduced by Cayley in 1845. Moreover the classification of three-qubit entanglements is related to the classification of N=2 supersymmetric STU black holes. There are further relationships between the attractor mechanism and local distillation protocols and between supersymmetry and the suppression of bit flip errors. At the microscopic level, the black holes are described by intersecting D3-branes whose wrapping around the six compact dimensions T 6 provides the string-theoretic interpretation of the charges and we associate the three-qubit basis vectors, |ABC>(A,B,C=0 or 1), with the corresponding 8 wrapping cycles. The black hole/qubit correspondence extends to the 56 charge N=8 black holes and the tripartite entanglement of seven qubits where the measure is provided by Cartan's E 7 contains [SL(2)] 7 invariant. The qubits are naturally described by the seven vertices ABCDEFG of the Fano plane, which provides the multiplication table of the seven imaginary octonions, reflecting the fact that E 7 has a natural structure of an O-graded algebra. This in turn provides a novel imaginary octonionic interpretation of the 56=7x8 charges of N=8: the 24=3x8 NS-NS charges correspond to the three imaginary quaternions and the 32=4x8 R-R to the four complementary imaginary octonions. We contrast this approach with that based on Jordan algebras and the Freudenthal triple system. N=8 black holes (or black strings) in five dimensions are also related to the bipartite entanglement of three qutrits (3-state systems

  5. Black hole quantum spectrum

    Science.gov (United States)

    Corda, Christian

    2013-12-01

    Introducing a black hole (BH) effective temperature, which takes into account both the non-strictly thermal character of Hawking radiation and the countable behavior of emissions of subsequent Hawking quanta, we recently re-analysed BH quasi-normal modes (QNMs) and interpreted them naturally in terms of quantum levels. In this work we improve such an analysis removing some approximations that have been implicitly used in our previous works and obtaining the corrected expressions for the formulas of the horizon's area quantization and the number of quanta of area and hence also for Bekenstein-Hawking entropy, its subleading corrections and the number of micro-states, i.e. quantities which are fundamental to realize the underlying quantum gravity theory, like functions of the QNMs quantum "overtone" number n and, in turn, of the BH quantum excited level. An approximation concerning the maximum value of n is also corrected. On the other hand, our previous results were strictly corrected only for scalar and gravitational perturbations. Here we show that the discussion holds also for vector perturbations. The analysis is totally consistent with the general conviction that BHs result in highly excited states representing both the "hydrogen atom" and the "quasi-thermal emission" in quantum gravity. Our BH model is somewhat similar to the semi-classical Bohr's model of the structure of a hydrogen atom. The thermal approximation of previous results in the literature is consistent with the results in this paper. In principle, such results could also have important implications for the BH information paradox.

  6. Violent flickering in Black Holes

    Science.gov (United States)

    2008-10-01

    Unique observations of the flickering light from the surroundings of two black holes provide new insights into the colossal energy that flows at their hearts. By mapping out how well the variations in visible light match those in X-rays on very short timescales, astronomers have shown that magnetic fields must play a crucial role in the way black holes swallow matter. Flickering black hole ESO PR Photo 36/08 Flickering black hole Like the flame from a candle, light coming from the surroundings of a black hole is not constant -- it flares, sputters and sparkles. "The rapid flickering of light from a black hole is most commonly observed at X-ray wavelengths," says Poshak Gandhi, who led the international team that reports these results. "This new study is one of only a handful to date that also explore the fast variations in visible light, and, most importantly how these fluctuations relate to those in X-rays." The observations tracked the shimmering of the black holes simultaneously using two different instruments, one on the ground and one in space. The X-ray data were taken using NASA's Rossi X-ray Timing Explorer satellite. The visible light was collected with the high speed camera ULTRACAM, a visiting instrument at ESO's Very Large Telescope (VLT), recording up to 20 images a second. ULTRACAM was developed by team members Vik Dhillon and Tom Marsh. "These are among the fastest observations of a black hole ever obtained with a large optical telescope," says Dhillon. To their surprise, astronomers discovered that the brightness fluctuations in the visible light were even more rapid than those seen in X-rays. In addition, the visible-light and X-ray variations were found not to be simultaneous, but to follow a repeated and remarkable pattern: just before an X-ray flare the visible light dims, and then surges to a bright flash for a tiny fraction of a second before rapidly decreasing again. None of this radiation emerges directly from the black hole, but from the

  7. PERAN BIDAN DALAM PELAKSANAAN PERMENKES NOMOR 631/MENKES/ PER/III/2011 SEBAGAIMANA TELAH DIUBAH DENGAN PERMENKES NOMOR 2562/MENKES/PER/XII/2011 TENTANG PETUNJUK TEKNIS JAMINAN PERSALINAN (Studi Kasus Pelayanan Kebidanan Di RSUD dr. H. Soewondo Kendal

    Directory of Open Access Journals (Sweden)

    . Sariyati

    2017-01-01

    Full Text Available The role of midwives in service delivery assurance in dr. H. Soewondo Kendal based on Permenkes No. 2562/MENKES /PER/XII/2011 on Technical Guidelines for Labor Warranty. The aim is to implement the appropriate authority midwifery services, with the ultimate goal of reducing the MMR (Maternal Mortality Rate and IMR (Infant Mortality Rate. If viewed from Permenkes 1464/Menkes /Per/X/2010 number of licenses and the implementation of midwifery practice, it is not really appropriate authority for the role of the midwife in the hospital to service delivery is a delivery service assurance of advanced midwives in hospitals. The scope of service includes pregnant women, maternity (risti, childbirth, newborns, family planning and treatment of complications in obstetrics. So based on the authority role of the midwife in the hospital should not be for the scope of services for maternity delivery guarantee (risti and treatment of complications in obstetrics

  8. Innovación y ruptura en la métrica de la poesía en al-Maqāmāt al-Luzūmiyya de al-Saraqusṭī (s. VI/XII)

    OpenAIRE

    Ferrando, Ignacio

    2016-01-01

    Al-Maqāmāt al-Luzūmiyya, la colección de 50 relatos de corte picaresco escritos en una exigente prosa rimada por Abū l-Ṭāhir al-Saraqusṭī en al-Andalus en el siglo VI/XII, han sido consideradas por los críticos occidentales como piezas de alta retórica y de virtuosismo lingüístico en las que el contenido es prácticamente irrelevante. Sin embargo, a partir de los años 80 del siglo pasado, algunos investigadores han tratado de incidir en el hecho de que esta obra contiene cierto grado de críti...

  9. La renta señorial de la Orden de San Juan en Castilla durante los siglos XII y XIII = Rents from the Lordships of the Order of Saint John in Castile during the Twelfth and Thirteenth Centuries

    Directory of Open Access Journals (Sweden)

    Carlos Barquero Goñi

    2016-06-01

    Full Text Available La Orden de San Juan obtuvo muchos recursos de sus dominios en Castilla durante los siglos XII y XIII. Sus fuentes de renta eran las contribuciones habituales en el régimen señorial durante la Edad Media. Sin embargo, el principal ingreso era una parte del diezmo eclesiástico que la Orden percibía en sus señoríos.The Order of Saint John collected significant resources from their domains in Castile during the twelfth and thirteenth centuries. Their sources of income were the usual contributions of the manorial system during the Middle Ages. Nevertheless, their main source of income was a fraction of the ecclesiastical tithe that the order perceived in their lordships.

  10. A propriedade fundiária arcaica: nova interpretação da regra do usus auctoritas fundi  da Lei das XII tábuas

    OpenAIRE

    Julio Cesar Lazzarini Lemos

    2011-01-01

    A chamada regra do usus auctoritas, presente na Lei das XII tábuas, é apontada, desde Cujácio (séc. XVI), e daí em diante por muitos juristas, como sendo uma antiga norma sobre a garantia do vendedor por meio de negócio formal, mancipatio em caso de evicção; o próprio sentido do vocábulo auctoritas seria «garantia», ou mesmo «dever de prestar garantia», neste caso particular inseparável da mancipatio. Mas o fragmento que traz essa regra USUS AUCTORITAS FUNDI BIENNIUM EST[O] nos foi transm...

  11. Black holes: a slanted overview

    International Nuclear Information System (INIS)

    Vishveshwara, C.V.

    1988-01-01

    The black hole saga spanning some seventy years may be broadly divided into four phases, namely, (a) the dark ages when little was known about black holes even though they had come into existence quite early through the Schwarzschild solution, (b) the age of enlightenment bringing in deep and prolific discoveries, (c) the age of fantasy that cast black holes in all sorts of extraordinary roles, and (d) the golden age of relativistic astrophysics - to some extent similar to Dirac's characterisation of the development of quantum theory - in which black holes have been extensively used to elucidate a number of astrophysical phenomena. It is impossible to give here even the briefest outline of the major developments in this vast area. We shall only attempt to present a few aspects of black hole physics which have been actively pursued in the recent past. Some details are given in the case of those topics that have not found their way into text books or review articles. (author)

  12. Cosmology with primordial black holes

    International Nuclear Information System (INIS)

    Lindley, D.

    1981-09-01

    Cosmologies containing a substantial amount of matter in the form of evaporating primordial black holes are investigated. A review of constraints on the numbers of such black holes, including an analysis of a new limit found by looking at the destruction of deuterium by high energy photons, shows that there must be a negligible population of small black holes from the era of cosmological nucleosynthesis onwards, but that there are no strong constraints before this time. The major part of the work is based on the construction of detailed, self-consistent cosmological models in which black holes are continually forming and evaporating The interest in these models centres on the question of baryon generation, which occurs via the asymmetric decay of a new type of particle which appears as a consequence of the recently developed Grand Unified Theories of elementary particles. Unfortunately, there is so much uncertainty in the models that firm conclusions are difficult to reach; however, it seems feasible in principle that primordial black holes could be responsible for a significant part of the present matter density of the Universe. (author)

  13. Black holes: the membrane paradigm

    International Nuclear Information System (INIS)

    Thorne, K.S.; Price, R.H.; Macdonald, D.A.

    1986-01-01

    The physics of black holes is explored in terms of a membrane paradigm which treats the event horizon as a two-dimensional membrane embedded in three-dimensional space. A 3+1 formalism is used to split Schwarzschild space-time and the laws of physics outside a nonrotating hole, which permits treatment of the atmosphere in terms of the physical properties of thin slices. The model is applied to perturbed slowly or rapidly rotating and nonrotating holes, and to quantify the electric and magnetic fields and eddy currents passing through a membrane surface which represents a stretched horizon. Features of tidal gravitational fields in the vicinity of the horizon, quasars and active galalctic nuclei, the alignment of jets perpendicular to accretion disks, and the effects of black holes at the center of ellipsoidal star clusters are investigated. Attention is also given to a black hole in a binary system and the interactions of black holes with matter that is either near or very far from the event horizon. Finally, a statistical mechanics treatment is used to derive a second law of thermodynamics for a perfectly thermal atmosphere of a black hole

  14. HUBUNGAN ANTARA PENGUASAAN MATA DIKLAT PRODUKTIF DAN NILAI PRAKTIK KERJA INDUSTRI DENGAN HASIL UJI KOMPETENSI KEAHLIAN SISWA KELAS XII TEKNIK KENDARAAN RINGAN DI SMK NEGERI 1 GANTIWARNO KLATEN TAHUN AJARAN 2014/2015

    Directory of Open Access Journals (Sweden)

    Andre Permana Putra

    2016-12-01

    Full Text Available This research aims to know the correlation between mastery of productive training subjek and the score of industry practice with student’s skill competency result, the correlation between industry practice with student’s skill competency result, the correlation between mastery productive training subjek with skill competency result of XII class student’s of light vehicle engineering SMK Negeri 1 Gantiwarno 2014/2015. This research is an ex-post facto study. The subject was class XII student of light vehicle engineering SMK Negeri 1Gantiwarno Klaten 2014/2015 consisting 65 student. This research was population research from 65 respondent. Data collection technike of this research was documentation. Partial correlation analysis was taken to know the correlation of independent variable with dependent variable, while to know the correlation both of independent variables together to dependent variable was using multiple correlation analysis. Before analysing data, there was prerequisite test such as normality test, linierity test and multikolinearity test. The result of this research showed that there is a positive and significant correlation between mastery productive training subject with student’s skill competency result. It is proved by the score of correlation is 0,410. There is a positive and significant correlation between the score of industry pratice with student’s skill competency result. It is proved by the score of correlation is 0,199. There is a positive and significant correlation between mastery productive training subject and the score industry practice with student’s skill competency result. It is proved by the score of correlation is 0,424.

  15. Why Blue-Collar Blacks Help Less

    OpenAIRE

    Smith, Sandra Susan; Young, Kara Alexis

    2013-01-01

    Why are blue-collar blacks less likely to help jobseekers than jobholders from other ethnoracial groups or even than more affluent blacks? Drawing from in-depth, semi-structured interviews with 97 black and Latino workers at one large, public sector employer, we find that blue-collar black workers both helped less proactively and rejected more requests for assistance than did blue-collar Latino and white-collar black workers. We attribute blue-collar blacks’ more passive engagement to their...

  16. Black holes a very short introduction

    CERN Document Server

    Blundell, Katherine

    2015-01-01

    Black holes are a constant source of fascination to many due to their mysterious nature. Black Holes: A Very Short Introduction addresses a variety of questions, including what a black hole actually is, how they are characterized and discovered, and what would happen if you came too close to one. It explains how black holes form and grow—by stealing material that belongs to stars—as well as how many there may be in the Universe. It also explores the large black holes found in the centres of galaxies, and how black holes power quasars and lie behind other spectacular phenomena in the cosmos.

  17. Black Hole Blows Big Bubble

    Science.gov (United States)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  18. Black holes and galaxy formation

    CERN Document Server

    Propst, Raphael J

    2010-01-01

    Galaxies are the basic unit of cosmology. The study of galaxy formation is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning. The physics of galaxy formation is complicated because it deals with the dynamics of stars, thermodynamics of gas and energy production of stars. A black hole is a massive object whose gravitational field is so intense that it prevents any form of matter or radiation to escape. It is hypothesized that the most massive galaxies in the universe- "elliptical galaxies"- grow simultaneously with the supermassive black holes at their centers, giving us much stronger evidence that black holes control galaxy formation. This book reviews new evidence in the field.

  19. Massive Black Holes and Galaxies

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Evidence has been accumulating for several decades that many galaxies harbor central mass concentrations that may be in the form of black holes with masses between a few million to a few billion time the mass of the Sun. I will discuss measurements over the last two decades, employing adaptive optics imaging and spectroscopy on large ground-based telescopes that prove the existence of such a massive black hole in the Center of our Milky Way, beyond any reasonable doubt. These data also provide key insights into its properties and environment. Most recently, a tidally disrupting cloud of gas has been discovered on an almost radial orbit that reached its peri-distance of ~2000 Schwarzschild radii in 2014, promising to be a valuable tool for exploring the innermost accretion zone. Future interferometric studies of the Galactic Center Black hole promise to be able to test gravity in its strong field limit.

  20. The black hole quantum atmosphere

    Science.gov (United States)

    Dey, Ramit; Liberati, Stefano; Pranzetti, Daniele

    2017-11-01

    Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate. Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan-Boltzmann law. In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor. We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about 4 MG, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon. This long distance origin of Hawking radiation could have a profound impact on our understanding of the information and transplanckian problems.

  1. The black hole quantum atmosphere

    Directory of Open Access Journals (Sweden)

    Ramit Dey

    2017-11-01

    Full Text Available Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate. Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan–Boltzmann law. In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor. We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about 4MG, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon. This long distance origin of Hawking radiation could have a profound impact on our understanding of the information and transplanckian problems.

  2. Geometric inequalities for black holes

    Energy Technology Data Exchange (ETDEWEB)

    Dain, Sergio [Universidad Nacional de Cordoba (Argentina)

    2013-07-01

    Full text: A geometric inequality in General Relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities, which are valid in the dynamical and strong field regime, play an important role in the characterization of the gravitational collapse. They are closed related with the cosmic censorship conjecture. In this talk I will review recent results in this subject. (author)

  3. Geometric inequalities for black holes

    International Nuclear Information System (INIS)

    Dain, Sergio

    2013-01-01

    Full text: A geometric inequality in General Relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities, which are valid in the dynamical and strong field regime, play an important role in the characterization of the gravitational collapse. They are closed related with the cosmic censorship conjecture. In this talk I will review recent results in this subject. (author)

  4. Black supernovae and black holes in non-local gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bambi, Cosimo [Center for Field Theory and Particle Physics and Department of Physics, Fudan University,200433 Shanghai (China); Theoretical Astrophysics, Eberhard-Karls Universität Tübingen,72076 Tübingen (Germany); Malafarina, Daniele [Department of Physics, Nazarbayev University,010000 Astana (Kazakhstan); Modesto, Leonardo [Center for Field Theory and Particle Physics and Department of Physics, Fudan University,200433 Shanghai (China)

    2016-04-22

    In a previous paper, we studied the interior solution of a collapsing body in a non-local theory of gravity super-renormalizable at the quantum level. We found that the classical singularity is replaced by a bounce, after which the body starts expanding. A black hole, strictly speaking, never forms. The gravitational collapse does not create an event horizon but only an apparent one for a finite time. In this paper, we solve the equations of motion assuming that the exterior solution is static. With such an assumption, we are able to reconstruct the solution in the whole spacetime, namely in both the exterior and interior regions. Now the gravitational collapse creates an event horizon in a finite comoving time, but the central singularity is approached in an infinite time. We argue that these black holes should be unstable, providing a link between the scenarios with and without black holes. Indeed, we find a non catastrophic ghost-instability of the metric in the exterior region. Interestingly, under certain conditions, the lifetime of our black holes exactly scales as the Hawking evaporation time.

  5. Black Psychology and Black Personality: Some Issues for Considerations

    Science.gov (United States)

    Baldwin, Joseph A.

    1976-01-01

    Discusses an emerging body of psychological literature by black behavioral scientists assumed to represent a radical departure in its conceptual orientation from the social pathology tradition advanced primarily by white behavioral scientists; and focuses on the construct of Self-Extension Orientation, a dynamic process which is assumed to…

  6. Black Students, Black Colleges: An African American College Choice Model.

    Science.gov (United States)

    McDonough, Patricia M.; Antonio, Anthony Lising; Trent, James W.

    1997-01-01

    Explores African Americans' college choice decisions, based on a national sample of 220,757 freshmen. Independent of gender, family income, or educational aspiration, the most powerful predictors for choosing historically black colleges and universities are geography, religion, the college's academic reputation, and relatives' desires. The top…

  7. Moodulitest komplekteeritav diivan Black = A modular sofa called Black

    Index Scriptorium Estoniae

    2007-01-01

    Autor Tiina Mang pälvis diivanikomplekti Black eest Eesti Sisearhitektide Liidu 2006. a. esemepreemia. T. Mangist, objektid, kuhu on valitud T. Mangi projekteeritud mööblit, näitused. 3 värv. vaadet, foto T. Mangist

  8. Interior structure of rotating black holes. III. Charged black holes

    International Nuclear Information System (INIS)

    Hamilton, Andrew J. S.

    2011-01-01

    This paper extends to the case of charged rotating black holes the conformally stationary, axisymmetric, conformally separable solutions presented for uncharged rotating black holes in a companion paper. In the present paper, the collisionless fluid accreted by the black hole may be charged. The charge of the black hole is determined self-consistently by the charge accretion rate. As in the uncharged case, hyper-relativistic counterstreaming between ingoing and outgoing streams drives inflation at (just above) the inner horizon, followed by collapse. If both ingoing and outgoing streams are charged, then conformal separability holds during early inflation, but fails as inflation develops. If conformal separability is imposed throughout inflation and collapse, then only one of the ingoing and outgoing streams can be charged: the other must be neutral. Conformal separability prescribes a hierarchy of boundary conditions on the ingoing and outgoing streams incident on the inner horizon. The dominant radial boundary conditions require that the incident ingoing and outgoing number densities be uniform with latitude, but the charge per particle must vary with latitude such that the incident charge densities vary in proportion to the radial electric field. The subdominant angular boundary conditions require specific forms of the incident number- and charge-weighted angular motions. If the streams fall freely from outside the horizon, then the prescribed angular conditions can be achieved by the charged stream, but not by the neutral stream. Thus, as in the case of an uncharged black hole, the neutral stream must be considered to be delivered ad hoc to just above the inner horizon.

  9. Black hole entropy, curved space and monsters

    International Nuclear Information System (INIS)

    Hsu, Stephen D.H.; Reeb, David

    2008-01-01

    We investigate the microscopic origin of black hole entropy, in particular the gap between the maximum entropy of ordinary matter and that of black holes. Using curved space, we construct configurations with entropy greater than the area A of a black hole of equal mass. These configurations have pathological properties and we refer to them as monsters. When monsters are excluded we recover the entropy bound on ordinary matter S 3/4 . This bound implies that essentially all of the microstates of a semiclassical black hole are associated with the growth of a slightly smaller black hole which absorbs some additional energy. Our results suggest that the area entropy of black holes is the logarithm of the number of distinct ways in which one can form the black hole from ordinary matter and smaller black holes, but only after the exclusion of monster states

  10. Atypical features of hyperthyroidism in Blacks

    International Nuclear Information System (INIS)

    Kalk, W.J.

    1980-01-01

    Hyperthyroidism is reportedly uncommon in the indigenous populations of Africa. The presenting symptoms volunteered, the symptoms elicited by direct questioning, and the results of physical examination were therefore prospectively compared in 60 Black and 56 White patients with thyrotoxicosis attending a single thyroid clinic. Fewer Blacks than Whites volunteered information about weight loss, while more Blacks complained only of the presence of a goitre. A 'chance' diagnosis of hyperthyroidism was made more frequently in Blacks. Symptomatology elicited by direct questioning and findings on physical examination were generally similar in each group, except that Blacks presented more frequently with complicated disease (cardiac failure and overt myopathy) and infiltrative ophthalmopathy. The frequency with which hyperthyroidism presents 'atypically' in Black compared with White patients may reflect educational, socio-economic and cultural differences in the Black and White populations, and may partly explain the infrequency with which this disease is diagnosed in Blacks

  11. Black Adolescent Fathers: Issues for Service Provision.

    Science.gov (United States)

    Smith, Linda Anderson

    1988-01-01

    Claims black adolescent fathers deserve attention of social work profession because they are a vulnerable population. Describes costs of adolescent parenthood, help seeking behavior of the black adolescent father, historical restriction of opportunities, and implications for social work practice. (ABL)

  12. Entropy of black holes with multiple horizons

    Science.gov (United States)

    He, Yun; Ma, Meng-Sen; Zhao, Ren

    2018-05-01

    We examine the entropy of black holes in de Sitter space and black holes surrounded by quintessence. These black holes have multiple horizons, including at least the black hole event horizon and a horizon outside it (cosmological horizon for de Sitter black holes and "quintessence horizon" for the black holes surrounded by quintessence). Based on the consideration that the two horizons are not independent each other, we conjecture that the total entropy of these black holes should not be simply the sum of entropies of the two horizons, but should have an extra term coming from the correlations between the two horizons. Different from our previous works, in this paper we consider the cosmological constant as the variable and employ an effective method to derive the explicit form of the entropy. We also try to discuss the thermodynamic stabilities of these black holes according to the entropy and the effective temperature.

  13. Black and White Differentials in Mortality.

    Science.gov (United States)

    Rene, Antonio A.; Clifford, Patrick R.

    1986-01-01

    Overviews vital statistics data, emphasizing differences in health status between the Black and White populations with respect to specific diseases and mortality. Discusses major causes of death among US Blacks. (GC)

  14. Disputes i compromisos entre l'església de Girona i la noblesa: Notes d'unes difícils relacions. Segles XI i XII

    Directory of Open Access Journals (Sweden)

    Salrach, Josep M.

    1999-12-01

    Full Text Available In this article are studied the disputes or conflicts between the ecclesiastic hierarchy and the aristocracy of the country of Girona in the era of the feudal change. The sources of information are the documents of the XI-XII Century of the Chartulary call of "Carlemany", of the bishop of Girona, edited by J. M. Marqués, and the documents of the XI Century of the cathedral of Gerona, edited by R. Marti. The article is split into two parts of unequal extension. In the first, the shortest, it is summarised the problem of the relationships between the Church and the civil power in the Late Antiquity and the High Middle Ages, until the XIXII Century. The approach is general, European, but is ended this part carrying the problems to the case of Catalonia. It is a study of the context in the one which the author attempts to find the bases of the attitude of the feudal nobility in theirs disputes with the Church. In the second part of the article are studied the disputes and the engagements (more the first tan the seconds between the cathedral of Gerona and the nobility. The analysis and the description are not effected in a way concrete, examining a dispute after other, that is to say. there is no studies of cases with lineages and personages identification, because prevails the global vision and the will of identifying the principal disputes and the general and dominant reasons of each part. The questions that they have guided the investigation are: With what obstacles stumbled the reform of the Church? Which were the concrete causes of the disputes? How they were solved these disputes? Which were the political bases, material, spiritual and cultural on those which the Church of Gerona sustained their engagements with the nobility? How they were articulated these engagements? Turned out to be it a work that interprets the reform of the Church in the framework of the feudal change process, and arrives to the conclusion of the fact that the reform was

  15. Bosonic instability of charged black holes

    International Nuclear Information System (INIS)

    Gaina, A.B.; Ternov, I.M.

    1986-01-01

    The processes of spontaneous and induced production and accumulation of charged bosons on quasibound superradiant levels in the field of Kerr-Newman black hole is analysed. It is shown that bosonic instability may be caused exclusively by the rotation of the black hole. Particulary, the Reissner-Nordstrom configuration is stable. In the case of rotating and charged black hole the bosonic instability may cause an increase of charge of the black hole

  16. Black hole holography and mean field evolution

    Science.gov (United States)

    Lowe, David A.; Thorlacius, Larus

    2018-01-01

    Holographic theories representing black holes are expected to exhibit quantum chaos. We argue if the laws of quantum mechanics are expected to hold for observers inside such black holes, then such holographic theories must have a mean field approximation valid for typical black hole states, and for timescales approaching the scrambling time. Using simple spin models as examples, we examine the predictions of such an approach for observers inside black holes, and more speculatively inside cosmological horizons.

  17. Black holes and traversible wormholes: a synthesis

    OpenAIRE

    Hayward, Sean A.

    2002-01-01

    A unified framework for black holes and traversible wormholes is described, where both are locally defined by outer trapping horizons, two-way traversible for wormholes and one-way traversible for black or white holes. In a two-dimensional dilaton gravity model, examples are given of: construction of wormholes from black holes; operation of wormholes for transport, including back-reaction; maintenance of an operating wormhole; and collapse of wormholes to black holes. In spherically symmetric...

  18. Will black holes eventually engulf the Universe?

    International Nuclear Information System (INIS)

    Martin-Moruno, Prado; Jimenez Madrid, Jose A.; Gonzalez-Diaz, Pedro F.

    2006-01-01

    The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models

  19. Building blocks of a black hole

    OpenAIRE

    Bekenstein, Jacob D.; Gour, Gilad

    2002-01-01

    What is the nature of the energy spectrum of a black hole ? The algebraic approach to black hole quantization requires the horizon area eigenvalues to be equally spaced. As stressed long ago by by Mukhanov, such eigenvalues must be exponentially degenerate with respect to the area quantum number if one is to understand black hole entropy as reflecting degeneracy of the observable states. Here we construct the black hole states by means of a pair of "creation operators" subject to a particular...

  20. Radiation from the LTB black hole

    OpenAIRE

    Firouzjaee, J. T.; Mansouri, Reza

    2011-01-01

    Does a dynamical black hole embedded in a cosmological FRW background emit Hawking radiation where a globally defined event horizon does not exist? What are the differences to the Schwarzschild black hole? What about the first law of black hole mechanics? We face these questions using the LTB cosmological black hole model recently published. Using the Hamilton-Jacobi and radial null geodesic-methods suitable for dynamical cases, we show that it is the apparent horizon which contributes to the...

  1. Re-Examining the Black on Black Crime Issue: A Theoretical Essay.

    Science.gov (United States)

    Perry, Robert L.

    1989-01-01

    Discusses Black on Black crime and provides evidence that it is directly linked to American societal problems. Covers the following historical and societal influences: (1) the legacy of slavery and Jim Crow; (2) Black migration and disorder in cities; (3) the use of alcohol and drugs; and (4) policing of the Black ghetto. (JS)

  2. Black Studies, Rap and the Academy. Black Literature and Culture Series.

    Science.gov (United States)

    Baker, Houston A., Jr.

    The relationships among Black Studies as an intellectual discipline and rap music are explored. It is argued that black urban culture has provided much of the impetus for Black Studies, and that the academy and those involved in the black studies discipline should feel a responsibility to take rap music seriously as the expression of urban youth,…

  3. The Growth of Public Schools for Blacks, and the Emergence of Professional Black Savannahians.

    Science.gov (United States)

    Perdue, Robert E.

    The history of the growth of public education for the black masses, including topics such as racial attitudes toward black education, the financial problems facing black schools, and the political pressures that led to the development of a system of education for blacks, is traced and discussed in this paper -- specifically as it concerns…

  4. Language and Stylistic Influences of the Black Folk Tradition of Black Literature.

    Science.gov (United States)

    Anderson, Edward

    Because the style and language of the black folk tradition have contributed significantly to the development of the English language, an analysis of black persuasive techniques and black communication systems can enhance the teaching of composition, rhetoric, and literature for both black and white students. Some of the persuasive techniques of…

  5. "No Cosby Show": Single Black Mother Homes and How Black Men Build Romantic Relationships

    Science.gov (United States)

    Moore, Maia Niguel

    2016-01-01

    This qualitative study explored the lives of 11 Black men to better understand how Black men who were raised in single Black mother homes build romantic relationships with Black women. One focus group and a series of individual in-person interviews were conducted with the participants who ranged between 23 and 43 years of age. Participants were…

  6. Black English: A Strength Analysis of Non-Standard English in Black Dialect.

    Science.gov (United States)

    Bousquet, Robert J.

    Many black students speak a nonprestige dialect called black English, which places them at a disadvantage academically and socially. This monograph describes the features of black English, defines its use, discusses several theories of its origin, and offers some methods for teaching black students standard spoken usage as another style of speech.…

  7. Black Hawkid harjutasid Pakri poolsaarel

    Index Scriptorium Estoniae

    2014-01-01

    USA 173. õhudessantbrigaadi Eestis viibiv kompanii ja Scoutspataljoni C-kompanii jalaväerühma kaitseväelased alustasid eile ühisõppust, mille käigus harjutatakse kahe Black Hawk UH-60 helikopteriga nelja Pakri poolsaarel asuva õppeobjekti ründamist

  8. Black Holes in Our Universe

    Indian Academy of Sciences (India)

    Current technologies have enabled glimpses at the many facetsof black holes, which we know to be plentiful in our cosmos.A panoramic view of the evidence for them is presented hereacross the large range of masses that they span. Author Affiliations. Prajval Shastri. Resonance – Journal of Science Education.

  9. The Award Winning Black Suns

    Science.gov (United States)

    Holbrook, Jarita

    2018-01-01

    Black Suns: An Astrophysics Adventure is a documentary film focusing on the annular and total solar eclipses of 2012. We made a different kind of astronomy documentary showing the human aspects rather than just focusing on pretty astronomy pictures. The film combines personal stories with science. Our heroes are Hakeem Oluseyi and Alphonse Sterling, who valiantly travel to study the solar corona during total solar eclipses. The goals of the film included presenting three dimensional scientists, to show their paths to becoming astrophysicists, and to show them as they collect data and work as scientists. Drama and tension surround taking data during the small window of time during totality. The Black Suns was filmed in Tokyo, Cairns, Tucson, and Melbourne Florida. Uniquely, the film began through a Kickstarter campaign to fund travel and filming in Tokyo. Many American Astronomical Society members donated to the film! Black Suns won the Jury Prize at the 2017 Art of Brooklyn Film Festival. Black Suns will be screening in full on ???.

  10. Satellite monitoring of black bear.

    Science.gov (United States)

    Craighead, J. J.; Craighead, F. C., Jr.; Varney, J. R.; Cote, C. E.

    1971-01-01

    Description of a feasibility experiment recently performed to test the use of a satellite system for telemetering environmental and physiological data from the winter den of a 'hibernating' black bear, Ursus americanus. The instrumentation procedure and evaluations of the equipment performance and sensory data obtained are discussed in detail.

  11. ECONOMIC CRISIS SUSTAINS BLACK MARKET

    Directory of Open Access Journals (Sweden)

    Dicoi Daniel -Ioan

    2012-12-01

    Full Text Available The purpose of this research is to bring out the fact that during the periods of economic crisis, the black market finds a warm place to develop and even to diversify the ways of expressing. Based on some data of the National Institute of Statistics and the Organization for Economic Co-operation and Development (OECD1 , I’m trying to prove the fact that during the last two years while the world economic crisis has occurred, the black market has been increasing and there have been new forms of expressing this phenomenon. Although there are some positive ways of this phenomenon, on the whole, the increasing of the black market percent of GDP represents a wound within a healthy economy, which if it cannot be stopped at least to be reduced. This work intends to make radiography of the present economic society, a period of economic crisis, during which the black market has found a warm place to express and extend, in most of the countries, including the developed ones, this phenomenon has reached alarming limits.

  12. 'Black holes': escaping the void.

    Science.gov (United States)

    Waldron, Sharn

    2013-02-01

    The 'black hole' is a metaphor for a reality in the psyche of many individuals who have experienced complex trauma in infancy and early childhood. The 'black hole' has been created by an absence of the object, the (m)other, so there is no internalized object, no (m)other in the psyche. Rather, there is a 'black hole' where the object should be, but the infant is drawn to it, trapped by it because of an intrinsic, instinctive need for a 'real object', an internalized (m)other. Without this, the infant cannot develop. It is only the presence of a real object that can generate the essential gravity necessary to draw the core of the self that is still in an undeveloped state from deep within the abyss. It is the moving towards a real object, a (m)other, that relativizes the absolute power of the black hole and begins a reformation of its essence within the psyche. © 2013, The Society of Analytical Psychology.

  13. Stellar dynamics and black holes

    Indian Academy of Sciences (India)

    Stellar dynamics and black holes. DAVID MERRITT. Department of Physics, Rochester Institute of Technology, 78 Lomb Memorial Drive, Rochester,. NY 14623, USA. E-mail: merritt@astro.rit.edu. Abstract. Chandrasekhar's most important contribution to stellar dynamics was the concept of dynamical friction. I briefly review ...

  14. From Pinholes to Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  15. Black Holes and Exotic Spinors

    Directory of Open Access Journals (Sweden)

    J. M. Hoff da Silva

    2016-05-01

    Full Text Available Exotic spin structures are non-trivial liftings, of the orthogonal bundle to the spin bundle, on orientable manifolds that admit spin structures according to the celebrated Geroch theorem. Exotic spin structures play a role of paramount importance in different areas of physics, from quantum field theory, in particular at Planck length scales, to gravity, and in cosmological scales. Here, we introduce an in-depth panorama in this field, providing black hole physics as the fount of spacetime exoticness. Black holes are then studied as the generators of a non-trivial topology that also can correspond to some inequivalent spin structure. Moreover, we investigate exotic spinor fields in this context and the way exotic spinor fields branch new physics. We also calculate the tunneling probability of exotic fermions across a Kerr-Sen black hole, showing that the exotic term does affect the tunneling probability, altering the black hole evaporation rate. Finally we show that it complies with the Hawking temperature universal law.

  16. [The black death in Norway].

    Science.gov (United States)

    Oeding, P

    1990-06-30

    The old Icelandic annals tell that the Black Death came to Bergen, Norway, in 1349 with a ship from England. This was probably at the beginning of September. From Bergen the plague spread rapidly northwards and southwards along the coast and over land to Eastern Norway. The Black Death remained in Norway for approximately six months. The epidemic must have been started by infected black rats and rat fleas in the grain cargo of the ship. The account in the annals, and experiences from other countries, indicate that pneumonic plague was dominant in Bergen at the start of the epidemic. After that the Black Death must have spread partly as pneumonic plague but mainly probably as bubonic plague, transmitted via human fleas from person to person. The rats cannot have played a part except in the initial phase. The annals say that 2/3 of Norway's population died. This is probably a big exaggeration. The mortality in Norway can hardly have been more than 40-50%. Even this is high compared with an estimated mortality of approximately 33% in England and on the continent.

  17. Transracial Adoption of Black Children

    Science.gov (United States)

    Chimezie, Amuzie

    1975-01-01

    The author discusses the advantages and disadvantages of the adoption of black children by white parents. He concludes that until empirical studies are made, placements should not proceed as if it had already been ascertained that transracial adoption is beneficial. (Author/BW)

  18. Why Black Officers Still Fail

    Science.gov (United States)

    2010-03-01

    National Endowment of the Arts reported that Whites were three times as likely as Blacks to attend a classical music performance, opera or ballet ...Conclusion Although one would like to believe that the Army has progressed to a point in its history where race is no longer a factor in the success or

  19. The Migration Experience of Blacks

    Science.gov (United States)

    Long, Larry

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights, concludes that in many ways northern cities seem to be characterized not so much by excessive migration of blacks from the south, but by inadequate migration from one northern metropolitan area to another. (Author/JM)

  20. Android for the Beaglebone Black

    CERN Document Server

    Henderson, Andrew

    2015-01-01

    If you are an Android app developer who wants to experiment with the hardware capabilities of the BeagleBone Black platform, then this book is ideal for you. You are expected to have basic knowledge of developing Android apps but no prior hardware experience is required.

  1. Black Hole Macro-Quantumness

    CERN Document Server

    Dvali, Gia

    2014-01-01

    It is a common wisdom that properties of macroscopic bodies are well described by (semi)classical physics. As we have suggested this wisdom is not applicable to black holes. Despite being macroscopic, black holes are quantum objects. They represent Bose-Einstein condensates of N-soft gravitons at the quantum critical point, where N Bogoliubov modes become gapless. As a result, physics governing arbitrarily-large black holes (e.g., of galactic size) is a quantum physics of the collective Bogoiliubov modes. This fact introduces a new intrinsically-quantum corrections in form of 1/N, as opposed to exp(-N). These corrections are unaccounted by the usual semiclassical expansion in h and cannot be recast in form of a quantum back-reaction to classical metric. Instead the metric itself becomes an approximate entity. These 1/N corrections abolish the presumed properties of black holes, such as non existence of hair, and are the key to nullifying the so-called information paradox.

  2. Eerste bevindingen onderzoek Black Mold

    NARCIS (Netherlands)

    Werd, de H.A.E.

    2008-01-01

    In de zomer van 2007 veroorzaakte de ziekte Black Mold grote schade in de rozenteelt. Omdat er weinig bekend is over preventie en bestrijding hebben PPO Bomen en Cultus Agro Advies een onderzoeksproject gestart, waarvan de eerste resultaten inmiddels bekend zijn.

  3. Black Womanhood and Feminist Standpoints.

    Science.gov (United States)

    Allen, Brenda J.

    1998-01-01

    Discusses challenges and consequences of being a member of two historically oppressed groups in the United States--Blacks and females. Relies on feminist standpoint theory--a distinctive element of contemporary feminist thought about how knowledge is constructed. Focuses on academe as a discursive site for constructing identity. (PA)

  4. Body Image Satisfaction among Blacks

    Science.gov (United States)

    Gustat, Jeanette; Carton, Thomas W.; Shahien, Amir A.; Andersen, Lori

    2017-01-01

    Satisfaction with body image is a factor related to health outcomes. The purpose of this study is to examine the relationship between body image satisfaction and body size perception in an urban, Black community sample in New Orleans, Louisiana. Only 42.2% of respondents were satisfied with their body image and 44.1% correctly perceived their body…

  5. Black Holes: A Selected Bibliography.

    Science.gov (United States)

    Fraknoi, Andrew

    1991-01-01

    Offers a selected bibliography pertaining to black holes with the following categories: introductory books; introductory articles; somewhat more advanced articles; readings about Einstein's general theory of relativity; books on the death of stars; articles on the death of stars; specific articles about Supernova 1987A; relevant science fiction…

  6. Motor neuron disease in blacks

    African Journals Online (AJOL)

    1989-08-19

    Aug 19, 1989 ... We reported earlier that motor neuron disease occurs more commonly among blacks than Parkinson's disease, which is relatively rare in this race group.! The hypothesis that these conditions, and other neuronal abiotrophies, are the result of previous subclinical neuronal insult and subsequent age-related.

  7. Wands of the Black Ring

    Czech Academy of Sciences Publication Activity Database

    Pravda, Vojtěch; Pravdová, Alena

    2005-01-01

    Roč. 37, č. 7 (2005), s. 1277-1287 ISSN 0001-7701 R&D Projects: GA ČR GP202/03/P017; GA AV ČR KJB1019403 Institutional research plan: CEZ:AV0Z10190503 Keywords : algebraic classification * Petrov classification * black ring Subject RIV: BA - General Mathematics Impact factor: 1.550, year: 2005

  8. A Black Hole Spectral Signature

    Science.gov (United States)

    Titarchuk, Lev; Laurent, Philippe

    2000-03-01

    An accreting black hole is, by definition, characterized by the drain. Namely, the matter falls into a black hole much the same way as water disappears down a drain matter goes in and nothing comes out. As this can only happen in a black hole, it provides a way to see ``a black hole'', an unique observational signature. The accretion proceeds almost in a free-fall manner close to the black hole horizon, where the strong gravitational field dominates the pressure forces. In this paper we present analytical calculations and Monte-Carlo simulations of the specific features of X-ray spectra formed as a result of upscattering of the soft (disk) photons in the converging inflow (CI) into the black hole. The full relativistic treatment has been implemented to reproduce these spectra. We show that spectra in the soft state of black hole systems (BHS) can be described as the sum of a thermal (disk) component and the convolution of some fraction of this component with the CI upscattering spread (Greens) function. The latter boosted photon component is seen as an extended power-law at energies much higher than the characteristic energy of the soft photons. We demonstrate the stability of the power spectral index over a wide range of the plasma temperature 0 - 10 keV and mass accretion rates (higher than 2 in Eddington units). We also demonstrate that the sharp high energy cutoff occurs at energies of 200-400 keV which are related to the average energy of electrons mec2 impinging upon the event horizon. The spectrum is practically identical to the standard thermal Comptonization spectrum when the CI plasma temperature is getting of order of 50 keV (the typical ones for the hard state of BHS). In this case one can see the effect of the bulk motion only at high energies where there is an excess in the CI spectrum with respect to the pure thermal one. Furthermore we demonstrate that the change of spectral shapes from the soft X-ray state to the hard X-ray state is clearly to be

  9. On black holes and gravitational waves

    CERN Document Server

    Loinger, Angelo

    2002-01-01

    Black holes and gravitational waves are theoretical entities of today astrophysics. Various observed phenomena have been associated with the concept of black hole ; until now, nobody has detected gravitational waves. The essays contained in this book aim at showing that the concept of black holes arises from a misinterpretation of general relativity and that gravitational waves cannot exist.

  10. A Black Hole in Our Galactic Center

    Science.gov (United States)

    Ruiz, Michael J.

    2008-01-01

    An introductory approach to black holes is presented along with astronomical observational data pertaining to the presence of a supermassive black hole at the center of our galaxy. Concepts of conservation of energy and Kepler's third law are employed so students can apply formulas from their physics class to determine the mass of the black hole…

  11. Compensating Scientism through "The Black Hole."

    Science.gov (United States)

    Roth, Lane

    The focal image of the film "The Black Hole" functions as a visual metaphor for the sacred, order, unity, and eternal time. The black hole is a symbol that unites the antinomic pairs of conscious/unconscious, water/fire, immersion/emersion, death/rebirth, and hell/heaven. The black hole is further associated with the quest for…

  12. Hawking radiation of black rings from anomalies

    International Nuclear Information System (INIS)

    Chen Bin; He Wei

    2008-01-01

    We derive Hawking radiation of five-dimensional black rings from gauge and gravitational anomalies using the method proposed by Robinson and Wilczek. We find, as in the black hole case, that the problem could reduce to a (1+1)-dimensional field theory and the anomalies result in correct Hawking temperature for neutral, dipole and charged black rings

  13. On Being an Angry Black Man

    Science.gov (United States)

    Quaye, Stephen John

    2017-01-01

    Black men are often seen as problems, threats, and thugs. The mere existence of a Black body is often met with fear. Using autoethnographic mystory, I blend personal stories, poetry, song lyrics, and analysis to subvert the angry Black man mantra and explore the productive use of anger to stimulate change.

  14. The Decline of Black Farming in America.

    Science.gov (United States)

    Browning, Pamela; And Others

    The rapid decline in the number of farms operated by blacks in the United States, and the consequences of this decline on the conditions of black farmers are the focus of this report. Chapter 1 compares the rate of agricultural land loss from 1900 to 1978 among blacks and whites. Chapter 2 outlines historical conditions, such as racism, lack of…

  15. The State of Black America, 1978.

    Science.gov (United States)

    Anderson, Bernard E.; And Others

    In this report seven scholars (Bernard Anderson, James Dumpson, Charles Hamilton, Robert Hill, Vernon Jordan, Jr., Bernard Watson and Robert Weaver) appraise the social, economic, political, and educational status of blacks and black families. Minimal gains and poor prospects for black female heads of families in the current recession job market…

  16. Area spectra of near extremal black holes

    International Nuclear Information System (INIS)

    Chen, Deyou; Yang, Haitang; Zu, Xiaotao

    2010-01-01

    Motivated by Maggiore's new interpretation of quasinormal modes, we investigate area spectra of a near extremal Schwarzschild-de Sitter black hole and a higher-dimensional near extremal Reissner-Nordstrom-de Sitter black hole. The result shows that the area spectra are equally spaced and irrelevant to the parameters of the black holes. (orig.)

  17. Extremal black holes in N=2 supergravity

    NARCIS (Netherlands)

    Katmadas, S.

    2011-01-01

    An explanation for the entropy of black holes has been an outstanding problem in recent decades. A special case where this is possible is that of extremal black holes in N=2 supergravity in four and five dimensions. The best developed case is for black holes preserving some supersymmetry (BPS),

  18. On Quantum Contributions to Black Hole Growth

    NARCIS (Netherlands)

    Spaans, M.

    2013-01-01

    The effects of Wheeler’s quantum foam on black hole growth are explored from an astrophysical per- spective. Quantum fluctuations in the form of mini (10−5 g) black holes can couple to macroscopic black holes and allow the latter to grow exponentially in mass on a time scale of 109 years.

  19. Black Hole Monodromy and Conformal Field Theory

    NARCIS (Netherlands)

    Castro, A.; Lapan, J.M.; Maloney, A.; Rodriguez, M.J.

    2013-01-01

    The analytic structure of solutions to the Klein-Gordon equation in a black hole background, as represented by monodromy data, is intimately related to black hole thermodynamics. It encodes the "hidden conformal symmetry" of a nonextremal black hole, and it explains why features of the inner event

  20. Transracial Adoption: The Black Community Perspective

    Science.gov (United States)

    Howard, Alicia; And Others

    1977-01-01

    How does a cross section of the black community feel about white parents adopting black children? This study suggests that the majority of blacks do not support the militant position against transracial adoption and, in fact, favor such adoption when the alternative is institutionalization. (Author)

  1. Blacks on TV: Adjusting the Image.

    Science.gov (United States)

    Bayles, Martha

    1985-01-01

    The stereotyping of Blacks on television has changed in nature but continues despite the networks' awkward efforts to avoid accusation of racism. Today, situation comedies and detective shows include Blacks in positive roles, but very few portray Blacks as realistically or authentically as Whites are portrayed. (KH)

  2. The Chicano and the Black Legend.

    Science.gov (United States)

    Sanchez, Porfirio

    An historical overview traces the Black Legend about persons of Spanish descent and seeks to demonstrate the influence of the Black Legend on Anglo attitudes towards Mexican Americans. The beginnings of the Black Legend are found in the sixteenth century when European countries in conflict with Spain used Spanish actions during the Sack of Rome,…

  3. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    loops [8]. In 1974, Hawking discovered that the black holes emit thermal radiation due to quantum effects [9]. So the black holes get evaporated depending upon their masses. Smaller the masses of the PBHs, quicker they evaporate. But the density of a black hole varies inversely with its mass. So high density is needed for ...

  4. White holes and eternal black holes

    International Nuclear Information System (INIS)

    Hsu, Stephen D H

    2012-01-01

    We investigate isolated white holes surrounded by vacuum, which correspond to the time reversal of eternal black holes that do not evaporate. We show that isolated white holes produce quasi-thermal Hawking radiation. The time reversal of this radiation, incident on a black hole precursor, constitutes a special preparation that will cause the black hole to become eternal. (paper)

  5. Black holes under external influence

    Indian Academy of Sciences (India)

    In particular we pay attention to the effect of the expulsion of the flux of external fields across charged and rotating black holes which are approaching extremal states. Recently this effect has been shown to occur for black hole solutions in string theory. We also discuss black holes surrounded by rings and disks and rotating ...

  6. The fuzzball proposal for black holes

    NARCIS (Netherlands)

    Skenderis, K.; Taylor, M.

    2008-01-01

    The fuzzball proposal states that associated with a black hole of entropy S, there are expS horizon-free non-singular solutions that asymptotically look like the black hole but generically differ from the black hole up to the horizon scale. These solutions, the fuzzballs, are considered to be the

  7. IQ Tests and the Black Culture

    Science.gov (United States)

    McNiel, Nathaniel D.

    1975-01-01

    On a test (Black Intelligence Test of Cultural Homogeneity) oriented toward the language, attitudes, and life-styles of Afro-Americans, white students perform more poorly than blacks do on tests oriented toward white middle-class values, indicating that there are important dissimilarities in the cultural backgrounds of blacks and whites.…

  8. Therapeutic Dimensions of the Black Aesthetic

    Science.gov (United States)

    Toldson, Ivory L.; Pasteur, Alfred B.

    1976-01-01

    The authors of this article see the black aesthetic largely in terms of the affective component. Emotional oneness which is foreign to the white world view is the means by which the black man can achieve optimal mental health and development. The therapeutic implications of the black aesthetic are outlined. (NG)

  9. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Abstract. Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the con- jecture that the primordial ...

  10. Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

    OpenAIRE

    Takahashi, Rohta

    2004-01-01

    Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin paramete...

  11. Black holes, qubits and octonions

    Energy Technology Data Exchange (ETDEWEB)

    Borsten, L. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)], E-mail: leron.borsten@imperial.ac.uk; Dahanayake, D. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)], E-mail: duminda.dahanayake@imperial.ac.uk; Duff, M.J. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)], E-mail: m.duff@imperial.ac.uk; Ebrahim, H. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom); Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Theory Group, Martin Fisher School of Physics, Brandeis University, MS057, 415 South Street, Waltham, MA 02454 (United States)], E-mail: hebrahim@brandeis.edu; Rubens, W. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)], E-mail: william.rubens06@imperial.ac.uk

    2009-02-15

    We review the recently established relationships between black hole entropy in string theory and the quantum entanglement of qubits and qutrits in quantum information theory. The first example is provided by the measure of the tripartite entanglement of three qubits (Alice, Bob and Charlie), known as the 3-tangle, and the entropy of the 8-charge STU black hole of N=2 supergravity, both of which are given by the [SL(2)]{sup 3} invariant hyperdeterminant, a quantity first introduced by Cayley in 1845. Moreover the classification of three-qubit entanglements is related to the classification of N=2 supersymmetric STU black holes. There are further relationships between the attractor mechanism and local distillation protocols and between supersymmetry and the suppression of bit flip errors. At the microscopic level, the black holes are described by intersecting D3-branes whose wrapping around the six compact dimensions T{sup 6} provides the string-theoretic interpretation of the charges and we associate the three-qubit basis vectors, |ABC>(A,B,C=0 or 1), with the corresponding 8 wrapping cycles. The black hole/qubit correspondence extends to the 56 charge N=8 black holes and the tripartite entanglement of seven qubits where the measure is provided by Cartan's E{sub 7} contains [SL(2)]{sup 7} invariant. The qubits are naturally described by the seven vertices ABCDEFG of the Fano plane, which provides the multiplication table of the seven imaginary octonions, reflecting the fact that E{sub 7} has a natural structure of an O-graded algebra. This in turn provides a novel imaginary octonionic interpretation of the 56=7x8 charges of N=8: the 24=3x8 NS-NS charges correspond to the three imaginary quaternions and the 32=4x8 R-R to the four complementary imaginary octonions. We contrast this approach with that based on Jordan algebras and the Freudenthal triple system. N=8 black holes (or black strings) in five dimensions are also related to the bipartite entanglement of

  12. Phase transition for black holes with scalar hair and topological black holes

    International Nuclear Information System (INIS)

    Myung, Yun Soo

    2008-01-01

    We study phase transitions between black holes with scalar hair and topological black holes in asymptotically anti-de Sitter spacetimes. As the ground state solutions, we introduce the non-rotating BTZ black hole in three dimensions and topological black hole with hyperbolic horizon in four dimensions. For the temperature matching only, we show that the phase transition between black hole with scalar hair (Martinez-Troncoso-Zanelli black hole) and topological black hole is second-order by using differences between two free energies. However, we do not identify what order of the phase transition between scalar and non-rotating BTZ black holes occurs in three dimensions, although there exists a possible decay of scalar black hole to non-rotating BTZ black hole

  13. Chandra Catches "Piranha" Black Holes

    Science.gov (United States)

    2007-07-01

    Supermassive black holes have been discovered to grow more rapidly in young galaxy clusters, according to new results from NASA's Chandra X-ray Observatory. These "fast-track" supermassive black holes can have a big influence on the galaxies and clusters that they live in. Using Chandra, scientists surveyed a sample of clusters and counted the fraction of galaxies with rapidly growing supermassive black holes, known as active galactic nuclei (or AGN). The data show, for the first time, that younger, more distant galaxy clusters contained far more AGN than older, nearby ones. Galaxy clusters are some of the largest structures in the Universe, consisting of many individual galaxies, a few of which contain AGN. Earlier in the history of the universe, these galaxies contained a lot more gas for star formation and black hole growth than galaxies in clusters do today. This fuel allows the young cluster black holes to grow much more rapidly than their counterparts in nearby clusters. Illustration of Active Galactic Nucleus Illustration of Active Galactic Nucleus "The black holes in these early clusters are like piranha in a very well-fed aquarium," said Jason Eastman of Ohio State University (OSU) and first author of this study. "It's not that they beat out each other for food, rather there was so much that all of the piranha were able to really thrive and grow quickly." The team used Chandra to determine the fraction of AGN in four different galaxy clusters at large distances, when the Universe was about 58% of its current age. Then they compared this value to the fraction found in more nearby clusters, those about 82% of the Universe's current age. The result was the more distant clusters contained about 20 times more AGN than the less distant sample. AGN outside clusters are also more common when the Universe is younger, but only by factors of two or three over the same age span. "It's been predicted that there would be fast-track black holes in clusters, but we never

  14. Modified dispersion relations and black hole physics

    International Nuclear Information System (INIS)

    Ling Yi; Li Xiang; Hu Bo

    2006-01-01

    A modified formulation of the energy-momentum relation is proposed in the context of doubly special relativity. We investigate its impact on black hole physics. It turns out that such a modification will give corrections to both the temperature and the entropy of black holes. In particular, this modified dispersion relation also changes the picture of Hawking radiation greatly when the size of black holes approaches the Planck scale. It can prevent black holes from total evaporation, as a result providing a plausible mechanism to treat the remnant of black holes as a candidate for dark matter

  15. Dyonic black hole in heterotic string theory

    International Nuclear Information System (INIS)

    Jatkar, D.P.; Mukherji, S.

    1997-01-01

    We study some features of the dyonic black hole solution in heterotic string theory on a six-torus. This solution has 58 parameters. Of these, 28 parameters denote the electric charge of the black hole, another 28 correspond to the magnetic charge, and the other two parameters are the mass and the angular momentum of the black hole. We discuss the extremal limit and show that in various limits it reduces to the known black hole solutions. The solutions saturating the Bogomolnyi bound are identified. An explicit solution is presented for the non-rotating dyonic black hole. (orig.)

  16. Black-hole creation in quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Chao, Wu [Rome, Univ. `La Sapienza` (Italy). International Center for Relativistic Astrophysics]|[Specola Vaticana, Vatican City State (Vatican City State, Holy See)

    1997-11-01

    It is proven that the probability of a black hole created from the de Sitter space-time background, at the Wkb level, is the exponential of one quarter of the sum of the black hole and cosmological horizon areas, or the total entropy of the universe. This is true not only for the spherically symmetric cases of the Schwarzschild or Reissner-Nordstroem black holes, but also for the rotating cases of the Kerr black hole and the rotating charged case of the Newman black hole. The de Sitter metric is the most probable evolution at the Planckian era of the universe.

  17. Few-layer black phosphorus nanoparticles.

    Science.gov (United States)

    Sofer, Zdenek; Bouša, Daniel; Luxa, Jan; Mazanek, Vlastimil; Pumera, Martin

    2016-01-28

    Herein, black phosphorus quantum dots and nanoparticles of a few layer thickness were prepared and characterized using STEM, AFM, dynamic light scattering, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and photoluminescence. Impact electrochemistry of the induvidual black phosphorus nanoparticles allows their size determination. The centrifugation of colloidal black phosphorus nanoparticles allowed separation of quantum dots with sizes up to 15 nm. These black phosphorus nanoparticles exhibit a large band gap and are expected to find a wide range of applications from semiconductors to biomolecule tags. The use of black phosphorus nanoparticles for vapour sensing was successfully demonstrated.

  18. Black hole entropy and quantum information

    CERN Document Server

    Duff, M J

    2006-01-01

    We review some recently established connections between the mathematics of black hole entropy in string theory and that of multipartite entanglement in quantum information theory. In the case of N=2 black holes and the entanglement of three qubits, the quartic [SL(2)]^3 invariant, Cayley's hyperdeterminant, provides both the black hole entropy and the measure of tripartite entanglement. In the case of N=8 black holes and the entanglement of seven qubits, the quartic E_7 invariant of Cartan provides both the black hole entropy and the measure of a particular tripartite entanglement encoded in the Fano plane.

  19. Black Holes Shed Light on Galaxy Formation

    Science.gov (United States)

    2000-01-01

    This videotape is comprised of several segments of animations on black holes and galaxy formation, and several segments of an interview with Dr. John Kormendy. The animation segments are: (1) a super massive black hole, (2) Centarus A active black hole found in a collision, (3) galaxy NGC-4261 (active black hole and jet model), (4) galaxy M-32 (orbits of stars are effected by the gravity of the black hole), (5) galaxy M-37 (motion of stars increases as mass of black hole increases), (6) Birth of active galactic nuclei, (7) the collision of two galaxy leads to merger of the black holes, (8) Centarus A and simulation of the collision of 2 galaxies. There are also several segments of an interview with John Kormendy. In these segments he discusses the two most important aspects of his recent black hole work: (1) the correlations between galaxies speed and the mass of the black holes, and (2) the existence of black holes and galactic formation. He also discusses the importance of the Hubble Space Telescope and the Space Telescope Imaging Spectrograph to the study of black holes. He also shows the methodology of processing images from the spectrograph in his office.

  20. Extremal vacuum black holes in higher dimensions

    International Nuclear Information System (INIS)

    Figueras, Pau; Lucietti, James; Rangamani, Mukund; Kunduri, Hari K.

    2008-01-01

    We consider extremal black hole solutions to the vacuum Einstein equations in dimensions greater than five. We prove that the near-horizon geometry of any such black hole must possess an SO(2,1) symmetry in a special case where one has an enhanced rotational symmetry group. We construct examples of vacuum near-horizon geometries using the extremal Myers-Perry black holes and boosted Myers-Perry strings. The latter lead to near-horizon geometries of black ring topology, which in odd spacetime dimensions have the correct number of rotational symmetries to describe an asymptotically flat black object. We argue that a subset of these correspond to the near-horizon limit of asymptotically flat extremal black rings. Using this identification we provide a conjecture for the exact 'phase diagram' of extremal vacuum black rings with a connected horizon in odd spacetime dimensions greater than five.