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1

Variation in the reproductive rate of bats  

Microsoft Academic Search

In many respects, bats have relatively slow life histories. However, the reproductive rate of bats (i.e., the proportion of females that reproduce in any breeding season) has not been critically examined. We compiled data on the reproductive rates of bats to test predictions based on life-history theory. Among 257 samples from 103 species, re - productive rate varied considerably and

Robert M. R. Barclay; Joel Ulmer; Cameron J. A. MacKenzie; Megan S. Thompson; Leif Olson; Julianne McCool; Elvie Cropley; Graeme Poll

2004-01-01

2

Management of Replacement Heifers for a High Reproductive and Calving Rate.  

E-print Network

calving early . Early calving cows wean more pounds of calf because their calves are older at weaning and have a higher rate of gain from birth to weaning (1, 2) . Table 1 summarizes a study in which 8,742 calves were divided into three groups based... . The following is an outline of a heifer development sys tem that has proven successful and economical on Table 1. The relationship between actual weaning weight of calves and their time of birth during a 50-day period (3). Weaningwt. Number of Weaning Weaning...

Beverly, John R.; Spitzer, John C.

1980-01-01

3

High rates of pregnancy loss by subordinates leads to high reproductive skew in wild golden lion tamarins (Leontopithecus rosalia)  

E-print Network

golden lion tamarins (Leontopithecus rosalia) MaLinda D. Henry, Sarah J. Hankerson, Jennifer M. Siani reproductive skew in wild golden lion tamarins (Leontopithecus rosalia), Hormones and Behavior (2013), doi: 10 in wild golden lion tamarins (Leontopithecus rosalia) MaLinda D. Henrya* , Sarah J. Hankersona1 , Jennifer

French, Jeffrey A.

4

Reproductive Health for Afghan Women: Decreasing High Maternal Mortality Rates by Increasing Access to Reproductive Health and Education A Proposal for Advocacy and Change  

Microsoft Academic Search

This proposal examines the social, cultural, political and structural factors that contribute to high maternal mortality rates in Afghanistan and women’s severe lack of access to adequate health services and education, particularly in the more rural areas of the country. Some of the factors contributing to high maternal mortality rates are distance, lack of trained female doctors and nurses, lack

Rosalia Abreu

2011-01-01

5

Variable male potential rate of reproduction: high male mating capacity as an adaptation to parasite-induced excess of females?  

PubMed Central

Numerous animals are known to harbour intracytoplasmic symbionts that gain transmission to a new host generation via female eggs and not male sperm. Bacteria of the genus Wolbachia are a typical example. They infect a large range of arthropod species and manipulate host reproduction in several ways. In terrestrial isopods (woodlice), Wolbachia are responsible for converting males into females (feminization (F)) in some species, or for infertility in certain host crosses in other species (cytoplasmic incompatibility (CI)). Wolbachia with the F phenotype impose a strong excess of females on their host populations, while Wolbachia expressing CI do not. Here, we test the possibility that male mating capacity (MC) is correlated with Wolbachia-induced phenotype. We show that males of isopod hosts harbouring F Wolbachia possess a strong MC (i.e. are able to mate with several females in a short time), while those of species harbouring CI Wolbachia possess a weaker MC. This pattern may be explained either by the selection of high MC following the increase in female-biased sex ratios, or because the F phenotype would lead to population extinction in species where MC is not sufficiently high. This last hypotheses is nevertheless more constrained by population structure. PMID:12965021

Moreau, Jerome; Rigaud, Thierry

2003-01-01

6

Variable male potential rate of reproduction: high male mating capacity as an adaptation to parasite-induced excess of females?  

PubMed

Numerous animals are known to harbour intracytoplasmic symbionts that gain transmission to a new host generation via female eggs and not male sperm. Bacteria of the genus Wolbachia are a typical example. They infect a large range of arthropod species and manipulate host reproduction in several ways. In terrestrial isopods (woodlice), Wolbachia are responsible for converting males into females (feminization (F)) in some species, or for infertility in certain host crosses in other species (cytoplasmic incompatibility (CI)). Wolbachia with the F phenotype impose a strong excess of females on their host populations, while Wolbachia expressing CI do not. Here, we test the possibility that male mating capacity (MC) is correlated with Wolbachia-induced phenotype. We show that males of isopod hosts harbouring F Wolbachia possess a strong MC (i.e. are able to mate with several females in a short time), while those of species harbouring CI Wolbachia possess a weaker MC. This pattern may be explained either by the selection of high MC following the increase in female-biased sex ratios, or because the F phenotype would lead to population extinction in species where MC is not sufficiently high. This last hypotheses is nevertheless more constrained by population structure. PMID:12965021

Moreau, Jérôme; Rigaud, Thierry

2003-07-22

7

High levels of habitat loss and fragmentation limit reproductive success by reducing home range size and provisioning rates of Northern saw-whet owls  

Microsoft Academic Search

Studies of the effects of habitat fragmentation have been heavily biased toward population and community questions, with less attention on the effects of habitat loss and fragmentation on individual behaviour and reproduction. We studied the effects of habitat amount and configuration on the foraging behaviour, provisioning rates and physiological condition of breeding male northern saw-whet owls (Aegolius acadicus) nesting in

Heather Lynn Hinam; Colleen Cassady St. Clair

2008-01-01

8

INTAKE RATES AND THE TIMING OF CROSSBILL REPRODUCTION  

Microsoft Academic Search

I measured the foraging rates of breeding and nonbreeding populations of White-winged Crossbills (Loxia leucoptera) and Red Crossbills (L. curvirostra) throughout the year in the northeastern United States and adjacent Canada. I compared actual food intake rates (80 samples from 26 populations) to those predicted for five hypotheses that pertain to the timing of reproduction. To form eggs, crossbills required

CRAIG W. BENKMAN

9

High survival during hibernation affects onset and timing of reproduction.  

PubMed

The timing of reproduction is one of the most crucial life history traits, with enormous consequences for the fitness of an individual. We investigated the effects of season and timing of birth on local survival probability in a small mammalian hibernator, the common dormouse (Muscardinus avellanarius). Local monthly survival probability was lowest in the early active season (May-August, ?(adult) = 0.75-0.88, ?(juvenile) = 0.61-0.68), increased during the late active season (August-October), and highest during hibernation (October-May, ?(adult) = 0.96-0.98, ?(juvenile) = 0.81-0.94). Consequently, dormice had an extremely high winter survival probability. We observed two peaks in the timing of reproduction (June and August/September, respectively), with the majority of juveniles born late in the active season. Although early investment in reproduction seems the better life history tactic [survival probability until onset of reproduction: ?(born early) = 0.46, 95% confidence interval (CI) 0.28-0.64; ?(born late) = 0.19, 95% CI = 0.09-0.28], only females with a good body condition (significantly higher body mass) invest in reproduction early in the year. We suggest the high over-winter survival in dormice allows for a unique life history pattern (i.e., combining slow and fast life history tactics), which leads to a bimodal seasonal birth pattern: (1) give birth as early as possible to allow even the young to breed before hibernating, and/or (2) give birth as late as possible (leaving just enough time for these young to fatten) and enter directly into a period associated with the highest survival rates (hibernation) until maturity. PMID:22095523

Bieber, Claudia; Juškaitis, Rimvydas; Turbill, Christopher; Ruf, Thomas

2012-05-01

10

High population increase rates.  

PubMed

In addition to its economic and ethnic difficulties, the USSR faces several pressing demographic problems, including high population increase rates in several of its constituent republics. It has now become clear that although the country's rigid centralized planning succeeded in covering the basic needs of people, it did not lead to welfare growth. Since the 1970s, the Soviet economy has remained sluggish, which as led to increase in the death and birth rates. Furthermore, the ideology that held that demography could be entirely controlled by the country's political and economic system is contradicted by current Soviet reality, which shows that religion and ethnicity also play a significant role in demographic dynamics. Currently, Soviet republics fall under 2 categories--areas with high or low natural population increase rates. Republics with low rates consist of Christian populations (Armenia, Moldavia, Georgia, Byelorussia, Russia, Lithuania, Estonia, Latvia, Ukraine), while republics with high rates are Muslim (Tadzhikistan, Uzbekistan, Turkmenistan, Kirgizia, Azerbaijan Kazakhstan). The later group has natural increase rates as high as 3.3%. Although the USSR as a whole is not considered a developing country, the later group of republics fit the description of the UNFPA's priority list. Another serious demographic issue facing the USSR is its extremely high rate of abortion. This is especially true in the republics of low birth rates, where up to 60% of all pregnancies are terminated by induced abortions. Up to 1/5 of the USSR's annual health care budget is spent on clinical abortions -- money which could be better spent on the production of contraceptives. Along with the recent political and economic changes, the USSR is now eager to deal with its demographic problems. PMID:12284289

1991-09-01

11

Individual variation in reproductive costs of reproduction: high-quality females always do better.  

PubMed

1. Although life-history theory predicts substantial costs of reproduction, individuals often show positive correlations among life-history traits, rather than trade-offs. The apparent absence of reproductive costs may result from heterogeneity in individual quality. 2. Using detailed longitudinal data from three contrasted ungulate populations (mountain goats, Oreamnos americanus; bighorn sheep, Ovis canadensis; and roe deer, Capreolus capreolus), we assessed how individual quality affects the probability of detecting a cost of current reproduction on future reproduction for females. We used a composite measure of individual quality based on variations in longevity (all species), success in the last breeding opportunity before death (goats and sheep), adult mass (all species), and social rank (goats only). 3. In all species, high-quality females consistently had a higher probability of reproduction, irrespective of previous reproductive status. In mountain goats, we detected a cost of reproduction only after accounting for differences in individual quality. Only low-quality female goats were less likely to reproduce following years of breeding than of nonbreeding. Offspring survival was lower in bighorn ewes following years of successful breeding than after years when no lamb was produced, but only for low-quality females, suggesting that a cost of reproduction only occurred for low-quality females. 4. Because costs of reproduction differ among females, studies of life-history evolution must account for heterogeneity in individual quality. PMID:18700872

Hamel, Sandra; Côté, Steeve D; Gaillard, Jean-Michel; Festa-Bianchet, Marco

2009-01-01

12

Low Reproductive Rates of Lake Superior Bald Eagles: Low Food Delivery Rates or Environmental Contaminants?  

Microsoft Academic Search

Reproductive rate (productivity) of bald eagles (Haliaeetus leucocephalus) nesting on the shores of Lake Superior was significantly less than that of neighboring eagles nesting in inland Wisconsin (1.0 vs. 1.3 young per breeding attempt, 1989–1993), and at other inland lake\\/riverine habitats in the Great Lakes Basin. It is possible that the current causes of low productivity on Lake Superior might

Cheryl R. Dykstra; Michael W. Meyer; D. Keith Warnke; William H. Karasov; David E. Andersen; William W. Bowerman IV; John P. Giesy

1998-01-01

13

Macroevolutionary speciation rates are decoupled from the evolution of intrinsic reproductive isolation in Drosophila and birds.  

PubMed

The rate at which speciation occurs varies greatly among different kinds of organisms and is frequently assumed to result from species- or clade-specific factors that influence the rate at which populations acquire reproductive isolation. This premise leads to a fundamental prediction that has never been tested: Organisms that quickly evolve prezygotic or postzygotic reproductive isolation should have faster rates of speciation than organisms that slowly acquire reproductive isolation. We combined phylogenetic estimates of speciation rates from Drosophila and birds with a method for analyzing interspecific hybridization data to test whether the rate at which individual lineages evolve reproductive isolation predicts their macroevolutionary rate of species formation. We find that some lineages evolve reproductive isolation much more quickly than others, but this variation is decoupled from rates of speciation as measured on phylogenetic trees. For the clades examined here, reproductive isolation--especially intrinsic, postzygotic isolation--does not seem to be the rate-limiting control on macroevolutionary diversification dynamics. These results suggest that factors associated with intrinsic reproductive isolation may have less to do with the tremendous variation in species diversity across the evolutionary tree of life than is generally assumed. PMID:24003144

Rabosky, Daniel L; Matute, Daniel R

2013-09-17

14

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Measurement error and bias in the maximum reproductive rate for the Ricker model  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Measurement error and bias in the maximum reproductive rate for the Ricker model Daniel G Kehler; Canadian Periodicals pg. 854 #12;Reproduced with permission of the copyright owner. Further reproduction

Myers, Ransom A.

15

Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female meerkats  

E-print Network

Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female Reproductive self-restraint Gestation Lactation Glucocorticoid hormones (GCs) have been studied intensively breeding events and among females. Concentrations of fGC generally tripled as pregnancy progressed. However

Festa-Bianchet, Marco

16

Individual heterogeneity in reproductive rates and cost of reproduction in a long-lived vertebrate  

PubMed Central

Individual variation in reproductive success is a key feature of evolution, but also has important implications for predicting population responses to variable environments. Although such individual variation in reproductive outcomes has been reported in numerous studies, most analyses to date have not considered whether these realized differences were due to latent individual heterogeneity in reproduction or merely random chance causing different outcomes among like individuals. Furthermore, latent heterogeneity in fitness components might be expressed differently in contrasted environmental conditions, an issue that has only rarely been investigated. Here, we assessed (i) the potential existence of latent individual heterogeneity and (ii) the nature of its expression (fixed vs. variable) in a population of female Weddell seals (Leptonychotes weddellii), using a hierarchical modeling approach on a 30-year mark–recapture data set consisting of 954 individual encounter histories. We found strong support for the existence of latent individual heterogeneity in the population, with “robust” individuals expected to produce twice as many pups as “frail” individuals. Moreover, the expression of individual heterogeneity appeared consistent, with only mild evidence that it might be amplified when environmental conditions are severe. Finally, the explicit modeling of individual heterogeneity allowed us to detect a substantial cost of reproduction that was not evidenced when the heterogeneity was ignored. PMID:23919151

Chambert, Thierry; Rotella, Jay J; Higgs, Megan D; Garrott, Robert A

2013-01-01

17

Limitation of marine phytoplankton reproductive rates by zinc, manganese, and iron1  

Microsoft Academic Search

The reproductive rates of 21 species of marine phytoplankton were measured in media in which free zinc, manganese, and iron ion activities were controlled at different levels using EDTA-trace metal ion buffer systems. In general, the reproductive rates of neritic species were limited by zinc activities below 1O-11.5 M, while those of oceanic species were either not limited or only

Larry E. Brand

1983-01-01

18

Low Reproductive Rate Predicts Species Sensitivity to Habitat Loss: A Meta-Analysis of Wetland Vertebrates  

PubMed Central

We tested the hypotheses that species with greater mobility and/or higher reproductive rates are less sensitive to habitat loss than species with lower mobility and/or reproductive rates by conducting a meta-analysis of wetland vertebrate responses to wetland habitat loss. We combined data from 90 studies conducted worldwide that quantified the relationship between wetland amount in a landscape and population abundance of at least one wetland species to determine if mobility (indexed as home range size and body length) and annual reproductive rate influence species responses to wetland loss. When analyzed across all taxa, animals with higher reproductive rates were less sensitive to wetland loss. Surprisingly, we did not find an effect of mobility on response to wetland loss. Overall, wetland mammals and birds were more sensitive to wetland loss than were reptiles and amphibians. Our results suggest that dispersal between habitat patches is less important than species’ reproductive rates for population persistence in fragmented landscapes. This implies that immigration and colonization rate is most strongly related to reproduction, which determines the total number of potential colonists. PMID:24651675

Quesnelle, Pauline E.; Lindsay, Kathryn E.; Fahrig, Lenore

2014-01-01

19

Vienna Yearbook of Population Research 2009, pp. 197-215 The net reproduction rate and the type-  

E-print Network

Vienna Yearbook of Population Research 2009, pp. 197-215 The net reproduction rate and the type- reproduction number in multiregional demography Hisashi Inaba* Abstract In order to study effects of migration of the 1970s, its key concept, the multiregional net reproduction rate, has been long neglected

Inaba, Hisashi

20

Low reproductive success of leatherback turtles, Dermochelys coriacea, is due to high embryonic mortality  

Microsoft Academic Search

We examined the mechanism responsible for low reproductive success in leatherback turtles (Dermochelys coriacea) at Playa Grande, Costa Rica: low egg fertilization versus high rates of embryonic death. Leatherbacks at this beach had a high rate of fertility (X=93.3%±2.5%, n=819). We incubated 10 eggs from every clutch encountered of 19 females during 3 months of the 1998–1999 nesting season. Fertility

Barbara A. Bell; James R. Spotila; Frank V. Paladino; Richard D. Reina

2004-01-01

21

Reproductive effects of sodium borates on male employees: birth rate assessment.  

PubMed Central

OBJECTIVES--The purpose of the study was to investigate potential reproductive effects of sodium borates on occupationally exposed male employees at a large mining and production facility in the Mojave Desert of California. METHODS--The standardised birth ratio (SBR) was used to assess fertility of the male employees. Live births were the measured end point, and the rate of female to male offspring was also assessed. Data were collected through a questionnaire after a series of on site introductory and explanatory meetings with the employees. Initial non-responders were followed up by telephone. Medical insurance records were assessed for those who declined to participate. RESULTS--The questionnaire was a good method of ascertainment for live births. There was no evidence of selection bias in the results. There was a highly significant excess of offspring fathered by the male employees. There was no evidence of a relation between exposure and this excess of offspring, nor were there any temporal differences during the period of observation (> 30 years). Also, there was an excess of the percentage of female offspring fathered by these male employees. This excess of female offspring was not significant. There was no evidence of an exposure relation to sodium borates with this excess of female offspring nor were there any temporal differences. CONCLUSION--Under the conditions studied, there were no adverse reproductive effects of high borate doses as reported from oral ingestion studies in animals. PMID:7849854

Whorton, M D; Haas, J L; Trent, L; Wong, O

1994-01-01

22

Spatial distribution of oviposition sites determines variance in the reproductive rate of European bitterling ( Rhodeus amarus )  

Microsoft Academic Search

Summary We investigated reproductive rate in relation to oviposition site distribution and quality in the European bitterling, Rhodeus amarus, a freshwater fish that spawns on the gills of living unionid mussels. In a laboratory experiment male bitterling led females to groups of four mussels at a significantly higher rate than single mussels, irrespective of mussel species. Females spawned significantly more

Miros?aw Przybylski; Martin Reichard; Rowena Spence; Carl Smith

2007-01-01

23

Probing the Effect of Human Normal Sperm Morphology Rate on Cycle Outcomes and Assisted Reproductive Methods Selection  

PubMed Central

Sperm morphology is the best predictor of fertilization potential, and the critical predictive information for supporting assisted reproductive methods selection. Given its important predictive value and the declining reality of semen quality in recent years, the threshold of normal sperm morphology rate (NSMR) is being constantly corrected and controversial, from the 4th edition (14%) to the 5th version (4%). We retrospectively analyzed 4756 cases of infertility patients treated with conventional-IVF(c-IVF) or ICSI, which were divided into three groups according to NSMR: ?14%, 4%–14% and <4%. Here, we demonstrate that, with decrease in NSMR(?14%, 4%–14%, <4%), in the c-IVF group, the rate of fertilization, normal fertilization, high-quality embryo, multi-pregnancy and birth weight of twins gradually decreased significantly (P<0.05), while the miscarriage rate was significantly increased (p<0.01) and implantation rate, clinical pregnancy rate, ectopic pregnancy rate, preterm birth rate, live birth rate, sex ratio, and birth weight(Singleton) showed no significant change. In the ICSI group, with decrease in NSMR (?14%, 4%–14%, <4%), high-quality embryo rate, multi-pregnancy rate and birth weight of twins were gradually decreased significantly (p<0.05), while other parameters had no significant difference. Considering the clinical assisted methods selection, in the NFMR ?14% group, normal fertilization rate of c-IVF was significantly higher than the ICSI group (P<0.05), in the 4%–14% group, birth weight (twins) of c-IVF were significantly higher than the ICSI group, in the <4% group, miscarriage of IVF was significantly higher than the ICSI group. Therefore, we conclude that NSMR is positively related to embryo reproductive potential, and when NSMR<4% (5th edition), ICSI should be considered first, while the NSMR?4%, c-IVF assisted reproduction might be preferred. PMID:25411962

Xiao, Xifeng; Li, Li; Liu, Chuang; Shi, Yongqian; Wang, Dong; Wang, Xiaohong

2014-01-01

24

High repetition rate fiber lasers  

E-print Network

This thesis reports work in high repetition rate femtosecond fiber lasers. Driven by the applications including optical arbitrary waveform generation, high speed optical sampling, frequency metrology, and timing and frequency ...

Chen, Jian, Ph. D. Massachusetts Institute of Technology

2009-01-01

25

Patient dropout in an assisted reproductive technology program: implications for pregnancy rates  

Microsoft Academic Search

Objective: To study patient dropout and its impact on crude and cumulative pregnancy rates (PRs) after assisted reproductive technology (ART).Design: Retrospective cohort study.Setting: University hospital-based tertiary care fertility clinic.Patient(s): Two hundred two couples applying for their first ART treatment cycle.Main Outcome Measure(s): Drop-out rate and PR per cycle, cumulative drop-out rate and cumulative PR.Result(s): After three treatment cycles, the cumulative

Jolande A. Land; Dorette A. Courtar; Johannes L. H. Evers

1997-01-01

26

Pollen flow and effects of population structure on selfing rates and female and male reproductive success in fragmented Magnolia stellata populations  

PubMed Central

Background Fragmentation of plant populations may affect mating patterns and female and male reproductive success. To improve understanding of fragmentation effects on plant reproduction, we investigated the pollen flow patterns in six adjacent local populations of Magnolia stellata, an insect-pollinated, threatened tree species in Japan, and assessed effects of maternal plant (genet) size, local genet density, population size and neighboring population size on female reproductive success (seed production rates), and effects of mating distance, paternal genet size, population size and separation of populations on male reproductive success. Results The seed production rate, i.e. the proportion of ovules that successfully turned into seeds, varied between 1.0 and 6.5%, and increased with increasing population size and neighboring population size, and with decreasing maternal genet size and local genet density. The selfing rate varied between 3.6 and 28.9%, and increased with increasing maternal genet size and with declining local genet density. Male reproductive success increased with increasing paternal genet size, and decreased with increasing mating distance and separation of population. Pollen flow between the populations was low (6.1%) and highly leptocurtic. Conclusions Our results indicate that habitat fragmentation, separation and reduced size of populations, affected mating patterns and reproductive success of M. stellata. Local competition for pollinators and plant display size were likely to alter the reproductive success. PMID:23517612

2013-01-01

27

High compression rate text summarization  

E-print Network

This thesis focuses on methods for condensing large documents into highly concise summaries, achieving compression rates on par with human writers. While the need for such summaries in the current age of information overload ...

Branavan, Satchuthananthavale Rasiah Kuhan

2008-01-01

28

Human Disturbance Influences Reproductive Success and Growth Rate in California Sea Lions (Zalophus californianus)  

PubMed Central

The environment is currently undergoing changes at both global (e.g., climate change) and local (e.g., tourism, pollution, habitat modification) scales that have the capacity to affect the viability of animal and plant populations. Many of these changes, such as human disturbance, have an anthropogenic origin and therefore may be mitigated by management action. To do so requires an understanding of the impact of human activities and changing environmental conditions on population dynamics. We investigated the influence of human activity on important life history parameters (reproductive rate, and body condition, and growth rate of neonate pups) for California sea lions (Zalophus californianus) in the Gulf of California, Mexico. Increased human presence was associated with lower reproductive rates, which translated into reduced long-term population growth rates and suggested that human activities are a disturbance that could lead to population declines. We also observed higher body growth rates in pups with increased exposure to humans. Increased growth rates in pups may reflect a density dependent response to declining reproductive rates (e.g., decreased competition for resources). Our results highlight the potentially complex changes in life history parameters that may result from human disturbance, and their implication for population dynamics. We recommend careful monitoring of human activities in the Gulf of California and emphasize the importance of management strategies that explicitly consider the potential impact of human activities such as ecotourism on vertebrate populations. PMID:21436887

French, Susannah S.; Gonzalez-Suarez, Manuela; Young, Julie K.; Durham, Susan; Gerber, Leah R.

2011-01-01

29

Low participation rates amongst Asian women: implications for research in reproductive medicine.  

PubMed

The last two decades have witnessed tremendous advances in the field of reproductive medicine, especially assisted reproductive technology and stem cell research. As research continues in future, it is vital to ensure that individuals from all ethnic backgrounds are represented in the study populations so that the findings of the research can be generalised for the benefit of all. Many studies, however, have noted a trend of low participation rates amongst Asian women in reproductive research. Inequalities in the ethnicity of research participants can be a source of substantial bias, and have major ethical and scientific ramifications. Several factors such as educational status, fear of wrong-doing, communication barriers, and socio-cultural beliefs have been suggested to play a role. There is a need for further exploration of the factors influencing Asian women's decision to accept or decline participation in reproductive research and for development of effective targeted strategies for research recruitment with the aim of encouraging research participation as well as donation of cryopreserved embryos or other reproductive tissues. PMID:24368021

Talaulikar, V S; Hussain, S; Perera, A; Manyonda, I T

2014-03-01

30

Cyclic variations in nitrogen uptake rate in soybean plants: uptake during reproductive growth  

NASA Technical Reports Server (NTRS)

Net uptake of NO3- by non-nodulated soybean plants [Glycine max (L.) Merr. cv. Ransom] growing in flowing hydroponic culture was measured daily during a 63 d period of reproductive development between the first florally inductive photoperiod and [unknown word] seed growth. Removal of NO3- from a replenished solution containing 1.0 mol m-3 NO3- was determined by ion chromatography. Uptake of NO3- continued throughout reproductive development. The net uptake rate of NO3- cycled between maxima and minima with a periodicity of oscillation of 3 to 7 d during the floral stage and about 6 d during the fruiting stage. Coupled with increasing concentrations of carbon and C : N ratios in tissues, the oscillations in net uptake rates of NO3- are evidence that the demand for carbohydrate by reproductive organs is contingent on the availability of nitrogen in the shoot pool rather than that the demand for nitrogen follows the flux of carbohydrate into reproductive tissues.

Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

1990-01-01

31

High-Rate Artificial Lift  

Microsoft Academic Search

This paper summarizes the major considerations in the selection, design, installation, operation, or repair of high-rate artificial-lift systems. The major types of artificial lift - sucker-rod pumps, gas-lift systems, electrical submersible pumps, hydraulic pumps and jets, and hydraulic turbine-driven pumps - will be discussed. An extensive bibliography of artificial-lift papers is included.

Joe Clegg

1988-01-01

32

High-rate artificial lift  

SciTech Connect

This paper summarizes the major considerations in the selection, design, installation, operation, or repair of high-rate artificial-lift systems. The major types of artificial lift - sucker-rod pumps, gas-lift systems, electrical submersible pumps, hydraulic pumps and jets, and hydraulic turbine-driven pumps - will be discussed. An extensive bibliography of artificial-lift papers is included.

Clegg, J.D.

1988-03-01

33

Population trend of the Yellowstone grizzly bear as estimated from reproductive and survival rates  

USGS Publications Warehouse

The trend of the Yellowstone grizzly bear (Ursus arctos horribilis) population was estimated using reproductive rates calculated from 22 individual females and survival rates from 400 female bear-years. The point estimate of the rate of increase was 4.6%, with 95% confidence limits of 0 and 9%. Caution in interpreting this result is advised because of possible biases in the population parameter estimates. The main prospects for improving present knowledge of the population trend appear to be further study of possible biases in the parameter estimates, and the continued use of radiotelemetry to increase the number of samples on which the estimates are based.

Eberhardt, L. L.; Blanchard, B. M.; Knight, R. R.

1993-01-01

34

Effects of mine acid on the longevity and reproductive rate of the gastrotricha Lepidodermella squammata (Dujardin)  

Microsoft Academic Search

Effects of mine acid on longevity and reproductive rate of the parthenogenic gastrotrich Lepidodermella squammata were studied under laboratory culture conditions. Water from unpolluted and polluted streams was used, directly or mixed, to establish a series of test conditions at pH 8.1, 7.1, 6.4, 5.2, 4.6 and 3.3. Eggs, cultured individually under each test condition, were observed at 12 h

Albert S. Faucon; William D. Hummon

1976-01-01

35

Individual variation in reproductive costs of reproduction: high-quality females always do better  

Microsoft Academic Search

Summary 1. Although life-history theory predicts substantial costs of reproduction, individuals often show positive correlations among life-history traits, rather than trade-offs. The apparent absence of reproductive costs may result from heterogeneity in individual quality. 2. Using detailed longitudinal data from three contrasted ungulate populations (mountain goats, Oreamnos americanus ; bighorn sheep, Ovis canadensis ; and roe deer, Capreolus capreolus ),

Sandra Hamel; Steeve D. Côté; Jean-Michel Gaillard; Marco Festa-Bianchet

2009-01-01

36

Reproductive ecology of tree swallows (Tachycineta bicolor) with high levels of polychlorinated biphenyl contamination  

SciTech Connect

Tree swallows(Tachycineta bicolor) breeding along the Hudson River forage extensively on PCB-contaminated insects that emerge from the river. The authors studied the reproductive ecology and behavior of tree swallows breeding at several sites along the Hudson River. Related work has shown that PCB levels in both eggs and chicks were among the highest ever reported in this species, with concentrations comparable to those found in aquatic organisms in the Hudson River. In 1994, reproductive success at PCB-contaminated sites was significantly impaired relative to other sites in New York. Reduced reproductive success was largely due to high levels of nest abandonment during incubation and reduced hatchability of eggs. In 1995, reproductive output was normal, but higher than expected rates of abandonment and supernormal clutches persisted. Growth and development of nestlings was not significantly impaired. Given the levels of contamination in this population, the success of most Hudson River tree swallows reinforces the importance of understanding interspecific differences in the effects of contaminants.

McCarty, J.P.; Secord, A.L.

1999-07-01

37

A. Michele Arntz Evan H. DeLucia Nicholas Jordan Contribution of photosynthetic rate to growth and reproduction  

E-print Network

and reproduction in Amaranthus hybridus Received: 27 March 1998 / Accepted: 28 August 1998 Abstract While, the functional signi®cance of this variation remains unclear, particularly for photosynthetic traits. To test the hypothesis that photosynthetic rate has direct eects on reproduction as well as contributing indirectly

DeLucia, Evan H.

38

[High dose rate prostate brachytherapy].  

PubMed

This article aims at presenting the interest of high dose rate brachytherapy in the radiation treatment of prostatic adenocarcinoma. We will discuss successively the biological and dosimetric specificity of brachytherapy for this particular cancer. Afterwards, we will review the main phase II and III studies, the therapeutic indications in the daily practice from the evidence based medicine as well as the techniques of external beam radiation therapy for the same indications. Finally, the principal avenues of development will be discussed. PMID:23578898

Nickers, P; Blanchard, P; Hannoun-Lévi, J-M; Bossi, A; Chapet, O; Guérif, S

2013-04-01

39

Variation in the reproductive rate of bats Robert M.R. Barclay, Joel Ulmer, Cameron J.A. MacKenzie, Megan S. Thompson,  

E-print Network

Variation in the reproductive rate of bats Robert M.R. Barclay, Joel Ulmer, Cameron J.A. Mac respects, bats have relatively slow life histories. However, the reproductive rate of bats (i data on the reproductive rates of bats to test predictions based on life-history theory. Among 257

Barclay, Robert

40

Bite rates in Rocky Mountain bighorn sheep ( Ovis canadensis ): effects of season, age, sex and reproductive status  

Microsoft Academic Search

We investigated the effects of vegetation biomass, crude protein content of consumed forage, age, sex and reproductive status on bite rates in Rocky Mountain bighorn sheep. We expected higher bite rates and vigilance in lactating females with young and higher bite rates in young growing individuals, than in non-reproducing females or rams. Lactating ewes had higher bite rates than yeld

K. E. Ruckstuhl; M. Festa-Bianchet; J. T. Jorgenson

2003-01-01

41

A new modelling approach to insect reproduction with same-shape reproduction distribution and rate summation: with particular reference to Russian wheat aphid.  

PubMed

Same-shape distribution model and rate summation approach are widely used to describe the insect developmental process. In this approach, by integrating a nonlinear deterministic developmental rate model and a probabilistic same-shape distribution model, the proportion of the cohort completing development is quantified as a function of accumulating developmental rates, which themselves are temperature dependent. This method is considered to be more accurate in modelling insect phenology because it can address a well-known biological fact, individual variability, that insect individual developmental rates respond to temperature differently, and because rate-summation essentially simulates developmental rates under variable temperatures instead of constant temperatures. By comparing insect development and reproduction with respect to their responses to temperatures, we argue for the extension of the same-shape and rate-summation approaches to modelling insect reproduction process under variable temperatures. We justify our arguments by the fact that individual variation universally exists in almost all biological characteristics, and the phenomenon that insect development and reproduction respond to temperature very similarly, which is supported by some endocrinological evidences reported in literature. In addition, the approach for testing the applicability of the original same-shape developmental modelling, experimentally verifying the sameness of the same-shape curves or that the shape of the curves is invariant with respect to the temperature regimes, equally applies to our extended version for reproduction modelling. We successfully tested the extension and its applicability with our experimental data of 1800 Russian wheat aphids' (RWA) (Diuraphis noxia (Mordvilko)) reproduction under various temperature and plant growth stage regimes. We also extended Taylor's (1981) nonlinear model for insect development to describe RWA mean (median) nymphal production under different temperatures and barley plant growth stages. Three same-shape distribution models, Weibull distribution, Stinner's model and logistic model, are used to construct the same-shape reproduction distribution models for RWA. The extensions performed in this paper contribute a new modelling approach for predicting insect reproduction under field variable temperatures and plant growth stages. The prediction model can be parameterized with data from typical laboratory demography experiments and further integrated into simulation models for insect population dynamics. Finally, we discussed why the sameness test of the same-shape distribution curves is sufficient in validating the approach and proposed a strategy for dealing with exceptional cases where the sameness test fails. PMID:19159500

Ma, Z S; Bechinski, E J

2009-10-01

42

High Resolution, High Frame Rate Video Technology  

NASA Technical Reports Server (NTRS)

Papers and working group summaries presented at the High Resolution, High Frame Rate Video (HHV) Workshop are compiled. HHV system is intended for future use on the Space Shuttle and Space Station Freedom. The Workshop was held for the dual purpose of: (1) allowing potential scientific users to assess the utility of the proposed system for monitoring microgravity science experiments; and (2) letting technical experts from industry recommend improvements to the proposed near-term HHV system. The following topics are covered: (1) State of the art in the video system performance; (2) Development plan for the HHV system; (3) Advanced technology for image gathering, coding, and processing; (4) Data compression applied to HHV; (5) Data transmission networks; and (6) Results of the users' requirements survey conducted by NASA.

1990-01-01

43

Individualised controlled ovarian stimulation (iCOS): maximising success rates for assisted reproductive technology patients  

PubMed Central

Background In the last two decades, pregnancy rates for patients undergoing in-vitro fertilisation (IVF) have significantly increased. Some of the major advances responsible for this improvement were the introduction of controlled ovarian stimulation (COS) for the induction of multiple follicle development, and the utilisation of mid-luteal gonadotropin-releasing hormone agonists to achieve pituitary down-regulation and full control of the cycle. As a result, a combination of a gonadotropin-releasing hormone agonist with high doses (150-450 IU/day) of recombinant follicle-stimulating hormone has become the current standard approach for ovarian stimulation. However, given the heterogeneity of patients embarking on IVF, and the fact that many different drugs can be used alone or in different combinations (generating multiple potential protocols of controlled ovarian stimulation), we consider the need to identify special populations of patients and adapt treatment protocols accordingly, and to implement a more individualised approach to COS. Discussion Studies on mild, minimal and natural IVF cycles have yielded promising results, but have focused on fresh embryo transfers and included relatively young patient populations who generally have the potential for more favourable outcomes. The efficacy of these protocols in patients with a poorer prognosis remains to be tested. When comparing protocols for COS, it is important to think beyond current primary endpoints, and to consider the ideal quality and quantity of oocytes and embryos being produced per stimulated patient, in order to achieve a pregnancy. We should also focus on the cumulative pregnancy rate, which is based on outcomes from fresh and frozen embryos from the same cycle of stimulation. Individualised COS (iCOS) determined by the use of biomarkers to test ovarian reserve has the potential to optimise outcomes and reduce safety issues by adapting treatment protocols according to each patient's specific characteristics. As new objective endocrine, paracrine, functional and/or genetic biomarkers of response are developed, iCOS can be refined further still, and this will be a significant step towards a personalised approach for IVF. Conclusions A variety of COS protocols have been adopted, with mixed success, but no single approach is appropriate for all patients within a given population. We suggest that treatment protocols should be adapted for individual patients through iCOS; this approach promises to be one of the first steps towards implementing personalised medicine in reproductive science. PMID:21693025

2011-01-01

44

Inbreeding and its Relevance to Early and Pre-reproductive Mortality Rates in Iran, an Ecological Study  

Microsoft Academic Search

Consanguinity has been a long-standing social habit among Iranians. The effect of consanguinity on early death (stillbirth plus infant death) and pre-reproductive mortality (death before age 15 years) was studied in an ecological study in 10 provinces of Iran (including, Boosheher, Chaharmahal-O-Bakhtiari, East Azarbaijan, Ilam, Fars, Kashan, Kerman, Kermanshah, Markazi, Semnan, and Yazd). The rates of early death and pre-reproductive

M Saadat

2003-01-01

45

Synchronized reproduction promotes species coexistence through reproductive facilitation  

E-print Network

Synchronized reproduction promotes species coexistence through reproductive facilitation Yu synchronized reproduction. The facilitation on reproduction may enhance species persistence and coexistence- meters, such as mortality and recruitment rates, and functions of reproductive facilitation. Both

Hsu, Sze-Bi

46

Bacterial colonization of the uterine cervix and success rate in assisted reproduction: results of a prospective survey  

Microsoft Academic Search

BACKGROUND: Overgrowth of bacteria in the birth canal is associated with an increased risk of late miscarriage, preterm labour, post-partum endometritis and low birthweight. Conception rates in assisted reproduction treatments (ART) remain frustratingly low. We examined whether the nature of bacterial flora, found in the uterine cervical canal at embryo transfer, is associated with the rate of conception in ART.

Raed Salim; Izhar Ben-Shlomo; Raul Colodner; Yoram Keness; Eliezer Shalev

47

Effects of subcutaneous transmitters on reproduction, incubation behavior, and annual return rates of female wood ducks  

USGS Publications Warehouse

Radiotransmitters attached externally to breeding waterfowl can have a variety of negative effects. Implanted transmitters can reduce potential deleterious effects; abdominal implants are used most commonly in waterfowl. Methods also have been developed to implant transmitters subcutaneously, but effects of subcutaneous implants on adult ducks have not been evaluated. In this study, we subcutaneously implanted radiotransmitters in pre-laying female wood ducks (Aix sponsa, n = 62) and compared nest initiation date, incubation behavior, body mass, and annual return rates of radiomarked females to a group of females that were not radiomarked. Ninety-six percent (50 of 52) of radiomarked females that were monitored for the entire breeding season initiated nests. Nesting date of radiomarked adult females did not differ from that of adult females without radios, but radiomarked yearling females nested earlier than yearlings not receiving transmitters. We found no differences in early- and late-incubation body mass, incubation constancy, recess frequency, and incubation period between radiomarked females and those without radios. Annual return rates of females that initiated nests did not differ between radiomarked females and those not receiving radios. Data suggest that implanting radiotransmitters subcutaneously in pre-laying female wood ducks did not negatively impact subsequent reproduction, incubation behavior, and survival.

Hepp, G.R.; Folk, T.H.; Hartke, K.M.

2002-01-01

48

Reproductive Peformance of Great Egrets (Ardea alba) at High Island, Texas  

E-print Network

REPRODUCTIVE PERFORMANCE OF GREAT EGRETS (Ardea alba) AT HIGH ISLAND, TEXAS A Thesis by ANDREW JOHN MCINNES Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... Andrew John McInnes REPRODUCTIVE PERFORMANCE OF GREAT EGRETS (Ardea alba) AT HIGH ISLAND, TEXAS A Thesis by ANDREW JOHN MCINNES Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

McInnes, Andrew

2012-02-14

49

http://www.jstor.org Effect of Reproductive Rate on Minimum Habitat Requirements of Forest-Breeding Birds  

E-print Network

.16). This is the first direct test for a negative relationship between minimum habitat requirements and annual repro have been identified as one of the major factors affecting these habitat-amount requirements. The purpose of this study was to test the prediction that species with higher reproductive rates require less

50

The dynamics of sexual conflict over mating rate with endosymbiont infection that affects reproductive phenotypes  

E-print Network

; reproductive traits; sexual selection; Wolbachia. Abstract Maternally inherited endosymbionts have been and rapid coevolution of reproductive traits (reviewed in Rice & Holland, 1997; Holland & Rice, 1998; Rice L U T I O N A R Y B I O L O G Y Keywords: coevolution; maternal inheritance; mathematical models

Gavrilets, Sergey

51

Foolproof completions for high rate production wells  

E-print Network

gravel pack (GP) and high rate water pack (HRWP) completions over high-permeability fracturing (HPF), known in the vernacular as a frac&pack (FP) for very high rate wells. While a properly designed GP completion may prevent sand production, it does...

Tosic, Slavko

2008-10-10

52

Foolproof completions for high rate production wells  

E-print Network

gravel pack (GP) and high rate water pack (HRWP) completions over high-permeability fracturing (HPF), known in the vernacular as a frac&pack (FP) for very high rate wells. While a properly designed GP completion may prevent sand production, it does...

Tosic, Slavko

2009-05-15

53

Extensive Pollen Flow but Few Pollen Donors and High Reproductive Variance in an Extremely Fragmented Landscape  

PubMed Central

Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (Nep) and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73–93%), fat-tailed dispersal kernels and large average pollination distances (??=?229–412 m). However, they also agreed in detecting very few pollen donors (Nep?=?4.3–10.2) and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14%) and strong spatial genetic structure (Sp?=?0.012), probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment. PMID:23152842

Gonzalez-Martinez, Santiago C.; Aparicio, Abelardo

2012-01-01

54

Plasticity of insect reproduction: testing models of flexible and fixed development in response to different growth rates  

Microsoft Academic Search

We tested alternative developmental hypotheses describing when during an insect oviposition cycle reproductive tactics are\\u000a determined. Newly eclosed adult females of the grasshopper Romalea guttata were raised on eight different feeding treatments consisting of a low food diet, a high food diet, and changes from high\\u000a to low food, or low to high food, at different times during the first

Gregory S. Moehrlin; Steven A. Juliano

1998-01-01

55

High strain rate properties of composites  

NASA Astrophysics Data System (ADS)

Polymer matrix composites are presently used in many fields due to their excellent mechanical properties such as high specific strength and stiffness. However, not much is known of these composites' response to impact loading, which usually occurs at strain rates much higher than the strain rates used to measure the quasi-static mechanical properties of materials. The use of static properties in the study of structures that undergo dynamic loading can produce excessive design weight or cause unexplained and untimely failure. The studies included in this dissertation provide the results of Split Hopkinson Pressure Bar experiments to determine the ultimate compressive strength and strain of composites at high strain rates. Most researchers are using specimens with different dimensions and geometry. For this reason, it is difficult to compare results of tests done by different people. Herein, the Split Hopkinson Pressure Bar facility at the University of Delaware is used to study the effect of specimen geometry at high strain rate tests. In addition, research is conducted at different fiber orientations to have a better understanding of the effect of high strain rate in loading directions different from the primary material axes. Environmental effects, specifically moisture effects, on the dynamic properties of composites are also investigated extensively for the first time and provide interesting results. There are no fundamental theories of failure and principles defining the general behavior of composites at high strain rates at the present. However, a new equation based on experimental results is introduced to predict material behavior at high strain rates.

Woldesenbet, Eyassu

56

High-rate lithium thionyl chloride cells  

NASA Technical Reports Server (NTRS)

A high-rate C cell with disc electrodes was developed to demonstrate current rates which are comparable to other primary systems. The tests performed established the limits of abuse beyond which the cell becomes hazardous. Tests include: impact, shock, and vibration tests; temperature cycling; and salt water immersion of fresh cells.

Goebel, F.

1982-01-01

57

Is Japan's Household Saving Rate Really High?  

Microsoft Academic Search

This paper discusses, and measures the quantitative impact of a number of conceptual issues relating to the household saving rate data in the National Accounts of Japan. It finds that Japan's seemingly high household saving rate is biased due to the exclusion of capital transfers and real capital gains, the valuation of depreciation at historical cost rather than at replacement

Charles Yuji Horioka

1995-01-01

58

Population dynamics of Salpa thompsoni near the Antarctic Peninsula: Growth rates and interannual variations in reproductive activity (1993-2009)  

NASA Astrophysics Data System (ADS)

The salp Salpa thompsoni has exhibited increased abundance in high latitude portions of the Southern Ocean in recent decades and is now frequently the numerically dominant zooplankton taxon in the Antarctic Peninsula region. The abundance increase of this species in high latitude waters is believed related to ocean warming. Due to its continuous filter feeding and production of dense rapidly sinking fecal pellets S. thompsoni is considered to be an important link in the export of particulate carbon from the surface waters. Hence basic information on the life history of this component of the Antarctic marine ecosystem is essential for assessing its impact given continued climate warming. Here we cover various aspects of the life history of S. thompsoni collected in the north Antarctic Peninsula during annual austral summer surveys of the US Antarctic Marine Living Resources (AMLR) Program between 1993 and 2009. We focus on seasonal and interannual variations in the size composition and abundance of the aggregate (sexual) and solitary (asexual) stages. This information is valuable for refining components of Southern Ocean food web models that explicitly deal with size-structured and life history information on zooplankton. Intraseasonal changes in length-frequency distribution of both stages are used to estimate their growth rates. These average 0.40 mm day-1 for aggregates and 0.23 mm day-1 for solitaries; together these represent ?7 week and ?7.5 month generation times, respectively, and a 9 month life cycle (i.e., onset of aggregate production year 1 to aggregate production year 2). Based on the maximum lengths typically found during January-March, the life spans of the aggregate and solitary stages can reach at least ?5 and ?15 months, respectively. Length-frequency distributions each year reflect interannual differences in timing of the initiation and peak reproductive output. Interannual differences in the abundance of total salps and proportions of the overwintering solitary stage are significantly correlated with El Niño Southern Oscillation indices (SOI and Nino3.4) prevailing over the previous 2 years. Massive salp blooms result from two successive summers of elevated solitary production following a reversal from La Niña to El Niño conditions. These results indicate the role of basin-scale atmospheric-oceanic processes in establishing optimal conditions that support aggregate and solitary stage reproduction, development and growth.

Loeb, V. J.; Santora, J. A.

2012-04-01

59

ISS Update: High Rate Communications System  

NASA Video Gallery

ISS Update Commentator Pat Ryan interviews Diego Serna, Communications and Tracking Officer, about the High Rate Communications System. Questions? Ask us on Twitter @NASA_Johnson and include the ha...

60

A HIGH-THROUGHPUT METHOD FOR ASSESSING CHEMICAL TOXICITY USING A CAENORHABDITIS ELEGANS REPRODUCTION ASSAY  

PubMed Central

The National Research Council has outlined the need for non-mammalian toxicological models to test the potential health effects of a large number of chemicals while also reducing the use of traditional animal models. The nematode Caenorhabditis elegans is an attractive alternative model because of its well-characterized and evolutionarily-conserved biology, low cost, and ability to be used in high-throughput screening. A high-throughput method is described for quantifying the reproductive capacity of C. elegans exposed to chemicals for 48 h from the last larval stage (L4) to adulthood using a COPAS Biosort. Initially, the effects of exposure conditions that could influence reproduction were defined. Concentrations of DMSO vehicle ? 1% did not affect reproduction. Previous studies indicated that C. elegans may be influenced by exposure to low pH conditions. At pHs greater than 4.5, C. elegans reproduction was not affected, however below this pH there was a significant decrease in the number of offspring. Cadmium chloride was chosen as a model toxicant to verify that automated measurements were comparable to those of traditional observational studies. EC50 values for cadmium for automated measurements (176-192 ?M) were comparable to those previously reported for a 72-h exposure using manual counting (151 ?M). The toxicity of seven test toxicants on C. elegans reproduction was highly correlative with rodent lethality suggesting that this assay may be useful in predicting the potential toxicity of chemicals in other organisms. PMID:20206647

Boyd, Windy A.; McBride, Sandra J.; Rice, Julie R.; Snyder, Daniel W.; Freedman, Jonathan H.

2010-01-01

61

Effects of high tissue concentrations of selenium on reproduction by bluegills  

Microsoft Academic Search

Recent studies have associated high body concentrations of selenium with declines in fish populations inhabiting cooling reservoirs of coal-fired electric power plants. Because some evidence indicated that these declines resulted from reduced reproduction, the authors made a series of 18 artificial crosses of bluegills Lepomis macrochirus possessing high and low body concentrations of Se to determine whether elevated Se in

ROBERT B. GILLESPIE; PAUL C. BAUMANN

1986-01-01

62

Atlantic Puffin (Fratercula arctica) chick diet and reproductive performance at colonies with high  

E-print Network

(Fratercula arctica) between two seabird colonies adjacent to ocean habitat with presumed high and low capAtlantic Puffin (Fratercula arctica) chick diet and reproductive performance at colonies with high- elin (Mallotus villosus) abundance in 1996­1998. We hypothesized that puffins at their colony at Gannet

Jones, Ian L.

63

Reproductive Peformance of Great Egrets (Ardea alba) at High Island, Texas.  

E-print Network

??Despite habitat perturbations and seasonal fluctuations in reproduction, many studies report no significant inter-annual variation in Great Egret reproductive performance. I examined the reproductive performance… (more)

McInnes, Andrew

2012-01-01

64

Latest Data Show Strong Fertility Center Offers Region's Best IVF Success Rates! The Society for Assisted Reproductive Technology (SART), the primary organization of  

E-print Network

Latest Data Show Strong Fertility Center Offers Region's Best IVF Success Rates! The Society for Assisted Reproductive Technology (SART), the primary organization of professionals dedicated to the practice of assisted reproductive technologies (ART) in the United States, annually collects and publishes

Goldman, Steven A.

65

Civilian Residential Fire Fatality Rates: Six High-Rate States Versus Six Low-Rate States.  

National Technical Information Service (NTIS)

The report presents results of an analysis of 1,600 fire fatalities occurring in six states with high fire-death rates and six states with low fire-death rates. Reasons for the differences in rates are explored, with special attention to victim age, sex, ...

J. R. Hall, S. G. Helzer

1983-01-01

66

THE INFLUENCE OF MODEL TIME STEP ON THE RELATIVE SENSITIVIY OF POPULATION GROWTH RATE TO REPRODUCTION  

EPA Science Inventory

In recent years there has been an increasing interest in using population models in environmental assessments. Matrix population models represent a valuable tool for extrapolating from life stage-specific stressor effects on survival and reproduction to effects on finite populati...

67

Use of Video Probe Does Not Affect Burrowing Owl Reproductive Parameters or Return Rates  

Microsoft Academic Search

We tested how repeated use of an infrared video probe influenced burrowing owl (Athene cunicularia) reproduction and recruitment. In 2001, we randomly assigned occupied burrows in Washington State, USA, to one of 2 groups: 1) inspected throughout the breeding season with an infrared video probe (n ¼ 38), or 2) never inspected with a probe (n ¼ 41). We did

Victoria Garcia; Courtney J. Conway

2009-01-01

68

Analytical Modeling of High Rate Processes.  

National Technical Information Service (NTIS)

A Modeling of terminal ballistic events requires accurate constitutive data at strain rates exceeding 10,000/sec and at high strains. The Split Hopkinson Pressure Bar can provide information in both tension and compression at high strains, but is limited ...

S. E. Jones, P. P. Gillis

1997-01-01

69

High genome-wide mutation rates in vegetatively propagated bermudagrass.  

PubMed

A cascade DNA amplification strategy that generates arbitrary signatures from amplification profiles (ASAP) was used to measure genome-wide mutation rates in bermudagrass (Cynodon). ASAP quantified nucleotide changes that were induced by irradiation, genetic instabilities and normal vegetative growth of cultivars and accessions of sterile interspecific hybrids. DNA sequence divergence between cultivar 'Tifway' and its gamma radiation-induced mutant 'Tifway II' (0.70 +/- 0.66%) was comparable to estimates in radiation-induced mutants and spontaneous sports of chrysanthemum (Chrysanthemum morifolium Ramat.). A similar divergence in sequence (0.95 +/- 0.20%) was observed in the pairwise comparison of 17 nondisjunctive 'Tifgreen' and 'Tifdwarf' accessions. Mutation during normal Tifdwarf vegetative growth was evaluated by planting sprigs and sampling their offspring. Somatic sequence divergence levels (0.004 +/- 0.007%) resulted in a mutation rate of 1.05 x 10-8 per nucleotide per generation, assuming that a bermudagrass sprig constitutes a generation of growth. These rates were comparable to those found in germinal cells and individuals of either human or Drosophila melanogaster, supporting the notion that eukaryotic evolution is generation rather than time dependent. The high accumulation of somatic mutations (10 per triploid genome) is consistent with a model whereby mutation load in a population exhibiting obligate vegetative reproduction is substantially higher than in a population under sexual or asexual reproduction. These constraints could be the cause of reported genetic instabilities in the Tifgreen-Tifdwarf complex. Finally, a long-term rate measured across accessions and indicative of the accumulation of mutations in 17 Tifgreen-Tifdwarf populations (µ = 1.02 x 10-8 per nucleotide per generation) was strikingly congruent with the bermudagrass vegetative mutation rate, suggesting absence of evolutionary constraints in the sampled genomic regions. Mutation rates calculated from across-accesions divergence estimates (5.18 +/- 0.53%) indicated that plant material was evolving 100 times faster (3.8 x 10-7 changes per nucleotide per year) than a molecular clock rate estimate for grasses, probably resulting from the compound effect of clonal growth and life span of the hybrid plant material. PMID:10447861

1999-07-01

70

Fifty fertile years: anthropologists' studies of reproduction in high altitude natives.  

PubMed

Early European colonists of the Andes had difficulties in reproducing, a fact that underpins the hypothesis that reproduction is impaired amongst all humans at high altitudes. Yet a 16th century missionary wrote, "… the Indians are healthiest and where they multiply the most prolifically is in these same cold air-tempers, … [yet most children of the Spaniards] when born in such regions do not survive." These observations suggest that humans at high altitudes are subjected to strong natural selection from hypoxia, cold and limited food sources and, furthermore, that human populations can and have adapted, and continue to adapt, to these conditions. Informed by multiple approaches and theoretical frameworks, anthropologists have investigated to what extent and precisely how high altitude environments impact human reproductive functioning and fertility. Analyses of the proximate determinants of natural fertility suggest that behaviors (breast/infant feeding practices in the Andes, and marriage practices and religious celibacy in the Himalaya) are major determinants of fertility in high altitude populations. Furthermore, data from Project REPA (Reproduction and Ecology in Provincía Aroma), a longitudinal study in rural Bolivia, demonstrate that fecundity is not impaired in this indigenous altiplano population, and that the risk for early pregnancy loss (EPL) is not elevated by environmental hypoxia but does vary seasonally with the agricultural cycle (contra to the assumption that EPLs are due almost entirely to genetically flawed concepti). This review discusses these and other findings that reveal the complex and dynamic adaptations of human reproductive functioning in high altitude environments. PMID:23382088

Vitzthum, Virginia J

2013-01-01

71

A high-strain-rate superplastic ceramic.  

PubMed

High-strain-rate superplasticity describes the ability of a material to sustain large plastic deformation in tension at high strain rates of the order of 10-2 to 10-1 s-1 and is of great technological interest for the shape-forming of engineering materials. High-strain-rate superplasticity has been observed in aluminium-based and magnesium-based alloys. But for ceramic materials, superplastic deformation has been restricted to low strain rates of the order of 10-5 to 10-4 s-1 for most oxides and nitrides with the presence of intergranular cavities leading to premature failure. Here we show that a composite ceramic material consisting of tetragonal zirconium oxide, magnesium aluminate spinel and alpha-alumina phases exhibits superplasticity at strain rates up to 1 s-1. The composite also exhibits a large tensile elongation, exceeding 1,050 per cent for a strain rate of 0.4 s-1. The tensile flow behaviour and deformed microstructure of the material indicate that superplasticity is due to a combination of limited grain growth in the constitutive phases and the intervention of dislocation-induced plasticity in the zirconium oxide phase. We suggest that the present results hold promise for the application of shape-forming technologies to ceramic materials. PMID:11565026

Kim, B N; Hiraga, K; Morita, K; Sakka, Y

2001-09-20

72

HIGH LEVELS OF MATERNALLY TRANSFERRED MERCURY DO NOT AFFECT REPRODUCTIVE OUTPUT OR EMBRYONIC SURVIVAL OF  

E-print Network

), in snakes, despite their abundance and high trophic position in many ecosystems where Hg is prevalent in snakes and that the authors did not measure all reproductive endpoints, further research is needed. Environ. Toxicol. Chem. 2013;32:619­626. # 2012 SETAC Keywords--Maternal transfer Snake Methylmercury

Hopkins, William A.

73

The career trajectory of a Black male high school basketball player: A social reproduction perspective  

Microsoft Academic Search

Interscholastic sport in the United States is a social institution within which the social relationships and attitudes needed to sustain the existing dominant economic and class relations of the larger society could be perpetuated or reproduced. This single case study allowed us to explore the question of social reproduction by examining the nuances of how a young Black male high

John N Singer; Reuben A Buford May

2011-01-01

74

Personality and reproductive success in a high-fertility human population  

E-print Network

Personality and reproductive success in a high-fertility human population Alexandra Alvergnea,b,1 February 12, 2010) The existence of interindividual differences in personality traits poses a challenge to evolutionary thinking. Although research on the ultimate consequences of personality differences in nonhuman

Lummaa, Virpi

75

A Visibility Matching Tone Reproduction Operator for High Dynamic Range Scenes  

Microsoft Academic Search

We present a tone reproduction operator that preserves visibility in high dynamic range scenes. Our method introduces a new histogram adjustment technique, based on the population of local adaptation luminances in a scene. To match subjective viewing experience, the method incorporates models for human contrast sensitivity, glare, spatial acuity and color sensitivity. We compare our results to previous work and

Gregory Ward Larson; Holly E. Rushmeier; Christine D. Piatko

1997-01-01

76

The number of reproductive workers in highly eusocial Hymenoptera: monogyny and monandry  

Microsoft Academic Search

Haplodiploidy results in relatedness asymmetries be- tween colony members of highly eusocial Hymenoptera. As a conse- quence, queen and reproductive workers are more related to their own sons than to each other's male offspring. Kin selection theory predicts multiple optima in male parentage: either the queen or the workers should produce all the males. Nevertheless, shared male parentage is common

P. S. Santos-Filho; A. Eterovic; A. M. P. Kleinert; V. L. Imperatriz-Fonseca

2009-01-01

77

High levels of maternally transferred mercury do not affect reproductive output or embryonic survival of northern watersnakes (Nerodia sipedon).  

PubMed

Maternal transfer is an important exposure pathway for contaminants because it can directly influence offspring development. Few studies have examined maternal transfer of contaminants, such as mercury (Hg), in snakes, despite their abundance and high trophic position in many ecosystems where Hg is prevalent. The objectives of the present study were to determine if Hg is maternally transferred in northern watersnakes (Nerodia sipedon) and to evaluate the effects of maternal Hg on reproduction. The authors captured gravid female watersnakes (n?=?31) along the South River in Waynesboro, Virginia, USA, where an extensive Hg-contamination gradient exists. The authors measured maternal tissue and litter Hg concentrations and, following birth, assessed (1) reproductive parameters (i.e., litter size and mass, neonate mass); (2) rates of infertility, death during development, stillbirths, malformations, and runts; and (3) the overall viability of offspring. Mercury concentrations in females were strongly and positively correlated with concentrations in litters, suggesting that N. sipedon maternally transfer Hg in proportion to their tissue residues. Maternal transfer resulted in high concentrations (up to 10.10?mg/kg dry wt total Hg) of Hg in offspring. The authors found little evidence of adverse effects of Hg on these measures of reproductive output and embryonic survival, suggesting that N. sipedon may be more tolerant of Hg than other vertebrate species. Given that this is the first study to examine the effects of maternally transferred contaminants in snakes and that the authors did not measure all reproductive endpoints, further research is needed to better understand factors that influence maternal transfer and associated sublethal effects on offspring. PMID:23233365

Chin, Stephanie Y; Willson, John D; Cristol, Daniel A; Drewett, David V V; Hopkins, William A

2013-03-01

78

High Bit Rate Experiments Over ACTS  

NASA Technical Reports Server (NTRS)

This paper describes two high data rate experiments chat are being developed for the gigabit NASA Advanced Communications Technology Satellite (ACTS). The first is a telescience experiment that remotely acquires image data at the Keck telescope from the Caltech campus. The second is a distributed global climate application that is run between two supercomputer centers interconnected by ACTS. The implementation approach for each is described along with the expected results. Also. the ACTS high data rate (HDR) ground station is also described in detail.

Bergman, Larry A.; Gary, J. Patrick; Edelsen, Burt; Helm, Neil; Cohen, Judith; Shopbell, Patrick; Mechoso, C. Roberto; Chung-Chun; Farrara, M.; Spahr, Joseph

1996-01-01

79

The role of sexual and asexual reproduction in structuring high latitude populations of the reef coral Pocillopora damicornis  

Microsoft Academic Search

The genotypic composition of populations of the asexually viviparous coral Pocillopora damicornis varies in a manner that challenges classical models of the roles of sexual and asexual reproduction. On the geographically isolated Hawaiian reefs and high latitude reefs in Western Australia, P. damicornis populations are highly clonal although it has been argued that sexual reproduction via broadcast spawning generates widely

K J Miller; D J Ayre

2004-01-01

80

High Resolution Measurement of the Glycolytic Rate  

PubMed Central

The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Ivan; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutierrez, Robin; Cordova, Alex; Valdebenito, Rocio; Frommer, Wolf B.; Barros, L. Felipe

2010-01-01

81

High resolution measurement of the glycolytic rate.  

PubMed

The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K(+), supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

Bittner, Carla X; Loaiza, Anitsi; Ruminot, Iván; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutiérrez, Robin; Córdova, Alex; Valdebenito, Rocío; Frommer, Wolf B; Barros, L Felipe

2010-01-01

82

High Rate for Type IC Supernovae  

SciTech Connect

Using an automated telescope we have detected 20 supernovae in carefully documented observations of nearby galaxies. The supernova rates for late spiral (Sbc, Sc, Scd, and Sd) galaxies, normalized to a blue luminosity of 10{sup 10} L{sub Bsun}, are 0.4 h{sup 2}, 1.6 h{sup 2}, and 1.1 h{sup 2} per 100 years for SNe type la, Ic, and II. The rate for type Ic supernovae is significantly higher than found in previous surveys. The rates are not corrected for detection inefficiencies, and do not take into account the indications that the Ic supernovae are fainter on the average than the previous estimates; therefore the true rates are probably higher. The rates are not strongly dependent on the galaxy inclination, in contradiction to previous compilations. If the Milky Way is a late spiral, then the rate of Galactic supernovae is greater than 1 per 30 {+-} 7 years, assuming h = 0.75. This high rate has encouraging consequences for future neutrino and gravitational wave observatories.

Muller, R.A.; Marvin-Newberg, H.J.; Pennypacker, Carl R.; Perlmutter, S.; Sasseen, T.P.; Smith, C.K.

1991-09-01

83

Baltimore District Tackles High Suspension Rates  

ERIC Educational Resources Information Center

This article reports on how the Baltimore District tackles its high suspension rates. Driven by an increasing belief that zero-tolerance disciplinary policies are ineffective, more educators are embracing strategies that do not exclude misbehaving students from school for offenses such as insubordination, disrespect, cutting class, tardiness, and…

Maxwell, Lesli A.

2007-01-01

84

High strain rate behaviour of polypropylene microfoams  

NASA Astrophysics Data System (ADS)

Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

2012-08-01

85

Pseudospark switches for high repetition rates and high current applications  

Microsoft Academic Search

The state-of-the-art of pseudospark switch (PSS) development is reported. In addition to the replacement of thyratrons for high power applications in TE-gas-discharge lasers, PSSs have been tested at high repetition rates up to 2 kHz. In order to minimize the erosion rate and to reduce total switch inductance, multichannel PSSs with various geometrical configurations have been investigated: linear, coaxial, and

K. Frank; O. Almen; P. Bickel; J. Christiansen; A. Gortler; W. Hartmann; C. Kozlik; A. Linsenmeyer; H. Loscher; F. Peter; A. Schwandner; R. Stark

1992-01-01

86

High strain rate response of an elastomer.  

NASA Astrophysics Data System (ADS)

Pressure-shear plate impact experiments have been conducted to study the mechanical response of an elastomer (polyurea) at very high strain rates: 10^5 - 10^6 s-1. Thin samples are cast between two hard steel plates. Longitudinal waves reverberating through the sample are used to determine the slope of the isentrope at compressive stresses greater than, say, 500 MPa - the pressure at impact. Release wave experiments, combined with plane wave simulations, are used to extend the isentrope into the tensile regime. Because the shearing resistance of polyurea depends strongly on pressure, two approaches are used to investigate the regime of high shearing rate and low pressure. First, an unloading longitudinal wave reflected from the rear surface of the target assembly is made to arrive at the sample midway through its loading by the incident shear wave. As a result, the sample is sheared at high strain rates and both high and low pressure during a single experiment. Second, the thickness of the flyer and front plates are selected such that the compressive pulse passes through the cast-in-place sample before the shear wave arrives, allowing the shearing resistance to be measured at zero pressure. Results of these experiments and their simulation will be presented.

Jiao, Tong; Clifton, Rodney; Grunschel, Stephen

2007-06-01

87

High variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria virginiana (Rosaceae)  

E-print Network

that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need are capable of both sexual and asexual reproduction. How such plants partition their reproductive effort

Ashley, Mary V.

88

Reproductive and behavioral abnormalities in tree swallows with high levels of PCB contamination  

SciTech Connect

Tree Swallows (Tachycineta bicolor) breeding along the Hudson River forage extensively on PCB contaminated insects that emerge from the river. The authors studied the reproductive ecology and behavior of tree swallows breeding at several sites along the Hudson River. These sites vary in the severity of PCB contamination. PCB levels in both eggs and chicks were found to be among the highest ever reported in this species, with concentrations comparable to those found in aquatic organisms in the Hudson River. In 1994 reproductive success at PCB contaminated sites was significantly impaired, relative to other sites in New York. Reduced reproductive success was largely attributed to high levels of nest abandonment during incubation and reduced hatchability of eggs. Growth and development of nestlings was not significantly impaired. Abnormal nest building behavior was also noted in 1994, and this was studied in detail in 1995. Nests from contaminated areas are significantly smaller than those at a nearby reference site and at other sites in New York. The authors suggest that the reduced reproductive outputs at these sites are, in large part, a result of effects on the behavior of incubating females. The population-level implications of these patterns are unknown.

McCarty, J. [Cornell Univ., Ithaca, NY (United States). Section of Ecology and Systematics; [Fish and Wildlife Service, Cortland, NY (United States); Secord, A. [Fish and Wildlife Service, Cortland, NY (United States); Tillitt, D. [National Biological Service, Columbia, MO (United States)

1995-12-31

89

High temperature electrochemical corrosion rate probes  

SciTech Connect

Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

2005-09-01

90

Does the silver moss Bryum argenteum exhibit sex-specific patterns in vegetative growth rate, asexual fitness or prezygotic reproductive investment?  

PubMed Central

Background and Aims Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Methods Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. Key Results The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Conclusions Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is the highest known for bryophytes. PMID:21320878

Horsley, Kimberly; Stark, Lloyd R.; McLetchie, D. Nicholas

2011-01-01

91

The adverse effects of high fat induced obesity on female reproductive cycle and hormones  

NASA Astrophysics Data System (ADS)

The prevalence of obesity, an established risk and progression factor for abnormal reproductive cycle and tissue damage in female mice. It leads to earlier puberty, menarche in young females and infertility. There are extensive range of consequences of obesity which includes type-2 diabetes, cardiovascular disease and insulin resistance. Obesity is the interaction between dietary intake, genes, life style and environment. The interplay of hormones estrogen, insulin, and leptin is well known on energy homeostasis and reproduction. The aim of this study is to determine the effect of high fat induced obesity on reproductive cycles and its hormonal abnormalities on mice model. Two week, 3 month and 8 month long normal (WT) and very high fat diet (VHFD) diet course is followed. When mice are fed with very high fat diet, there is a drastic increase in weight within the first week later. There was a significant (p<0.001) increase in leptin levels in 6 month VHFD treated animals. 2 week, 3 month and 6 month time interval pap smear test results showed number of cells, length of estrous cycle and phases of the estrous cycle changes with VHFD mice(n=30) compared to normal diet mice(n=10). These results also indicate that the changes in the reproductive cycles in VHFD treated female mice could be due to the changes in hormones. Histo-pathological analyses of kidney, ovary, liver, pancreas, heart and lungs showed remarkable changes in some tissue on exposure to very high fat. Highly deposited fat packets observed surrounding the hepatocytes and nerve cells.

Donthireddy, Laxminarasimha Reddy

92

Fifty fertile years: Anthropologists' studies of reproduction in high altitude natives.  

PubMed

Early European colonists of the Andes had difficulties in reproducing, a fact that underpins the hypothesis that reproduction is impaired amongst all humans at high altitudes. Yet a 16th century missionary wrote, "… the Indians are healthiest and where they multiply the most prolifically is in these same cold air-tempers, … [yet most children of the Spaniards] when born in such regions do not survive." These observations suggest that humans at high altitudes are subjected to strong natural selection from hypoxia, cold and limited food sources and, furthermore, that human populations can and have adapted, and continue to adapt, to these conditions. Informed by multiple approaches and theoretical frameworks, anthropologists have investigated to what extent and precisely how high altitude environments impact human reproductive functioning and fertility. Analyses of the proximate determinants of natural fertility suggest that behaviors (breast/infant feeding practices in the Andes, and marriage practices and religious celibacy in the Himalaya) are major determinants of fertility in high altitude populations. Furthermore, data from Project REPA (Reproduction and Ecology in Provincía Aroma), a longitudinal study in rural Bolivia, demonstrate that fecundity is not impaired in this indigenous altiplano population, and that the risk for early pregnancy loss (EPL) is not elevated by environmental hypoxia but does vary seasonally with the agricultural cycle (contra to the assumption that EPLs are due almost entirely to genetically flawed concepti). This review discusses these and other findings that reveal the complex and dynamic adaptations of human reproductive functioning in high altitude environments. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc. PMID:23362150

Vitzthum, Virginia J

2013-01-30

93

High rate pulse processing algorithms for microcalorimeters  

SciTech Connect

It has been demonstrated that microcalorimeter spectrometers based on superconducting transition-edge-sensor can readily achieve sub-100 eV energy resolution near 100 keV. However, the active volume of a single microcalorimeter has to be small to maintain good energy resolution, and pulse decay times are normally in the order of milliseconds due to slow thermal relaxation. Consequently, spectrometers are typically built with an array of microcalorimeters to increase detection efficiency and count rate. Large arrays, however, require as much pulse processing as possible to be performed at the front end of the readout electronics to avoid transferring large amounts of waveform data to a host computer for processing. In this paper, they present digital filtering algorithms for processing microcalorimeter pulses in real time at high count rates. The goal for these algorithms, which are being implemented in the readout electronics that they are also currently developing, is to achieve sufficiently good energy resolution for most applications while being (a) simple enough to be implemented in the readout electronics and (b) capable of processing overlapping pulses and thus achieving much higher output count rates than the rates that existing algorithms are currently achieving. Details of these algorithms are presented, and their performance was compared to that of the 'optimal filter' that is the dominant pulse processing algorithm in the cryogenic-detector community.

Rabin, Michael [Los Alamos National Laboratory; Hoover, Andrew S [Los Alamos National Laboratory; Bacrania, Mnesh K [Los Alamos National Laboratory; Tan, Hui [XIA-LLC; Breus, Dimitry [XIA-LLC; Henning, Wolfgang [XIA-LLC; Sabourov, Konstantin [XIA-LLC; Collins, Jeff [XAI-LLC; Warburton, William K [XIA-LLC; Dorise, Bertrand [NIST; Ullom, Joel N [NIST; [NON LANL

2009-01-01

94

Amplified Warming Rates in High Elevation Regions  

NASA Astrophysics Data System (ADS)

We use ground-based and satellite-retrieved observations in conjunction with output from global climate model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to determine whether warming rates in high elevation regions are significantly different than in their lower elevation surroundings. In addition, for regions where there is enhanced warming at higher elevations, we investigate several of the potential mechanisms that may contribute to this enhancement. For the mid-latitudes in the Northern Hemisphere, the multi-model ensemble indicates that warming rates during the 21st century will be enhanced at high elevations relative to their lower elevation counterparts at the same latitude. This effect is most pronounced for daily minimum temperatures during the cold season in the Tibetan Plateau/Himalayan region. A neural network analysis is used to identify and quantify some of the potential mechanisms responsible for enhanced warming rates, including the effects of variables such as atmospheric water vapor, clouds, snow cover, and aerosols on the radiation and surface heat budgets. We also demonstrate that satellite retrievals can be used to expand the often sparse ground-based observations in such regions and that they provide the correct relationships between variables. Please fill in your abstract text.

Miller, James; Naud, Catherine; Chen, Yonghua; Ghatak, Debjani; Rangwala, Imtiaz; Sinsky, Eric

2014-05-01

95

High strain rate behavior of polyurea compositions  

NASA Astrophysics Data System (ADS)

High-strain-rate response of three polyurea compositions with varying molecular weights has been investigated using a Split Hopkinson Pressure Bar arrangement equipped with aluminum bars. Three polyurea compositions were synthesized from polyamines (Versalink, Air Products) with a multi-functional isocyanate (Isonate 143L, Dow Chemical). Amines with molecular weights of 1000, 650, and a blend of 250/1000 have been used in the current investigation. These materials have been tested to strain rates of over 6000/s. High strain rate results from these tests have shown varying trends as a function of increasing strain. While higher molecular weight composition show lower yield, they do not show dominant hardening behavior at lower strain. On the other hand, the blend of 250/1000 show higher load bearing capability but lower strain hardening effects than the 600 and 1000 molecular weight amine based materials. Results indicate that the initial increase in the modulus of the blend of 250/1000 may lead to the loss of strain hardening characteristics as the material is compressed to 50% strain, compared to 1000 molecular weight amine based material.

Joshi, Vasant S.; Milby, Christopher

2012-03-01

96

High Strain Rate Behavior of Polyurea Compositions  

NASA Astrophysics Data System (ADS)

Polyurea has been gaining importance in recent years due to its impact resistance properties. The actual compositions of this viscoelastic material must be tailored for specific use. It is therefore imperative to study the effect of variations in composition on the properties of the material. High-strain-rate response of three polyurea compositions with varying molecular weights has been investigated using a Split Hopkinson Pressure Bar arrangement equipped with titanium bars. The polyurea compositions were synthesized from polyamines (Versalink, Air Products) with a multi-functional isocyanate (Isonate 143L, Dow Chemical). Amines with molecular weights of 1000, 650, and a blend of 250/1000 have been used in the current investigation. The materials have been tested up to strain rates of 6000/s. Results from these tests have shown interesting trends on the high rate behavior. While higher molecular weight composition show lower yield, they do not show dominant hardening behavior. On the other hand, the blend of 250/1000 show higher load bearing capability but lower strain hardening effects than the 600 and 1000 molecular weight amine based materials. Refinement in experimental methods and comparison of results using aluminum Split Hopkinson Bar is presented.

Joshi, Vasant; Milby, Christopher

2011-06-01

97

High strain rate deformation of layered nanocomposites.  

PubMed

Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10?nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers. PMID:23132014

Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A; Thomas, Edwin L

2012-01-01

98

High strain rate deformation of layered nanocomposites  

NASA Astrophysics Data System (ADS)

Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10?nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

2012-11-01

99

Effects of functionalized fullerenes on bifenthrin and tribufos toxicity to Daphnia magna: Survival, reproduction, and growth rate.  

PubMed

Incorporation of carbon nanomaterials into industrial and consumer products is increasing, yet their impact on aquatic ecosystems alone and in chemical mixtures is largely unknown. Carbon nanomaterials may be found in the aquatic environment as mixtures with pesticides because of their proposed use in agriculture as smart delivery systems and nanosensors. The interaction effects of a functionalized fullerene ([1,2-methanofullerene C??]-61-carboxylic acid) (fC??) at 52.8?µg/L and the hydrophobic pesticides bifenthrin and tribufos were examined. The test organism was Daphnia magna, and response variables included 48-h survival, reproduction (bifenthrin, 70-d; tribufos, 21-d), and 10-d growth. Both pesticides reduced D. magna survival and reproduction (p < 0.05). Fullerenes significantly increased bifenthrin acute toxicity but did not significantly affect chronic endpoints or growth (p > 0.05). Median lethal concentrations (LC50s), median inhibition concentrations (IC50s) for days surviving, and IC50s for reproduction were 0.86, 0.55, and 0.49?µg/L for bifenthrin; 0.22, 0.39, and 0.77?µg/L for fC??-bifenthrin mix; 6.63, 9.89, and 5.79?µg/L for tribufos; and 9.17, 8.17, and 6.59?µg/L for fC??-tribufos mix. Mixtures did not affect instantaneous growth rate (p > 0.05). These results suggest that fC?? had little effect on pesticide chronic toxicity but influenced acute toxicity. Given the widespread application of nanotechnology, the influence of nanomaterials on environmental contaminants is an important consideration. Thus, our results may be useful in the development and use of nanotechnology in agricultural practices. PMID:20853424

Brausch, Kathryn A; Anderson, Todd A; Smith, Philip N; Maul, Jonathan D

2010-11-01

100

High frame-rate digital radiographic videography  

SciTech Connect

High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100-microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

King, N.S.P.; Cverna, F.H.; Albright, K.L.; Jaramillo, S.A.; Yates, G.J.; McDonald, T.E. [Los Alamos National Lab., NM (United States); Flynn, M.J.; Tashman, S. [Henry Ford Health System, Detroit, MI (United States)

1994-09-01

101

Fuel droplet burning rates at high pressures.  

NASA Technical Reports Server (NTRS)

Combustion of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane was observed in air under natural convection conditions, at pressures up to 100 atm. The droplets were simulated by porous spheres, with diameters in the range from 0.63 to 1.90 cm. The pressure levels of the tests were high enough so that near-critical combustion was observed for methanol and ethanol. Due to the high pressures, the phase-equilibrium models of the analysis included both the conventional low-pressure approach as well as high-pressure versions, allowing for real gas effects and the solubility of combustion-product gases in the liquid phase. The burning-rate predictions of the various theories were similar, and in fair agreement with the data. The high-pressure theory gave the best prediction for the liquid-surface temperatures of ethanol and propanol-1 at high pressure. The experiments indicated the approach of critical burning conditions for methanol and ethanol at pressures on the order of 80 to 100 atm, which was in good agreement with the predictions of both the low- and high-pressure analysis.

Canada, G. S.; Faeth, G. M.

1973-01-01

102

Microalgal separation from high-rate ponds  

SciTech Connect

High rate ponding (HRP) processes are playing an increasing role in the treatment of organic wastewaters in sunbelt communities. Photosynthetic oxygenation by algae has proved to cost only one-seventh as much as mechanical aeration for activated sludge systems. During this study, an advanced HRP, which produces an effluent equivalent to tertiary treatment has been studied. It emphasizes not only waste oxidation but also algal separation and nutrient removal. This new system is herein called advanced tertiary high rate ponding (ATHRP). Phosphorus removal in HRP systems is normally low because algal uptake of phosphorus is about one percent of their 200-300 mg/L dry weights. Precipitation of calcium phosphates by autofluocculation also occurs in HRP at high pH levels, but it is generally not complete due to insufficient calcium concentration in the pond. In the case of Richmond where the studies were conducted, the sewage is very low in calcium. Therefore, enhancement of natural autoflocculation was studied by adding small amounts of lime to the pond. Through this simple procedure phosphorus and nitrogen removals were virtually complete justifying the terminology ATHRP.

Nurdogan, Y.

1988-01-01

103

Reproductive effects of inorganic borates on male employees: birth rate assessment.  

PubMed Central

The purpose of this study was to investigate the potential for reproductive effects of inorganic borate compounds on male employees. The standardized birth ratio (SBR) methodology was used to assess fertility among male employees, using live births as the measured end point. The ratio of female to male births was also assessed. Data were collected via questionnaires and telephone follow-up interviews. Medical insurance records were assessed for nonresponders. Exposures were assessed using three semiquantitative categories. We found a statistically significant increase in fertility as measured by live births among the employees of the inorganic borate facility. There does not appear to be any decrease in fertility due to exposures either as analyzed by the borate exposure categories or over time, which is an indirect measure of exposures. We found a nonstatistically significant increase in the percentage of female offspring. This increase was due, not to a deficiency of male offspring, but rather to a marked increase in the numbers of female offspring. This increase in percentage female offspring does not appear to be related to exposures to inorganic borates. Based on the data, exposures to inorganic borates do not appear to adversely affect fertility in this population. PMID:7889872

Whorton, D; Haas, J; Trent, L

1994-01-01

104

High repetition rate nitrogen ion laser  

SciTech Connect

The average power of a pulsed discharge laser may be increased by increasing the single pulse energy or by pulsing the laser at a higher rate without a substantial loss of single pulse energy. Single pulse energy can be enhanced by increasing the energy deposition to the medium, and by scaling to larger discharge volumes. The realization of high repetition rates (HRR's) is often accomplished by the addition of specialized power supplies, pulse-forming-networks, and laser heads. In this work, a HRR N{sub 2}+ laser has been developed and its output characterized as a function of gas pressure, temperature, velocity, energy deposition, and repetition rate. It is shown that a self-excited superradiant device is more susceptible to HRR failure modes than a similar oscillator-amplifier arrangement, the difference arising from gain and saturation considerations. With this understanding, A HRR N{sub 2}+ oscillator-amplifier was constructed yielding pulse energies of 4.5 mJ and 0.25 W average power at 60 pps, while capable of several hour gas fill lifetimes.

Harshaw, R.C.

1984-01-01

105

Pros and cons of estimating the reproduction number from early epidemic growth rate of influenza A (H1N1) 2009  

Microsoft Academic Search

BACKGROUND: In many parts of the world, the exponential growth rate of infections during the initial epidemic phase has been used to make statistical inferences on the reproduction number, R, a summary measure of the transmission potential for the novel influenza A (H1N1) 2009. The growth rate at the initial stage of the epidemic in Japan led to estimates for

Hiroshi Nishiura; Gerardo Chowell; Muntaser Safan; Carlos Castillo-Chavez

2010-01-01

106

Effects of twinning on the subsequent reproductive performance and productive lifespan of high-producing dairy cows.  

PubMed

This study was designed to determine the effects of twinning on the subsequent reproductive performance and productive lifespan of high milk-producing dairy cows. The data analyzed were taken from complete reproductive records for 4861 Holstein Friesian cows comprising a commercial herd, including data for 12 587 calving events from April 1, 2001 to March 31, 2012. The twinning rate was 5.6%, and 9.6% of the cows delivered twins at least once during their life. Conception rates before Days 90, 120, and 300 postpartum were 20.8%, 36.9%, and 74.5%, and 34.2%, 51.8%, and 85.0% for cows delivering twins and singletons, respectively. Cox regression analysis revealed that twinning reduced the chances of conception before Day 90 by a factor of 0.76. Also, the median calving to conception interval was significantly longer for cows calving twins (134 ± 4.5 days) than for cows delivering singletons (108 ± 0.8 days; P < 0.001). Moreover, in cows in which conception was successful, the risk of abortion was higher for cows that calved twins than for those calving singletons (13.7% vs. 10.3%, respectively; P = 0.01). Culling rates before Days 90, 120, and 300 postpartum were 15.6%, 16.1%, and 28.6%, and 7.6%, 8.7%, and 15.9% for cows calving twins and singletons, respectively. Cox regression analysis of the factors affecting the culling rate before Day 300 postpartum revealed a 1.41 times greater hazard ratio of culling for cows calving twins than cows calving singletons. Further, mean productive lifespan was almost 300 days shorter for primiparous twinners (N = 48, 602 ± 493 days) than for nontwinners (N = 2592; 899 ± 581 days; P < 0.01), and 200 days shorter for secundiparous twinners (N = 126, 914 ± 429 days) than for nontwinners undergoing at least two lactations (N = 1936, 1101 ± 522 days; P < 0.01). Kaplan-Meier survival curves for productive lifespan differed between primiparous twinners and non-twinners (P < 0.001), and between secundiparous twinners and nontwinners having at least two lactations (P = 0.017). Differences in culling patterns for twinners and nontwinners were not restricted to the subsequent lactation but continued as long as 800 days after first calving, strongly suggesting long-term negative effects of twinning. As an economic implication of our findings, we suggest that twin embryo reduction at the moment of pregnancy diagnosis could be a profitable strategy to cut twinning rates and abolish their detrimental effects on subsequent reproductive performance and productive lifespan. PMID:23043948

Andreu-Vázquez, C; Garcia-Ispierto, I; Ganau, S; Fricke, P M; López-Gatius, F

2012-12-01

107

Study on high rate MRPC for high luminosity experiments  

NASA Astrophysics Data System (ADS)

Multi-gap Resistive Plate Chambers (MRPC) has been used to construct time-of-flight system in the field of nuclear and particle physics, due to their high-precision timing properties, high efficiency, reliability and coverage of large area. With the increase of accelerator luminosity, MRPCs have to withstand particle fluxes up to several tens of kHz/cm2 in view of the next generation physics experiments, such as the SIS-100/300 at FAIR-CBM, SoLID at JLab and NICA at JINR. But the MRPC assembled with float glass has very low rate capability not exceeding some hundreds of Hz/cm2. Two possible solutions for increasing rate capability, one is to reduce the bulk resistivity of glass and the other is to reduce the electrode thickness. Tsinghua University has done R&D on high rate MRPC for many years. A special low resistive glass with bulk resistivity around 1010?.cm was developed. We also studied the rate capability changes with glass thickness. In this paper we describe the performance of low resistive glass and two kinds of high rate MRPC (Pad readout and Strip readout) tested by deuterium beams. The results show that the tolerable particle flux can reach 70 kHz/cm2. In the mean time, MRPCs assembled with three thickness (0.7 mm, 0.5 mm and 0.35 mm) of float glass were also tested with deuteron beams, the results show that the three detectors can afford particle rate up to 500 Hz/cm2, 0.75 kHz/cm2 and 3 kHz/cm2, respectively.

Wang, Y.; Huang, X.; Lv, P.; Zhu, W.; Shi, L.; Xie, B.; Cheng, J.; Li, Y.

2014-08-01

108

Image-guided high dose rate endorectal brachytherapy  

SciTech Connect

Fractionated high dose rate endorectal brachytherapy (HDR-EBT) using CT-based treatment planning is an alternative method for preoperative down-sizing and down-staging of advanced rectal adeno-carcinomas. The authors present an image guidance procedure that was developed to ensure daily dose reproducibility for the four brachytherapy treatment fractions. Since the applicator might not be placed before each treatment fraction inside the rectal lumen in the same manner as it was placed during the 3D CT volume acquisition used for treatment planning, there is a shift along the catheter axis that may have to be performed. The required shift is determined by comparison of a daily radiograph with the treatment planning digitally-reconstructed radiograph (DRR). A procedure is developed for DRR reconstruction from the 3D data set used for the treatment planning, and two possible daily longitudinal shifts are illustrated: above and below the planning dose distribution. The authors also describe the procedure for rotational alignment illustrated on a clinical case. Reproduction of the treatment planned dose distribution on a daily basis is crucial for the success of fractionated 3D based brachytherapy treatments. Due to the cylindrical symmetry of the applicator used for preoperative HDR-EBT, two types of adjustments are necessary: applicator rotation and dwell position shift along the applicator's longitudinal axis. The impact of the longitudinal applicator shift prior to treatment delivery for 62 patients treated in our institution is also assessed.

Devic, Slobodan; Vuong, Te; Moftah, Belal; Evans, Michael; Podgorsak, Ervin B.; Poon, Emily; Verhaegen, Frank [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec, H3G 1A4 (Canada); Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec, H3G 1A4 (Canada); Department of Medical Physics, McGill University Health Centre, Montreal, Quebec, H3G 1A4 (Canada)

2007-11-15

109

High repetition rate alexandrite laser divergence measurements  

NASA Astrophysics Data System (ADS)

Beam divergence measurements were performed on a high repetition rate alexandrite laser currently being developed for a Los Alamos National Laboratory photochemistry research program, and were found to be spherically correctable and approximately constant at 8 times diffraction limited over a large input power range. A 0.5 x 10 cm alexandrite rod was pumped in a double ellipse head at a constant 42 joules/pulse input energy at repetition rates of 75 to 200 Hz. Several resonators were employed over the input power range to compensate for the thermal lensing, which varied from 0.63 to 0.12 m. The divergence measurements were performed by splitting a fraction of the output beam, passing it through a long focal length lens, and measuring the transmission percentage through calibrated apertures at the focal plane. This measurement was performed for seven resonators and cross-checked by imaging the far field pattern through a TV camera system and observing the spot sizes. With a similar experimental setup, a Glan prism was placed extra-cavity to examine the magnitude of depolarization losses due to stress induced birefringence under pumped conditions. No measurable effect was found up to 1 kW input power.

Birrell, S. E.; Rapoport, W. R.; Budgor, A. B.

110

A high data rate recorder for astronomy  

NASA Technical Reports Server (NTRS)

A magnetic tape recorder developed for the special requirements of radio astronomy and geodesy is described. These requirements include a high bit packing density and long record times. The current version of this longitudinal recorder used by the Very Long Baseline Array (VLBA) records 5.5 Terabits on a 14-in diameter reel of inch-wide tape. A maximum record rate of 256 Mb/s is achieved in the VLBA configuration with one recorder operating at 4 ms and utilizing 32 of the heads in a single stack. The VLBA recorders have been tested using a longitudinal density of 2.25 fr/micron; 448 data + 56 system tracks are recorded in 14 passes, each lasting 50 min, for a total record time (at 128 Mb/s) of 12 h on 14-in diameter reel of inch-wide 13-microns-thick D1-equivalent tape.

Hinteregger, H. F.; Rogers, A. E. E.; Cappallo, R. J.; Webber, J. C.; Petrachenko, W. T.

1991-01-01

111

Consideration of wear rates at high velocity  

NASA Astrophysics Data System (ADS)

The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. Overall, the wear environment is truly three-dimensional. The attempt to characterize three-dimensional wear was not economically feasible because it must be analyzed at the micro-mechanical level to get results. Thus, an engineering approximation was carried out. This approximation was based on a metallographic study identifying the need to include viscoplasticity constitutive material models, coefficient of friction, relationships between the normal load and velocity, and the need to understand wave propagation. A sled test run at the Holloman High Speed Test Track (HHSTT) was considered for the determination of high velocity wear rates. In order to adequately characterize high velocity wear, it was necessary to formulate a numerical model that contained all of the physical events present. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were analyzed. During this rocket sled test, the slipper traveled 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s. This type of environment was never considered previously in terms of wear evaluation. Each of the features of the metallography were obtained through micro-mechanical experimental techniques. The byproduct of this analysis is that it is now possible to formulate a model that contains viscoplasticity, asperity collisions, temperature and frictional features. Based on the observations of the metallographic analysis, these necessary features have been included in the numerical model, which makes use of a time-dynamic program which follows the movement of a slipper during its experimental test run. The resulting velocity and pressure functions of time have been implemented in the explicit finite element code, ABAQUS. Two-dimensional, plane strain models were used to determine the state of stress within the slipper and the pressure distribution along the bottom. Local submodel collisions between the slipper and a 6 mum radius hemispherical asperity were analyzed to determine mechanical and melt wear rates. A simplified damage criterion of maximum Mises stress was used to determine the damaged volume during the slipper and asperity collision. Overall, the model predicts a total wear volume that is approximately 36% of the total wear measured during the metallographic analysis.

Hale, Chad S.

112

High corticosterone, not high energy cost, correlates with reproductive success in the burrow-nesting ancient murrelet.  

PubMed

Theory and observations suggest that offspring abandonment in animals may occur when the costs to future reproductive output of current reproductive effort outweigh the fitness benefits of rearing the current brood. While hormonal cues (i.e. corticosterone) or energy reserves are believed to be involved, few studies have directly focused on the proximate cues influencing behaviours directly related to reproductive success. To address this information gap, we determined the incubation metabolic rates and corticosterone (CORT) levels of naturally fasting and freely incubating ancient murrelets (Synthliboramphus antiquus). Respiratory quotient (RQ) increased with date, suggesting that incubating ancient murrelets shifted from strictly lipid-based metabolism towards more protein-based metabolism as incubation progressed. Birds that hatched only one nestling had higher levels of circulating CORT than those which hatched two, suggesting that birds which laid only a single egg found incubation more stressful than those which laid two. However, CORT levels and incubation shift lengths were not correlated, suggesting that birds that undertook prolonged incubation shifts did so only when their energy stores were not jeopardized. PMID:24391929

Shoji, Akiko; Elliott, Kyle H; O'Reilly, Kathleen M; Gaston, Anthony J

2013-01-01

113

High Corticosterone, Not High Energy Cost, Correlates with Reproductive Success in the Burrow-Nesting Ancient Murrelet  

PubMed Central

Theory and observations suggest that offspring abandonment in animals may occur when the costs to future reproductive output of current reproductive effort outweigh the fitness benefits of rearing the current brood. While hormonal cues (i.e. corticosterone) or energy reserves are believed to be involved, few studies have directly focused on the proximate cues influencing behaviours directly related to reproductive success. To address this information gap, we determined the incubation metabolic rates and corticosterone (CORT) levels of naturally fasting and freely incubating ancient murrelets (Synthliboramphus antiquus). Respiratory quotient (RQ) increased with date, suggesting that incubating ancient murrelets shifted from strictly lipid-based metabolism towards more protein-based metabolism as incubation progressed. Birds that hatched only one nestling had higher levels of circulating CORT than those which hatched two, suggesting that birds which laid only a single egg found incubation more stressful than those which laid two. However, CORT levels and incubation shift lengths were not correlated, suggesting that birds that undertook prolonged incubation shifts did so only when their energy stores were not jeopardized. PMID:24391929

Shoji, Akiko; Elliott, Kyle H.; O'Reilly, Kathleen M.; Gaston, Anthony J.

2013-01-01

114

Potential and realized rates of vegetative reproduction in Spirodela polyrhiza, Lemna minor, and Wolffia borealis  

Microsoft Academic Search

The rate of vegetative propagule development was estimated in three duckweed (Lemnaceae) species, Spirodela polyrhiza, Lemna minor, and Wolffia borealis, by measuring the number of daughter fronds produced over the life span of mother fronds. Under the same constant environmental conditions, plants of L. minor lived the longest (31.3 days) and produced the most daughter fronds (14.0), yet W. borealis

Gordon D. Lemon; Usher Posluszny; Brian C. Husband

2001-01-01

115

Linking Reproduction and Survival Can Improve Model Estimates of Vital Rates Derived from Limited Time-  

E-print Network

Research Unit, Fisheries Centre, AERL, University of British Columbia, Vancouver, British Columbia, Canada output that reduces the number of parameters that need to be estimated by models designed to determine combinations of birth and death rates that produce historic counts of animal populations. We applied our

116

Estimating Pesticide Effects on Fecundity Rates of Wild Birds Using Current Laboratory Reproduction Tests  

Microsoft Academic Search

Regulatory agencies have used laboratory toxicity tests for decades to assess potential risks of pesticide use to wildlife, but questions remain about the ecological significance of test results. Population models may provide a valuable tool for projecting the consequences of pesticide use if information exists on the relationship between exposure and effects on survival and fecundity rates. We review issues

Richard S. Bennett; Matthew A. Etterson

2006-01-01

117

Effects of Stocking Rate, Improved Pasture and Weaning Age on the Reproductive Performance of Primiparous Cows  

Microsoft Academic Search

Ninety two primiparous cows at three years old (46 Braford - 46 Hereford), were assigned to stocking rates (SR) of 240 kg\\/ha (T1) and 320 kg\\/ha (T2) on natural pasture, from 09.01.00 to 03.06.01, or 400 kg\\/ha (T3) on improved pasture of ryegrass (Lolium multiflorum L.) during 80 days postpartum, and after, at same SR of T2 on natural pasture

Bernardo Augusto; Albornoz Pötter; José Fernando Piva Lobato

118

Forest edge creates small-scale variation in reproductive rate of sika deer  

Microsoft Academic Search

Habitat edges are considered to have an important role in determining the abundance of deer in forest landscapes, but to our\\u000a knowledge there are few lines of evidence indicating that forest edge enhances the vital rate of deer. We examined pregnancy\\u000a of female sika deer in Boso peninsula, central Japan, and explored how forest edges, food availability in forests, and

Tadashi Miyashita; Maki Suzuki; Daisuke Ando; Go Fujita; Keiji Ochiai; Masahiko Asada

2008-01-01

119

Factors affecting feeding rate, reproduction and growth of an oligochaete Lumbriculus variegatus (Müller)  

Microsoft Academic Search

Worm density of a deposit feeding oligochaete (Lumbriculus variegatus) did not affect egestion whereas both temperature and\\u000a sediment type had a significant influence. The worms egested less actively at the lowest temperature (6 °C). The egestion\\u000a rate, expressed as mg dry feces produced, was highest in the sandy sediment and lowest in the sediment derived almost exclusively\\u000a from decaying plant

Matti T. Leppänen; Jussi V. K. Kukkonen

1998-01-01

120

High rate PLD of diamond-like-carbon utilizing high repetition rate visible lasers  

SciTech Connect

Pulsed Laser Deposition (PLD) has been shown to be an effective method for producing a wide variety of thin films of high-value-added materials. The high average powers and high pulse repetition frequencies of lasers under development at LLNL make it possible to scale-up PLD processes that have been demonstrated in small systems in a number of university, government, and private laboratories to industrially meaningful, economically feasible technologies. A copper vapor laser system at LLNL has been utilized to demonstrate high rate PLD of high quality diamond-like-carbon (DLC) from graphite targets. The deposition rates for PLD obtained with a 100 W laser were {approx} 2000 {mu}m{center_dot}cm{sup 2}/h, or roughly 100 times larger than those reported by chemical vapor deposition (CVD) or physical vapor deposition (PVD) methods. Good adhesion of thin (up to 2 pm) films has been achieved on a small number of substrates that include SiO{sub 2} and single crystal Si. Present results indicate that the best quality DLC films can be produced at optimum rates at power levels and wavelengths compatible with fiber optic delivery systems. If this is also true of other desirable coating systems, this PLD technology could become an extremely attractive industrial tool for high value added coatings.

McLean, W. II; Fehring, E.J.; Dragon, E.P.; Warner, B.E.

1994-09-15

121

In situ high rate growth of high temperature superconductor tapes  

SciTech Connect

In situ high rate growth of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} superconducting films has been carried out using e-beam deposition. A deposition flux controller is developed to monitor and control the deposition rates using tunable diode laser based atomic absorption. Wide range of temperatures, deposition rates, and oxygen fluxes including atomic and molecular oxygen, as well as ozone, have been explored in order to understand both kinetic and thermodynamic stability. Critical current density above 1 MA/cm{sup 2} has been achieved on SrTiO{sub 3} substrate samples in growth rate up to 75 {angstrom}/sec. Samples prepared on IBAD YSZ/Ni tapes exhibit similar R(T)s and x-ray diffraction patterns. However, critical current densities of the tapes are around kA/cm{sup 2} or lower. The poor critical current density of the tape is attributed to interaction between the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} film and the YSZ buffer layer.

Hammond, M. R. B. (Malcom R. Beasley); Peng, L. S. (Luke S.); Wang, W. (Weizhi); Jo, W.; Ohnishi, T. (Tsuyoshi); Marshall, A. F. (Ann F.); Hammond, R. H. (Robert H.); Beasley, M. R. (Malcom R.); Peterson, E. J. (Eric J.); Ericson, R. (Richard)

2001-01-01

122

High resolution, high rate x-ray spectrometer  

DOEpatents

It is an object of the invention to provide a pulse processing system for use with detected signals of a wide dynamic range which is capable of very high counting rates, with high throughput, with excellent energy resolution and a high signal-to-noise ratio. It is a further object to provide a pulse processing system wherein the fast channel resolving time is quite short and substantially independent of the energy of the detected signals. Another object is to provide a pulse processing system having a pile-up rejector circuit which will allow the maximum number of non-interfering pulses to be passed to the output. It is also an object of the invention to provide new methods for generating substantially symmetrically triangular pulses for use in both the main and fast channels of a pulse processing system.

Goulding, F.S.; Landis, D.A.

1983-07-14

123

Tradeoff between offspring mass and subsequent reproduction in a highly iteroparous mammal  

E-print Network

subsequent reproductive success or survival. We used longitudinal data on marked mountain goatsOreamnos americanus to assess if offspring mass at weaning affected maternal survival and future reproduction

Festa-Bianchet, Marco

124

Effects of Reproductive Status on Energy Intake, Ingestion Rates, and Dietary Composition  

E-print Network

Science + Business Media, LLC 2007 Abstract The limiting factor for fitness in female primates of their diet as measured by insect consumption and proportion of protein. Pregnant and cycling females did the consumption of quality foods, high in available nutrients, females can increase their likelihood of producing

Fedigan, Linda M.

125

Success rates and cost of a live birth following fresh assisted reproduction treatment in women aged 45 years and older, Australia 2002- 2004  

Microsoft Academic Search

BACKGROUND: The aim of this study was to calculate assisted reproductive technology (ART) success rates for fresh autologous and donor cycles in women aged ? 45 and the resultant cost per live birth. METHODS: We per- formed a retrospective population-based study of 2339 ART cycles conducted in Australia, 2002-2004 to women aged ? 45 years. The cost-outcome study was performed

Elizabeth Sullivan; Yueping Wang; Michael Chapman; Georgina Chambers

2008-01-01

126

Reproductive efficiency is a major determinant of cow-calf profitability. The bull's contribution to pregnancy rates  

E-print Network

fertile bulls. Fertility of the male is a major contributor to overall reproductive performance in mating movement of sperm cells · A normal male reproductive tract · Physical normality of the bull, general health · Libido or sex drive of the bull · Social interactions between bulls · Age of the bull · Body condition

Liskiewicz, Maciej

127

Investigating the life-cycle and growth rate of Pediastrum boryanum and the implications for wastewater treatment high rate algal ponds.  

PubMed

The colonial alga Pediastrum boryanum has beneficial characteristics for wastewater treatment High Rate Algal Ponds (HRAP) including high biomass productivity and settleability. Our previous work has shown that these characteristics are enhanced when a portion of gravity harvested algae is recycled back to the pond. To help understand the mechanisms behind the improved performance of P. boryanum dominated HRAP with algal recycling, this study investigated the life-cycle of P. boryanum. Experiments determined the exact timing and growth rate of P. boryanum life-cycle stages ('juvenile', 'growth' and 'reproductive') under four combinations of light and temperature (250 or 120 ?Mol/m(2)/s; 20 or 10 °C). Single juvenile 16-celled colonies were grown in microcosms on an inverted microscope and photographed every 15 min until reproduction ceased. Two asexual life-cycles and a rarely occurring sexual life-cycle were observed. The time required to achieve asexual reproductive maturity increased from 52 h (high light and temperature) to 307 h (low light and temperature), indicating that the minimum hydraulic retention time or mean cell residence time (MCRT) must be higher than these values to sustain a P. boryanum HRAP culture under ambient conditions. The net growth rate of a P. boryanum colony varied between life-cycle stages (growth > juvenile > reproductive). This suggests that the higher biomass productivity measured in HRAP with algal recycling could be due to both the increased MCRT and an increase in the net growth rate of the HRAP culture by 'seeding' with faster growing colonies. PMID:24852411

Park, Jason B K; Craggs, Rupert J; Shilton, Andy N

2014-09-01

128

Reproductive biology of Acrolophia cochlearis (Orchidaceae): estimating rates of cross-pollination in epidendroid orchids  

PubMed Central

Background and Aims Pollen fates strongly influence mating success in plants but are difficult to quantify. By promoting foraging constancy in pollinators, floral rewards such as nectar may enhance the overall efficiency of pollen transfer. However, this can also lead to high levels of geitonogamy. Pollen fates were studied in Acrolophia cochlearis, a member of a terrestrial epidendroid orchid genus that includes both rewarding and deceptive species. Methods Pollinator observations were conducted. Pollen transfer efficiency (PTE), the proportion of removed pollinia deposited on stigmas, was measured in a large population at regular intervals throughout the 5-month flowering season. The level of cross-pollination in two populations was estimated from the percentage of seeds with embryos in naturally pollinated fruits. Key Results Acrolophia cochlearis (and a congener A. micrantha) produce minute but concentrated nectar rewards. Observations showed that A. cochlearis is pollinated exclusively by a solitary bee species, Colletes claripes. Although both sexes visited flowers, only males carried pollinaria. Overall levels of pollination and PTE of the rewarding A. cochlearis were much higher than in a deceptive congener, A. capensis. Seeds resulting from self-fertilization had a significantly lower probability of containing viable embryos than did those from cross-fertilization. This dichotomy in fruit quality was used to estimate that cross-pollination occurred in approx. 66 % of A. cochlearis flowers in a large dense population and approx. 10 % in a small sparse population. Traits of A. cochlearis that limit geitonogamy include pollinarium reconfiguration that exceeds the visit time of pollinators and rapid flower senescence following visitation. Conclusions Presence of a nectar reward in Acrolophia cochlearis results in high levels of PTE. It is estimated that approx. 33–90 % of fruits in natural populations arise from self-pollination in this species. PMID:19001427

Peter, Craig I.; Johnson, Steven D.

2009-01-01

129

High data rate systems for the future  

NASA Technical Reports Server (NTRS)

Information systems in the next century will transfer data at rates that are much greater than those in use today. Satellite based communication systems will play an important role in networking users. Typical data rates; use of microwave, millimeter wave, or optical systems; millimeter wave communication technology; modulators/exciters; solid state power amplifiers; beam waveguide transmission systems; low noise receiver technology; optical communication technology; and the potential commercial applications of these technologies are discussed.

Chitwood, John

1991-01-01

130

Parid reproductive behavior  

Microsoft Academic Search

North American Parids are excellent organisms for research on the evolution of avian reproductive behavior, and how these are influenced by intra- and interspecific interactions. As cavity-nesting birds, they exhibit high reproductive success and populations of most Parid species exist in high numbers throughout their range. As social birds, their reproductive behavior is shaped by group dynamics, including flock hierarchy

Daniel J. Mennill; Theresa M. Burg; Robert L. Curry; Kathy Martin; Andrea R. Norris; Laurene Ratcliffe; Matthew W. Reudink; Lindsay M. Rossano; Kristin A. Schubert

131

Adaptive hierarchical-filtering technique for high-quality magazine image reproduction  

NASA Astrophysics Data System (ADS)

This paper describes a novel adaptive-hierarchical-filtering technique to achieve high-quality magazine image reproduction on computer peripherals such as color copier, or scanner plus printer. Commercial magazine images are halftoned images. Unacceptable noises and moire distortion may result when halftone images are copied (i.e., scanned and printed). In this paper, we analyze moire patterns formation characterized by the following factors: Moire patterns formation depends on the following factors: (1) halftone screen frequency, how many lines per inch (i.e., lpi) (2) scan frequency, how many dot per inch, (dpi) (3) screen angle which is the screen orientation against the scan direction, (4) scanner aperture (i.e., scanner characteristics), (5) halftoning and printing mechanisms, (6) viewing conditions. Error diffusion tends to randomize the moire patterns, and cluster-dot or line screen show more moire distortion. We developed a set of variable- length low-pass filters that have a nice inheritance of canceling aliased low frequency components (moire distortion). High pass filtering is also applied to sharpen image edges. A hierarchical filter classifier was developed to determine that an edge is either a global true edge (for sharpening enhancement) or a local halftone's micro-structural edge (for LPF for moire reduction). Depending on the classifier, adaptive LPF is applied to achieve the smooth transition between sharp edges and smooth halftone regions. Thus, we achieve overall high-quality output images. Experimental results have been shown the effectiveness of the presented technique that works well on wide combinations of above- mentioned 6 factors for high-quality magazine image reproduction.

Shu, Joseph S.; Lin, Tsung Nan; Bhattacharjya, Anoop K.; Shiozaki, Tadashi

2000-06-01

132

Factors Associated with the Reproductive Health Risk Behavior of High School Students in the Republic of the Marshall Islands  

ERIC Educational Resources Information Center

This study revealed factors associated with reproductive health risk behavior among high school students in the Republic of the Marshall Islands. The survey was conducted among high school students from grades 9 through 12 at 2 schools in Majuro, the capital of the Marshall Islands. The questions asked inquired about knowledge, attitude, and…

Suzuki, Keiko; Motohashi, Yutaka; Kaneko, Yoshihiro

2006-01-01

133

Concordance Rates of Birth Defects After Assisted Reproductive Technology Among 17 258 Japanese Twin Pregnancies: A Nationwide Survey, 2004-2009  

PubMed Central

Background Most twins after assisted reproductive technology (ART) are dizygotic. Analysis of dizygotic twin pairs is useful in assessing familial aggregation in the development of birth defects. Methods Using nationwide post-ART data from the Japan Society of Obstetrics and Gynecology, recurrence risk ratios (RRRs)—defined as probandwise concordance rates of birth defects in twins divided by the prevalence of birth defects in the general population—were calculated as indicators of familial aggregation. Birth defects were then reclassified according to the ICD-10 categories corresponding to codes Q00–Q99. From 2004 to 2009, there were 17 258 twin pregnancies. Results At least 1 birth defect was noted in 236 twin pairs: 11 concordant and 225 discordant pairs. Regarding major organ systems, high probandwise concordance rates were observed for congenital malformations of eye, ear, face, and neck (11.8%), cleft lip and cleft palate (10.5%), congenital malformations of the nervous system (9.8%), and other congenital malformations of the digestive system (9.5%). High RRRs were observed for congenital malformations of eye, ear, face, and neck (RRR = 233), specifically other congenital malformations of the ear (RRR = 449); congenital malformations of the great arteries (RRR = 235), specifically those of the patent ductus arteriosus (RRR = 530); and for cleft lip and cleft palate (RRR = 208), specifically cleft palate with cleft lip (RRR = 609). The probandwise concordance rate of any birth defect (8.9%) was nearly identical to the approximated recurrence risk of sib-pairs (8.8%), which assumed multifactorial inheritance. Conclusions The present findings suggest that familial aggregation is a factor in some birth defects. PMID:23132150

Ooki, Syuichi

2013-01-01

134

High-frame-rate digital radiographic videography  

Microsoft Academic Search

High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to

Nicholas S. King; Frank H. Cverna; Kevin L. Albright; Steven A. Jaramillo; George J. Yates; Thomas E. McDonald; Michael J. Flynn; Scott Tashman

1994-01-01

135

High performance interconnection between high data rate networks  

NASA Technical Reports Server (NTRS)

The bridge/gateway system needed to interconnect a wide range of computer networks to support a wide range of user quality-of-service requirements is discussed. The bridge/gateway must handle a wide range of message types including synchronous and asynchronous traffic, large, bursty messages, short, self-contained messages, time critical messages, etc. It is shown that messages can be classified into three basic classes, synchronous and large and small asynchronous messages. The first two require call setup so that packet identification, buffer handling, etc. can be supported in the bridge/gateway. Identification enables resequences in packet size. The third class is for messages which do not require call setup. Resequencing hardware based to handle two types of resequencing problems is presented. The first is for a virtual parallel circuit which can scramble channel bytes. The second system is effective in handling both synchronous and asynchronous traffic between networks with highly differing packet sizes and data rates. The two other major needs for the bridge/gateway are congestion and error control. A dynamic, lossless congestion control scheme which can easily support effective error correction is presented. Results indicate that the congestion control scheme provides close to optimal capacity under congested conditions. Under conditions where error may develop due to intervening networks which are not lossless, intermediate error recovery and correction takes 1/3 less time than equivalent end-to-end error correction under similar conditions.

Foudriat, E. C.; Maly, K.; Overstreet, C. M.; Zhang, L.; Sun, W.

1992-01-01

136

A readout unit for high rate applications  

Microsoft Academic Search

The LHCb readout unit (RU) is a custom entry stage to the readout network of a data-acquisition or trigger system. It performs subevent building from multiple link inputs toward a readout network via a PCI network interface or alternatively toward a high-speed link, via an S-link interface. Incoming event fragments are derandomized, buffered and assembled into single subevents. This process

José Toledo; François Bal; David Domínguez; Angel Guirao; H. Miller

2002-01-01

137

The Effect of Minimum Wage Rates on High School Completion  

ERIC Educational Resources Information Center

Does increasing the minimum wage reduce the high school completion rate? Previous research has suffered from (1. narrow time horizons, (2. potentially inadequate measures of states' high school completion rates, and (3. potentially inadequate measures of minimum wage rates. Overcoming each of these limitations, we analyze the impact of changes in…

Warren, John Robert; Hamrock, Caitlin

2010-01-01

138

HIGH-THROUGHPUT CELLULAR ASSAYS FOR MODELING TOXICITY IN THE FISH REPRODUCTIVE SYSTEM  

EPA Science Inventory

The most important benefit of this project is the experimental evaluation of all essential steps in the development and testing of adverse outcome pathways (AOP) for a diverse set of reproductive and non-reproductive toxicants. In contrast to human testing and the toxicity pat...

139

High-repetition rate, commercial pseudospark switches for pulsed modulators  

Microsoft Academic Search

Experimental results of high-repetition rate pseudospark switch testing are reported. High-repetition rate operation was investigated with special regard to applications including copper vapor lasers, high-repetition-rate high-average power excimer lasers, and linear induction accelerators. Typical test parameters are hold-off voltage on the order of 15-25 kV, peak currents on the order of 10 kA, and pulse durations on the order of

P. Bickel; J. Christiansen; K. Frank; A. Gortler; W. Hartmann; R. Kowalewicz; A. Linsenmever; A. Kozlik; R. Stark; P. Wiesneth

1990-01-01

140

High rates of nonbreeding adult bald eagles in southeastern Alaska  

SciTech Connect

Present knowledge of bald eagle (Haliaeetus leucocephalus) demography is derived primarily from populations in environments that have been drastically altered by man. Most reproductive studies were done in the 1960's and 1970's when chemical toxins were inhibiting bald eagle productivity. Earlier, the removal of old-growth forests and decimation of anadromous fish runs by Euro-Americans may have greatly reduced bald eagle abundance from presettlement levels. Historical trends in this species are of interest because fundamental differences may exist between populations in pristine and man-altered environments. One difference may be breeding rate. Surpluses of nonbreeding adult bald eagles during the nesting season are rarely mentioned in the literature. Most surveys of reproductive success focus exclusively on eagles at nest sites, which assumes nearly all adults attempt to breed each year. The authors report that a majority of adults in the relatively pristine habitats of southeastern Alaska do not breed annually. This finding is important because if surpluses of non-breeding adults are a natural feature of the population, then hypotheses on density dependent population regulation and the evolution of delayed maturation are suggested. If, on the other hand, the abundance of nonbreeders is an artifact of recent environmental perturbations, serious population declines may occur in southeastern Alaska.

Hansen, A.J.; Hodges, J.I. Jr.

1985-01-01

141

Reproductive limits of a late-flowering high-mountain Mediterranean plant along an elevational climate gradient  

Microsoft Academic Search

Summary • Mountain plants are particularly sensitive to climate warming because snowmelt timing exerts a direct control on their reproduction. Current warming is leading to earlier snowmelt dates and longer snow-free periods. Our hypothesis is that high- mountain Mediterranean plants are not able to take advantage of a lengthened snow-free period because this leads to longer drought that truncates the

L. Giménez-Benavides; A. Escudero; J. M. Iriondo

2007-01-01

142

Dose rate in brachytherapy using after-loading machine: Pulsed or high-dose rate?  

PubMed

Since February 2014, it is no longer possible to use low-dose rate 192iridium wires due to the end of industrial production of IRF1 and IRF2 sources. The Brachytherapy Group of the French society of radiation oncology (GC-SFRO) has recommended switching from iridium wires to after-loading machines. Two types of after-loading machines are currently available, based on the dose rate used: pulsed-dose rate or high-dose rate. In this article, we propose a comparative analysis between pulsed-dose rate and high-dose rate brachytherapy, based on biological, technological, organizational and financial considerations. PMID:25195117

Hannoun-Lévi, J-M; Peiffert, D

2014-10-01

143

High rate data acquisition from Spacelab/Shuttle  

NASA Technical Reports Server (NTRS)

The need for high data rates from a variety of experiments on Spacelab/Shuttle produced the requirement for the Spacelab High Rate Multiplexer/Demultiplexer system. This system acquires serial digital data at asynchronous bit rates from up to sixteen experiments, two data buses, three voice links, two tape recorders, and a universal time channel. Experiment data rates may vary from 200 bps to 16 Mbps while recorded data rates range from 250 Kbps to 32 Mbps. The High Rate Multiplexer (HRM) accepts these data inputs and forms a serial PCM output at flexible rates up to 48 Mbps. This PCM output is transmitted to ground by a Ku-Band RF link via the Tracking and Data Relay Satellite System (TDRSS) or recorded on board for delayed transmission. A complementary ground based High Rate Demultiplexer (HRDM) accepts and demultiplexes the composite PCM data at ground processing locations.

Coffey, R.

1978-01-01

144

High strain rate deformation in FCC metals and alloys  

SciTech Connect

The effect of strain rate, and particularly of high strain rates, on deformation mechanisms in materials is of fundamental interest to those who model and analyze dynamic loading. In many materials the strain rate sensitivity is known to increase dramatically when the strain rate is raised above approx.10/sup 3/ s/sup -1/. This increase has been interpreted previously as a transmission in deformation mechanism from thermal activation control at low strain rate to dislocation drag control at high strain rate. In copper, copper-aluminum alloys and stainless steel, recent measurements have shown that the increased rate sensitivity found at high strain rates is not due to a transition in deformation mechanism but rather can be explained with standard thermal activation theory. These findings and their implications regarding the formulation of constitutive behavior are presented.

Follansbee, P.S.

1985-01-01

145

Test Scores, Dropout Rates, and Transfer Rates as Alternative Indicators of High School Performance  

Microsoft Academic Search

This study investigated the relationships among several different indicators of high school performance: test scores, dropout rates, transfer rates, and attrition rates. Hierarchical linear models were used to analyze panel data from a sample of 14,199 students who took part in the National Education Longitudinal Survey of 1988. The results generally support the notion of an alternative as opposed to

Russell W. Rumberger; Gregory J. Palardy

2005-01-01

146

Test Scores, Dropout Rates, and Transfer Rates as Alternative Indicators of High School Performance  

ERIC Educational Resources Information Center

This study investigated the relationships among several different indicators of high school performance: test scores, dropout rates, transfer rates, and attrition rates. Hierarchical linear models were used to analyze panel data from a sample of 14,199 students who took part in the National Education Longitudinal Survey of 1988. The results…

Rumberger, Russell W.; Palardy, Gregory J.

2005-01-01

147

An empirical test of evolutionary theories for reproductive senescence and reproductive effort  

E-print Network

An empirical test of evolutionary theories for reproductive senescence and reproductive effort that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life

Bronikowski, Anne

148

Achieving high participation rates: Lessons taught by successful DSM programs  

SciTech Connect

Participation rate is one of the most critical factors affecting the success of utility demand-side management programs. This paper reviews data and discusses characteristics of utility DSM programs with the highest participation rates in 18 different program categories. Factors linked with high participation rates in each category are assessed.

Nadel, S.; Pye, M.; Jordan, J.

1994-12-31

149

Endocrinology of year-round reproduction in a highly seasonal habitat: environmental variability in testosterone and glucocorticoids in baboon males  

PubMed Central

In conditions characterized by energetic constraints, such as in periods of low food availability, some trade-offs between reproduction and self-maintenance may be necessary; even year-round breeders may then be forced to exhibit some reproductive seasonality. Prior research has largely focused on female reproduction and physiology, and few studies have evaluated the impact of environmental factors on males. Here we assessed the effects of season and ambient temperatures on fecal glucocorticoid (fGC) and testosterone (fT) levels in male baboons in Amboseli, Kenya. The Amboseli basin is a highly challenging, semi-arid tropical habitat that is characterized by strongly seasonal patterns of rainfall and by high ambient temperatures. We previously reported that female baboons were impacted by these challenging environmental conditions. We ask here whether male baboons in the same environment and groups as females exhibit similar physiological effects. We found that after accounting for male age and individual variability, males exhibited higher fGC levels and lower fT levels during the dry season than during the wet season. Furthermore, fT but not fGC levels were lower in months of high average daily maximum temperatures, suggesting a direct impact of heat on testes. Our results demonstrate that male baboons, like females, experience ecological stress that alters their reproductive physiology. The impact of the environment on male reproduction deserves more attention both in its own right and because alteration in male physiology may contribute to the reduction in female fertility observed in challenging environments. PMID:20721938

Gesquiere, Laurence R.; Onyango, Patrick O.; Alberts, Susan C.; Altmann, Jeanne

2010-01-01

150

Reproduction & life I. Reproductive cycles  

E-print Network

Reproduction & life histories I. Reproductive cycles II. Reproduction in Amphibians III. Reproduction in Reptiles IV. Parental care V. Life Histories #12;I. Reproductive cycles A. Environmental In amphibians: Oogonia are self-renewing stem cells that persist for the life of the frog l Can generate a new

Dever, Jennifer A.

151

High-shear-rate capillary viscometer for inkjet inks  

SciTech Connect

A capillary viscometer developed to measure the apparent shear viscosity of inkjet inks at high apparent shear rates encountered during inkjet printing is described. By using the Weissenberg-Rabinowitsch equation, true shear viscosity versus true shear rate is obtained. The device is comprised of a constant-flow generator, a static pressure monitoring device, a high precision submillimeter capillary die, and a high stiffness flow path. The system, which is calibrated using standard Newtonian low-viscosity silicone oil, can be easily operated and maintained. Results for measurement of the shear-rate-dependent viscosity of carbon-black pigmented water-based inkjet inks at shear rates up to 2x10{sup 5} s{sup -1} are discussed. The Cross model was found to closely fit the experimental data. Inkjet ink samples with similar low-shear-rate viscosities exhibited significantly different shear viscosities at high shear rates depending on particle loading.

Wang Xi [FUJIFILM Dimatix, Inc., Lebanon, New Hampshire 03766 (United States); Carr, Wallace W.; Bucknall, David G. [School of Polymer, Textile, and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Morris, Jeffrey F. [Department of Chemical Engineering and Benjamin Levich Institute for Physico-Chemical Hydrodynamics, City College of New York, New York, New York 10031 (United States)

2010-06-15

152

High Lifetime Pregnancy and Low Contraceptive Usage Among Sex Workers Who Use Drugs- An Unmet Reproductive Health Need  

PubMed Central

Background The objective of this study was to describe levels of pregnancy and contraceptive usage among a cohort of street-based female sex workers (FSWs) in Vancouver. Methods The study sample was obtained from a community-based prospective cohort study (2006-2008) of 211 women in street-based sex work who use drugs, 176 of whom had reported at least one prior pregnancy. Descriptive statistics were used to estimate lifetime pregnancy prevalence, pregnancy outcomes (miscarriage, abortion, adoption, child apprehension, child custody), and contraceptive usage. In secondary analyses, associations between contraceptive usage, individual and interpersonal risk factors and high number of lifetime pregnancies (defined as greater than the sample mean of 4) were examined. Results Among our sample, 84% reported a prior pregnancy, with a mean of 4 lifetime pregnancies (median = 3; IQR: 2-5). The median age of women reporting 5+ pregnancies was 38 years old [interquartile range (IQR): 25.0-39.0] compared to 34 years [IQR: 25.0-39.0] among women reporting 4 or fewer prior pregnancies. 45% were Caucasian and 47% were of Aboriginal ancestry. We observed high rates of previous abortion (median = 1;IQR:1-3), apprehension (median = 2; IQR:1-4) and adoption (median = 1; IQR:1-2) among FSWs who reported prior pregnancy. The use of hormonal and insertive contraceptives was limited. In bivariate analysis, tubal ligation (OR = 2.49; [95%CI = 1.14-5.45]), and permanent contraceptives (e.g., tubal ligation and hysterectomy) (OR = 2.76; [95%CI = 1.36-5.59]) were both significantly associated with having five or more pregnancies. Conclusion These findings demonstrate high levels of unwanted pregnancy in the context of low utilization of effective contraceptives and suggest a need to improve the accessibility and utilization of reproductive health services, including family planning, which are appropriately targeted and tailored for FSWs in Vancouver. PMID:21851622

2011-01-01

153

HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW  

EPA Science Inventory

This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

154

High Graduate Unemployment Rate and Taiwanese Undergraduate Education  

ERIC Educational Resources Information Center

An expansion in higher education in combination with the recent global economic recession has resulted in a high college graduate unemployment rate in Taiwan. This study investigates how the high unemployment rate and financial constraints caused by economic cutbacks have shaped undergraduates' class choices, job needs, and future income…

Wu, Chih-Chun

2011-01-01

155

Failure mode transitions in polymers under high strain rate loading  

Microsoft Academic Search

A rather unusual failure mode transition from brittle to ductile at high strain rates occurs under a combined pressure and\\u000a shear loading. This transition also represents a change in the failure mode from a normal stress dominated fracture mode at\\u000a low loading rates to a shear stress dominated shear banding failure at high strain rates. While most such observations have

K. Ravi-Chandar; J. Lu; B. Yang; Z. Zhu

2000-01-01

156

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans  

Microsoft Academic Search

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive

Amanda M. Sparkman; Stevan J. Arnold; Anne M. Bronikowski

2007-01-01

157

Evaluation of reproductive tract infection during early post-partum period and its relationship with subsequent reproductive performance in high milk producing dairy cows.  

PubMed

Clinically normal Holstein-Friesian cows (n = 43) were used to establish a relationship between the evaluations of the uterine condition by vaginoscopy, Metricheck, endometrial cytology (EC) and ultrasonography (US) during post-partum period (pp), and subsequent reproductive performance. The uterine status of the selected cows was evaluated by EC, Metricheck, US and vaginoscopy on a weekly basis from the third week (W3) to the seventh week (W7) pp. The animals were bred after a voluntary waiting period of 45-60 days pp and diagnosed for pregnancy status at 45 days after breeding by US. First service conception rate (FSCR) of bred animals was 32.6% (14/43). There was no significant difference in polymorphonuclear leucocyte percentage between conceived and non-conceived cows during different weeks post-partum. First service conception rate in animals with normal vaginal discharge as detected by Metricheck was significantly low when compared to those of abnormal discharge during W3 (2.3% vs 30.3%; p?reproductive performance of dairy cattle. PMID:21707786

Senosy, W; Uchiza, M; Tameoka, N; Izaike, Y; Osawa, T

2012-04-01

158

Development of Korean Academy of Medical Sciences Guideline Rating the Physical Impairment; Kidney, Bladder, Urethra, Male and Female Reproductive Systems (Preliminary Report)  

PubMed Central

For the evaluation of the kidney impairment, serum creatinine concentrations or glomerular filtration rates are mainly used, and the conditions of solitary or transplanted kidney and chronic dialysis are also taken into the considerations. Some symptoms and signs of the chronic renal disability in spite of adequate treatment add one additional grade. For evaluating bladder and urethral impairment, the criteria include voiding symptoms and signs. The patients with urinary diversions have impairment grades depending on the alteration of upper urinary tract function. For penile impairment, the degrees are evaluated using the international index of erectile function, nocturnal penile tumescence and color doppler ultrasonography. For evaluating impairment of other male reproductive organs, functional and anatomical changes of these organs, analysis of the semen or hormones and the state of solitary testis are used as the criteria. For evaluating impairment of female reproductive organs, pregnancy potential, requirement of continuous treatment and the ability of sexual intercourse are used. Also, degree of impairment is modified according to the ages in evaluating female reproductive systems. We have tried to make this evaluation system objective, scientific, and convenient, but still find it leaving much to be desired. PMID:19503685

Yu, Ji Hyeong; Kim, Sang Hyun; Sohn, Seung Hwan; Paik, Kyung Hoon; Lee, Jeong Zoo; Kim, Jang Hwan; Park, Jong Kwan; Ryu, Ki-Sung; Jun, Jong Kwan; Cho, Yong Kyoon

2009-01-01

159

When to pay the cost of reproduction? A brood size manipulation experiment in great tits ( Parus major )  

Microsoft Academic Search

Parental investment (PI) theory assumes that optimal parental investment is a function of expected cost\\/benefit ratio of current versus future reproduction. This study tests the prediction of PI theory that in a species with high adult mortality, paying of reproductive costs can be induced or prevented by manipulation of brood reproductive value (RV). Analysis of recruitment rates in a 10-year

Peeter Hõrak

2003-01-01

160

Reproduction & life I. Reproductive cycles  

E-print Network

reproduction IV. Parental care I. Reproductive cycles A. Environmental stimuli Moisture, temperature, food Straddle Glued Independent Foam nests Most frogs are oviporous Categorized by egg deposition location #12

Dever, Jennifer A.

161

Plants and Photosynthesis: Level III, Unit 3, Lesson 1; The Human Digestive System: Lesson 2; Functions of the Blood: Lesson 3; Human Circulation and Respiration: Lesson 4; Reproduction of a Single Cell: Lesson 5; Reproduction by Male and Female Cells: Lesson 6; The Human Reproductive System: Lesson 7; Genetics and Heredity: Lesson 8; The Nervous System: Lesson 9; The Glandular System: Lesson 10. Advanced General Education Program. A High School Self-Study Program.  

ERIC Educational Resources Information Center

This self-study program for the high-school level contains lessons in the following subjects: Plants and Photosynthesis; The Human Digestive System; Functions of the Blood; Human Circulation and Respiration; Reproduction of a Single Cell; Reproduction by Male and Female Cells; The Human Reproductive System; Genetics and Heredity; The Nervous…

Manpower Administration (DOL), Washington, DC. Job Corps.

162

Self-mixing laser Doppler vibrometry with high optical sensitivity: application to real-time sound reproduction  

Microsoft Academic Search

Nanometre vibration measurement of an audio speaker and a highly sensitive sound reproduction experiment have been successfully demonstrated by a self-aligned optical feedback vibrometry technique using the self-mixing modulation effect in a laser-diode-pumped microchip solid-state laser. By applying nanometre vibrations to the speaker, which produced nearly inaudible music below 20 dB (200 µPa) sound pressure level, we could reproduce clear

Kazutaka Abe; Kenju Otsuka; Jing-Yuan Ko

2003-01-01

163

Orientation and rate dependence in high strain-rate compression of single-crystal silicon  

NASA Astrophysics Data System (ADS)

High strain-rate (??˜106-109s-1) compression of single crystal Si reveals strong orientation- and rate-dependent precursor stresses. At these high compression rates, the peak elastic stress, ?E_Peak, for Si [100], [110], and [111] exceeds twice the Hugoniot elastic limit. Near the loading surface, the rate at which Si evolves from uniaxial compression to a three-dimensional relaxed state is exponentially dependent on ?E_Peak and independent of initial crystal orientation. At later times, the high elastic wave speed results in a temporal decoupling of the elastic precursor from the main inelastic wave. A rapid high-?? increase in the measured elastic stress at the onset of inelastic deformation is consistent with a transition from dislocation flow mediated by thermal activation to a phonon drag regime.

Smith, R. F.; Minich, R. W.; Rudd, R. E.; Eggert, J. H.; Bolme, C. A.; Brygoo, S. L.; Jones, A. M.; Collins, G. W.

2012-12-01

164

Fast molecular evolution associated with high active metabolic rates in poison frogs.  

PubMed

Molecular evolution is simultaneously paced by mutation rate, genetic drift, and natural selection. Life history traits also affect the speed of accumulation of nucleotide changes. For instance, small body size, rapid generation time, production of reactive oxygen species (ROS), and high resting metabolic rate (RMR) are suggested to be associated with faster rates of molecular evolution. However, phylogenetic correlation analyses failed to support a relationship between RMR and molecular evolution in ectotherms. In addition, RMR might underestimate the metabolic budget (e.g., digestion, reproduction, or escaping predation). An alternative is to test other metabolic rates, such as active metabolic rate (AMR), and their association with molecular evolution. Here, I present comparative analyses of the associations between life history traits (i.e., AMR, RMR, body mass, and fecundity) with rates of molecular evolution of and mitochondrial loci from a large ectotherm clade, the poison frogs (Dendrobatidae). My results support a strong positive association between mass-specific AMR and rates of molecular evolution for both mitochondrial and nuclear loci. In addition, I found weaker and genome-specific covariates such as body mass and fecundity for mitochondrial and nuclear loci, respectively. No direct association was found between mass-specific RMR and rates of molecular evolution. Thus, I provide a mechanistic hypothesis of the link between AMRs and the rate of molecular evolution based on an increase in ROS within germ line cells during periodic bouts of hypoxia/hyperoxia related to aerobic exercise. Finally, I propose a multifactorial model that includes AMR as a predictor of the rate of molecular evolution in ectothermic lineages. PMID:22337863

Santos, Juan C

2012-08-01

165

FAST TRACK COMMUNICATION High rate straining of tantalum and copper  

NASA Astrophysics Data System (ADS)

High strain rate measurements reported recently for several tantalum and copper crystal/polycrystal materials are shown to follow dislocation mechanics-based constitutive relations, first at lower strain rates, for dislocation velocity control of the imposed plastic deformations and, then at higher rates, transitioning to nano-scale dislocation generation control by twinning or slip. For copper, there is the possibility of added-on slip dislocation displacements to be accounted for from the newly generated dislocations.

Armstrong, R. W.; Zerilli, F. J.

2010-12-01

166

Housing prices and the high Chinese saving rate puzzle  

Microsoft Academic Search

China's over 25% aggregate household saving rate is one of the highest in the world. One popular view attributes the high saving rate to fast-rising housing prices in China. However, cross-sectional data do not show a significant relationship between housing prices and household saving rates. This article uses a simple consumption-saving model to explain why rising housing prices per se

Xin Wang; Yi Wen

2012-01-01

167

High-energy diets may induce a pre-diabetic state altering testicular glycolytic metabolic profile and male reproductive parameters.  

PubMed

Diabetes mellitus is a metabolic disorder that may arise from diet habits and is growing to epidemic proportions. Young male diabetic patients present high infertility/subfertility prevalence resulting from impaired reproductive function and poor semen quality. We aimed to evaluate the effects of a high-energy diet (HED) on glucose tolerance/insulin levels and correlate the observed effects on male reproductive function with overall testicular metabolism. After 1 month, HED fed rats showed increased glycaemic levels, impaired glucose tolerance and hypoinsulinaemia. Moreover, an imbalance of intratesticular and serum testosterone levels was observed, whereas those of 17?-estradiol were not altered. High-energy diet also affected the reproductive parameters, with HED rats exhibiting a significant increase in abnormal sperm morphology. Glycolytic metabolism was favoured in testicles of HED rats with an increased expression of both glucose transporters 1 (GLUT1) and 3 (GLUT3) and the enzyme phosphofrutokinase 1. Moreover, lactate production and the expression of metabolism-associated genes and proteins involved in lactate production and transport were also enhanced by HED. Alanine testicular content was decreased and thus intratesticular lactate/alanine ratio in HED rats was increased, suggesting increased oxidative stress. Other energetic substrates such as acetate and creatine were not altered in testis from HED rats, but intratesticular glycine content was increased in those animals. Taken together, these results suggest that HED induces a pre-diabetic state that may impair reproductive function by modulating overall testicular metabolism. This is the first report on testicular metabolic features and mechanisms related with the onset of a pre-diabetic state. PMID:23495257

Rato, L; Alves, M G; Dias, T R; Lopes, G; Cavaco, J E; Socorro, S; Oliveira, P F

2013-05-01

168

Higher Minimum Wage and High School Dropout Rates  

Microsoft Academic Search

We explore whether higher levels of the real minimum wage have differing effects on high school dropout rates across students of various races and ethnicities (whites, African Americans, Hispanics, and Asians). Using a panel of data across Maryland counties and annual observations in 1993-2004, we found higher real minimum wages to be associated with higher dropout rates for Hispanic students,

Stephanie O. Crofton; William L. Anderson; Emily C. Rawe

2009-01-01

169

High rate fingerprinting codes and the fingerprinting capacity Ehsan Amiri  

E-print Network

High rate fingerprinting codes and the fingerprinting capacity Ehsan Amiri G´abor Tardos Abstract fingerprinting codes. In this paper we consider fingerprinting with the mark- ing assumption and design codes possible rate (the fingerprinting capacity) for any fixed number of pirates. We prove new up- per bounds

Tardos, Gábor

170

Rural and Urban High School Dropout Rates: Are They Different?  

ERIC Educational Resources Information Center

This study estimates the high school dropout rate in rural and urban areas, the determinants of dropping out, and whether the differences in graduation rates have changed over time. We use geocoded data from two nationally representative panel household surveys (NLSY 97 and NLSY 79) and a novel methodology that corrects for biases in graduation…

Jordan, Jeffrey L.; Kostandini, Genti; Mykerezi, Elton

2012-01-01

171

A proposed deformation mechanism for high strain-rate superplasticity  

SciTech Connect

Superplasticity at high deformation rates is desirable in order to make superplastic forming more practical. Recently, superplasticity was achieved at strain rates between 10{sup {minus}2} and 100 s{sup {minus}1} in powder-metallurgy (PM) processed and mechanically alloyed (MA) aluminum alloys. The purpose of this paper is to understand the rate-controlling-deformation mechanisms for ultrafine-grained aluminum materials where high-strain-rate superplasticity is observed. The stress-strain rate relations for IM, PM and MA materials are analyzed in terms of deformation mechanism maps, and in terms of the contribution of subgrain boundaries to the enhancement of grain boundary sliding. Conclusions are as follows: (1) Lattice-diffusion-controlled grain boundary sliding is believed to be the rate-controlling mechanisms for high-strain-rate superplasticity in PM and MA aluminum alloys. (2) Construction of deformation mechanisms maps based on diffusional creep, grain boundary sliding and dislocation creep illustrate the importance of grain size in achieving high-strain- rate-superplasticity. (3) The Ball-Hutchinson model for grain-boundary sliding has been modified to include the influence of subgrain size in enhancing the grain boundary sliding process. (4) The introduction of threshold stress for grain boundary sliding and the important contribution of grain and subgrains permit unification of all superplastic IM, PM and MA aluminum data available.

Kim, W.J. [Hong Ik Univ., Seoul (Korea, Republic of)] [Hong Ik Univ., Seoul (Korea, Republic of); Taleff, E.; Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Sciences and Engineering] [Stanford Univ., CA (United States). Dept. of Materials Sciences and Engineering

1995-05-15

172

High Strain Rate Characterisation of a Polymer Bonded Sugar  

Microsoft Academic Search

The mechanical properties of a polymer bonded sugar consisting of 78% sugar crystals, of modal particle size 310 mum, dispersed in an HTPB binder have been characterized in a split Hopkinson pressure bar system at a strain rate of 103 s-1 and temperatures from -100 to +20 °C. These high rate experiments were supplemented by further experiments in an Instron

P. R. Laity; C. R. Siviour; P. D. Church; W. G. Proud

2006-01-01

173

High Strain Rate Characterisation of a Polymer Bonded Sugar  

Microsoft Academic Search

The mechanical properties of a polymer bonded sugar consisting of 78% sugar crystals, of modal particle size 310 ?m, dispersed in an HTPB binder have been characterized in a split Hopkinson pressure bar system at a strain rate of 103 s?1 and temperatures from ?100 to +20 °C. These high rate experiments were supplemented by further experiments in an Instron

P. R. Laity; C. R. Siviour; P. D. Church; W. G. Proud

2006-01-01

174

Life Table and Predation of Lemnia biplagiata (Coleoptera: Coccinellidae) Fed on Aphis gossypii (Homoptera: Aphididae) with a Proof on Relationship Among Gross Reproduction Rate, Net Reproduction Rate, and Preadult Survivorship  

Microsoft Academic Search

The life history and predation rate of Lemnia biplagiata (Swartz) fed on Aphis gossypii Glover was studied at 25C in the laboratory. The raw data were analyzed based on the age-stage, two-sex life table to take the variable developmental rate among individuals and both sexes into consideration. The intrinsic rate of increase (r) is 0.1570 d1, the Þnite rate of

Jih-Zu Yu; Hsin Chi; Bing-Huei Chen

2005-01-01

175

Measuring growth rate in high-throughput growth phenotyping.  

PubMed

Growth rate is an important variable and parameter in biology with a central role in evolutionary, functional genomics, and systems biology studies. In this review the pros and cons of the different technologies presently available for high-throughput measurements of growth rate are discussed. Growth rate can be measured in liquid microcultivation of individual strains, in competition between strains, as growing colonies on agar, as division of individual cells, and estimated from molecular reporters. Irrespective of methodology, statistical issues such as spatial biases and batch effects are crucial to investigate and correct for to ensure low false discovery rates. The rather low correlations between studies indicate that cross-laboratory comparison and standardization are pressing issue to assure high-quality and comparable growth-rate data. PMID:21095113

Blomberg, Anders

2011-02-01

176

Slow rate of molecular evolution in?high-elevation?hummingbirds  

PubMed Central

Estimates of relative rates of molecular evolution from a DNA-hybridization phylogeny for 26 hummingbird species provide evidence for a negative association between elevation and rate of single-copy genome evolution. This effect of elevation on rate remains significant even after taking into account a significant negative association between body mass and molecular rate. Population-level processes do not appear to account for these patterns because (i) all hummingbirds breed within their first year and (ii) the more extensive subdivision and speciation of bird populations living at high elevations predicts a positive association between elevation and rate. The negative association between body mass and molecular rate in other organisms has been attributed to higher mutation rates in forms with higher oxidative metabolism. As ambient oxygen tensions and temperature decrease with elevation, the slow rate of molecular evolution in high-elevation hummingbirds also may have a metabolic basis. A slower rate of single-copy DNA change at higher elevations suggests that the dynamics of molecular evolution cannot be separated from the environmental context. PMID:9435240

Bleiweiss, Robert

1998-01-01

177

NON-ARRHENIUS RATE CONSTANTS IN HIGHLY EXOTHERMIC REACTIONS  

Microsoft Academic Search

Highly exothermic chemical reactions can produce chemical species with much kinetic energy. Since the Arrhenius expression for the rate constant is based on the assumption that the kinetic energy distribution is approximately a Maxwellian, a study has been carried out to determine if the Arrhenius expression is always valid for chemical reactions initiated by products of highly exothermic reactions. A

K. KELLY; M. D. KOSTIN

1989-01-01

178

The Hahnemann High School Behavior (HHSB) rating scale  

Microsoft Academic Search

In a 1973 critical review of classroom overt behavior rating scales (Spivack & Swift, 1973), the authors noted that little attention had been given to the mea. surement of behaviors at the junior and senior high school levels. As of that data only four scales dealt with youngsters beyond the sixth grade, only three beyond junior high school, and of

George Spivack; Marshall Swift

1977-01-01

179

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs  

PubMed Central

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs. PMID:23874921

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

180

Study of High Strain Rate Response of Composites  

NASA Technical Reports Server (NTRS)

The objective of the research was to continue the experimental study of the effect of strain rate on mechanical response (deformation and failure) of epoxy resins and carbon fibers/epoxy matrix composites, and to initiate a study of the effects of temperature by developing an elevated temperature test. The experimental data provide the information needed for NASA scientists for the development of a nonlinear, rate dependent deformation and strength models for composites that can subsequently be used in design. This year effort was directed into testing the epoxy resin. Three types of epoxy resins were tested in tension and shear at various strain rates that ranges from 5 x 10(exp -5), to 1000 per second. Pilot shear experiments were done at high strain rate and an elevated temperature of 80 C. The results show that all, the strain rate, the mode of loading, and temperature significantly affect the response of epoxy.

Gilat, Amos

2003-01-01

181

Compressive behaviour of concrete at high strain rates  

Microsoft Academic Search

Experimental techniques commonly used for high strain-rate testing of concrete in compression, together with the methods used\\u000a for measurement and recording of stress and strain, are critically assessed in the first part of this paper. The physical\\u000a capability of each loading method is discussed and some consideration is given to the definitions used for specifying the\\u000a loading rate. The second

P. H. Bischoff; S. H. Perry

1991-01-01

182

High rates of nitrogen fixation in equatorial upwelling region  

NASA Astrophysics Data System (ADS)

Surface waters in upwelling regions of the ocean are generally rich in nutrients. Scientists had thought that these areas would have low rates of nitrogen fixation because diazotrophs—microbes that convert nitrogen gas from the atmosphere into usable forms, such as ammonia—could use the nutrients in the water directly instead of having to fix nitrogen gas. However, researchers recently recorded high rates of nitrogen fixation in an upwelling region in the equatorial Atlantic.

Balcerak, Ernie

2013-05-01

183

Why Are Saving Rates so High in China?  

Microsoft Academic Search

In this paper, we define “The Chinese Saving Puzzle� as the persistently high national saving rate at 34–53 percent of gross domestic product (GDP) in the past three decades and a surge in the saving rate by 11 percentage points from 2000–2008. Using data from the Flow of Funds Accounts (FFA) and Urban Household Surveys (UHS) supplemented by the findings

Dennis Tao Yang; Junsen Zhang; Shaojie Zhou

2011-01-01

184

Image enhancement for sonograms acquired by high frame rate mode  

NASA Astrophysics Data System (ADS)

Sonography performed in high frame rate aims to achieve high temporal resolution. Echocardiography and fetal echocardiography are typical examinations performed in this manner. In general, image quality of sonograms acquired by high frame rate mode is poorer compared to that acquired by low frame rate mode. Poor definition and rich of noises are drawbacks usually found in the images obtained in high frame rate. We propose an approach to improve image quality of the sonograms, in which the noises can effectively be removed from the corrupted images and the definition of textures can also be enhanced. Three techniques are involved in the approach: image interpolation, addition of spatial information and averaging image by cycle spinning. The first technique is employed to generate extra spatial information. The second one intends to extract high frequency information from the original image and add the information to the high frequency subbands so that the image can further be enhanced. The last technique aims to remove noises by averaging images which have been undergone frame shifting and coefficient addition. Our experimental results show that noises randomly scattered in the images, not speckles, are effectively removed, and the definition of texture is further reinforced.

Lee, Wen-Li; Chen, Mei-Juan

2010-03-01

185

Damage formation during high strain rate deformation of PBS9501  

NASA Astrophysics Data System (ADS)

A key aspect of the response of an explosive formulation to high strain rate loading is damage formation. In addition to the effect on immediate strength properties, damage, once formed, can lead to an undesirable increase in sensitivity and rate of burning. Methodologies for understanding and characterising the damage formed during loading are therefore vital if we are to claim a true understanding of the mechanical properties of these materials. This paper presents results from experiments on stimulant, PBS9501, of a polymer bonded explosive. High strain rate loading was performed in a split Hopkinson pressure bar, using speckle metrology and high speed photography to build up a more complete data-set on the formation of damage in this material. X-ray microtomography was also applied to examine internal damage in recovered specimens.

Siviour, Clive; Proud, William

2007-06-01

186

Reproductive Hazards  

MedlinePLUS

... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

187

Flexible high-repetition-rate ultrafast fiber laser.  

PubMed

High-repetition-rate pulses have widespread applications in the fields of fiber communications, frequency comb, and optical sensing. Here, we have demonstrated high-repetition-rate ultrashort pulses in an all-fiber laser by exploiting an intracavity Mach-Zehnder interferometer (MZI) as a comb filter. The repetition rate of the laser can be tuned flexibly from about 7 to 1100 GHz by controlling the optical path difference between the two arms of the MZI. The pulse duration can be reduced continuously from about 10.1 to 0.55 ps with the spectral width tunable from about 0.35 to 5.7 nm by manipulating the intracavity polarization controller. Numerical simulations well confirm the experimental observations and show that filter-driven four-wave mixing effect, induced by the MZI, is the main mechanism that governs the formation of the high-repetition-rate pulses. This all-fiber-based laser is a simple and low-cost source for various applications where high-repetition-rate pulses are necessary. PMID:24226153

Mao, Dong; Liu, Xueming; Sun, Zhipei; Lu, Hua; Han, Dongdong; Wang, Guoxi; Wang, Fengqiu

2013-01-01

188

Flexible high-repetition-rate ultrafast fiber laser  

PubMed Central

High-repetition-rate pulses have widespread applications in the fields of fiber communications, frequency comb, and optical sensing. Here, we have demonstrated high-repetition-rate ultrashort pulses in an all-fiber laser by exploiting an intracavity Mach-Zehnder interferometer (MZI) as a comb filter. The repetition rate of the laser can be tuned flexibly from about 7 to 1100?GHz by controlling the optical path difference between the two arms of the MZI. The pulse duration can be reduced continuously from about 10.1 to 0.55?ps with the spectral width tunable from about 0.35 to 5.7?nm by manipulating the intracavity polarization controller. Numerical simulations well confirm the experimental observations and show that filter-driven four-wave mixing effect, induced by the MZI, is the main mechanism that governs the formation of the high-repetition-rate pulses. This all-fiber-based laser is a simple and low-cost source for various applications where high-repetition-rate pulses are necessary. PMID:24226153

Mao, Dong; Liu, Xueming; Sun, Zhipei; Lu, Hua; Han, Dongdong; Wang, Guoxi; Wang, Fengqiu

2013-01-01

189

Flexible high-repetition-rate ultrafast fiber laser  

NASA Astrophysics Data System (ADS)

High-repetition-rate pulses have widespread applications in the fields of fiber communications, frequency comb, and optical sensing. Here, we have demonstrated high-repetition-rate ultrashort pulses in an all-fiber laser by exploiting an intracavity Mach-Zehnder interferometer (MZI) as a comb filter. The repetition rate of the laser can be tuned flexibly from about 7 to 1100 GHz by controlling the optical path difference between the two arms of the MZI. The pulse duration can be reduced continuously from about 10.1 to 0.55 ps with the spectral width tunable from about 0.35 to 5.7 nm by manipulating the intracavity polarization controller. Numerical simulations well confirm the experimental observations and show that filter-driven four-wave mixing effect, induced by the MZI, is the main mechanism that governs the formation of the high-repetition-rate pulses. This all-fiber-based laser is a simple and low-cost source for various applications where high-repetition-rate pulses are necessary.

Mao, Dong; Liu, Xueming; Sun, Zhipei; Lu, Hua; Han, Dongdong; Wang, Guoxi; Wang, Fengqiu

2013-11-01

190

High shear rate hemofiltration: influence of fiber dimensions and shear rates.  

PubMed

The variation of ultrafiltration flow rate (QF) at high transmembrane pressure with inlet wall shear rate (gamma w) was found to be proportional to gamma wn, with n ranging from 0.45 to 0.55, when gamma w increases up to 4,500 s-1. To test whether long filters operated at high shear rates were more efficient than shorter ones for the same inlet blood flow, we made experiments with 10- and 20-cm filters with same number of fibers (550) at various shear rates from 700 to 3,000 s-1. The filtration rates provided by the 20-cm filter were found to be 5-15% larger than those provided by two 10-cm filters arranged in parallel and 10-20% smaller than those provided by two 10-cm filters arranged in a series. The explanation lies in the rapid decay of QF with distance from the inlet due to the developing concentration boundary layer. When pulsations are imposed on the inlet blood flow, the filtration rate was seen to increase by 10-20%, and the effect of plugging was seen to decrease in small-area hemofilters. PMID:2705891

Gupta, B B; Ding, L H; Jaffrin, M Y

1989-04-01

191

High Strain Rate Testing of HMX Based Explosives  

NASA Astrophysics Data System (ADS)

The split-Hopkinson pressure bar (SHPB) apparatus was used to measure the mechanical behavior of a Navy explosive PBXC-129 with strain rates up to 3000 s-1 . PBXC-129 is a high solids loading explosive material. The high strain response of the PBXC-129 indicates that the material has typical behavior that would be expected from explosives and propellant materials. At the higher strain rates the material shows significant stiffening with possible reaction. The stress-strain curves and material response properties are presented in this paper for PBXC-129 material.

John, Henry

1999-06-01

192

High-rate timing RPC with ceramics electrodes  

NASA Astrophysics Data System (ADS)

A resistive plate counter for timing purposes in the high-rate environment of the Compressed Baryonic Matter Experiment has been developed at the Forschungszentrum Dresden-Rossendorf. The detector electrodes are made of a ceramics composite. Detector tests have been performed with minimum ionizing single electrons, delivered by the electron accelerator ELBE with a time accuracy of few picoseconds. The ceramics RPC shows an all-time high-rate capability for electron fluxes up to 2.7×105s-1cm-2.

Naumann, L.; Kotte, R.; Stach, D.; Wüstenfeld, J.

2011-04-01

193

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. A method for retrieving the cumulus entrainment rate from ground based observations  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without at Madison pg. n/a #12;Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. #12;Reproduced with permission of the copyright owner. Further reproduction prohibited

Wisconsin at Madison, University of

194

Animal Reproduction  

NSDL National Science Digital Library

From Dr. Michael Gregory of Clinton Community College, this site is a concise overview of animal reproduction. The site addresses important aspects of sexual and asexual reproduction, the male and female reproductive systems, fertilization, and the importance of hormones. Visitors to the site will find diagrams outlining biological processes especially helpful.

Gregory, Michael

2007-12-14

195

Low Primary Cesarean Rate and High VBAC Rate With Good Outcomes in an Amish Birthing Center  

PubMed Central

PURPOSE Recent national guidelines encourage a trial of labor after cesarean (TOLAC) as a means of increasing vaginal births after cesarean (VBACs) and decreasing the high US cesarean birth rate and its consequences (2010 National Institute of Health Consensus Statement and American College of Obstetricians and Gynecologists revised guideline). A birthing center serving Amish women in Southwestern Wisconsin offered an opportunity to look at the effects of local culture and practices that support vaginal birth and TOLAC. This study describes childbirth and perinatal outcomes during a 17-year period in LaFarge, Wisconsin. METHODS We undertook a retrospective analysis of the records of all women admitted to the birth center in labor. Main outcome measures include rates of cesarean deliveries, TOLAC and VBAC deliveries, and perinatal outcomes for 927 deliveries between 1993 and 2010. RESULT S The cesarean rate was 4% (35 of 927), the TOLAC rate was 100%, and the VBAC rate was 95% (88 of 92). There were no cases of uterine rupture and no maternal deaths. The neonatal death rate of 5.4 of 1,000 was comparable to that of Wisconsin (4.6 of 1,000) and the United States (4.5 of 1,000). CONCLUSIONS Both the culture of the population served and a number of factors relating to the management of labor at the birthing center have affected the rates of cesarean delivery and TOLAC. The results of the LaFarge Amish study support a low-technology approach to delivery where good outcomes are achieved with low cesarean and high VBAC rates. PMID:23149530

Deline, James; Varnes-Epstein, Lisa; Dresang, Lee T.; Gideonsen, Mark; Lynch, Laura; Frey, John J.

2012-01-01

196

Ultra High-Rate Germanium (UHRGe) Modeling Status Report  

SciTech Connect

The Ultra-High Rate Germanium (UHRGe) project at Pacific Northwest National Laboratory (PNNL) is conducting research to develop a high-purity germanium (HPGe) detector that can provide both the high resolution typical of germanium and high signal throughput. Such detectors may be beneficial for a variety of potential applications ranging from safeguards measurements of used fuel to material detection and verification using active interrogation techniques. This report describes some of the initial radiation transport modeling efforts that have been conducted to help guide the design of the detector as well as a description of the process used to generate the source spectrum for the used fuel application evaluation.

Warren, Glen A.; Rodriguez, Douglas C.

2012-06-07

197

Coal plasticity at high heating rates and temperatures  

SciTech Connect

Using a high temperature plastometer with a new cone-shaped shearing disk, the effect of shear rate ({gamma}R) on the apparent viscosity of softened coal was studied. For {gamma}R from 2.01 s{sup {minus}1} to 10.7 s{sup {minus}1}, no shear rate effect on the viscosity of Pittsburgh No. 8 high volatile bituminous coal was observed. Three other coals, each of different ranks ranging from high volatile bituminous to low volatile bituminous, were also studied. Although lower in tar and extractable yields than high volatile bituminous coals, medium and low volatile bituminous coals were found to be very plastic. Their good plastic behavior is therefore hypothesized to arise from their ability to generate higher molecular weight liquid fragments ( macrometaplast'') which are not represented by tar and extractable yields.

Gerjarusak, S.; Peters, W.A.; Howard, J.B.

1992-02-01

198

High variance in reproductive success of the Pacific oyster ( Crassostrea gigas, Thunberg) revealed by microsatellite-based parentage analysis of multifactorial crosses  

Microsoft Academic Search

Marine bivalves are known to have small Ne\\/N ratios, both in wild and hatchery-propagated populations. This has been interpreted as the consequence of a high variance in reproductive success. However, how much of this variance could be attributed to pre-zygotic reproductive factors or to post-zygotic selection was not yet estimated. To estimate the relative effect of these factors, we have

P Boudry; B Collet; F Cornette; V Hervouet; F Bonhomme

2002-01-01

199

Reliability modeling of electronic systems subjected to high strain rates  

Microsoft Academic Search

Electronic products are subjected to high G-levels during mechanical shock and vibration. Failure-modes include solder-joint failures, pad cratering, chip-cracking, copper trace fracture, and underfill fillet failures. The second-level interconnects may be experience high-strain rates and accrue damage during repetitive exposure to mechanical shock. Industry migration to leadfree solders has resulted in proliferation of a wide variety of solder alloy compositions.

Pradeep Lall; Sandeep Shantaram; David Locker

2012-01-01

200

Numerical simulation of ductile fracture during high strain rate deformation  

Microsoft Academic Search

A numerical integration scheme is presented for integration of the pressure-sensitive yield criterion due to Gurson, suitable for explicit dynamic finite element calculations. This scheme utilizes a sub-increment approach to maintain stability for the large strain increments and intense triaxiality that can occur under high strain rate loading. A number of validation problems are presented after which two laboratory-scale high

M. J. Worswick; P. Pelletier

1998-01-01

201

Performance Evaluation of High-Rate GPS Seismometers  

NASA Astrophysics Data System (ADS)

High-rate GPS observations with higher than once-per-second sampling are getting increasingly important for seismology. Unlike a traditional seismometer which measures short period vibration using accelerometers, the GPS receiver can measure its antenna position directly and record long period seismic wave and permanent displacements as well. The high-rate GPS observations are expected to provide new insights in understanding the whole aspects of earthquake process. In this study, we investigated dynamic characteristics of the high-rate GPS receivers capable of outputting the observations at up to 50Hz. This higher output rate, however, doesn't mean higher dynamics range of the GPS observations. Since many GPS receivers are designed for low dynamics applications, such as static survey, personal and car navigation, the bandwidth of the loop filters tend to be narrower in order to reduce the noise level of the observations. The signal tracking loop works like a low-pass filter. Thus the narrower the bandwidth, the lower the dynamics range. In order to extend this dynamical limit, high-rate GPS receivers might use wider loop bandwidth for phase tracking. In this case, the GPS observations are degraded by higher noise level in return. In addition to the limitation of the loop bandwidth, higher acceleration due to earthquake may cause the steady state error in the signal tracking loop. As a result, kinematic solutions experience undesirable position offsets, or the receiver may lose the GPS signals in an extreme case. In order to examine those effects for the high-rate GPS observations, we made an experiment using a GPS signal simulator and several geodetic GPS receivers, including Trimble Net-R8, NovAtel OEMV, Topcon Net-G3A, and Javad SIGMA-G2T. We set up the zero-baseline simulation scenario in which the rover receiver was vibrating in a periodic motion with the frequency from 1Hz to 10Hz around the reference station. The amplitude of the motion was chosen to provide up to 10G acceleration to emulate high frequency and high acceleration earthquake motion. The simulation results showed that the amplitude was too small when the frequency was higher than 5Hz, and kinematic solutions were buried under the noise level. The jerk was also too high in such high frequency region, and no receiver was capable of maintaining signal lock. Many receivers lost signal under the acceleration higher than 4G. We also found that the accuracy of high-rate GPS observations was independent of sampling rate of the receivers, and the 50Hz sampling rate provides better resolution to the kinematic solutions. Our experiment suggested that, in the given environment and receiver sets, higher sampling interval was recommended to measure the ground motion in higher resolution. On the other hand, the dynamic characteristics of the signal tracking loop put a limit on the frequency and the acceleration of the antenna motion, and it would be quite difficult to capture the ground vibration with higher than 5Hz in frequency and 4G in acceleration. We will further continue our experiments to find the optimal configurations of the high-rate GPS receivers to monitor seismic events.

Kato, T.; Ebinuma, T.

2011-12-01

202

High-rate quantum cryptography in untrusted networks  

E-print Network

We extend the field of continuous-variable quantum cryptography to a network formulation where two honest parties connect to an untrusted relay by insecure quantum links. To generate secret correlations, they transmit coherent states to the relay where a continuous-variable Bell detection is performed and the outcome broadcast. Even though the detection could be fully corrupted and the links subject to optimal coherent attacks, the honest parties can still extract a secret key, achieving high rates when the relay is proximal to one party, as typical in public networks with access points or proxy servers. Our theory is confirmed by an experiment generating key-rates which are orders of magnitude higher than those achievable with discrete-variable protocols. Thus, using the cheapest possible quantum resources, we experimentally show the possibility of high-rate quantum key distribution in network topologies where direct links are missing between end-users and intermediate relays cannot be trusted.

Stefano Pirandola; Carlo Ottaviani; Gaetana Spedalieri; Christian Weedbrook; Samuel L. Braunstein; Seth Lloyd; Tobias Gehring; Christian S. Jacobsen; Ulrik L. Andersen

2013-12-15

203

2000-2006 Texas High Plains Cotton Variety Ratings  

E-print Network

2000-2006 Texas High Plains Cotton Variety Ratings for Bacterial Blight Dr. Terry Wheeler Research Plant Pathologist Texas Agricultural Experiment Station and Dr. Jason E. Woodward Extension Plant 4021B2RF Americot 1532B2RF ST 4892BR BW 8391B2RF Americot 427R BW 9775B2RF Americot 8120 Cotton States

Mukhtar, Saqib

204

Thermomechanical treatment for high strain rate superplastic aluminum matrix composites  

SciTech Connect

Thermomechanical treatment with hot extrusion is described for a high strain rate superplastic Si{sub 3}N{sub 4p}/6061Al composite. Dynamic precipitation was caused during hot extrusion, which played an important role in grain refinement. As a result, very small grain size of about 1 {mu}m was obtained by hot extrusion.

Mabuchi, Mamoru [Government Industrial Research Institute, Nagoya (Japan); Higashi, Kenji [Univ. of Osaka Prefecture, Sakai (Japan). Dept. of Mechanical Engineering

1993-12-31

205

High strain rate constitutive equation for aluminium metal matrix composites  

SciTech Connect

In this paper, high strain rate constitutive equations are presented for two different types of Al Metal Matrix Composite materials. Simple dynamic compression test results in conjunction with a numerical technique are used to determine the constants of this equation. For comparison, tests were also conducted on pure aluminum. Finally, some important issues relevant to the constitutive models for MMC are outlined.

Hamouda, A.M.S.; Hashmi, M.S.J. [Dublin City Univ. (Ireland). Advance Materials Processing Centre

1993-12-31

206

High Heart Rate as Predictor of Essential Hypertension  

Microsoft Academic Search

Although essential hypertension seems to have a strong hereditary component, the triggering mechanism is unclear. It is likely that the central nervous system via autonomic sympathetic overactivation plays a key role in the development of hypertension. High heart rate has proven to be a strong predictor for cardiovascular disease and a predictor of the development of essential hypertension. Because heart

Trygve B. Tjugen; Arnljot Flaa; Sverre E. Kjeldsen

2009-01-01

207

Corrected High-Frame Rate Anchored Ultrasound with Software Alignment  

ERIC Educational Resources Information Center

Purpose: To improve lingual ultrasound imaging with the Corrected High Frame Rate Anchored Ultrasound with Software Alignment (CHAUSA; Miller, 2008) method. Method: A production study of the IsiXhosa alveolar click is presented. Articulatory-to-acoustic alignment is demonstrated using a Tri-Modal 3-ms pulse generator. Images from 2 simultaneous…

Miller, Amanda L.; Finch, Kenneth B.

2011-01-01

208

Plant respirometer enables high resolution of oxygen consumption rates  

NASA Technical Reports Server (NTRS)

Plant respirometer permits high resolution of relatively small changes in the rate of oxygen consumed by plant organisms undergoing oxidative metabolism in a nonphotosynthetic state. The two stage supply and monitoring system operates by a differential pressure transducer and provides a calibrated output by digital or analog signals.

Foster, D. L.

1966-01-01

209

Childhood Onset Schizophrenia: High Rate of Visual Hallucinations  

ERIC Educational Resources Information Center

Objective: To document high rates and clinical correlates of nonauditory hallucinations in childhood onset schizophrenia (COS). Method: Within a sample of 117 pediatric patients (mean age 13.6 years), diagnosed with COS, the presence of auditory, visual, somatic/tactile, and olfactory hallucinations was examined using the Scale for the Assessment…

David, Christopher N.; Greenstein, Deanna; Clasen, Liv; Gochman, Pete; Miller, Rachel; Tossell, Julia W.; Mattai, Anand A.; Gogtay, Nitin; Rapoport, Judith L.

2011-01-01

210

High-rate Iranian blowout controlled while still burning  

Microsoft Academic Search

Oil well firefighters used ingenuity and equipment designed in the field to cap a high-rate blowout well in Iran without extinguishing the fire. Well AZ-50, located about 25 km southeast of Ahwaz, Iran, blew out on Feb. 14, 1993, and was finally controlled on Mar. 31, 1993, by a firefighting team from the National Iranian Oil Co. The estimated open

H. Bahmani; A. Azarpanah

1994-01-01

211

High-repetition-rate excimer laser for micromachining  

Microsoft Academic Search

Excimer lasers are nowadays well established UV laser sources for the wide area of micromachining. Their high energy and average power at short UV wavelengths makes them ideal for ablation of various materials e. g. polyamide and PMMA. The typical excimer laser sources used in micro machining deliver several hundred mJ of energy at repetition rates of up to 400

Ludolf Herbst; Ingo Klaft; Thomas Wenzel; Ulrich Rebhan

2003-01-01

212

High production rate of IBAD-MgO buffered substrate  

NASA Astrophysics Data System (ADS)

The conventional IBAD (Ion Beam Assisted Deposition) process using fluorite materials yields low production rates, resulting in high production cost, which reduces the motivation for practical application in spite of its high quality. The IBAD process using rock salt materials, e.g. MgO, is well known as a strong candidate of practical application due to its potential of high production rate and high in-plane grain alignment. In this work, the IBAD-MgO process was investigated for a newly developed architecture of PLD (Pulsed Laser Deposition)-CeO 2/sputter-LMO (LaMnO 3)/IBAD-MgO/sputter-GZO (Gd 2Zr 2O 7)/Hastelloy TM to make long buffered metal tapes with high properties and a high production rate. The 50 m-long IBAD-MgO substrates with about 4° of ? ?CeO 2 in an XRD ? scan could be fabricated repeatedly. A GdBCO (GdBa 2Cu 3O x) layer deposited on the buffered substrate showed the minimum Ic value of 325 A/cm-w in a 41 m-long tape. Almost of the tape showed 500-600 A/cm-w of Ic value. The deposition time for the IBAD-MgO layer was 60 s which was about 2 orders of magnitude shorter than the conventional IBAD process. The production rate of 24 m/h was realized at the IBAD-MgO process to fabricate the GdBCO coated conductor with high Jc and Ic properties.

Yoshizumi, M.; Miyata, S.; Ibi, A.; Fukushima, H.; Yamada, Y.; Izumi, T.; Shiohara, Y.

2009-10-01

213

High-rate mechanical properties of energetic materials  

NASA Astrophysics Data System (ADS)

Compared to the many thousands of studies that have been performed on the energy release mechanisms of high energy materials, relatively few studies have been performed (a few hundred) into their mechanical properties. Since it is increasingly desired to model the high rate deformation of such materials, it is of great importance to gather data on their response so that predictive constitutive models can be constructed. This paper reviews the state of the art concerning what is known about the mechanical response of high energy materials. Examples of such materials are polymer bonded explosives (used in munitions), propellants (used to propel rockets), and pyrotechnics (used to initiate munitions and also in flares).

Walley, S. M.; Siviour, C. R.; Drodge, D. R.; Williamson, D. M.

2010-01-01

214

Magnetic Implosion for Novel Strength Measurements at High Strain Rates  

SciTech Connect

Recently Lee and Preston have proposed to use magnetic implosions as a new method for measuring material strength in a regime of large strains and high strain rates inaccessible to previously established techniques. By its shockless nature, this method avoids the intrinsic difficulties associated with an earlier approach using high explosives. The authors illustrate how the stress-strain relation for an imploding liner can be obtained by measuring the velocity and temperature history of its inner surface. They discuss the physical requirements that lead us to a composite liner design applicable to different test materials, and also compare the code-simulated prediction with the measured data for the high strain-rate experiments conducted recently at LANL. Finally, they present a novel diagnostic scheme that will enable us to remove the background in the pyrometric measurement through data reduction.

Lee, H.; Preston, D.L.; Bartsch, R.R.; Bowers, R.L.; Holtkamp, D.; Wright, B.L.

1998-10-19

215

High Strain Rate Characterisation of a Polymer Bonded Sugar  

NASA Astrophysics Data System (ADS)

The mechanical properties of a polymer bonded sugar consisting of 78% sugar crystals, of modal particle size 310 ?m, dispersed in an HTPB binder have been characterized in a split Hopkinson pressure bar system at a strain rate of 103 s-1 and temperatures from -100 to +20 °C. These high rate experiments were supplemented by further experiments in an Instron at 10-3 s-1. The material behavior is compared to that of other polymer bonded explosives and simulants. In order to further understand the structural deformation mechanisms specimens of both pristine material and that after Instron testing were examined using X-ray microtomography.

Laity, P. R.; Siviour, C. R.; Church, P. D.; Proud, W. G.

2006-07-01

216

Ultra-high cooling rate utilizing thin film evaporation  

PubMed Central

This research introduces a cell cryopreservation method, which utilizes thin film evaporation and provides an ultra-high cooling rate. The microstructured surface forming the thin film evaporation was fabricated from copper microparticles with an average diameter of 50??m. Experimental results showed that a cooling rate of approximately 5×104?°C/min was achieved in a temperature range from 10?°C to ?187?°C. The current investigation will give birth to a cell cryopreservation method through vitrification with relatively low concentrations of cryoprotectants. PMID:23093807

Su, Fengmin; Ma, Hongbin; Han, Xu; Chen, Hsiu-hung; Tian, Bohan

2012-01-01

217

Methane hydrates with a high capacity and a high formation rate promoted by biosurfactants.  

PubMed

Lignosulfonates, which are byproducts of the pulp and paper industry, can be used as promoters for the formation of methane hydrates with a high capacity up to 170 v/v and a high formation rate. PMID:23073027

Wang, Weixing; Huang, Zhan; Chen, Haoran; Tan, Zhuyan; Chen, Caixing; Sun, Luyi

2012-12-11

218

Multiplexed CV quantum teleportation for high rates in quantum communication  

E-print Network

A major challenge of today's quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols which encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode vs. multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, significantly increasing the achievable quantum communication rates in comparison to single-mode coding, but als...

Christ, Andreas; Silberhorn, Christine

2012-01-01

219

High Mutation Rates in the Mitochondrial Genomes of Daphnia pulex  

E-print Network

data in population genetics and phylogenetics, key parameters describing the process of mitochondrial, the variation in the mtDNA mutation process within species or between lineages with contrasting reproductive in evolutionary genetics. Studies of population differentiation (Avise 2000), popula- tion/species divergence time

Lynch, Michael

220

High rates of evolution preceded the origin of birds.  

PubMed

The origin of birds (Aves) is one of the great evolutionary transitions. Fossils show that many unique morphological features of modern birds, such as feathers, reduction in body size, and the semilunate carpal, long preceded the origin of clade Aves, but some may be unique to Aves, such as relative elongation of the forelimb. We study the evolution of body size and forelimb length across the phylogeny of coelurosaurian theropods and Mesozoic Aves. Using recently developed phylogenetic comparative methods, we find an increase in rates of body size and body size dependent forelimb evolution leading to small body size relative to forelimb length in Paraves, the wider clade comprising Aves and Deinonychosauria. The high evolutionary rates arose primarily from a reduction in body size, as there were no increased rates of forelimb evolution. In line with a recent study, we find evidence that Aves appear to have a unique relationship between body size and forelimb dimensions. Traits associated with Aves evolved before their origin, at high rates, and support the notion that numerous lineages of paravians were experimenting with different modes of flight through the Late Jurassic and Early Cretaceous. PMID:24471891

Puttick, Mark N; Thomas, Gavin H; Benton, Michael J

2014-05-01

221

Ultra-high frame rate tissue Doppler imaging.  

PubMed

We describe a new tissue Doppler imaging (TDI) method, ultra-high frame rate tissue Doppler imaging (UFR-TDI). With two broad transmit beams covering only the ventricular walls, we achieve 1200 frames/s in a four-chamber apical view. We examined 10 healthy volunteers to study the feasibility of this method. Ultra-high-frame-rate TDI provided peak annular velocities and time to peak S' intervals in good agreement with those measured with conventional TDI. Moreover, UFR-TDI provided additional information in early and late systole: In all subjects, the method was able to separate the timing of electrical activation, start of mechanical contraction, mitral valve closure and start of ejection. The earliest mechanical activation was seen before mitral valve closure. The method was also able to measure the propagation speed of the mechanical wave created by aortic valve closure. PMID:24210859

Brekke, Birger; Nilsen, Lars C L; Lund, Joakim; Torp, Hans; Bjastad, Tore; Amundsen, Brage H; Stoylen, Asbjorn; Aase, Svein A

2014-01-01

222

High removal rate laser-based coating removal system  

SciTech Connect

A compact laser system is disclosed that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1,000 ft{sup 2}/hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

Matthews, D.L.; Celliers, P.M.; Hackel, L.; Da Silva, L.B.; Dane, C.B.; Mrowka, S.

1999-11-16

223

SHEAR LOCALIZATION AND CHEMICAL REACTION IN HIGH-STRAIN, HIGH-STRAIN-RATE DEFORMATION OF  

E-print Network

SHEAR LOCALIZATION AND CHEMICAL REACTION IN HIGH-STRAIN, HIGH-STRAIN-RATE DEFORMATION OF Ti.6±1 mm. Thermodynamic and kinetic calculations yield the reaction rate outside the shear bands a decisive role in accelerating chemical reactions, particularly, converting an exothermic reaction

Meyers, Marc A.

224

Method for generating high-energy and high repetition rate laser pulses from CW amplifiers  

DOEpatents

A method for obtaining high-energy, high repetition rate laser pulses simultaneously using continuous wave (CW) amplifiers is described. The method provides for generating micro-joule level energy in pico-second laser pulses at Mega-hertz repetition rates.

Zhang, Shukui

2013-06-18

225

Frequent sexual reproduction and high intraspecific variation in Salix arctica: Implications for a terrestrial feedback to climate change in the High Arctic  

NASA Astrophysics Data System (ADS)

Genetic variation at molecular loci may underlie important variation in the phenotypes of arctic plants. Such intraspecific variation may be a neglected but important component of biological diversity in the Arctic that could impact how arctic ecosystems respond to climate change. Here, we characterized genetic and phenotypic variation in Salix arctica and evaluated the effect of S. arctica on ecosystem CO2 exchange, a process by which terrestrial ecosystems in the Arctic feedback to the global climate system. We found high genetic variation at microsatellite loci of S. arctica collected from an inland and a coastal site in Greenland that indicates sexual reproduction has occurred frequently as the ice sheet has retreated. Across the North American range of S. arctica, ten chloroplast DNA haplotypes were identified. Haplotype diversity and allelic richness were high overall and similar across regions with different glacial histories. Phenotypic variation in ecologically important traits varied substantially in a High Arctic population of S. arctica. In a widespread High Arctic ecosystem, a net loss of CO2 to the atmosphere was observed except where S. arctica was present. We suggest that high genetic variation in S. arctica is in part a result of frequent sexual reproduction, and that the phenotypic variation we observed is likely to be at least partially genetic-based. This would enable a productive High Arctic species to adapt and potentially prosper as climate changes, and thus affect the terrestrial feedback of the Arctic to the climate system.

Steltzer, Heidi; Hufbauer, Ruth A.; Welker, Jeffery M.; Casalis, Maxime; Sullivan, Patrick F.; Chimner, Rodney

2008-09-01

226

Do high rates of cigarette consumption increase delay discounting?  

Microsoft Academic Search

The present report attempts to help clarify the causal or consequent relation between frequently reported high rates of delay discounting (DD) associated with cigarette-smoking status in adults. Delay-discount functions of adolescent smokers and young-adult smokers and nonsmokers from two earlier studies [Reynolds, B., Karraker, K., Horn, K., Richards, J.B., 2003. Delay and probability discounting as related to different stages of

Brady Reynolds

2004-01-01

227

High dose rate (HDR) brachytherapy quality assurance: a practical guide.  

PubMed

The widespread adoption of high dose rate brachytherapy with its inherent dangers necessitates adoption of appropriate quality assurance measures to minimize risks to both patients and medical staff. This paper is aimed at assisting someone who is establishing a new program or revising one already in place into adhere to the recently issued Nuclear Regulatory Commission (USA) regulations and the guidelines from the American Association of Physicists in Medicine. PMID:21614233

Wilkinson, D A

2006-04-01

228

Nutrient requirements for high rate conversion of acetate to methane  

Microsoft Academic Search

In this research, nutrient requirements for high rate conversion of acetate to methane were examined with acetate enrichment cultures at 35°C. By employing a pH stat as the cultivation system, the pH and acetate concentration were maintained, respectively, at about 6.8 and greater than or equal to 2000 mg\\/l in the reactor. Ni and Fe limitation in the pH stat

Takashima

1987-01-01

229

High-dose-rate remote afterloaders for intraoperative radiation therapy.  

PubMed

Intraoperative radiation therapy (IORT) is a treatment option that directly irradiates a surgically exposed tumor or tumor bed while preventing radiation exposure of normal tissues. This article discusses the high-dose-rate intraoperative radiation therapy (HDR-IORT) technique by reviewing the roles of IORT team members, discussing needed equipment and supplies, describing quality assurance processes, explaining the HDR-IORT treatment delivery procedure, and reviewing the post-treatment phase. PMID:18050890

Gao, Song; Delclos, Marc E; Tomas, Lyvia C; Crane, Christopher H; Beddar, Sam

2007-11-01

230

An MWPC readout chip for high rate environment  

Microsoft Academic Search

An application-specified integration circuit (ASIC) has been fabricated in order to readout data from a multiwire proportional chamber (MWPC) that is installed in a high-rate environment, 16 channels and an ancillary control circuit are packed in a chip, and a channel consists of an LVDS receiver and 100-stage shift register array for delay. Hit data from the chamber is once

H. Kano; C. Fukunaga; M. Ikeno; O. Sasaki; K. Sato; S. Matsuura

2001-01-01

231

Decoding of high rate convolutional codes using the dual trellis  

Microsoft Academic Search

This paper deals with a posteriori probability (APP) decoding of high-rate convolutional codes, using the dual code's trellis. After deriving the dual APP (DAPP) algorithm from the APP relation, its trellis-based implementation is addressed. The challenge involved in practical implementation of a DAPP decoder is then highlighted. Metric representation schemes similar to the log domain used for log-APP decoding are

Sudharshan Srinivasan; Steven S. Pietrobon

2010-01-01

232

High strain rate deformation in particle reinforced metal matrix composites  

Microsoft Academic Search

A micromechanics study is carried out for the high strain rate deformation of ceramic particle reinforced metal matrix composites. The ceramic particles are taken to be elastic, equal-sized, spherical and uniformly distributed in the matrix. The stress-strain behavior of the matrix material is assumed to be elastic-perfectly plastic or power-law strain hardening of the Ramberg-Osgood type, coupled with power-law strain

G. Bao; Z. Lin

1996-01-01

233

High-data-rate ultrasonic through-metal communication.  

PubMed

A link-adaptive frequency division multiplexing (OFDM) ultrasonic physical layer is proposed for high-data-rate communications through metal walls. The ultrasonic link allows for communication without physical penetration of the metal barrier. Link-adaptive OFDM mitigates the severe frequency- selective fading of the ultrasonic channel and greatly improves throughput over impulse or narrowband communication systems. Throughput improvements of 300% are demonstrated over current narrowband low-frequency techniques, and show improved spectral efficiency over high-frequency techniques found in the literature. PMID:23007780

Wanuga, Kevin; Bielinski, Magda; Primerano, Richard; Kam, Moshe; Dandekar, Kapil R

2012-09-01

234

Weighting nonlinearities on future high aggregate data rate PONs.  

PubMed

In this paper we address high aggregate data rate coherent UDWDM-PONs (ultra-dense wavelength-division multiplexing passive optical networks) related physical impairments. Firstly, analog to digital converter resolution and laser linewidth are optimized giving the minimal signal to noise ratio penalty for UDWDM-PON systems at 10 Gb/s per user/wavelength. Secondly, inter-channel nonlinearities impact on high-order modulation formats at 1-2.5 Gb/s per channel and 100 km-reach is studied by means of Volterra series simulations. PMID:22274240

Reis, Jacklyn D; Neves, Darlene M; Teixeira, António L

2011-12-19

235

Sex-specific survival rates of adult roseate terns: are males paying a higher reproductive cost than females?  

USGS Publications Warehouse

A long-term mark-recapture/resighting program has been carried out on the Roseate Terns (Sterna dougallii) nesting at Falkner Island, Connecticut, USA from the late 1980s through the mid 2000s, and from 1995-1998 an intensive collaborative study of food-provisioning of chicks by their parents also was conducted on many of the banded individuals at this site. Adult female Roseate Terns have significantly higher 'local survival' rates than do males. While both sexes feed their young, males usually have higher prey delivery rates than do females and do most feeding of the (oldest if more than one) chick just before it fledges. Males usually depart at the same time as the (oldest) fledgling, while successful females parents may linger at the colony site for up to two weeks. The lower 'local survival' rate of males probably does not represent lower colony-site fidelity, but instead may reflect the price they pay for doing more 'child care,' especially if fledglings are still dependant on them for food during post breeding dispersal and (at least early) migration.

Spendelow, J.A.; Shealer, D.A.; Hatfield, J.S.; Nichols, J.D.; Nisbet, I.C.T.

2005-01-01

236

Reproductive hormone secretions and first service conception rate subsequent to ovulation control with Synchro-Mate B.  

PubMed

Two groups of beef females receiving suboptimal energy diets were treated with Synchro-Mate B to control ovulation. The first group consisted of 30 suckled cows and 16 heifers. These females were bled 10 days and immediately prior to the implantation of norgestomet implants, at implant removal, 24, 27, 30, 33 and 36 hours and 9 and 16 days post-implant removal. The second group which consisted of 40 cows and 8 heifers was handled in the same manner except no blood samples were collected from 24 to 36 hours following implant removal. Calves were removed from all the cows for 48 hours, beginning at implant removal. All animals were artifically inseminated 48 hours following implant removal. Blood plasma was assayed for concentrations of progesterone and LH. The first service conception rate was 21% and 40% for groups 1 and 2. Several factors were identified that reduced the first service conception rate. In summary, Snychro-Mate B is an effective method to synchronize estrus in cattle. However, stress subsequent to implant removal should be avoided in order to obtain a higher first service conception rate. PMID:16725635

Hixon, D L; Kesler, D J; Troxel, T R; Vincent, D L; Wiseman, B S

1981-08-01

237

Improving the precision of high-rate GPS  

NASA Astrophysics Data System (ADS)

In order to improve the accuracy of high-rate (1 Hz) displacements for geophysical applications such as seismology it is important to reduce systematic errors at seismic frequencies. One such GPS error source that overlaps with seismic frequencies and is not currently modeled is multipath. This study investigates the frequencies and repetition of multipath in high-rate GPS time series in order to maximize the effectiveness of techniques relying upon the geometric repeatability of GPS satellite orbits. The implementation of the aspect repeat time adjustment (ARTA) method described here uses GPS position time series to estimate time-varying and site-dependent shifts. As demonstrated for high-rate GPS sites in southern California this technique significantly reduces positioning noise at periods from 20 to 1000 s. For a 12-hour time series, ARTA methods improve the standard deviation of the north component from 8.2 to 5.1 mm and the east component from 6.3 to 4.0 mm. After applying ARTA corrections, common mode errors are removed by stacking. This method further improves the standard deviations to 3.0 and 2.6 mm for the north and east components, respectively.

Larson, Kristine M.; Bilich, Andria; Axelrad, Penina

2007-05-01

238

Optical communication demonstration and high-rate link facility  

NASA Astrophysics Data System (ADS)

Motivated by demands for faster, better, cheaper spacecraft, NASA is developing deep-space optical communication technology which promises reduced mass, volume, and power consumption compared to radio-frequency technology. While earth-orbiting optical receivers may eventually be employed, initial deep-space optical communication links are expected to utilize terrestrial telescope receivers. As the communication beam passes through the atmosphere, atmospheric turbulence causes the beam to scintillate, dramatically impacting its temporal and transverse nature. The statistics of these effects must be measured extensively if optical deep-space communication links are to be fully modeled and the design of deep-space communication links optimized. Sponsored by the Engineering Research and Technology Development program, the purposes of the Optical Communication Demonstration and High-Rate Link Facility are to demonstrate a Gbps-class optical downlink, gather extensive link statistics, and provide high-rate downlink capability. The Optical Communication Demonstration and High-Rate Link Facility will be deployed to the International Space Station by flight UF-4, currently scheduled for May 2002.

Sandusky, John; Jeganathan, Muthu; Ortiz, Gerry; Biswas, Abi; Lee, Shinhak; Wilson, Keith; Parker, George; Lesh, James

1999-01-01

239

Unisexual reproduction.  

PubMed

Sexual reproduction is ubiquitous throughout the eukaryotic kingdom, but the capacity of pathogenic fungi to undergo sexual reproduction has been a matter of intense debate. Pathogenic fungi maintained a complement of conserved meiotic genes but the populations appeared to be clonally derived. This debate was resolved first with the discovery of an extant sexual cycle and then unisexual reproduction. Unisexual reproduction is a distinct form of homothallism that dispenses with the requirement for an opposite mating type. Pathogenic and nonpathogenic fungi previously thought to be asexual are able to undergo robust unisexual reproduction. We review here recent advances in our understanding of the genetic and molecular basis of unisexual reproduction throughout fungi and the impact of unisex on the ecology and genomic evolution of fungal species. PMID:24880737

Roach, Kevin C; Feretzaki, Marianna; Sun, Sheng; Heitman, Joseph

2014-01-01

240

Mechanical Solder Characterisation Under High Strain Rate Conditions  

NASA Astrophysics Data System (ADS)

Using a setup for high strain rate tensile experiments the mechanical behavior of two lead-free tin based solders is investigated. The first alloy is SnAg1.3Cu0.5Ni. The second alloy has a higher silver content but no addition of Ni. Solder joints are the main electrical, thermal and mechanical interconnection technology on the first and second interconnection level. With the recent rise of 3D packaging technologies many novel interconnection ideas are proposed with innovative or visionary nature. Copper pillar, stud bump, intermetallic (SLID) and even spring like joints are presented in a number of projects. However, soldering will remain one of the important interconnect technologies. Knowing the mechanical properties of solder joints is important for any reliability assessment, especially when it comes to vibration and mechanical shock associated with mobile applications. Taking the ongoing miniaturization and linked changes in solder joint microstructure and mechanical behavior into account the need for experimental work on that issue is not satisfied. The tests are accomplished utilizing miniature bulk specimens to match the microstructure of real solder joints as close as possible. The dogbone shaped bulk specimens have a crucial diameter of 1 mm, which is close to BGA solder joints. Experiments were done in the strain rate range from 20 s-1 to 600 s-1. Solder strengthening has been observed with increased strain rate for both SAC solder alloys. The yield stress increases by about 100% in the investigated strain rate range. The yield level differs strongly. A high speed camera system was used to assist the evaluation process of the stress and strain data. Besides the stress and strain data extracted from the experiment the ultimate fracture strain is determined and the fracture surfaces are evaluated using SEM technique considering rate dependency.

Meier, Karsten; Roellig, Mike; Wiese, Steffen; Wolter, Klaus-Juergen

2010-11-01

241

High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer  

SciTech Connect

Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3-23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

Ghadjar, Pirus, E-mail: pirus.ghadjar@insel.ch [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Bojaxhiu, Beat [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Simcock, Mathew [Swiss Group for Clinical Cancer Research Coordinating Center, Bern (Switzerland); Terribilini, Dario; Isaak, Bernhard [Division of Medical Radiation Physics, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Gut, Philipp; Wolfensberger, Patrick; Broemme, Jens O.; Geretschlaeger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M. [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland)

2012-07-15

242

High rate reactive sputtering of MoN(x) coatings  

NASA Technical Reports Server (NTRS)

High rate reactive sputtering of MoN(x) films was performed using feedback control of the nitorgen partial pressure. Coatings were made at four different target powers: 2.5, 5.0, 7.5 and 10 kW. No hysteresis was observed in the nitrogen partial pressure vs. flow plot, as is typically seen for the Ti-N system. Four phases were determined by X-ray diffraction: molybdenum, Mo-N solid solution, Beta-Mo2N and gamma-Mo2N. The hardness of the coatings depended upon composition, substrate bias, and target power. The phases present in the hardest films differed depending upon deposition parameters. For example, the Beta-Mo2N phase was hardest (load 25 gf) at 5.0 kW with a value of 3200 kgf/sq mm, whereas the hardest coatings at 10 kW were the gamma-Mo2N phase (3000 kgf/sq mm). The deposition rate generally decreased with increasing nitrogen partial pressure, but there was a range of partial pressures where the rate was relatively constant. At a target power of 5.0 kW, for example, the deposition rates were 3300 A/min for a N2 partial pressure of 0.05 - 1.0 mTorr.

Rudnik, Paul J.; Graham, Michael E.; Sproul, William D.

1991-01-01

243

Sexual reproduction in Hawaiian Acropora  

NASA Astrophysics Data System (ADS)

Sexual reproductive maturity was evaluated in Acropora valida, Acropora cytherea and Acropora humilis at French Frigate Shoals, Northwest Hawaiian Islands during two consecutive summers. Acropora valida gonads matured at different rates in different habitats in both years. Spawning was inferred by the sudden disappearance of gonads of mature size. Histological sections of fertile polyps confirmed the maturity of gonads prior to spawning. An isolated colony of A. humilis spawned in early summer. Strong indications of sexually mature colonics of A. cytherea exist, but clear temporal patterns were not apparent. Lunar period of spawning in reef flat A. valida and A. humilis differed from that reported for these species from other regions. The three species did not overlap in time of spawning. Previous ideas concerning the allochthonous origin of larval recruits, as well as the absence of Acropora from high islands of the Hawaiian chain, are re-evaluated in light of new evidence for sexual reproductive capacity by native populations.

Kenyon, Jean C.

1992-04-01

244

Degradation rate of ultra-high molecular weight polyethylene.  

PubMed

Ultra-high molecular weight polyethylene components for total joint replacement chemically degrade before and after implantation, and the degradation is associated with an increase in density. The goal of this study was to determine the average rate of density change in these components following sterilization by gamma radiation in air as a function of shelf age and implantation time. Using the density gradient column method, density profiles were obtained through the thickness from loaded and unloaded regions of 10 retrieved Insall-Burstein/Posterior-Stabilized II tibial components and one operating-room inventory component for which the initial density profile and patient history (if applicable) were known. The average density of the components increased at a constant rate of 0.000186 g/cc/month during the first 50 months after sterilization (r2 = 0.54) but was not significantly affected by loading (p > 0.05). The quantitative degradation rates may be useful to help verify kinetic models to predict bulk degradative changes on the basis of micro-structural and chemical processes. This research also suggests the hypothesis that degradation of ultra-high molecular weight polyethylene can be modeled in terms of changes in bulk or average properties. PMID:9066527

Kurtz, S M; Rimnac, C M; Bartel, D L

1997-01-01

245

High rate ECR etching of III-V nitride materials  

NASA Astrophysics Data System (ADS)

The III-V nitride compound semiconductors are attracting considerable attention for blue and ultraviolet light emitting diodes (LED's) and lasers as well as high temperature electronics due to their wide band gaps and high dielectric constants. The recent progress observed in the growth of these materials has not been matched by progress in processing techniques to fabricate more highly sophisticated devices. Patterning these materials has been especially difficult due to the relatively inert chemical nature of the group-III nitrides. The authors review dry etch techniques which have been used to pattern these materials including electron cyclotron resonance (ECR), reactive ion etch (RIE), and chemically assisted ion beam etching (CAIBE). ECR etch rates greater than 3800 A/min for InN, 3500 A/min for GaN, and 1170 A/min for AlN are reported. Etch anisotropy, surface morphology, and near-surface stoichiometry are discussed.

Shul, R. J.; Howard, A. J.; Kilcoyne, S. P.; Pearton, S. J.; Abernathy, C. R.; Vartuli, C. B.; Barnes, P. A.; Bozack, M. J.

246

Magnetic accretion in high-accretion rate polars  

NASA Astrophysics Data System (ADS)

The spectral components of polars -- strongly magnetic CVs -- are barely disentangled without sufficient spectral coverage. XMM-Newton plus NuSTAR can solve the riddle but the frequent low states of the brightest members prevented systematic studies of high-accretion rate polars (HARPs). We thus began TOO-like XMM-Newton observations of the brightest systems in their high states and propose to continue in AO13 with one further trigger. We will investigate the physics of the hard X-ray emitting shock, the heated accretion pole cap, the atmosphere of the white dwarf, the absorption in the shock and in the flow, the lines in the accretion flow and the reflection from the white dwarf by phase-resolved X-ray spectroscopy and high-speed OM-photometry.

Schwope, Axel

2013-10-01

247

Effect of bis(tributyltin) oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia  

NASA Astrophysics Data System (ADS)

A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L-1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control ( P<0.01) after 24 days exposure to concentrations higher than 10 ng TBTO L-1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase ( r m), from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration (60 ng L-1), where all females aborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased r m compared with that of control (an effect associated with decreased sex ratio). The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.

Huang, Ying; Zhu, Liyan; Qiu, Xuchun; Zhang, Tianwen

2010-03-01

248

Multianode cylindrical proportional counter for high count rates  

DOEpatents

A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (< 60 keV) at count rates of greater than 10/sup 5/ counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

Hanson, J.A.; Kopp, M.K.

1980-05-23

249

Multianode cylindrical proportional counter for high count rates  

DOEpatents

A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (<60 keV) at count rates of greater than 10.sup.5 counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

Hanson, James A. (Madison, WI); Kopp, Manfred K. (Oak Ridge, TN)

1981-01-01

250

Risk Factors for Malformations and Impact on Reproductive Performance and Mortality Rates of Schmallenberg Virus in Sheep Flocks in the Netherlands  

PubMed Central

In Northwestern Europe, an epizootic outbreak of congenital malformations in newborn lambs due to infection with Schmallenberg virus (SBV) started at the end of 2011. The objectives of this study were to describe clinical symptoms of SBV infection, the effect of infection on mortality rates, and reproductive performance in sheep, as well as to identify and quantify flock level risk factors for SBV infections resulting in malformations in newborn lambs. A case-control study design was used, with 93 case flocks that had notified malformed lambs and 84 control flocks with no such lambs. Overall animal seroprevalence in case flocks was estimated at 82.0% (95% CI: 74.3–87.8), and was not significantly different from the prevalence in control flocks being 76.4% (95% CI: 67.2–83.6). The percentages of stillborn lambs or lambs that died before weaning, repeat breeders, and lambs with abnormal suckling behaviour were significantly higher in case flocks compared to control flocks. However, effect of SBV infection on mortality rates and reproductive performance seemed to be limited. Multivariable analysis showed that sheep flocks with an early start of the mating season, i.e. before August 2011 (OR?=?33.1; 95% CI: 10.0–109.8) and in August 2011 (OR?=?8.2; 95% CI: 2.7–24.6) had increased odds of malformations in newborn lambs caused by SBV compared to sheep flocks with a start of the mating season in October 2011. Other flock-level risk factors for malformations in newborn lambs were purchase of silage (OR 5.0; 95% CI: 1.7–15.0) and flocks with one or more dogs (OR?=?3.3; 95% CI: 1.3–8.3). Delaying mating until October could be a potential preventive measure for naïve animals to reduce SBV induced losses. As duration of immunity after infection with SBV is expected to last for several years, future SBV induced congenital malformations are mainly expected in offspring of early mated seronegative animals. PMID:24937443

Luttikholt, Saskia; Veldhuis, Anouk; van den Brom, Rene; Moll, Lammert; Lievaart-Peterson, Karianne; Peperkamp, Klaas; van Schaik, Gerdien; Vellema, Piet

2014-01-01

251

ASSISTED REPRODUCTIVE TECHNOLOGY REPORTS (ART REPORTS)  

EPA Science Inventory

The Society for Assisted Reproductive Technology (SART), an organization of ART providers affiliated with the American Society for Reproductive Medicine (ASRM), has been collecting data and publishing annual reports of pregnancy success rates for fertility clinics in the United S...

252

The high strain-rate behaviour of selected tissue analogues.  

PubMed

The high strain-rate response of four readily available tissue simulants has been investigated via plate-impact experiments. Comparison of the shock response of gelatin, ballistic soap (both sub-dermal tissue simulants), lard (adipose layers) and Sylgard(®) (a potential brain simulant) allowed interrogation of the applicability of such monolithic tissue surrogates in the ballistic regime. The gelatin and lard exhibited classic linear Hugoniot equations-of-state in the US-uP plane; while for the ballistic soap and Sylgard(®) a polymer-like non-linear response was observed. In the P/?X-v/v0 plane there was evidence of separation of the simulant materials into distinct groups, suggesting that a single tissue simulant is inadequate to ensure a high-fidelity description of the high strain-rate response of complex mammalian tissue. Gelatin appeared to behave broadly hydrodynamically, while soap, lard and Sylgard(®) were observed to strengthen in a material-dependent manner under specific loading conditions at elevated shock loading pressures/stresses. This strengthening behaviour was tentatively attributed to a further polymeric-like response in the form of a re-arrangement of the molecular chains under loading (a steric effect). In addition, investigation of lateral stress data from the literature showed evidence of operation of a material-independent strengthening mechanism when these materials were stressed above 2.5-3.0GPa, tentatively linked to the generically polymeric-like underlying microstructure of the simulants under consideration. PMID:23778063

Appleby-Thomas, G J; Hazell, P J; Sheldon, R P; Stennett, C; Hameed, A; Wilgeroth, J M

2014-05-01

253

Handling high data rate detectors at Diamond Light Source  

NASA Astrophysics Data System (ADS)

An increasing number of area detectors, in use at Diamond Light Source, produce high rates of data. In order to capture, store and process this data High Performance Computing (HPC) systems have been implemented. This paper will present the architecture and usage for handling high rate data: detector data capture, large volume storage and parallel processing. The EPICS area Detector frame work has been adopted to abstract the detectors for common tasks including live processing, file format and storage. The chosen data format is HDF5 which provides multidimensional data storage and NeXuS compatibility. The storage system and related computing infrastructure include: a centralised Lustre based parallel file system, a dedicated network and a HPC cluster. A well defined roadmap is in place for the evolution of this to meet demand as the requirements and technology advances. For processing the science data the HPC cluster allow efficient parallel computing, on a mixture of ×86 and GPU processing units. The nature of the Lustre storage system in combination with the parallel HDF5 library allow efficient disk I/O during computation jobs. Software developments, which include utilising optimised parallel file reading for a variety of post processing techniques, are being developed in collaboration as part of the Pan-Data EU Project (www.pan-data.eu). These are particularly applicable to tomographic reconstruction and processing of non crystalline diffraction data.

Pedersen, U. K.; Rees, N.; Basham, M.; Ferner, F. J. K.

2013-03-01

254

Diamond detector for high rate monitors of fast neutrons beams  

SciTech Connect

A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G. [Dipartimento di Fisica, Universita degli Studi di Milano-Bicocca, and Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milano (Italy); Energy Department, Politecnico di Milano, Milano (Italy); Dipartimento di Fisica, Centro NAST, Universita degli Studi di Roma Tor Vergata, Roma (Italy); STFC, ISIS facility, Rutherford Appleton Laboratory, Chilton Didcot Oxfordshire (United Kingdom); Dipartimento di Fisica, Universita degli Studi di Milano-Bicocca, and Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milano (Italy)

2012-06-19

255

Cross-border reproductive care: a phenomenon expressing the controversial aspects of reproductive technologies.  

PubMed

Cross-border reproductive care, also called reproductive tourism, refers to the travelling of citizens from their country of residence to another country in order to receive fertility treatment through assisted reproductive technology. Several reasons account for cross-border reproductive care: (i) a certain kind of treatment is forbidden by law in the couple's own country or is inaccessible to the couple because of their demographic or social characteristics; (ii) foreign centres report higher success rates compared with those of the centres in the country of residence; (iii) a specific treatment may be locally unavailable because of a lack of expertise or because the treatment is considered experimental or insufficiently safe; and (iv) limited access to the treatment in the couple's home country because of long waiting lists, excessive distance from a centre or high costs. Although cross-border reproductive care can be viewed as a safety valve, the phenomenon is often associated with a high risk of health dangers, frustration and disparities. Solutions to these problematic effects need to be considered in the light of the fact that cross-border reproductive care is a growing phenomenon. PMID:20113964

Ferraretti, Anna Pia; Pennings, Guido; Gianaroli, Luca; Natali, Francesca; Magli, M Cristina

2010-02-01

256

Dating violence victimization and perpetration rates among high school students.  

PubMed

This school-based sample provides the largest estimate of physical and psychological dating violence (DV) victimization and the only report of DV perpetration among high school students. Among 14,190 students in relationships, 33.4% disclosed DV by a partner (victimization) and 20.2% used these same behaviors against a partner (perpetration) in the past 12 months. Physical DV victimization (13%) was less frequently disclosed than psychological DV (23%). Rates of DV victimization and perpetration were highest among females, those receiving free or reduced-price meals, those not exclusively attracted to the opposite sex, students reporting parental or guardian partner violence, binge drinking, and bullying. PMID:25344558

Coker, Ann L; Clear, Emily R; Garcia, Lisandra S; Asaolu, Ibitola O; Cook-Craig, Patricia G; Brancato, Candace J; Williams, Corrine M; Bush, Heather M; Fisher, Bonnie S

2014-10-01

257

Diversification and reproductive isolation: cryptic species in the only New World high-duty cycle bat, Pteronotus parnellii  

PubMed Central

Background Molecular techniques are increasingly employed to recognize the presence of cryptic species, even among commonly observed taxa. Previous studies have demonstrated that bats using high-duty cycle echolocation may be more likely to speciate quickly. Pteronotus parnellii is a widespread Neotropical bat and the only New World species to use high-duty cycle echolocation, a trait otherwise restricted to Old World taxa. Here we analyze morphological and acoustic variation and genetic divergence at the mitochondrial COI gene, the 7th intron region of the y-linked Dby gene and the nuclear recombination-activating gene 2, and provide extensive evidence that P. parnellii is actually a cryptic species complex. Results Central American populations form a single species while three additional species exist in northern South America: one in Venezuela, Trinidad and western Guyana and two occupying sympatric ranges in Guyana and Suriname. Reproductive isolation appears nearly complete (only one potential hybrid individual found). The complex likely arose within the last ~6 million years with all taxa diverging quickly within the last ~1-2 million years, following a pattern consistent with the geological history of Central and northern South America. Significant variation in cranial measures and forearm length exists between three of the four groups, although no individual morphological character can discriminate these in the field. Acoustic analysis reveals small differences (5–10 kHz) in echolocation calls between allopatric cryptic taxa that are unlikely to provide access to different prey resources but are consistent with divergence by drift in allopatric species or through selection for social recognition. Conclusions This unique approach, considering morphological, acoustic and multi-locus genetic information inherited maternally, paternally and bi-parentally, provides strong support to conclusions about the cessation of gene flow and degree of reproductive isolation of these cryptic species. PMID:23360354

2013-01-01

258

Reproduction and Feeding of the Electric Fish Brachyhypopomus gauderio (Gymnotiformes: Hypopomidae) and the Discussion of a Life History Pattern for Gymnotiforms from High Latitudes  

PubMed Central

The reproductive biology and feeding habits of the electric fish Brachyhypopomus gauderio were studied. The species has seasonal reproductive behavior, with breeding occurring during the Southern Hemisphere spring and summer, and having a positive relation with the photoperiod variation. Brachyhypopomus gauderio was defined as a fractional spawner, with low relative fecundity and high first maturation size. Sexual dimorphism was registered, males undergoing hypertrophy of the distal portion of caudal filament. The results on reproductive biology herein obtained are in agreement with data concerning gymnotiforms from Southern Brazil and Uruguay, pointing to an ecological pattern for the species from high latitudes, differing from species with tropical distribution. According to the analysis of the food items, B. gauderio feed mainly on autochthonous insects, likewise the other gymnotiforms previously investigated, leading to conclude that there is no variation on the diet of the species of the order related to climatic conditions or even to habitat of occurrence. PMID:25207924

Giora, Julia; Tarasconi, Hellen M.; Fialho, Clarice B.

2014-01-01

259

High revision rate following artificial urethral sphincter implantation.  

PubMed

Abstract Objective. In severe cases of stress urinary incontinence (SUI), with sphincter dysfunction, the artificial urinary sphincter AMS 800™ may be the last solution. The purpose of this study was to evaluate the outcome of surgical intervention for SUI with the AMS 800 in patients who were treated at Sahlgrenska University Hospital, Gothenburg. The primary aim of the study was to determine the complications related to the operation. Material and methods. A retrospective follow-up was done by reviewing medical records. The material comprised 97 men, who underwent their first AMS 800 implantation between May 1997 and June 2010 at Sahlgrenska University Hospital. Results. The revision rate was 28%, including an infection rate of 3% and an erosion rate of 7%. The mean follow-up for revised patients was 3 years. The median time until revision was 1 year. Seventy-five per cent of all patients were satisfied with the operation at 6 months' follow-up. Radical prostatectomy was the reason behind incontinence in 84% of patients in this series. Conclusion. The results clearly demonstrate a need for revision procedures in a considerable proportion of patients implanted with an AMS 800 device. Patient satisfaction was high, but although this operation has extremely low mortality it has its complications and the system will need to be replaced in time. PMID:24930564

Andreasson, Anders; Fall, Magnus; Persson, Erik; Stranne, Johan; Peeker, Ralph

2014-12-01

260

Resistance of the boreal forest to high burn rates.  

PubMed

Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30-500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks. PMID:25201981

Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

2014-09-23

261

On the response of rubbers at high strain rates.  

SciTech Connect

In this report, we examine the propagation of tensile waves of finite deformation in rubbers through experiments and analysis. Attention is focused on the propagation of one-dimensional dispersive and shock waves in strips of latex and nitrile rubber. Tensile wave propagation experiments were conducted at high strain-rates by holding one end fixed and displacing the other end at a constant velocity. A high-speed video camera was used to monitor the motion and to determine the evolution of strain and particle velocity in the rubber strips. Analysis of the response through the theory of finite waves and quantitative matching between the experimental observations and analytical predictions was used to determine an appropriate instantaneous elastic response for the rubbers. This analysis also yields the tensile shock adiabat for rubber. Dispersive waves as well as shock waves are also observed in free-retraction experiments; these are used to quantify hysteretic effects in rubber.

Niemczura, Johnathan Greenberg (University of Texas-Austin)

2010-02-01

262

Magnetic accretion in high-accretion rate polars  

NASA Astrophysics Data System (ADS)

The spectral components of polars were barely disentangled by previous X-ray missions. The physics of magnetic accretion non-relativistic environment is therefore still puzzling. XMM-Newton can solve the riddle, but the frequent low states prevented systematic studies of high-accretion rate polars (HARPs). We thus began TOO-like XMM-Newton observations of the brightest systems in their heigh states. We are in the process creating a synoptic view on the HARPs and propose to continue in AO8 with one further trigger. We investigate the hard X-ray emitting shock, the heated accretion pole cap, the atmosphere of the white dwarf, absorption in the shock and in the flow, the lines in the flow and the reflection from the white dwarf by phase-resolved CCD- and RGS-spectroscopy and high-speed OM-photometry.

Schwope, Axel

2008-10-01

263

Magnetic accretion in high-accretion rate polars  

NASA Astrophysics Data System (ADS)

The spectral components of polars were barely disentangled by previous X-ray missions. The physics of magnetic accretion non-relativistic environment is therefore still puzzling. XMM-Newton can solve the riddle, but the frequent low states prevented systematic studies of high-accretion rate polars (HARPs). We thus began T00-like XMM-Newton observations of the brightest systems in their heigh states. We are in the process creating a synoptic view on the HARPs and propose to continue in AO11 with one further trigger. We investigate the hard X-ray emitting shock, the heated accretion pole cap, the atmosphere of the white dwarf, absorption in the shock and in the flow, the lines in the flow and the reflection from the white dwarf by phase-resolved CCD- and RGS-spectroscopy and high-speed OM-photometry.

Schwope, Axel

2011-10-01

264

Mechanism of high strain rate superplasticity in aluminium alloy composites  

SciTech Connect

A constitutive equation has been obtained through an analysis of high strain rate superplasticity (HSRS) data on a 2124 Al-Si{sub 3}-N{sub 4} composite. The parametric dependencies of HSRS in composites are different from those observed in conventional aluminium alloys and mechanically alloyed alloys. The HSRS in composites exhibits high activation energy values of 293--338 kJ mol{sup {minus}1} and an inverse grain size and reinforcement size dependence. It is suggested that the mechanism of HSRS in composites is interface controlled superplasticity. This is depicted on a new superplasticity mechanism map for composites. The map can be used as a guideline for designing composites for optimum superplasticity.

Mishra, R.S.; Mukherjee, A.K. [Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering and Materials Science] [Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering and Materials Science; Bieler, T.R. [Michigan State Univ., East Lansing, MI (United States). Dept. of Materials Science and Mechanics] [Michigan State Univ., East Lansing, MI (United States). Dept. of Materials Science and Mechanics

1997-02-01

265

High-rate lithium thionyl-chloride battery development  

SciTech Connect

We have developed a lithium thionyl-chloride cell for use in a high rate battery application to provide power for a missile computer and stage separation detonators. The battery pack contains 20 high surface area ``DD`` cells wired in a series-parallel configuration to supply a nominal 28 volts with a continuous draw of 20 amperes. The load profile also requires six squib firing pulses of one second duration at a 20 ampere peak. Performance and safety of the cells were optimized in a ``D`` cell configuration before progressing to the longer ``DD` cell. Active surface area in the ``D`` cell is 735 cm{sup 2}, and 1650 cm{sup 2} in the ``DD`` cell. The design includes 1.5M LiAlCl{sub 4}/SOCl{sub 2} electrolyte, a cathode blend of Shawinigan Acetylene Black and Cabot Black Pearls 2000 carbons, Scimat ETFE separator, and photoetched current collectors.

Cieslak, W.R.; Weigand, D.E.

1993-12-31

266

High rates of methane emissions from south taiga wetland ponds.  

NASA Astrophysics Data System (ADS)

Since wetland ponds are often assumed to be insignificant sources of methane, there is a limited data about its fluxes. In this study, we found surprisingly high rates of methane emission at several shallow ponds in the south taiga zone of West Siberia. Wetland ponds within the Great Vasyugan Mire ridge-hollow-pool patterned bog system were investigated. 22 and 24 flux measurements from ponds and surrounded mires, respectively, were simultaneously made by a static chamber method in July, 2011. In contrast to previous measurements, fluxes were measured using the small boat with floated chamber to avoid disturbance to the water volume. Since the ebullition is most important emission pathway, minimization of physical disturbance provoking gas bubbling significantly increases the data accuracy. Air temperature varied from 15 to 22° C during the measurements, and pH at different pond depths - from 4.4 to 5. As it was found, background emission from surrounding ridges and hollows was 1.7/2.6/3.3 mgC·m-2·h1 (1st/2nd/3rd quartiles). These rates are in a perfect correspondence with the typical methane emission fluxes from other south taiga bogs. Methane emission from wetland ponds turned out to be by order of magnitude higher (9.3/11.3/15.6 mgC·m-2·h1). Comparing to other measurements in West Siberia, many times higher emissions (70.9/111.6/152.3 mgC·m-2·h1) were found in forest-steppe and subtaiga fen ponds. On the contrary, West Siberian tundra lakes emit methane insignificantly, with the flux rate close to surrounding wetlands (about 0.2-0.3 mgC·m-2·h1). Apparently, there is a naturally determined distribution of ponds with different flux rates over different West Siberia climate-vegetation zones. Further investigations aiming at revelation of the zones with different fluxes would be helpful for total flux revision purposes. With respect to other studies, high emission rates were already detected, for instance, in Baltic ponds (Dzyuban, 2002) and U.K. lakes (Casper et al., 2000). Annual CH4 emission from West Siberia south taiga ponds with area of 0.6·106 Mha was estimated to be 0.26 MtCH4·yr-1.

Glagolev, M.; Kleptsova, I.; Maksyutov, S.

2012-04-01

267

Effects of Selection for Honey Bee Worker Reproduction on Foraging Traits  

PubMed Central

The “reproductive ground plan” hypothesis (RGPH) proposes that reproductive division of labour in social insects had its antecedents in the ancient gene regulatory networks that evolved to regulate the foraging and reproductive phases of their solitary ancestors. Thus, queens express traits that are characteristic of the reproductive phase of solitary insects, whereas workers express traits characteristic of the foraging phase. The RGPH has also been extended to help understand the regulation of age polyethism within the worker caste and more recently to explain differences in the foraging specialisations of individual honey bee workers. Foragers that specialise in collecting proteinaceous pollen are hypothesised to have higher reproductive potential than individuals that preferentially forage for nectar because genes that were ancestrally associated with the reproductive phase are active. We investigated the links between honey bee worker foraging behaviour and reproductive traits by comparing the foraging preferences of a line of workers that has been selected for high rates of worker reproduction with the preferences of wild-type bees. We show that while selection for reproductive behaviour in workers has not altered foraging preferences, the age at onset of foraging of our selected line has been increased. Our findings therefore support the hypothesis that age polyethism is related to the reproductive ground plan, but they cast doubt on recent suggestions that foraging preferences and reproductive traits are pleiotropically linked. PMID:18318602

Oldroyd, Benjamin P; Beekman, Madeleine

2008-01-01

268

High renesting rates in arctic-breeding Dunlin (Calidris alpina): a clutch-removal experiment  

USGS Publications Warehouse

The propensity to replace a clutch is a complex component of avian reproduction and poorly understood. We experimentally removed clutches from an Arctic-breeding shorebird, the Dunlin (Calidris alpina arcticola), during early and late stages of incubation to investigate replacement clutch rates, renesting interval, and mate and site fidelity between nesting attempts. In contrast to other Arctic studies, we documented renesting by radiotracking individuals to find replacement clutches. We also examined clutch size and mean egg volume to document changes in individual females’ investment in initial and replacement clutches. Finally, we examined the influence of adult body mass, clutch volume, dates of clutch initiation and nest loss, and year on the propensity to renest. We found high (82–95%) and moderate (35–50%) rates of renesting for early and late incubation treatments. Renesting intervals averaged 4.7–6.8 days and were not different for clutches removed early or late in incubation. Most pairs remained together for renesting attempts. Larger females were more likely to replace a clutch; female body mass was the most important parameter predicting propensity to renest. Clutches lost later in the season were less likely to be replaced. We present evidence that renesting is more common in Arctic-breeding shorebirds than was previously thought, and suggest that renesting is constrained by energetic and temporal factors as well as mate availability. Obtaining rates of renesting in species breeding at different latitudes will help determine when this behavior is likely to occur; such information is necessary for demographic models that include individual and population-level fecundity estimates.

Gates, H. River; Lanctot, Richard B.; Powell, Abby N.

2013-01-01

269

Reproduction & life I. Reproductive cycles  

E-print Network

1 Reproduction & life histories I. Reproductive cycles II. Modes of Fertilization III. Asexual;2 OOGENESIS in amphibians Oogonia are self-renewing stem cells that persist for the life of the frog Can of oocytes in the frog. During the first 3 years of life, three cohorts of oocytes are produced. The drawings

Dever, Jennifer A.

270

Reproduction & life I. Reproductive cycles  

E-print Network

1 Reproduction & life histories I. Reproductive cycles II. Modes of Fertilization III. Asexual that persist for the life of the frog Can generate a new cohort of oocytes each year Ova energetically more is encased w/shell Growth of oocytes in the frog. During the first 3 years of life, three cohorts of oocytes

Dever, Jennifer A.

271

The 2011 Grímsvötn Eruption From High Rate Geodesy  

NASA Astrophysics Data System (ADS)

High rate geodetic measurements at volcanoes can give displacements at sub second intervals, revealing surface deformation associated with magma movements. The Grímsvötn volcano lies beneath the Vatnajökull icecap, Iceland, limiting the near field monitoring efforts to a single nunatak, Mt. Grímsfjall, on the southern caldera rim. A 5 Hz GPS station and an electronic tilt meter are located at Grímsfjall. The colocation of these instruments (GPS and tilt station) allows us to relate the observed surface deformation to pressure change in a magma chamber assuming a simple Mogi source within an elastic half space. During the 21-28 May 2011 Grímsvötn eruption a continuous stream of data, despite the eruption plume and lightning, was transmitted to Reykjavík. The tiltmeter measures N-S and E-W components of tilt, the N-S component was recorded at 100 samples per second (sps) but the E-W component at 4 sps. The high rate data from the GPS station at Grímsfjall (GFUM) were analyzed using the Track part of GAMIT/GLOBK. We produced kinematic solutions at 5 Hz and 1 Hz intervals using reference stations in 40-120 km distance of the volcano. To minimize multipath effects we applied sidereal filtering and stacked the individual solutions to further improve the signal to noise ratio. The resulting deformation time series suggests a rapid pressure drop starting about 50 minutes prior to the onset of the eruption when over 20 km high plume formed. The characteristics of the GPS and tilt data time series suggests that the main signal was induced by a single source of fixed location and geometry throughout the eruption; a shallow magma chamber. Small deviations in displacement direction prior to the onset of the eruption can be explained by the opening of the feeder dike. We see a total displacement of 57 cm in direction ˜N38.5°W and down at the GPS station, suggesting a source depth of ~1.7 km. About 20% of the displacement preceded the eruption and more than 95% took place within 24 hours of the onset of deformation. Thus real time high rate geodesy could play an important role in foreseeing both the onset and the evolution of explosive eruptions.

Hreinsdottir, S.; Grapenthin, R.; Sigmundsson, F.; Roberts, M. J.; Holmjarn, J.; Geirsson, H.; Arnadottir, T.; Bennett, R. A.; Villemin, T.; Ofeigsson, B. G.; Sturkell, E. C.

2011-12-01

272

Transfer functions for high-rate GNSS receivers  

NASA Astrophysics Data System (ADS)

In recent years the development of GPS receivers with sampling rates as high as 100Hz has sparked interest in capturing high-dynamic motions and has potentially enlarged the applicability in navigation, positioning and Earth monitoring. The additional yield of information due to increased sampling rates, however, may be counteracted by a strong correlation of the measurements in time. Unfortunately, the tracking loop filters of the receivers produce correlations exactly in the frequency range (1-100Hz) of the expected benefit of high-rate receivers. The consequences of the correlations between subsequent epochs can be demonstrated by increased amplitude and phase retrieval errors during accelerated motions. The magnitude of these deviations directly depends on the bandwidth of the used tracking loops. A minimization of tracking loop-induced errors can be achieved in two ways: (1) by the optimization of the receiver tracking loop parameters (a larger bandwidth reduces the amplitude errors at high accelerations) and (2) by inverse filtering with a pre-estimated receiver transfer function. Especially for receivers with low and fixed tracking loop bandwidths the determination of a transfer function is crucial. In this presentation an approach to retrieve an empirical transfer function will be demonstrated. A lot of GPS coordinate time series with a broad variety of motions generated by a single-axis shake table have been produced. The discrepancies between the actual shake table motion (measured by inductive sensors) and the motions derived from the data of various GPS receivers are the basis for the determination of (receiver-specific) transfer functions.. The discrete transfer functions are modeled as an Autoregressive Moving Average (ARMA) using the least-squares method. The transfer function can be decomposed into two terms, the moving average of the input (shake table or signal simulator) and the auto-regression of the output (GPS signal). The major challenges to retrieve an empirical transfer function from real measurements are the measurement noise and the time-dependent parameters (e.g. changes in the tracking loop bandwidths dependent on the signal strength).

Häberling, Simon; Rothacher, Markus; Geiger, Alain

2014-05-01

273

The politics of reproduction.  

PubMed

The topic of human reproduction encompasses events throughout the human and especially female life-cycle as well as ideas and practices surrounding fertility, birth, and child care. Most of the scholarship on the subject, up through the 1960s, was based on cross-cultural surveys focused on the beliefs, norms, and values surrounding reproductive behaviors. Multiple methodologies and subspecialties, and fields like social history, human biology, and demography were utilized for the analysis. The concept of the politics of reproduction synthesizes local and global perspectives. The themes investigated include: the concept of reproduction, population control, and the internationalization of state and market interests (new reproductive technologies); social movements and contested domains; medicalization and its discontents; fertility and its control; adolescence and teen pregnancy; birth; birth attendants; the construction of infancy and the politics of child survival; rethinking the demographic transition; networks of nurturance; and meanings of menopause. The medicalization of reproduction is a central issue of studies of birth, midwifery, infertility, and reproductive technologies. Scholars have also analyzed different parts of the female life-cycle as medical problems. Other issues worth analysis include the internationalization of adoption and child care workers; the crisis of infertility of low-income and minority women who are not candidates for expensive reproductive technologies; the concerns of women at high risk for HIV whose cultural status depends on their fertility; questions of reproduction concerning, lesbians and gay men (artificial insemination and discrimination in child rearing); the study of menopause; and fatherhood. New discourse analysis is used to analyze state eugenic policies; conflicts over Western neocolonial influences in which women's status as childbearers represent nationalist interests; fundamentalist attacks on abortion rights; and the AIDS crisis. PMID:12288961

Ginsburg, F; Rapp, R

1991-01-01

274

High dose rate intraluminal irradiation in recurrent endobronchial carcinoma  

SciTech Connect

Palliative therapy for previously irradiated patients with symptomatic recurrent endobronchial malignancy is a difficult problem. We have had the opportunity to treat 20 such patients with high dose rate (50-100 rad/min) endobronchial brachytherapy. Eligible patients had received previous high dose thoracic irradiation (TDF greater than or equal to 90), a performance status of greater than or equal to 50, and symptoms caused by a bronchoscopically defined and implantable lesion. The radiation is produced by a small cobalt-60 source (0.7 Ci) remotely afterloaded by cable control. The source is fed into a 4 mm diameter catheter which is placed with bronchoscopic guidance; it may oscillate if necessary to cover the lesion. A dose of 1,000 rad at 1 cm from the source is delivered. We have performed 22 procedures in 20 patients, four following YAG laser debulking. Most had cough, some with hemoptysis. Eight had dyspnea secondary to obstruction and three had obstructive pneumonitis. In 12, symptoms recurred with a mean time to recurrence of 4.3 months (range 1-9 months). Eighteen patients were followed-up and reexamined via bronchoscope 1-2.5 months following the procedure; two were lost to follow-up. All had at least 50 percent clearance of tumor, and six had complete clearance; most regressions were documented on film or videotape. In six, the palliation was durable. The procedure has been well tolerated with no toxicity. We conclude that palliative endobronchial high dose rate brachytherapy is a useful palliative modality in patients with recurrent endobronchial symptomatic carcinoma.

Seagren, S.L.; Harrell, J.H.; Horn, R.A.

1985-12-01

275

High flow rate development: process optimization using megasonic immersion development (MID)  

NASA Astrophysics Data System (ADS)

In previous study the high impact of development by-products on Critical Dimension (CD) through the microloading effect has been demonstrated for a Novolak resist. In this paper, through further tests involving Chemically Amplified Resist (CAR) and Novolak resist, the microloading effect of development is characterized and tentative mechanism is presented. Megasonic Immersion Development (MID), a high flow rate development technique similar to the Proximity Gap Suction Development (PGSD), was used and compared with spin spray development and puddle development. On TOK IP3600, a Novolak resist, we have explored a wide range of process conditions with MID. Developer temperature was varied from 5°C to 40°C with TMAH developer concentration of 1.9% and 2.38% resulting in an isofocal dose range of 90mJ to 190mJ. Exposure Focus Matrix (EFM) with a specific microloading pattern and resist cross sections were performed. The best conditions are quite far from the standard process advised by the resist supplier. Very nice standing wave profile was obtained at high temperature development. On CAR, JEOL 9000MVII, a 50kV e-beam vector scan tool, and ETEC ALTA 4300, a DUV raster scan tool, were used with different develop process techniques including MID. FujiFilm Arch FEP-171 positive CAR and Sumitomo NEB-22 negative CAR were used on 50kV writing tool. Sumitomo PEK-130 was used on DUV writing tool. FEP-171 and PEK-1300 show microloading effect on high density patterns but not NEB-22. MID shows also improved reproduction of develop features in the chrome and a 20% improvement of CD uniformity. The results of this study seem to indicate that a closer look in their development process is needed for 90nm and 65nm technologies.

Courboin, Daniel; Choi, Jong Woo; Jung, Sang Hyun; Baek, Seung Hee; Kim, Lee Ju

2004-12-01

276

High-rate treatment of terephthalate in anaerobic hybrid reactors.  

PubMed

The anaerobic degradation of terephthalate as sole substrate was studied in three anaerobic upflow reactors. Initially, the reactors were operated as upflow anaerobic sludge bed (UASB) reactors and seeded with suspended methanogenic biomass obtained from a full-scale down-flow fixed film reactor, treating wastewater generated during production of purified terephthalic acid. The reactors were operated at 30, 37, and 55 degrees C. The terephthalate removal capacities remained low in all three reactors (<4 mmolxL-1xday-1, or 1 g of chemical oxygen demand (COD)xL-1xday-1) due to limitations in biomass retention. Batch experiments with biomass from the UASB reactors revealed that, within the mesophilic temperature range, optimal terephthalate degradation is obtained at 37 degrees C. No thermophilic terephthalate-degrading culture could be obtained in either continuous or batch cultures. To enhance biomass retention, the reactors were modified to anaerobic hybrid reactors by introduction of two types of reticulated polyurethane (PUR) foam particles. The hybrid reactors were operated at 37 degrees C and seeded with a mixture of biomass from the UASB reactors operated at 30 and 37 degrees C. After a lag period of approximately 80 days, the terephthalate conversion capacity of the hybrid reactors increased exponentially at a specific rate of approximately 0.06 day-1, and high removal rates were obtained (40-70 mmolxL-1xday-1, or 10-17 g of CODxL-1xday-1) at hydraulic retention times between 5 and 8 h. These high removal capacities could be attributed to enhanced biomass retention by the development of biofilms on the PUR carrier material as well as the formation of granular biomass. Biomass balances over the hybrid reactors suggested that either bacterial decay or selective wash-out of the terephthalate fermenting biomass played an important role in the capacity limitations of the systems. The presented results suggest that terephthalate can be degraded at high volumetric rates if sufficiently long sludge ages can be maintained, and the reactor pH and temperature are close to their optima. PMID:10356251

Kleerebezem, R; Ivalo, M; Hulshoff Pol, L W; Lettinga, G

1999-01-01

277

NEONATAL LOW- AND HIGH-DOSE EXPOSURE TO ESTRADIOL BENZOATE IN THE MALE RAT: II. EFFECTS ON THE MALE PUBERTY AND THE REPRODUCTIVE TRACT  

EPA Science Inventory

NEONATAL LOW- AND HIGH-DOSE EXPOSURE TO ESTRADIOL BENZOATE IN THE MALE RAT: II. EFFECTS ON MALE PUBERTY AND THE REPRODUCTIVE TRACT. Oliver Putz, Christian B. Schwartz, Gerald A. LeBlanc, Ralph L. Cooper, Gail S. Prins ABSTRACT Environmental contaminants with estrogen...

278

Wastewater treatment high rate algal ponds for biofuel production.  

PubMed

While research and development of algal biofuels are currently receiving much interest and funding, they are still not commercially viable at today's fossil fuel prices. However, a niche opportunity may exist where algae are grown as a by-product of high rate algal ponds (HRAPs) operated for wastewater treatment. In addition to significantly better economics, algal biofuel production from wastewater treatment HRAPs has a much smaller environmental footprint compared to commercial algal production HRAPs which consume freshwater and fertilisers. In this paper the critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO(2) addition, species control, control of grazers and parasites and bioflocculation are discussed. PMID:20674341

Park, J B K; Craggs, R J; Shilton, A N

2011-01-01

279

New developments in very high rate silver oxide electrodes  

NASA Astrophysics Data System (ADS)

Cathodes for primary silver/zinc cells were prepared using chemically synthesized silver oxides (both monovalent and divalent). The oxides were mixed with PTFE binder but with no conductive fillers for this work. The electrodes were discharged galvanostatically over a broad range of current densities (40-500 mA cm -2) and temperature (7-40 °C) in 6.3 M KOH electrolyte. The discharge capacity was greater than 90% of the theoretical value for both oxides under such conditions. At high rate (500 mA cm -2) the overvoltage of the monovalent oxide is about 50 mV less than that for the divalent oxide. A 42% improvement in energy density over anodized silver cathodes was demonstrated with the chemical AgO electrodes.

Smith, David F.; Graybill, George R.; Grubbs, Robert K.; Gucinski, James A.

280

High-rate Iranian blowout controlled while still burning  

SciTech Connect

Oil well firefighters used ingenuity and equipment designed in the field to cap a high-rate blowout well in Iran without extinguishing the fire. Well AZ-50, located about 25 km southeast of Ahwaz, Iran, blew out on Feb. 14, 1993, and was finally controlled on Mar. 31, 1993, by a firefighting team from the National Iranian Oil Co. The estimated open flow potential of producing Well AZ-50 was 60,000 bo/d and 50 MMsfd of associated gas, making this well among the world's largest blowouts. The well control operation was difficult because the flame height reached 117 m, the fluid velocity 2, 180 fps at the well-head, and the flame temperature 4,150 F. The paper describes operations.

Bahmani, H.; Azarpanah, A. (National Iranian Oil Co., Ahwaz (Iran, Islamic Republic of))

1994-09-19

281

High rate time-space-position-information for high dynamic GPS integrated navigation systems  

Microsoft Academic Search

The 746 Test Squadron (746 TS) has developed and implemented a high accuracy, high rate integrated Differential Global Positioning System\\/Inertial Navigation System (DGPS\\/INS) Time, Space, and Position Information (TSPI) truth reference to verify aircraft navigation system performance during flight tests. Specifically, the 746 TS participated in a fighter aircraft program. The 746 TSs unique truth reference system exploits the low

B. J. Bohenek; D. A. Ruff; J. F. Raquet

1996-01-01

282

REPRODUCTIVE POTENTIAL PREDICTS LONGEVITY OF FEMALE MEDITERRANEAN FRUIT FLIES  

E-print Network

REPRODUCTIVE POTENTIAL PREDICTS LONGEVITY OF FEMALE MEDITERRANEAN FRUIT FLIES (reproductive clock@wald.ucdavis.edu). #12;ABSTRACT Reproduction exacts a price in terms of decreased survival. Our analysis of the interplay laying with age. This defines an individual's rate of reproductive exhaustion. This rate is shown

Müller, Hans-Georg

283

ESTIMATION OF REPRODUCTIVE RATES OF BURROWING OWLS LEAH R. GORMAN,1 Oregon Cooperative Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University,  

E-print Network

to observe, such as the burrowing owl (Athene cunicularia). We compared methods for estimating reproductive reliable estimates. JOURNAL OF WILDLIFE MANAGEMENT 67(3):493­500 Key words: Athene cunicularia, brood size

Rosenberg, Daniel K.

284

Bioethical aspects of regenerative and reproductive medicine.  

PubMed

The birth announced in 1997 of Dolly, the lamb cloned from the somatic mammary cells of an adult ewe, and the discovery of human embryonic stem cells in 1998 have been the most exciting developments in the biological sciences in the past decade. Reproductive somatic cell nuclear transfer (SCNT) in additional species has been inefficient in that relatively few births, harmful side effects and high fetal and neonatal death rates have resulted from many attempts. Ongoing debates about the ethics of reproductive SCNT have revealed that some researchers regard human reproductive SCNT as morally unacceptable in all circumstances, others see merit in reproductive SCNT in certain circumstances and others await more information before making judgment about the ethical status of the procedure. Regenerative medicine and emerging biotechnologies started to revolutionize the practice of medicine. Advances in stem cell biology, including embryonic and postnatal somatic stem cells, have made the prospect of tissue regeneration a potential reality. Mammal cloning experiments have provided new impetus to the prospect of regenerative medicine through stem cell research. The procedure of SCNT could be used to create the raw material to replace defective or senescent tissue as a natural extension of the biology of stem cells. Researchers working in reproductive medicine should consider the potential hope given to many patients against the requisite and ethically contentious creation of human blastocysts for therapeutic intent. PMID:16879561

Yoshimura, Yasunori

2006-05-01

285

An integrated CMOS high data rate transceiver for video applications  

NASA Astrophysics Data System (ADS)

This paper presents a 5 GHz CMOS radio frequency (RF) transceiver built with 0.18 ?m RF-CMOS technology by using a proprietary protocol, which combines the new IEEE 802.11n features such as multiple-in multiple-out (MIMO) technology with other wireless technologies to provide high data rate robust real-time high definition television (HDTV) distribution within a home environment. The RF frequencies cover from 4.9 to 5.9 GHz: the industrial, scientific and medical (ISM) band. Each RF channel bandwidth is 20 MHz. The transceiver utilizes a direct up transmitter and low-IF receiver architecture. A dual-quadrature direct up conversion mixer is used that achieves better than 35 dB image rejection without any on chip calibration. The measurement shows a 6 dB typical receiver noise figure and a better than 33 dB transmitter error vector magnitude (EVM) at -3 dBm output power.

Yaping, Liang; Dazhi, Che; Cheng, Liang; Lingling, Sun

2012-07-01

286

Highly nonlinear defect-induced carrier recombination rates in semiconductors  

NASA Astrophysics Data System (ADS)

Defects in semiconductors can induce recombination of carriers and thus can strongly influence the efficiency and performance of solid-state devices. In the analysis of device performance, defect-induced recombination is often assumed to depend linearly on the carrier concentration or to be given by a sum of Shockley-Read-Hall expressions taken independently for each known defect level. Under these assumptions, defect-induced recombination increases with carrier concentration more slowly than both band-to-band radiative recombination and Auger recombination and becomes relatively less important at higher carrier concentrations. However, we show that defects with multiple defect levels can induce recombination with a highly nonlinear dependence on carrier concentration. For such defects, the usual assumptions about the relative importance of different recombination mechanisms at different carrier concentrations may fail. In order to demonstrate the potential impact of this phenomenon on realistic devices, we incorporate the defect-induced recombination rates obtained from our analysis into a microscopic InGaN/GaN light-emitting diode (LED) model. Our results indicate that a particular class of defects with plausible properties can induce a loss of optical efficiency at carrier concentrations relevant for high-power LED operation.

Modine, N. A.; Armstrong, A. M.; Crawford, M. H.; Chow, W. W.

2013-10-01

287

High rates of substance use in French youths 13/7/07 High prevalence rates of tobacco, alcohol and drug use in adolescents and  

E-print Network

High rates of substance use in French youths 13/7/07 1 High prevalence rates of tobacco, alcohol;33(1):122-33" DOI : 10.1016/j.addbeh.2007.09.009 #12;High rates of substance use in French youths 13/7/07 2 Abstract Background: Rates of substance use among adolescents have increased in the 1990s, however little is known

Paris-Sud XI, Université de

288

Diagnostic value of sperm DNA fragmentation and sperm high-magnification for predicting outcome of assisted reproduction treatment  

PubMed Central

Over the last years, major improvements in the field of male infertility diagnosis have been achieved. The aim of this study was to determine the diagnostic usefulness of sperm DNA integrity and sperm vacuolisation for predicting outcome in infertile couples undergoing in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) treatments. A cohort study from 152 infertile couples undergoing sperm DNA fragmentation and high-magnification tests prior to an assisted reproduction treatment was designed. We found that the most predictive cutoff for pregnancy was 25.5% of DNA fragmentation with a negative predictive value of 72.7% (P=0.02). For the degree of vacuolisation, the best predictor of pregnancy was 73.5% of vacuolated sperm grades III+IV with a negative predictive value of 39.4% (P=0.09), which was not statistically significant. In conclusion, sperm DNA fragmentation greater than 25.5% could be associated with higher probability of failure IVF treatment. Regarding the results of the sperm analysis at high magnification, they do not allow us to predict whether or not patients will become pregnant. PMID:23912311

Lopez, Gemma; Lafuente, Rafael; Checa, Miguel A; Carreras, Ramon; Brassesco, Mario

2013-01-01

289

High Strain Rate Response of Sandwich Composites with Nanophased Cores  

NASA Astrophysics Data System (ADS)

Polyurethane foam materials have been used as core materials in a sandwich construction with S2-Glass/SC-15 facings. The foam material has been manufactured from liquid polymer precursors of polyurethane. The precursors are made of two components; part-A (diphenylmethane diisocyanate) and part-B (polyol). In one set of experiments, part-A was mixed with part-B to manufacture the foam. In another set, TiO2 nanoparticles have been dispersed in part-A through ultrasonic cavitation technique. The loading of nanoparticles was 3% by weight of the total polymer precursor. The TiO2 nanoparticles were spherical in shape, and were about 29 nm in diameter. Sonic cavitation was carried out with a vibrasound liquid processor at 20 kHz frequency with a power intensity of about 100 kW/m2. The two categories of foams manufactured in this manner were termed as neat and nanophased. Sandwich composites were then fabricated using these two categories of core materials using a co-injection resin transfer molding (CIRTM) technique. Test samples extracted from the panel were subjected to quasi-static as well as high strain rate loadings. Rate of loading varied from 0.002 s-1 to around 1300 s-1. It has been observed that infusion of nanoparticles had a direct correlation with the cell geometry. The cell dimensions increased by about 46% with particle infusion suggesting that nanoparticles might have worked as catalysts during the foaming process. Correspondingly, enhancement in thermal properties was also noticed especially in the TGA experiments. There was also a significant improvement in mechanical properties due to nanoparticle infusion. Average increase in sandwich strength and energy absorption with nanophased cores was between 40 60% over their neat counterparts. Details of manufacturing and analyses of thermal and mechanical tests are presented in this paper.

Mahfuz, Hassan; Uddin, Mohammed F.; Rangari, Vijaya K.; Saha, Mrinal C.; Zainuddin, Shaik; Jeelani, Shaik

2005-05-01

290

Asexual Reproduction in Holothurians  

PubMed Central

Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed. PMID:25405228

Dolmatov, Igor Yu.

2014-01-01

291

Teacher-ratings and self-ratings of social competency in adolescents with low- and high-depressive symptoms.  

PubMed

A comparison of teacher-ratings and self-ratings of adolescents' social competency was investigated. One hundred five high school students completed the Reynolds Adolescent Depression Scale (RADS; Reynolds, 1987) and were divided according to their scores into three groups: the lowest quartile [low-depressive symptoms (LDS) group (n = 27)], the highest quartile [high-depressive symptoms (HDS) group (n = 28)], and the remainder. Students also rated themselves and were rated by their teachers on a social competency scale. A 2 (High- and Low-Depressive Groups) x 2 (Teacher-Ratings and Self-Ratings) ANOVA was conducted using social competency rating scores as the dependent variable. The two main effects were significant (p < .01). Adolescents with low-depressive symptoms rated themselves and were rated by their teachers as more socially competent than adolescents with high-depressive symptoms; additionally, self-ratings of social competency were higher than teacher-ratings. Results are discussed in the context of an adolescent optimistic bias or a teacher pessimistic bias. PMID:7963079

Dalley, M B; Bolocofsky, D N; Karlin, N J

1994-08-01

292

REPRODUCTION WITHIN MARMOTINE GROUND SQUIRRELS (SCIURIDAE, XERINAE, MARMOTINI): PATTERNS  

E-print Network

REPRODUCTION WITHIN MARMOTINE GROUND SQUIRRELS (SCIURIDAE, XERINAE, MARMOTINI): PATTERNS AMONG The sciurid tribe Marmotini has a distinctive, highly specialized reproductive profile characterized genera of marmotines follow the reproductive profile of the tribe. In fact, included in the tribe

Hayssen, Virginia

293

Costs of reproduction in a long-lived bird: large clutch size is associated with low survival in the presence of a highly virulent disease  

PubMed Central

Fitness costs of reproduction are expected to be more pronounced when the environmental conditions deteriorate. We took advantage of a natural experiment to investigate the costs of reproduction among common eiders (Somateria mollissima) nesting at a site in the Arctic, where an avian cholera epizootic appeared at different magnitudes. We tested the predictions that larger reproductive effort (clutch size) is associated with lower survival or breeding probability the following year, and that this relationship was more pronounced under heightened exposure to the disease. Our results indicate that large clutch sizes were associated with lower survival of female eider ducks, but only when there was heightened exposure to avian cholera, as indexed by eider mortality on site. No cost was observed when cholera was absent or when lesser exposure was evident. This supports the hypothesis that fitness costs of high reproductive effort are higher under unfavourable conditions such as a disease epizootic, and further indicates that being a conservative breeder can increase survival probability, given the presence of a highly virulent disease. PMID:19324661

Descamps, Sebastien; Gilchrist, H. Grant; Bety, Joel; Buttler, E. Isabel; Forbes, Mark R.

2009-01-01

294

Cryogenic, high-resolution x-ray detector with high count rate capability  

DOEpatents

A cryogenic, high-resolution X-ray detector with high count rate capability has been invented. The new X-ray detector is based on superconducting tunnel junctions (STJs), and operates without thermal stabilization at or below 500 mK. The X-ray detector exhibits good resolution (.about.5-20 eV FWHM) for soft X-rays in the keV region, and is capable of counting at count rates of more than 20,000 counts per second (cps). Simple, FET-based charge amplifiers, current amplifiers, or conventional spectroscopy shaping amplifiers can provide the electronic readout of this X-ray detector.

Frank, Matthias (Oakland, CA); Mears, Carl A. (Windsor, CA); Labov, Simon E. (Berkeley, CA); Hiller, Larry J. (Livermore, CA); Barfknecht, Andrew T. (Menlo Park, CA)

2003-03-04

295

Schooling for Work in New Zealand: Reproduction, Contestation and Transformation in three High Schools  

Microsoft Academic Search

This study records messages given to students about work within three high schools in New Zealand. Attention was given to overt and covert messages, and to those messages embedded in the structure of schooling itself. The study contributes to the debate within the ‘new’ sociology of education in that it focuses on the relationship between schooling and the established order

Ronald G. Sultana

1990-01-01

296

Time reproduction during high and low attentional tasks in Alzheimer's Disease "A watched kettle never boils".  

PubMed

A wealth of empirical evidence suggests that directing attention to temporal processing increases perceived duration, whereas drawing attention away from it has the opposite effect. Our work investigates this phenomenon by comparing perceived duration during a high attentional and a low attentional task in Alzheimer's Disease (AD) patients since these participants tend to show attentional deficits. In the high attentional task, AD patients and older adults were asked to perform the interference condition of the Stroop test for 15s while in the low attentional task, they had to fixate on a cross for the same length of time. In both conditions, participants were not aware they would be questioned about timing until the end of the task when they had to reproduce the duration of the previously-viewed stimulus. AD patients under-reproduced the duration of previously-exposed stimulus in the high attentional relative to the low attentional task, and the same pattern was observed in older adults. Due to their attentional deficits, AD patients might be overwhelmed by the demand of the high attentional task, leaving very few, if any, attentional resources for temporal processing. PMID:24794142

El Haj, Mohamad; Omigie, Diana; Moroni, Christine

2014-07-01

297

High exposure rates of anticoagulant rodenticides in predatory bird species in intensively managed landscapes in Denmark.  

PubMed

The extensive use of anticoagulant rodenticides (ARs) for rodent control has led to widespread secondary exposure in nontarget predatory wildlife species. We investigated exposure rates and concentrations of five ARs in liver samples from five raptors and six owls from Denmark. A total of 430 birds were analysed. ARs were detected in 84-100 % of individual birds within each species. Multiple AR exposure was detected in 73 % of all birds. Average number of substances detected in individual birds was 2.2 with no differences between owls and raptors. Difenacoum, bromadiolone, and brodifacoum were the most prevalent substances and occurred in the highest concentrations. Second-generation ARs made up 96 % of the summed AR burden. Among the six core species (sample size >30), summed AR concentrations were lower in rough-legged buzzard (Buteo lagopus) and long-eared owl (Asio otus) than in barn owl (Tyto alba), buzzard (B. buteo), kestrel (Falco tinnunculus), and tawny owl (Strix aluco). There was a strong tendency for seasonal variations in the summed AR concentration with levels being lowest during autumn, which is probably related to an influx of less-exposed migrating birds from northern Scandinavia during autumn. High hepatic AR residue concentrations (>100 ng/g wet weight), which have been associated with symptoms of rodenticide poisoning and increased mortality, were recorded high frequencies (12.9-37.4 %) in five of the six core species. The results suggest that the present use of ARs in Denmark, at least locally, may have adverse effects on reproduction and, ultimately, population status in some raptors and owls. PMID:22588365

Christensen, Thomas Kjær; Lassen, Pia; Elmeros, Morten

2012-10-01

298

High-dose-rate brachytherapy in uterine cervical carcinoma  

SciTech Connect

Purpose: High-dose-rate (HDR) brachytherapy is in wide use for curative treatment of cervical cancer. The American Brachytherapy Society has recommended that the individual fraction size be <7.5 Gy and the range of fractions should be four to eight; however, many fractionation schedules, varying from institution to institution, are in use. We use 9 Gy/fraction of HDR in two to five fractions in patients with carcinoma of the uterine cervix. We found that our results and toxicity were comparable to those reported in the literature and hereby present our experience with this fractionation schedule. Methods and Materials: A total of 121 patients with Stage I-III carcinoma of the uterine cervix were treated with HDR brachytherapy between 1996 and 2000. The total number of patients analyzed was 113. The median patient age was 53 years, and the histopathologic type was squamous cell carcinoma in 93% of patients. The patients were subdivided into Groups 1 and 2. In Group 1, 18 patients with Stage Ib-IIb disease, tumor size <4 cm, and preserved cervical anatomy underwent simultaneous external beam radiotherapy to the pelvis to a dose of 40 Gy in 20 fractions within 4 weeks with central shielding and HDR brachytherapy of 9 Gy/fraction, given weekly, and interdigitated with external beam radiotherapy. The 95 patients in Group 2, who had Stage IIb-IIIb disease underwent external beam radiotherapy to the pelvis to a dose of 46 Gy in 23 fractions within 4.5 weeks followed by two sessions of HDR intracavitary brachytherapy of 9 Gy each given 1 week apart. The follow-up range was 3-7 years (median, 36.4 months). Late toxicity was graded according to the Radiation Therapy Oncology Group criteria. Results: The 5-year actuarial local control and disease-free survival rate was 74.5% and 62.0%, respectively. The actuarial local control rate at 5 years was 100% for Stage I, 80% for Stage II, and 67.2% for Stage III patients. The 5-year actuarial disease-free survival rate was 88.8% for Stage I, 76.52% for Stage II, and 50.4% for Stage III patients. Local failure occurred in 2 (11.1%) of the 18 Group 1 patients and in 20 (21.0%) of the 95 Group 2 patients. Distant failure occurred in none of the Group 1 patients and in 8 (8.4%) of the 95 Group 2 patients. None of the patients developed Grade 3 rectal toxicity. Grade 3 bladder toxicity was observed in 2 patients. The actuarial risk of Grade 3 or worse late toxicity was 3.31%. Conclusion: The results of our study indicate that HDR brachytherapy at 9 Gy/fraction is both safe and effective in the management of carcinoma of the cervix, with good local control and a minimum of normal tissue toxicity.

Patel, Firuza D. [Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh (India)]. E-mail: patelfd@glide.net.in; Rai, Bhavana [Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Mallick, Indranil [Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Sharma, Suresh C. [Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh (India)

2005-05-01

299

Effect of High Dietary Levels of Aureomycin on Reproductive Performance and Antibiotic Resistant Organisms in the Digestive Tract of the Hen  

E-print Network

EFFECT OF HIGH DIETARY LEVEIS GF AUREOMYCIN ON REPRODUCTIVE PERFORMANCE AND ANTIBIOTIC RESISTANT ORGANISMS IN THE DIGESTIVE TRACT OF THE HEN A Thesis Harry Donald Stelsner Submitted to the Graduate School of the Agricultural and, Mechanical... College of Texas in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE Ma)or Subject: Poultry Science May 1960 EFFECT OF HIGH DIETARY LPfEIB OF AUREOMYCIN ON REPRODUCTIFE PERFORMANCE AND ANTIBIOTIC RESISTANT ORGANISMS IN TKE...

Stelzner, Harry Donald

2012-06-07

300

Preconception care: promoting reproductive planning  

PubMed Central

Introduction Preconception care recognizes that many adolescent girls and young women will be thrust into motherhood without the knowledge, skills or support they need. Sixty million adolescents give birth each year worldwide, even though pregnancy in adolescence has mortality rates at least twice as high as pregnancy in women aged 20-29 years. Reproductive planning and contraceptive use can prevent unintended pregnancies, unsafe abortions and sexually-transmitted infections in adolescent girls and women. Smaller families also mean better nutrition and development opportunities, yet 222 million couples continue to lack access to modern contraception. Method A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for adolescents, women and couples of reproductive age on MNCH outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture. Results Comprehensive interventions can prevent first pregnancy in adolescence by 15% and repeat adolescent pregnancy by 37%. Such interventions should address underlying social and community factors, include sexual and reproductive health services, contraceptive provision; personal development programs and emphasizes completion of education. Appropriate birth spacing (18-24 months from birth to next pregnancy compared to short intervals <6 months) can significantly lower maternal mortality, preterm births, stillbirths, low birth weight and early neonatal deaths. Conclusion Improving adolescent health and preventing adolescent pregnancy; and promotion of birth spacing through increasing correct and consistent use of effective contraception are fundamental to preconception care. Promoting reproductive planning on a wider scale is closely interlinked with the reliable provision of effective contraception, however, innovative strategies will need to be devised, or existing strategies such as community-based health workers and peer educators may be expanded, to encourage girls and women to plan their families.

2014-01-01

301

Gene expression rate comparison for multiple high-throughput datasets.  

PubMed

Microarray provides genome-wide transcript profiles, whereas RNA-seq is an alternative approach applied for transcript discovery and genome annotation. Both high-throughput techniques show quantitative measurement of gene expression. To explore differential gene expression rates and understand biological functions, the authors designed a system which utilises annotations from Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathways and Gene Ontology (GO) associations for integrating multiple RNA-seq or microarray datasets. The developed system is initiated by either estimating gene expression levels from mapping next generation sequencing short reads onto reference genomes or performing intensity analysis from microarray raw images. Normalisation procedures on expression levels are evaluated and compared through different approaches including Reads Per Kilobase per Million mapped reads (RPKM) and housekeeping gene selection. Such gene expression levels are shown in different colour shades and graphically displayed in designed temporal pathways. To enhance importance of functional relationships of clustered genes, representative GO terms associated with differentially expressed gene cluster are visually illustrated in a tag cloud representation. PMID:24067413

Chen, Chien-Ming; Shih, Tsan-Huang; Pai, Tun-Wen; Liu, Zhen-Long; Chang, Margaret Dah-Tsyr; Hu, Chin-Hwa

2013-10-01

302

Algal biofuels from wastewater treatment high rate algal ponds.  

PubMed

This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (?10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (?30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO(2) has, under suitable climatic conditions, the potential to double production (to ?60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest. PMID:21330711

Craggs, R J; Heubeck, S; Lundquist, T J; Benemann, J R

2011-01-01

303

Early onset of reproductive function in female rats treated with a high-fat diet.  

PubMed

Puberty onset in mammals is tightly coupled to the animal's nutritional and metabolic state. In the present study, we evaluated the effects of a high-fat diet on leptin and adiponectin levels, leptin mRNA expression and puberty onset in female rats. On day 21, female rats were divided into 2 groups, normal food (NF) and high-fat food (HF). The HF group showed a significantly earlier (P<0.001) date of vaginal opening and lower body weight (P<0.001) than the NF group. The rats fed the HF food had a significantly heavier uterus (P<0.05) than those fed the NF food, whereas the serum leptin and adiponectin levels and leptin mRNA expression were not significantly different between the NF and HF groups. We speculate that the fat-induced nutritional imbalance in young females may lead to neuroendocrine dysfunction during adolescence. PMID:23154420

Fungfuang, Wirasak; Nakao, Nobuhiko; Nakada, Tomoaki; Yokosuka, Makoto; Saito, Toru R

2013-05-01

304

High-order harmonic generation using a high-repetition-rate turnkey laser  

E-print Network

We generate high-order harmonics at high pulse repetition rates using a turnkey laser. High-order harmonics at 400 kHz are observed when argon is used as target gas. In neon we achieve generation of photons with energies exceeding 90 eV ($\\sim$13 nm) at 20 kHz. We measure a photon flux of 4.4$\\cdot10^{10}$ photons per second per harmonic in argon at 100 kHz. Many experiments employing high-order harmonics would benefit from higher repetition rates, and the user-friendly operation opens up for applications of coherent extreme ultra-violet pulses in new research areas.

Lorek, Eleonora; Heyl, Christoph Michael; Carlström, Stefanos; Pale?ek, David; Zigmantas, Donatas; Mauritsson, Johan

2014-01-01

305

Reproductive Hazards in the Lab Reproductive Hazards  

E-print Network

Reproductive Hazards in the Lab Reproductive Hazards The term reproductive hazard refers to agents (radiation, x-rays, chemicals or biologicals) that affect the reproductive health of women or men to have healthy children. Reproductive hazards may have harmful effects on libido, sexual behavior, or sperm

de Lijser, Peter

306

High-k (k=30) amorphous hafnium oxide films from high rate room temperature deposition  

SciTech Connect

Amorphous hafnium oxide (HfO{sub x}) is deposited by sputtering while achieving a very high k{approx}30. Structural characterization suggests that the high k is a consequence of a previously unreported cubiclike short range order in the amorphous HfO{sub x} (cubic k{approx}30). The films also possess a high electrical resistivity of 10{sup 14} {Omega} cm, a breakdown strength of 3 MV cm{sup -1}, and an optical gap of 6.0 eV. Deposition at room temperature and a high deposition rate ({approx}25 nm min{sup -1}) makes these high-k amorphous HfO{sub x} films highly advantageous for plastic electronics and high throughput manufacturing.

Li, Flora M.; Bayer, Bernhard C.; Hofmann, Stephan; Milne, William I.; Flewitt, Andrew J. [Department of Engineering, Electrical Engineering Division, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Dutson, James D.; Wakeham, Steve J.; Thwaites, Mike J. [Plasma Quest Ltd., Unit 1B, Rose Estate, Osborn Way, Hook, Hampshire RG27 9UT (United Kingdom)

2011-06-20

307

A High Repetition Rate Plasma Focus for High Energy Density Plasma Studies  

NASA Astrophysics Data System (ADS)

Large, high energy density plasma sources such as Sandia's Z-machine or the National Ignition Facility are limited to low repetition rate operation (˜1 shot per day). Intermediate facilities still have low data rates (˜10 shots per day). Alameda Applied Sciences Corporation has demonstrated a plasma focus operating from 200- 500 kA, capable of firing shots at 0.1 Hz. A typical run gathers data over ˜1000 shots. Such high data rates allow validation and verification of numerical simulation codes with a statistically significant data set over a wide variety of operating conditions. A variety of terminal measurements (current and voltage), neutron yield, optical emission spectroscopy, hard x-ray images and zipper array data are used to characterize the source. Additional diagnostics such as interferometry, x-ray back lighting and soft x-ray spectroscopy are discussed.

Bures, Brian; Krishnan, Mahadevan; Madden, Robert

2011-11-01

308

Evaluation of the Infestation Rate of Blaesoxipha alcedo in the Carrion Roller Scarab Canthon cyanellus cyanellus and Its Effect on Reproductive Behavior.  

PubMed

This study documents Blaesoxipha alcedo (Aldrich; Diptera: Sarcophagidae) parasitizing the necrophagous ball roller beetle Canthon cyanellus cyanellus LeConte collected over 2?yr, and evaluates the reproductive behavior of parasitized beetles. Up to 52% of the beetles collected in the field had been parasitized and exhibited modified sexual behavior. In general, 21% of the males and 24% of the females had been parasitized. The number of parasitized males peaked in August 2000 (52%), but that of females peaked in May 2001 (52%). The lowest percentage of parasitized males (7%) was recorded in September 2000, June 2001, and July 2001; for females, parasitism was lowest in June 2000 (10%). The larva of this sarcophagid fly penetrates the host through the tegumentary membrane, leaving a scar. The larvae feed on the gonads of male and female C. c. cyanellus, castrating them, causing the loss of their ability to recognize individuals of the opposite sex, preventing reproduction, and lowering overall reproductive success. PMID:25347831

Ortiz Domínguez, Maribel; Favila, Mario E

2014-01-01

309

Characterization of Composites Response at High Rates of Loading  

NASA Technical Reports Server (NTRS)

The objective of the proposed research is to experimentally study the effect of strain rate on mechanical response (deformation and failure) carbon fiber/epoxy matrix composites. The experimental data provide the information needed for the development of a nonlinear, rate dependent deformation and strength models that can subsequently be used in design. This year effort was directed into testing the epoxy resin. Two types of epoxy were tested each in tension and shear at various strain rate that ranges from 5x10(exp -5), to 700/s. The results show that both the strain rate and the mode of loading affect the epoxy response.

Gilat, Amos

2002-01-01

310

Reproductive Health  

NSDL National Science Digital Library

BioMed Central contains hundreds of important online journals in its archives, and Reproductive Health is certainly one that visitors will want to look over when they have a few moments. Reproductive Health is the official journal of the Geneva Foundation for Medical Education and Research, and was started in June 2004. It covers all aspects of human reproduction, and recent pieces have dealt with cervical cancer, maternity care, and other related topics. Visitors can view the ten most accessed articles from the journal, sign up to receive an RSS feed of the latest articles, and also email articles to friends and colleagues. For those who might be interested in submitting an article for consideration, they can also do that via this site.

311

High-fidelity reproduction of spatiotemporal visual signals for retinal prosthesis.  

PubMed

Natural vision relies on spatiotemporal patterns of electrical activity in the retina. We investigated the feasibility of veridically reproducing such patterns with epiretinal prostheses. Multielectrode recordings and visual and electrical stimulation were performed on populations of identified ganglion cells in isolated peripheral primate retina. Electrical stimulation patterns were designed to reproduce recorded waves of activity elicited by a moving visual stimulus. Electrical responses in populations of ON parasol cells exhibited high spatial and temporal precision, matching or exceeding the precision of visual responses measured in the same cells. Computational readout of electrical and visual responses produced similar estimates of stimulus speed, confirming the fidelity of electrical stimulation for biologically relevant visual signals. These results suggest the possibility of producing rich spatiotemporal patterns of retinal activity with a prosthesis and that temporal multiplexing may aid in reproducing the neural code of the retina. PMID:24910077

Jepson, Lauren H; Hottowy, Pawel; Weiner, Geoffrey A; Dabrowski, W?adys?aw; Litke, Alan M; Chichilnisky, E J

2014-07-01

312

Strain rate dependence of dynamic flow stress considering viscous drag for 6061 aluminium alloy at high strain rates  

NASA Astrophysics Data System (ADS)

In order to evaluate the strain rate dependence of the dynamic flow stress of aluminium alloys, 6061-O and -T6, high strain rate tests are performed at strain rates ranging from about 1000/s to 30000/s, and strain rate reduction tests are also conducted in the strain rate range from about 10000/s to 20000/s. A steep increase in the flow stress is observed for 6061-O at the strain rate of about 5000/s. The above phenomenon, however, is not observed for 6061-T6 in the strain rate range where the strain rate reduction tests is conducted. A simplified model for a dislocation kinetics under a dynamic plastic deformation is used to consider the deformation mechanism in the above strain rate ranges, which reveals that the steep increase in the flow stress of 6061-O is attributed to the rate dependence of the viscous drag on the dislocation motion. It is estimated that the velocity of moving dislocation of 6061-T6 is lower than that of 6061-O at a given strain rate, and that 6061-T6 is higher in a mobile dislocation density than 6061-O. The model predicts also that the increase in the mobile dislocation density shifts the transition region, or the strain rates in which the steep increase in the flow stress becomes to appear, to the higher strain rate side.

Sakino, K.

2006-08-01

313

Characterization of Composites Response at High Rates of Deformation  

NASA Technical Reports Server (NTRS)

The objective of the proposed research is to experimentally study the effect of strain rate on mechanical response (deformation and failure) of IM-7/977-2 carbon fiber/epoxy matrix composites. The experimental data will provide the information needed for the development of a nonlinear, rate dependent deformation and strength model for this material that can subsequently be used in design.

Gilat, Amos

2001-01-01

314

High Rates of Vertical Crustal Movement near Ventura, California.  

PubMed

Fission track, radiometric, and paleomagnetic age determinations in marine sedimentary rocks of the Ventura Basin make it possible to estimate the vertical components of displacement rates for the last 2 million years. The basin subsided at rates up to 9.5 +/- 2.5 millimeters per year until about 0.6 million years ago, when subsidence virtually ceased. Since then, the northern margin of the basin has been rising at an average rate of 10 +/- 2 millimeters per year, about the same rate as that based on the geodetic record north and west of Ventura since 1960 but considerably lower than the rate along the San Andreas fault at Palmdale since 1960. PMID:17756098

Yeats, R S

1977-04-15

315

High-pitch dual-source CT coronary angiography: systolic data acquisition at high heart rates  

Microsoft Academic Search

Objective  To assess the effect of systolic data acquisition for electrocardiography (ECG)-triggered high-pitch computed tomography (CT)\\u000a on motion artefacts of coronary arteries in patients with high heart rates (HRs).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Eighty consecutive patients (15 women, age 67?±?14 years) with HR??70 bpm underwent CT angiography of the thoracic aorta (CTA)\\u000a on 128-slice dual-source CT in ECG-triggered high-pitch acquisition mode (pitch?=?3.2) set at 60% (group A,

Robert Goetti; Gudrun Feuchtner; Paul Stolzmann; Lotus Desbiolles; Michael Alexander Fischer; Christoph Karlo; Stephan Baumueller; Hans Scheffel; Hatem Alkadhi; Sebastian Leschka

2010-01-01

316

Highly pathogenic porcine reproductive and respiratory syndrome virus GP5 B antigenic region is not a neutralizing antigenic region.  

PubMed

In 2006, highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) caused great economic losses emerged in China and continues to be a threat for the pig industry. B antigenic region (AR) ((37)SHL/FQLIYNL(45)) of GP5 was considered to be a major linear neutralizing AR in PRRSV classical strains. However, peptide-purified antibodies against this AR did not neutralize PRRSV in a recent report. Compared with classical PRRSV, one amino acid mutation (L/F(39)? I(39)) was found in B AR of HP-PRRSV. To study the ability of B AR of HP-PRRSV to induce neutralizing antibody (NA) in vitro and in vivo, rabbit antisera against B AR with and without the mutation and pig hyperimmune sera with high titer of NAs against HP-PRRSV were prepared. Immunofluorescence assays (IFA) showed that the two rabbit antisera both had reactivity to classical PRRSV CH-1a and HP-PRRSV HuN4 with no observable difference in IFA titer. However, antisera did not have neutralizing activity against classical PRRSV CH-1a and HP-PRRSV HuN4. No correlation was observed between the levels of anti-B AR peptide antibodies and NAs in pig hyperimmune sera that were detected by indirect ELISA and virus neutralization, respectively. B AR peptide-specific serum antibodies had no neutralizing activity and, GST-B fusion protein could not inhibit neutralization of NAs in pig hyperimmune sera. Based on these findings, we conclude that B AR of HP-PRRSV is not a neutralizing AR of HP-PRRSV GP5. PMID:22771210

Leng, Chao-Liang; An, Tong-Qing; Chen, Jia-Zeng; Gong, Da-Qing; Peng, Jin-Mei; Yang, Yong-Qian; Wu, Jiang; Guo, Juan-Juan; Li, Deng-Yun; Zhang, Yi; Meng, Zhen-Xiang; Wu, Yu-Quan; Tian, Zhi-Jun; Tong, Guang-Zhi

2012-10-12

317

Reproduction in domestic buffalo.  

PubMed

The domestic buffalo is an indispensable livestock resource to millions of smallholder farmers in developing countries, particularly in Asia. Although its reproductive biology is basically similar to that of cattle, there are important differences and unique characteristics that need to be considered in order to apply modern reproductive technologies to improve its productivity. Under most smallholder production systems, the reproductive efficiency of buffalo is compromised by factors related to climate, management, nutrition and diseases. However, when managed and fed properly, buffalo can have good fertility and provide milk, calves and draught power over a long productive life. The basic technical problems associated with artificial insemination in buffalo were largely overcome two decades ago, but the technology has not had the expected impact in some developing countries, because largely of infrastructural and logistic problems. Approaches involving the use of hormones for treating anoestrus and for synchronizing oestrus have had varying rates of success, depending on the protocols used and the incidence of underlying problems that cause infertility. Embryo technologies such as multiple ovulation embryo transfer, in vitro embryo production, cryopreservation and cloning are being intensively studied but have had far lower success rates than in cattle. Improving the productivity of buffalo requires an understanding of their potential and limitations under each farming system, development of simple intervention strategies to ameliorate deficiencies in management, nutrition and healthcare, followed by judicious application of reproductive technologies that are sustainable with the resources available to buffalo farmers. PMID:18638124

Perera, B M A O

2008-07-01

318

High natural fusion rates in a botryllid ascidian  

Microsoft Academic Search

Many benthic colonial invertebrates have the ability to fuse and form chimeras with compatible colonies. Botryllid ascidians\\u000a are model organisms for the study of the evolution of and molecular basis for allorecognition, and fusion rates have been\\u000a determined for different populations and species by random sampling and fusion testing between individuals. However, natural\\u000a fusion rates over time have not been

Erica L. Westerman; Jennifer A. Dijkstra; Larry G. Harris

2009-01-01

319

High rate properties of porcine skull bone tissue  

NASA Astrophysics Data System (ADS)

Several recent studies have shown the importance of understanding the nature of blast injuries. Traditionally, the lungs and other air filled organs were the focus of these injuries but it is being discovered that some level of brain trauma may result after encountering a blast. These injuries are referred to as traumatic brain injuries, or TBI. There has been many clinical studies and statistical analyses done concerning these injuries, but there is still no physical understanding of the problem. In order to develop a model of how this injury can occur, rate dependent material properties of the tissues the stress wave will travel through are needed. In this study, the compressive response of porcine skull bone through the thickness direction was experimentally determined over a wide range of rates, ranging from 0.001 sec -1 to approximately 3000 sec-1. The results reveal that for most mechanical properties there is a clear rate dependence of the material. However, only one subset of the skull section appeared to have a rate dependent initial modulus, with the rest showing no significant statistical dependence on loading rate. Other mechanical properties appeared to be affected by the loading rate, including the strain energy density.

Herwig, Kyle Jeffry

320

Design and analysis of a high-rate acoustic link for underwater video transmission  

E-print Network

A high bit rate acoustic link for underwater video transmission is examined. Currently, encoding standards support video transmission at bit rates as low as 64 kbps. While this rate is still above the limit of commercially ...

Pelekanakis, Konstantinos

2004-01-01

321

High recombination rate in natural populations of Plasmodium falciparum  

PubMed Central

Malaria parasites are sexually reproducing protozoa, although the extent of effective meiotic recombination in natural populations has been debated. If meiotic recombination occurs frequently, compared with point mutation and mitotic rearrangement, linkage disequilibrium between polymorphic sites is expected to decline with increasing distance along a chromosome. The rate of this decline should be proportional to the effective meiotic recombination rate in the population. Multiple polymorphic sites covering a 5-kb region of chromosome 9 (the msp1 gene) have been typed in 547 isolates from six populations in Africa to test for such a decline and estimate its rate in populations of Plasmodium falciparum. The magnitude of two-site linkage disequilibrium declines markedly with increasing molecular map distance between the sites, reaching nonsignificant levels within a map range of 0.3–1.0 kb in five of the populations and over a larger map distance in the population with lowest malaria endemicity. The rate of decline in linkage disequilibrium over molecular map distance is at least as rapid as that observed in most chromosomal regions of other sexually reproducing eukaryotes, such as humans and Drosophila. These results are consistent with the effective recombination rate expected in natural populations of P. falciparum, predicted on the basis of the underlying molecular rate of meiotic crossover and the coefficient of inbreeding caused by self-fertilization events. This is conclusive evidence to reject any hypothesis of clonality or low rate of meiotic recombination in P. falciparum populations. Moreover, the data have major implications for the design and interpretation of population genetic studies of selection on P. falciparum genes. PMID:10200292

Conway, David J.; Roper, Cally; Oduola, Ayoade M. J.; Arnot, David E.; Kremsner, Peter G.; Grobusch, Martin P.; Curtis, Chris F.; Greenwood, Brian M.

1999-01-01

322

Sensitive, high-strain, high-rate bodily motion sensors based on graphene-rubber composites.  

PubMed

Monitoring of human bodily motion requires wearable sensors that can detect position, velocity and acceleration. They should be cheap, lightweight, mechanically compliant and display reasonable sensitivity at high strains and strain rates. No reported material has simultaneously demonstrated all the above requirements. Here we describe a simple method to infuse liquid-exfoliated graphene into natural rubber to create conducting composites. These materials are excellent strain sensors displaying 10(4)-fold increases in resistance and working at strains exceeding 800%. The sensitivity is reasonably high, with gauge factors of up to 35 observed. More importantly, these sensors can effectively track dynamic strain, working well at vibration frequencies of at least 160 Hz. At 60 Hz, we could monitor strains of at least 6% at strain rates exceeding 6000%/s. We have used these composites as bodily motion sensors, effectively monitoring joint and muscle motion as well and breathing and pulse. PMID:25100211

Boland, Conor S; Khan, Umar; Backes, Claudia; O'Neill, Arlene; McCauley, Joe; Duane, Shane; Shanker, Ravi; Liu, Yang; Jurewicz, Izabela; Dalton, Alan B; Coleman, Jonathan N

2014-09-23

323

A high-efficiency Transition Radiation Detector for high-counting-rate environments  

NASA Astrophysics Data System (ADS)

A prototype Transition Radiation Detector (TRD) with a new configuration was built and tested. The prototype consists of two individual multiwire proportional chambers (MWPC) that share a thin common central pad readout electrode. Measurements with a 55Fe source and e, ? and p of 1.5 GeV/ c showed a very good energy, position resolution and a better e/? discrimination compared to the standard structure with a single MWPC. No significant deterioration of the resolutions is observed up to counting rates of 2×105 particles cm-2 s-1. These results open the possibility of constructing TRDs with a high e/? discrimination and granularity even for high-counting rate experiments with a reasonable number of layers.

Petrovici, M.; Petri?, M.; Berceanu, I.; Simion, V.; Barto?, D.; C?t?nescu, V.; Herghelegiu, A.; M?gureanu, C.; Mois?, D.; Radu, A.; Klein-Bösing, M.; Wessels, J. P.; Wilk, A.; Andronic, A.; Garabatos, C.; Simon, R.; Uhlig, F.

2007-09-01

324

ABORTED FRUITS OF OPUNTIA MICRODASYS (CACTACEAE): INSURANCE AGAINST REPRODUCTIVE FAILURE  

E-print Network

ABORTED FRUITS OF OPUNTIA MICRODASYS (CACTACEAE): INSURANCE AGAINST REPRODUCTIVE FAILURE 1 N, but plantlet provenance did not. The high fruit abortion rate resulting from environmental and maternal effects provided suitable conditions for establishment of plantlets. Key words: clonal propagation; fruit abortion

Mandujano, María del Carmen

325

Effusion Rates from High Temporal, Low Spatial Resolution Sensors  

NASA Astrophysics Data System (ADS)

The effusion rate of a volcano can be a key indicator of the health and dynamics of the magma system. Often, it is hard to properly gauge or calculate an effusion rate from the ground; especially in the North Pacific, where reaching an erupting volcano is often cost prohibitive or logistically impossible. Satellite remote sensing provides the opportunity to calculate effusion rates at semi-regular intervals using the mid- and thermal-infrared sensor bands and some assumptions, primarily temperature of the lava and the area of the vent. Traditionally, effusion rates have been calculated using sensors with ~1 km or smaller spatial resolution (AVHRR, MODIS, etc). These sensors only tend to capture images of the north pacific ~5-10 times per day. This relatively infrequent temporal resolution can cause some time gaps in a data series. Geostationary sensors, like the GOES sensor, capture images of the North Pacific nearly every 15 minutes (about 90 images per day) at a spatial resolution of ~ 4 km. The tradeoff between coarser spatial resolution and tighter temporal resolution will help to fill in gaps of datasets created with only one type/resolution of sensor. The ability to use multiple sensors to calculate effusion rates will also increase the number of available tools for undertaking satellite based monitoring of volcanoes in remote regions. On May 13, 2013, Pavlof Volcano in Alaska began erupting beginning with a series of thermal anomalies seen in AVHRR data. The lava flows resulting from the eruption were visible in GOES a day later on May 14, 2013, indicating that the flows were likely spreading from the summit, and were hot, fresh lava (as opposed to a warm dome or subsurface heating). Veniaminof Volcano, just over 100 miles northeast of Pavlof, began erupting one month later on June 13, 2013. Veniaminof lava flows became visible in GOES data on the same day, only a few hours after the first thermal anomalies detected in AVHRR data, indicating that the lava flows began very soon after the initiation of activity. For both of these eruptions, UAF/GI remote sensing has an archive of all AVHRR and MODIS images as well as the ability to view GOES imagery as it is received. This allows for the effusion rates for all three sensors to be calculated, compared, and used to calibrate one another as a test of the ability to use coarse spatial resolution data to calculate accurate effusion rates at remote volcanoes. In general GOES data yields higher effusion rates due to its larger spatial resolution and the effect that has on the area assumption. The trends in effusion rate match well between sensors.

Worden, A. K.; Dehn, J.; Webley, P.

2013-12-01

326

High rate ECR etching of III-V nitride materials.  

National Technical Information Service (NTIS)

The III-V nitride compound semiconductors are attracting considerable attention for blue and ultraviolet light emitting diodes (LEDs) and lasers as well as high temperature electronics due to their wide band gaps and high dielectric constants. The recent ...

R. J. Shul, A. J. Howard, S. P. Kilcoyne, S. J. Pearton, C. R. Abernathy

1994-01-01

327

Compact, high-repetition-rate OPCPA system for high harmonic generation  

NASA Astrophysics Data System (ADS)

A compact, high-repetition rate optical parametric chirped pulse amplifier system emitting CEP-stable, few-cycle pulses with 10 ?J of pulse energy is reported for the purpose of high-order harmonic generation. The system is seeded from a commercially available, CEP-stabilized Ti:sapphire oscillator, delivering an octave-spanning spectrum from 600-1200 nm. The oscillator output serves on the one hand as broadband signal for the parametric amplification process and on the other hand as narrowband seed for an Ytterbium-based fiber preamplifier with subsequent main amplifiers and frequency doubling. Broadband parametric amplification up to 17 ?J at 200 kHz repetition rate was achieved in two 5 mm BBO crystals using non-collinear phase matching in the Poynting-vector-walk-off geometry. Efficient pulse compression down to 6.3 fs is achieved with chirped mirrors leading to a peak power exceeding 800 MW. We observed after warm-up time a stability of < 0.5 % rms over 100 min. Drifts of the CE-phase in the parametric amplifier part could be compensated by a slow feedback to the set point of the oscillator phase lock. The CEP stability was measured to be better than 80 mrad over 15 min (3 ms integration time). The experimentally observed output spectra and energies could be well reproduced by simulations of the parametric amplification process based on a (2+1)-dimensional nonlinear propagation code, providing important insight for future repetition rate scaling of OPCPA systems. The system is well-suited for attosecond science experiments which benefit from the high repetition rate. First results for high-order harmonic generation in argon will be presented.

Matyschok, Jan; Binhammer, Thomas; Lang, Tino; Prochnow, Oliver; Rausch, Stefan; Rudawski, Piotr; Harth, Anne; Miranda, Miguel; Guo, Chen; Lorek, Eleonora; Mauritsson, Johan; Arnold, Cord L.; L'Huillier, Anne; Morgner, Uwe

2014-03-01

328

High-power high-repetition-rate copper-vapor-pumped dye laser  

Microsoft Academic Search

The design and development of an efficient high average power dye laser oscillator-amplifier system developed at the Laser & Plasma Technology Division, Bhabha Atomic Research Center, is reported. The dye laser is pumped by a 6.5-kHz repetition rate copper vapor laser. The signal beam to the dye amplifier is obtained from an efficient narrow-band grazing incidence grating dye laser oscillator

Sunita Singh; Kamalesh Dasgupta; Sasi Kumar; K. G. Manohar; L. G. Nair; U. K. Chatterjee

1994-01-01

329

Social Rating of Best and Poorest High-school Students  

Microsoft Academic Search

This investigation queried whether (1) there are qualities in addition to intelligence which affect scholarship in high school, and (2) whether the best students do not also possess greater chances of post-school success. The subjects were 165 students of a small high school and the criteria of judgment the estimates of nine high school teachers who were personally acquainted with

P. V. Sangren

1923-01-01

330

Inclusive High Schools and Dropout Rates: A Phenomenological Approach  

ERIC Educational Resources Information Center

The purpose of the study was to examine the positive impact of inclusive high schools on high school students. Educators have expressed concern about the increasing number of high school dropouts and the alarming number of students between the ages of 16 and 24 who graduate without the skills or the knowledge to secure or maintain employment. An…

Holloway, Connie F.

2010-01-01

331

High rate science data handling on Space Station Freedom  

NASA Technical Reports Server (NTRS)

A study by NASA's User Information System Working Group for Space Station Freedom (SSF) has determined that the proposed onboard Data Management System, as initially configured, will be incapable of handling the data-generation rates typical of numerous scientific sensor payloads; many of these generate data at rates in excess of 10 Mbps, and there are at least four cases of rates in excess of 300 Mbps. The SSF Working Group has accordingly suggested an alternative conceptual architecture based on technology expected to achieve space-qualified status by 1995. The architecture encompasses recorders with rapid data-ingest capabilities and massive storage capabilities, optical delay lines allowing the recording of only the phenomena of interest, and data flow-compressing image processors.

Handley, Thomas H., Jr.; Masline, Richard C.

1990-01-01

332

Electrochemical corrosion rate probes for high temperature energy applications  

SciTech Connect

Electrochemical corrosion rate (ECR) probes were constructed and exposed along with mass loss coupons in a N2/O2/CO2/H2O environment to determine ECR probe operating characteristics. Temperatures ranged from 450 to 800 C and both ECR probes and mass loss coupons were coated with ash. Results are presented in terms of the probe response to temperature, the measured zero baseline, and the quantitative nature of the probes. The effect of Stern-Geary constant and the choice of electrochemical technique used to measure the corrosion rate are also discussed. ECR probe corrosion rates were a function of time, temperature, and process environment and were found to be quantitative for some test conditions. Measured Stern-Geary constants averaged 0.0141 V/decade and the linear polarization technique was found to be more quantitative than the electrochemical noise technique.

Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Cayard, M.S. (InterCorr International Inc.); Eden, D.A. (InterCorr International Inc.)

2004-01-01

333

Pioneer spacecraft operation at low and high spin rates  

NASA Technical Reports Server (NTRS)

The feasibility of executing major changes upward or downward from the nominal spin rate for which the Pioneer F&G spacecraft was designed was investigated along with the extent of system and subsystem modifications required to implement these mode changes in future spacecraft evolving from the baseline Pioneer F and G. Results of a previous study are re-examined and updated for an extended range of spin rate variations for missions that include outer planet orbiters, outer planet flyby and outer planet probe delivery. However, in the interest of design simplicity and cost economy, major modifications of the baseline Pioneer system and subsystem concept were avoided.

1973-01-01

334

The High Cost of South Carolina's Low Graduation Rate. School Choice Issues in the State  

ERIC Educational Resources Information Center

Research has documented a crisis in South Carolina's high school graduation rate. While state officials report a graduation rate above 70 percent, researchers from South Carolina and elsewhere place the rate just above 50 percent, with rates among minority students lower than 50 percent. South Carolina's graduation rate is the worst of all 50…

Gottlob, Brian J.

2007-01-01

335

High Bit Rate Continuous-Variable Quantum Key Distribution  

E-print Network

Here, we demonstrate that a practical Continuous Variables Quantum Key Distribution (CVQKD) protocol relying on the Gaussian modulation of coherent states features secret key rates that cannot be achieved with standard qubit Discrete Variables (DV) QKD protocols. Notably, we report for the first time a practical postprocessing that allows to extract more than one bit of secret key per channel use.

Paul Jouguet; David Elkouss; Sébastien Kunz-Jacques

2014-06-04

336

High-bit-rate continuous-variable quantum key distribution  

NASA Astrophysics Data System (ADS)

Here, we demonstrate that a practical continuous-variable quantum key distribution (QKD) protocol relying on the Gaussian modulation of coherent states features secret key rates that cannot be achieved with standard qubit discrete-variable QKD protocols. Notably, we report a practical postprocessing that allows us to extract more than 1 bit of secret key per channel use.

Jouguet, Paul; Elkouss, David; Kunz-Jacques, Sébastien

2014-10-01

337

Six Habits of the Highly Effective E-Rate Applicant  

ERIC Educational Resources Information Center

Since its inception in 1997, the Schools and Libraries Program of the Federal Communications Commission's Universal Service Fund, more commonly known as E-Rate, has committed more than $30 billion to offset the cost of certain digital and telecommunication services and products that are essential for schools and libraries to receive…

Harrington, John

2011-01-01

338

Laser balancing system for high material removal rates  

Microsoft Academic Search

A laser technique to remove material in excess of 10 mg\\/sec from a spinning rotor is described. This material removal rate is 20 times greater than previously reported for a surface speed of 30 m\\/sec. Material removal enhancement was achieved by steering a focused laser beam with moving optics to increase the time of laser energy interaction with a particular

M. G. Jones; G. Georgalas; A. L. Ortiz

1984-01-01

339

Asexual reproduction and anterior regeneration under high and low temperatures in the sponge associate Polydora colonia (Polychaeta: Spionidae)  

Microsoft Academic Search

Regeneration in polychaetes is an important process because of its role in recovery after injury and in asexual reproduction via architomy. This study examined architomy and regeneration in the spionid worm, Polydora colonia (Moore 1907) a symbiont of sponges. Based on collections of P. colonia from Long Island, New York, prevalence of architomy was 24% (188 out of 780 worms)

Andrew A. David; Jason D. Williams

2011-01-01

340

Fabrication of superconducting materials by high-energy - high-rate processing  

SciTech Connect

Techniques involving high energy-high rate processing were employed to fabricate superconducting materials. A homopolar generator (HPG), producing low voltage-high current electrical discharges of short duration, was used to consolidate powders through pulsed resistive heating, and a railgun, powered by a capacitor bank, was used to prepare thin films from source material accelerated electromagnetically to a substrate at ambient temperature. Bulk Nb-Ge samples formed by reactive sintering during the powder consolidation by the application of the HPG contain various phases (NbGe{sub 2}, Nb{sub 5}Ge{sub 3} and {beta}), and some evidence of Nb{sub 3}Ge exists. Thin films, synthesized by railgun deposition of Nb and Ge, contain hexagonal Nb{sub 5}Ge{sub 3}, as well as NbO{sub 2} and/or NbO and Nb particles in some cases, but Nb{sub 3}Ge is absent. Production of high-T{sub c} YBa{sub 2}Cu{sub 3}O{sub x} (123 compound) by conventional solid-state reaction and consolidation of this compound by high energy-high rate processing were examined under different experimental conditions. Calcining the precursor powders at 900{degree}C does not produce single-phase 123 compounds, whereas high-quality 123 phase forms on calcining at 925 and 950{degree}C. The best consolidated sample exhibits a resistive superconducting transition at 91.1 K with a transition width less than 1 K.

Lee, S.J.

1988-01-01

341

Lab Exercise #8 Reproductive Value "Reproductive value of an individual of age x is a measure of the extent to which it  

E-print Network

F&WL 501 Lab Exercise #8 ­ Reproductive Value "Reproductive value of an individual of age x ..." Schaffer 1974 (Ecology 55:291-303) Today's lab will review several ways of measuring reproductive value rates on optimal reproductive effort at a given age. Part A. Calculating Reproductive value Work

Rotella, Jay J.

342

Models of Evolution of Reproductive Isolation  

PubMed Central

Mathematical models are presented for the evolution of postmating and premating reproductive isolation. In the case of postmating isolation it is assumed that hybrid sterility or inviability is caused by incompatibility of alleles at one or two loci, and evolution of reproductive isolation occurs by random fixation of different incompatibility alleles in different populations. Mutations are assumed to occur following either the stepwise mutation model or the infinite-allele model. Computer simulations by using Itô's stochastic differential equations have shown that in the model used the reproductive isolation mechanism evolves faster in small populations than in large populations when the mutation rate remains the same. In populations of a given size it evolves faster when the number of loci involved is large than when this is small. In general, however, evolution of isolation mechanisms is a very slow process, and it would take thousands to millions of generations if the mutation rate is of the order of 10-5 per generation. Since gene substitution occurs as a stochastic process, the time required for the establishment of reproductive isolation has a large variance. Although the average time of evolution of isolation mechanisms is very long, substitution of incompatibility genes in a population occurs rather quickly once it starts. The intrapopulational fertility or viability is always very high. In the model of premating isolation it is assumed that mating preference or compatibility is determined by male- and female-limited characters, each of which is controlled by a single locus with multiple alleles, and mating occurs only when the male and female characters are compatible with each other. Computer simulations have shown that the dynamics of evolution of premating isolation mechanism is very similar to that of postmating isolation mechanism, and the mean and variance of the time required for establishment of premating isolation are very large. Theoretical predictions obtained from the present study about the speed of evolution of reproductive isolation are consistent with empirical data available from vertebrate organisms. PMID:6840540

Nei, Masatoshi; Maruyama, Takeo; Wu, Chung-I

1983-01-01

343

High School Attrition Rates Across Texas Education Service Center Regions  

ERIC Educational Resources Information Center

The examination of historical trend data on the number and percent of students lost from public school enrollment prior to graduation from high school is becoming increasingly important since distinct trends are emerging on a regional basis. This study examines regional trends in Texas on the number and percent of students lost from public high

Johnson, Roy

2008-01-01

344

A new high rate, fast charge, sealed, lead acid battery  

Microsoft Academic Search

A new approach to the design of lead acid batteries has been developed based on the use of very thin lead foil current collectors and very high current carrying capacity. The basic cell construction and the performance characteristics for the new cell are described. Spiral wrap cells based on this electrode concept exhibit extremely high power output with excellent capacity

T. Juergens; R. F. Nelson; M. A. Ruderman

1994-01-01

345

High Mortality Rate After Extubation Failure After Pediatric Cardiac Surgery  

Microsoft Academic Search

The objective of this study was to evaluate the different causes of extubation failure and the consequent mortality rates\\u000a in a pediatric population after cardiac surgery. We studied 184 consecutive patients with a median age of 9 months (range,\\u000a 0–165). In 158 patients, extubation was successful (group A). Nine patients were reintubated for upper airway obstruction\\u000a and finally extubated successfully

A. D. J. Ten Harkel; M. M. J. van der Vorst; M. G. Hazekamp; J. Ottenkamp

2005-01-01

346

High strain-rate plastic flow in Al and Fe  

NASA Astrophysics Data System (ADS)

Thin Fe and Al foils were ramp-compressed over several to tens of ns timescales to study the time-dependence associated with the onset of plastic flow. Peak stress states of 15-200 GPa were achieved through laser ramp-compression where the strain rate was varied, shot-to-shot, between 106 to 108 s-1. Our data combined with data from other dynamic compression platforms reveals a strong correlation between the peak elastic precursor stress, ?E, and the strain rate at the onset of plastic flow, ?.p. In fcc Al, phonon drag dislocation flow dominates above ?.p~103s-1 and ?E ˜ 0.03 GPa where ?E scales as ?.p0.43. By contrast, the Al alloy 6061-T6 exhibits a relatively weak dependency of ?E with ?.p up to strain rates of ˜107 s-1. Our Fe data, reveals a sharp increase in ?E at ?.p>5×106s-1. This is consistent with a transition in plastic flow to a phonon drag regime.

Smith, R. F.; Eggert, J. H.; Rudd, R. E.; Swift, D. C.; Bolme, C. A.; Collins, G. W.

2011-12-01

347

High temperature electronic excitation and ionization rates in gases  

NASA Technical Reports Server (NTRS)

The relaxation times for electronic excitation due to electron bombardment of atoms was found to be quite short, so that electron kinetic temperature (T sub e) and the electron excitation temperature (T asterisk) should equilibrate quickly whenever electrons are present. However, once equilibrium has been achieved, further energy to the excited electronic states and to the kinetic energy of free electrons must be fed in by collisions with heavy particles that cause vibrational and electronic state transitions. The rate coefficients for excitation of electronic states produced by heavy particle collision have not been well known. However, a relatively simple semi-classical theory has been developed here which is analytic up to the final integration over a Boltzmann distribution of collision energies; this integral can then be evaluated numerically by quadrature. Once the rate coefficients have been determined, the relaxation of electronic excitation energy can be evaluated and compared with the relaxation rates of vibrational excitation. Then the relative importance of these two factors, electronic excitation and vibrational excitation by heavy particle collision, on the transfer of energy to free electron motion, can be assessed.

Hansen, Frederick

1991-01-01

348

Comparison of RBE values of high- LET ?-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death  

PubMed Central

Background Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues, e.g. DNA double strand breaks (DSB), chromosome aberrations and cell reproductive inactivation. However, variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy: the Relative Biological Effectiveness (RBE) for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. Methods To evaluate relationships between DNA-DSB, chromosome aberrations and the clinically most relevant effect of cell reproductive death, for ionizing radiations of different LET, dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with ?-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci (IRIF) of DNA repair related proteins, indicative of DSB, were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Results Our results show that, although both investigated radiation types induce similar numbers of IRIF per absorbed dose, only a small fraction of the DSB induced by the low-LET gamma-rays result in chromosome rearrangements and cell reproductive death, while this fraction is considerably enhanced for the high-LET alpha-radiation. Calculated RBE values derived for the linear components of dose-effect relations for gamma-H2AX foci, cell reproductive death, chromosome fragments and colour junctions are 1.0 ± 0.3, 14.7 ± 5.1, 15.3 ± 5.9 and 13.3 ± 6.0 respectively. Conclusions These results indicate that RBE values for IRIF (DNA-DSB) induction provide little valid information on other biologically-relevant end points in cells exposed to high-LET radiations. Furthermore, the RBE values for the induction of the two types of chromosome aberrations are similar to those established for cell reproductive death. This suggests that assays of these aberrations might yield relevant information on the biological effectiveness in high-LET radiotherapy. PMID:21651780

2011-01-01

349

High strength semi-active energy absorbers using shear- and mixedmode operation at high shear rates  

NASA Astrophysics Data System (ADS)

This body of research expands the design space of semi-active energy absorbers for shock isolation and crash safety by investigating and characterizing magnetorheological fluids (MRFs) at high shear rates ( > 25,000 1/s) under shear and mixed-mode operation. Magnetorheological energy absorbers (MREAs) work well as adaptive isolators due to their ability to quickly and controllably adjust to changes in system mass or impact speed while providing fail-safe operation. However, typical linear stroking MREAs using pressure-driven flows have been shown to exhibit reduced controllability as impact speed (shear rate) increases. The objective of this work is to develop MREAs that improve controllability at high shear rates by using pure shear and mixed shear-squeeze modes of operation, and to present the fundamental theory and models of MR fluids under these conditions. A proof of concept instrument verified that the MR effect persists in shear mode devices at shear rates corresponding to low speed impacts. This instrument, a concentric cylinder Searle cell magnetorheometer, was then used to characterize three commercially available MRFs across a wide range of shear rates, applied magnetic fields, and temperatures. Characterization results are presented both as flow curves according to established practice, and as an alternate nondimensionalized analysis based on Mason number. The Mason number plots show that, with appropriate correction coefficients for operating temperature, the varied flow curve data can be collapsed to a single master curve. This work represents the first shear mode characterization of MRFs at shear rates over 10 times greater than available with commercial rheometers, as well as the first validation of Mason number analysis to high shear rate flows in MRFs. Using the results from the magnetorheometer, a full scale rotary vane MREA was developed as part of the Lightweight Magnetorheological Energy Absorber System (LMEAS) for an SH-60 Seahawk helicopter crew seat. Characterization tests were carried out on the LMEAS using a 40 vol% MRF used in the previous magnetorheometer tests. These were analyzed using both flow curves and apparent viscosity vs. Mason number diagrams. The nondimensionalized Mason number analysis resulted in data for all conditions of temperature, fluid composition, and shear rate, to collapse onto a single characteristic or master curve. Significantly, the temperature corrected Mason number results from both the bench top magnetorheometer and full scale rotary vane MREA collapse to the same master curve. This enhances the ability of designers of MRFs and MREAs to safely and effectively apply characterization data collected in low shear rate, controlled temperature environments to operational environments that may be completely different. Finally, the Searle cell magnetorheometer was modified with an enforced eccentricity to work in both squeeze and shear modes simultaneously to achieve so called squeeze strengthening of the working MRF, thereby increasing the apparent yield stress and the specific energy absorption. By squeezing the active MR fluid, particles undergo compression-assisted aggregation into stronger, more robust columns which resist shear better than single chains. A hybrid model describing the squeeze strengthening behavior is developed, and recommendations are made for using squeeze strengthening to improve practical MREA devices.

Becnel, Andrew C.

350

Terminal Investment: Individual Reproduction of Ant Queens Increases with Age  

PubMed Central

The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the number of workers caring for them was kept constant. Cardiocondyla, and probably also other ants, therefore resemble the few select organisms with similar age-specific reproductive investment, such as corals, sturgeons, or box turtles (e.g., [1]), but they differ in being more short-lived and lacking individual, though not social, indeterminate growth. Furthermore, in contrast to most other organisms, in which average life span declines with increasing reproductive effort, queens with high egg laying rates survived as long as less fecund queens. PMID:22509399

Heinze, Jurgen; Schrempf, Alexandra

2012-01-01

351

Redefining reproductive surgery.  

PubMed

With the availability of and improvements in in vitro fertilization (IVF), the role of reproductive surgery has been questioned. Yet, the scope of reproductive surgery today is much larger than in the past. Hysteroscopic correction of intrauterine disease is an important endoscopic procedure in women with infertility. Evidence suggests that correction of intrauterine disease is often followed by spontaneous pregnancy and improved IVF outcome. Hysteroscopic examination should be considered after 1 failed IVF. Today, it is clear that removal of the hydrosalpinx leads to a higher IVF-related live birth rate. The procedure should be performed thoroughly without compromising the ovarian blood supply. The IVF pregnancy rate is not affected by the presence of ovarian endometriomas, and small endometriomas need not be removed; however, large and symptomatic endometriomas that interfere with oocyte retrieval should be excised. When excision of the cyst wall is difficult, fenestration and ablation should be considered. This might lead to an increased recurrence rate, but is associated with less interference of the ovarian reserve. Although the role of reproductive surgery as primary treatment for tuboperitoneal infertility is limited, it has an important role in enhancing the outcome of IVF treatment and in preservation of fertility. Surgical preservation of fertility consists of ovarian suspension, ovarian excision for cryopreservation, and ovarian tissue transplantation. PMID:22348901

Tulandi, Togas; Marzal, Alicia

2012-01-01

352

Finite Rate Chemistry Effects in Highly Sheared Turbulent Premixed Flames  

Microsoft Academic Search

Detailed scalar structure measurements of highly sheared turbulent premixed flames stabilized on the piloted premixed jet\\u000a burner (PPJB) are reported together with corresponding numerical calculations using a particle based probability density function\\u000a (PDF) method. The PPJB is capable of stabilizing highly turbulent premixed jet flames through the use of a small stoichiometric\\u000a pilot that ensures initial ignition of the jet

Matthew J. Dunn; Assaad R. Masri; Robert W. Bilger; Robert S. Barlow

2010-01-01

353

High Rate of Sexual Dysfunction Following Surgery for Rectal Cancer  

PubMed Central

Purpose Although rectal cancer is a very common malignancy and has an improved cure rate in response to oncological treatment, research on rectal-cancer survivors' sexual function remains limited. Sexual dysfunction (SD) after rectal cancer treatment was measured, and possible predisposing factors that may have an impact on the development of this disorder were identified. Methods Patients undergoing curative rectal cancer surgery from January 2012 to September 2013 were surveyed using questionnaires. The female sexual function index or the International Index of Erectile Function was recorded. A multiple logistic regression was used to test associations of clinical factors with outcomes. Results Fifty-six men (56%) and 28 women (44%) who completed the questionnaire were included in the study. A total of 76 patients of the 86 patients (90.5%) with the diagnosis of rectal cancer who were included in this study reported different levels of SD after radical surgery. A total of 64 patients (76%) from the whole cohort reported moderate to severe SD after treatment of rectal cancer. Gender (P = 0.011) was independently associated with SD. Female patients reported significantly higher rates of moderate to severe SD than male patients. Patients were rarely treated for dysfunction. Conclusion Sexual problems after surgery for rectal cancer are common, but patients are rarely treated for SD. Female patients reported higher rates of SD than males. These results point out the importance of sexual (dys)function in survivors of rectal cancer. More attention should be drawn to this topic for clinical and research purposes. PMID:25360427

Ertekin, Caglar; Tinay, Ilker; Yegen, Cumhur

2014-01-01

354

Comparison of traditional low-dose-rate to optimized and nonoptimized high-dose-rate tandem and ovoid dosimetry  

Microsoft Academic Search

Purpose: Few dose specification guidelines exist when attempting to perform high-dose-rate (HDR) dosimetry. The purpose of this study was to model low-dose-rate (LDR) dosimetry, using parameters common in HDR dosimetry, to achieve the “pear-shape” dose distribution achieved with LDR tandem and ovoid applications.Methods and Materials: Radiographs of Fletcher-Suit LDR applicators and Nucletron “Fletcher-like” HDR applicators were taken with the applicators

William E Decker; Beth Erickson; Katherine Albano; Michael Gillin

2001-01-01

355

Mechanical model for yield strength of nanocrystalline materials under high strain rate loading  

Microsoft Academic Search

To understand the high strain rate deformation mechanism and determine the grain size, strain rate and porosity dependent\\u000a yield strength of nanocrystalline materials, a new mechanical model based on the deformation mechanism of nanocrystalline\\u000a materials under high strain rate loading was developed. As a first step of the research, the yield behavior of the nanocrystalline\\u000a materials under high strain rate

Rong-tao Zhu; Jian-qiu Zhou; Lu Ma; Zhen-zhong Zhang

2008-01-01

356

Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources.  

PubMed

In this Letter, we report on the efficient generation of electrons from metals using multiphoton photoemission by use of nanostructured plasmonic surfaces to trap, localize, and enhance optical fields. The plasmonic surface increases absorption over normal metals by more than an order of magnitude, and due to the localization of fields, this results in over 6 orders of magnitude increase in effective nonlinear quantum yield. We demonstrate that the achieved quantum yield is high enough for use in rf photoinjectors operating as electron sources for MHz repetition rate x-ray free electron lasers. PMID:25166390

Polyakov, A; Senft, C; Thompson, K F; Feng, J; Cabrini, S; Schuck, P J; Padmore, H A; Peppernick, S J; Hess, W P

2013-02-15

357

High power high repetition rate VCSEL array side-pumped pulsed blue laser  

NASA Astrophysics Data System (ADS)

High power, kW-class, 808 nm pump modules based on the vertical-cavity surface-emitting laser (VCSEL) technology were developed for side-pumping of solid-state lasers. Two 1.2 kW VCSEL pump modules were implemented in a dual side-pumped Q-switched Nd:YAG laser operating at 946 nm. The laser output was frequency doubled in a BBO crystal to produce pulsed blue light. With 125 ?s pump pulses at a 300 Hz repetition rate 6.1 W QCW 946 nm laser power was produced. The laser power was limited by thermal lensing in the Nd:YAG rod.

van Leeuwen, Robert; Zhao, Pu; Chen, Tong; Xu, Bing; Watkins, Laurence; Seurin, Jean-Francois; Xu, Guoyang; Miglo, Alexander; Wang, Qing; Ghosh, Chuni

2013-03-01

358

Brachytherapy: current status and future strategies -- can high dose rate replace low dose rate and external beam radiotherapy?  

PubMed

Brachytherapy delivers the most conformal high dose radiotherapy possible to the prostate, using either a low dose rate (LDR) or high dose rate (HDR) technique. It may be used either alone as monotherapy or in combination with external beam radiotherapy (EBRT) as a local boost. Comparative efficacy studies, including one randomised controlled trial, consistently show higher cancer control rates when brachytherapy is used compared with EBRT alone, with even some evidence of improvement in survival. There are now extensive mature data supporting the use of LDR as monotherapy for patients with low-risk and selected intermediate-risk disease, with most series reporting long-term disease control rates of over 90% after high-quality implants. HDR is most commonly combined with EBRT to treat intermediate- and high-risk disease, with disease control rates of over 90% reported. The low alpha/beta ratio of prostate cancer combined and the ability to optimally sculpt dose distribution provides the biological and dosimetric rationale for HDR. HDR enables more consistent implant quality than LDR, with evidence of lower acute and late toxicity. Many dose and fractionation schedules of HDR in combination with EBRT have been investigated, but a single fraction of 10-15 Gy is commonly combined with EBRT to a dose of 40-50 Gy to treat intermediate- and high-risk disease. High disease control rates are also reported with HDR as monotherapy, particularly in patients with low- and intermediate-risk disease. Although older series have delivered four to six fractions of HDR, there is growing evidence to support the delivery of HDR in three or even two fractions. Single-fraction HDR monotherapy is now being investigated and if early data are confirmed with longer follow-up, may well become the treatment of choice for many men with localised prostate cancer. PMID:23727431

Morton, G C; Hoskin, P J

2013-08-01

359

Adolescent health in Milwaukee: High rates of teenage pregnancy  

E-print Network

school students must pass one class of health education to graduate Project Health (PH) is, and ­ Center for Urban Population Health · The project developed a new high school health education curriculum centered on constructivist and project-based learning theories Goal of PH is: · To test a new project-based

360

Do Ubiquitous Laptop Initiatives Decrease the High School Dropout Rate?  

ERIC Educational Resources Information Center

In 2007, Mooresville Graded School District developed a strategic plan to infuse twenty-first-century learning skills into the schools by providing staff and students in grades four through twelve with a laptop computer. In late fall of 2007, Mooresville High School deployed laptops to all certified staff and to the entire student body in the…

Basham, Misty Dawn

2012-01-01

361

Attenuation characteristics of high rate home-networking PLC signals  

Microsoft Academic Search

This paper reports an experimental investigation of the influence of the high-frequency (HF) signal attenuation on the load in residences and offices. A laboratory test and actual measurements were performed in a residence and an office. The experiments show that the attenuation characteristics are more dependent on the number of loads than the type of loads connected. In addition, the

Charles J. Kim; Mohamed F. Chouikha

2002-01-01

362

Laser balancing system for high material removal rates  

NASA Technical Reports Server (NTRS)

A laser technique to remove material in excess of 10 mg/sec from a spinning rotor is described. This material removal rate is 20 times greater than previously reported for a surface speed of 30 m/sec. Material removal enhancement was achieved by steering a focused laser beam with moving optics to increase the time of laser energy interaction with a particular location on the circumferential surface of a spinning rotor. A neodymium:yttrium aluminum garnet (Nd:YAG) pulse laser was used in this work to evaluate material removal for carbon steel, 347 stainless steel, Inconal 718, and titanium 6-4. This technique is applicable to dynamic laser balancing.

Jones, M. G.; Georgalas, G.; Ortiz, A. L.

1984-01-01

363

Development of high brightness, high repetition rate photoelectron injectors at STFC Daresbury Laboratory  

NASA Astrophysics Data System (ADS)

Accelerator drivers for Energy Recovery Linac (ERL) and Free-Electron Laser (FEL) based light sources demand electron injectors which deliver high brightness bunches on the several hundreds of picocoulomb scale, at repetition rates between 1 MHz and 1 GHz (or higher), corresponding to an average current between 0.1 and 100 mA. Simultaneous satisfaction of these injector requirements is considerably beyond the current state-of-the-art. Daresbury Laboratory is concentrating efforts on the development of high average current III-V and XnY3-nSb photocathode-based DC and SRF photocathode guns for ERL applications. The ultimate goal of this research is their integration with the ALICE ERL.

Militsyn, B. L.; Burrows, I.; Cash, R. J.; Chanlek, N.; Fell, B. D.; Jones, L. B.; Kosolobov, S. N.; McKenzie, J. W.; Middleman, K. J.; Scheibler, H. E.; Terekhov, A. S.

2011-05-01

364

High-power, high repetition-rate, green-pumped, picosecond LBO optical parametric oscillator.  

PubMed

We report on a picosecond, green-pumped, lithium triborate optical parametric oscillator with record-high output power. It was synchronously pumped by a frequency-doubled (530 nm), pulse-compressed (4.4 ps), high-repetition-rate (230 MHz), fiber-amplified gain-switched laser diode. For a pump power of 17 W, a maximum signal and idler power of 3.7 W and 1.8 W was obtained from the optical parametric oscillator. A signal pulse duration of ~3.2 ps was measured and wide tunability from 651 nm to 1040 nm for the signal and from 1081 nm to 2851 nm for the idler was achieved. PMID:22453380

Kienle, Florian; Teh, Peh Siong; Lin, Dejiao; Alam, Shaif-Ul; Price, Jonathan H V; Hanna, D C; Richardson, David J; Shepherd, David P

2012-03-26

365

Evolution of Population with Sexual and Asexual Reproduction in Changing Environment  

NASA Astrophysics Data System (ADS)

Using a lattice model based on Monte Carlo simulations, we study the role of the reproduction pattern on the fate of an evolving population. Each individual is under the selection pressure from the environment and random mutations. The habitat ("climate") is changing periodically. Evolutions of populations following two reproduction patterns are compared, asexual and sexual. We show, via Monte Carlo simulations, that sexual reproduction by keeping more diversified populations gives them better chances to adapt themselves to the changing environment. However, in order to obtain a greater chance to mate, the birth rate should be high. In the case of low birth rate and high mutation probability there is a preference for the asexual reproduction.

He, Mingfeng; Yu, Changliang; Ruan, Hongbo; Yao, Lei

366

An overview of male reproductive studies of boron with an emphasis on studies of highly exposed Chinese workers  

Microsoft Academic Search

Boron treatment of rats, mice, and dogs has been associated with testicular toxicity, characterized by inhibited spermiation at lower dose levels and a reduction in epididymal sperm count at higher dose levels. The no-adverse-effect level for reproductive effects in male rats is 17.5mg B\\/kg bw\\/day. Earlier studies in human workers and populations have not identified adverse effects of boron exposure

Anthony R. Scialli; Jens Peter Bonde; Irene Brüske-Hohlfeld; B. Dwight Culver; Yanhong Li; Frank M. Sullivan

2010-01-01

367

Ray-based and wavefront-based holographic displays for high-density light-field reproduction  

Microsoft Academic Search

This paper introduces holographic 3D displays for ray-based and wavefront-based light-field reproductions. As a raybased display though a hard copy 3D image, a holographic 3D printer is introduced, which automatically outputs highresolution full-parallax holographic stereograms from 3D image data. Fine-quality full-color 3D images were experimentally obtained with excellent gloss and texture appearances. As a wavefront-based display, we have proposed a

Masahiro Yamaguchi

2011-01-01

368

Reproduction in chinchilla (Chinchilla lanigera): current status of environmental control of gonadal activity and advances in reproductive techniques.  

PubMed

A review of the biology of reproduction of chinchilla, focusing on environmental control of the gonadal activity, is presented. Chinchilla is a South American hystricomorph rodent genus currently considered almost extinct in the wild. However, a domestic form is still widespread in breeding farms around the world. Information regarding their reproductive biology has been obtained from studies on captive animals. In the case of Chinchilla lanigera, a seasonal reproductive pattern has been frequently reported in breeding facilities, but factors that might trigger gonadal activity have not been identified. The available information on reproductive productivity in farms worldwide shows a range of 1.2 to 2.4 deliveries per female per yr (with up to 2.1 weaned young per female per yr). Indeed, as found in all rodents, chinchillas can multiply at high fecundity and fertility rates (4 to 6 follicles mature during estrous cycles). Some new research avenues are postulated to improve the control of gonadal activity by means of environmental and/or pharmacologic factors. Furthermore, reproductive techniques that have been validated in chinchilla are reviewed (noninvasive hormone monitoring, semen collection, sperm cryopreservation, estrus induction), and several technical steps are proposed to be able to achieve AI. Because domesticated chinchilla still share some genomic characteristics with their counterparts in the wild, validated reproductive techniques in chinchilla males and females might contribute to the success of breeding programs. PMID:22541170

Busso, J M; Ponzio, M F; Fiol de Cuneo, M; Ruiz, R D

2012-07-01

369

High Efficiency Power Combining of Ka-Band TWTs for High Data Rate Communications  

NASA Technical Reports Server (NTRS)

Future NASA deep space exploration missions are expected in some cases to require telecommunication systems capable of operating at very high data rates (potentially 1 Gbps or more) for the transmission back to Earth of large volumes of scientific data, which means high frequency transmitters with large bandwidth. Among the Ka band frequencies of interest are the present 500 MHz Deep Space Network (DSN) band of 31.8 to 32.3 GHz and a broader band at 37-38 GHz allocated for space science [1]. The large distances and use of practical antenna sizes dictate the need for high transmitter power of up to 1 kW or more. High electrical efficiency is also a requirement. The approach investigated by NASA GRC is a novel wave guide power combiner architecture based on a hybrid magic-T junction for combining the power output from multiple TWTs [1,2]. This architecture was successfully demonstrated and is capable of both high efficiency (90-95%, depending on frequency) and high data rate transmission (up to 622 Mbps) in a two-way power combiner circuit for two different pairs of Ka band TWTs at two different frequency bands. One pair of TWTs, tested over a frequency range of 29.1 to 29.6 GHz, consisted of two 110-115W TWTs previously used in uplink data transmission evaluation terminals in the NASA Advanced Communications Technology Satellite (ACTS) program [1,2]. The second pair was two 100W TWTs (Boeing 999H) designed for high efficiency operation (greater than 55%) over the DSN frequency band of 31.8 to 32.3 GHz [3]. The presentation will provide a qualitative description of the wave guide circuit, results for power combining and data transmission measurements, and results of computer modeling of the magic-T and alternative hybrid junctions for improvements in efficiency and power handling capability. The power combiner results presented here are relevant not only to NASA deep space exploration missions, but also to other U.S. Government agency programs.

Wintucky, E. G.; Simons, R. N.; Vaden, K. R.; Lesny, G. G.; Glass, J. L.

2006-01-01

370

High Suspension Schools and Dropout Rates for Black and White Students  

ERIC Educational Resources Information Center

This study examined the association between school suspension rates and dropout rates in a statewide sample of 289 Virginia public high schools. The contribution of suspension rates on dropout rates was examined for both Black and White students, after controlling for school demographics (school racial composition, percentage of students eligible…

Lee, Talisha; Cornell, Dewey; Gregory, Anne; Fan, Xitao

2011-01-01

371

Modeling the concentration-response function of the herbicide dinoseb on Daphnia magna (survival time, reproduction) and Pseudokirchneriella subcapitata (growth rate).  

PubMed

Models describing dose-response relationships are becoming increasingly popular in ecotoxicology. They allow simple and thorough evaluations of toxicity test results, including inter- and extrapolations to concentrations or exposure times other than those tested. Simple parametric regression models are of particular interest because their parameters may be attributed mechanistic meanings and they can be applied without sophisticated mathematical and computational support. We recently proposed a four-parameter logistic regression model to fit the survival data of Daphnia magna under dinoseb stress. The model parameters are the maximum survival time, the minimum time required for an individual to die, effect concentration, EC(50), and a curve shape parameter. This model has now been applied to compare the lethality and reproduction toxicity of D. magna and the growth inhibition of Pseudokirchneriella subcapitata under dinoseb stress. It can be fitted adequately to all the measured data and the parameters can be attributed biological meanings in any of the three endpoints. A comparison of the modeled concentration-response functions of all three endpoints for dinoseb toxicity shows that the range of ECs with respect to both D. magna and algae is steep (a decrease of between 0.1 and 0.6 mg/L). The survival and reproduction of D. magna exhibit similar characteristic concentration-response functions and toxicities. The statistical no-effect concentration (SNEC) is 0.14 (survival) and 0.11 (reproduction)mg/L, respectively. On the other hand, algae seem to be less sensitive to dinoseb than D. magna (SNEC: 0.48 mg/L). However, further investigations of individual algae may lead to a more suitable comparison. We speculate that the four parameters of the model function can be related to specific properties of chemicals and organisms. Characterization of these properties would allow simple and appropriate estimation of the toxic effects of these chemicals. PMID:15978287

Chèvre, Nathalie; Brazzale, Alessandra R; Becker-van Slooten, Kristin; Behra, Renata; Tarradellas, Joseph; Guettinger, Herbert

2005-09-01

372

Unisexual Reproduction Reverses Muller's Ratchet.  

PubMed

Cryptococcus neoformans is a pathogenic basidiomycetous fungus that engages in outcrossing, inbreeding, and selfing forms of unisexual reproduction as well as canonical sexual reproduction between opposite mating types. Long thought to be clonal, >99% of sampled environmental and clinical isolates of C. neoformans are MAT?, limiting the frequency of opposite mating-type sexual reproduction. Sexual reproduction allows eukaryotic organisms to exchange genetic information and shuffle their genomes to avoid the irreversible accumulation of deleterious changes that occur in asexual populations, known as Muller's ratchet. We tested whether unisexual reproduction, which dispenses with the requirement for an opposite mating-type partner, is able to purge the genome of deleterious mutations. We report that the unisexual cycle can restore mutant strains of C. neoformans to wild-type genotype and phenotype, including prototrophy and growth rate. Furthermore, the unisexual cycle allows attenuated strains to purge deleterious mutations and produce progeny that are returned to wild-type virulence. Our results show that unisexual populations of C. neoformans are able to avoid Muller's ratchet and loss of fitness through a unisexual reproduction cycle involving ?-? cell fusion, nuclear fusion, and meiosis. Similar types of unisexual reproduction may operate in other pathogenic and saprobic eukaryotic taxa. PMID:25217049

Roach, Kevin C; Heitman, Joseph

2014-11-01

373

Magnetic accretion in high-accretion rate polars  

NASA Astrophysics Data System (ADS)

The spectral components of polars -- strongly magnetic CVs -- were barely disentangled by previous X-ray missions. The physics of accretion in a strongly magnetic, non-relativistic environment is therefore still puzzling. XMM-Newton, in principle, can solve the riddle. But even in its 7th year, only one of the bright, classical polars was observed in a high accretion state by XMM-Newton. We propose a triggered observation of a further such system. We will investigate the physics of the hard X-ray emitting shock, the heated accretion pole cap, the atmosphere of the white dwarf, the absorption in the shock and in the flow, the lines in the accretion flow and the reflection from the white dwarf by phase-resolved CCD- and RGS-spectroscopy and by high-speed OM-photometry.

Schwope, Axel

2007-10-01

374

Superplastic forming at high strain rates after severe plastic deformation  

Microsoft Academic Search

An Al-3% Mg-0.2% Sc alloy was fabricated by casting and subjected to severe plastic deformation through equal-channel angular pressing to a strain of ?8. The grain size after pressing was ?0.2 ?m and increased to ?1.1 ?m when holding at 673 K for 10 min. Very high tensile elongations were recorded at 673 K with a maximum elongation of ?2280%

Z Horita; M Furukawa; M Nemoto; A. J Barnes; T. G Langdon

2000-01-01

375

The next generation high data rate VCSEL development at SEDU  

NASA Astrophysics Data System (ADS)

In May of 2012, Emcore's VCSEL FAB and VCSEL based transceiver business joined Sumitomo Electric Device Innovations USA (SEDU). After this change of ownership, our high speed VCSEL development effort continues. In this paper, we will report the progress we made in the past year in our 25Gbps to 28Gbps VCSEL. This next generation device is targeted for EDR, 32GFC as well as other optical interconnect applications.

Xie, Chuan; Li, Neinyi; Huang, Shenghong; Liu, Chiyu; Wang, Li; Jackson, Kenneth P.

2013-03-01

376

Can rising housing prices explain China’s high household saving rate?  

Microsoft Academic Search

China’s average household saving rate is one of the highest in the world. One popular view attributes the high saving rate to fast rising housing prices and other costs of living in China. This article uses simple economic logic to show that rising housing prices and living costs per se cannot explain China’s high household saving rate. Although borrowing constraints

Xin Wang; Yi Wen

2010-01-01

377

14 CFR 63.20 - Applications, certificates, logbooks, reports, and records; falsification, reproduction, or...  

Code of Federal Regulations, 2010 CFR

...reports, and records; falsification, reproduction, or alteration. 63.20 Section...reports, and records; falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2010-01-01

378

14 CFR 63.20 - Applications, certificates, logbooks, reports, and records; falsification, reproduction, or...  

...reports, and records; falsification, reproduction, or alteration. 63.20 Section...reports, and records; falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2014-01-01

379

14 CFR 65.20 - Applications, certificates, logbooks, reports, and records: Falsification, reproduction, or...  

...reports, and records: Falsification, reproduction, or alteration. 65.20 Section...reports, and records: Falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2014-01-01

380

14 CFR 63.20 - Applications, certificates, logbooks, reports, and records; falsification, reproduction, or...  

Code of Federal Regulations, 2011 CFR

...reports, and records; falsification, reproduction, or alteration. 63.20 Section...reports, and records; falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2011-01-01

381

14 CFR 65.20 - Applications, certificates, logbooks, reports, and records: Falsification, reproduction, or...  

Code of Federal Regulations, 2012 CFR

...reports, and records: Falsification, reproduction, or alteration. 65.20 Section...reports, and records: Falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2012-01-01

382

14 CFR 63.20 - Applications, certificates, logbooks, reports, and records; falsification, reproduction, or...  

Code of Federal Regulations, 2012 CFR

...reports, and records; falsification, reproduction, or alteration. 63.20 Section...reports, and records; falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2012-01-01

383

14 CFR 65.20 - Applications, certificates, logbooks, reports, and records: Falsification, reproduction, or...  

Code of Federal Regulations, 2011 CFR

...reports, and records: Falsification, reproduction, or alteration. 65.20 Section...reports, and records: Falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2011-01-01

384

14 CFR 63.20 - Applications, certificates, logbooks, reports, and records; falsification, reproduction, or...  

Code of Federal Regulations, 2013 CFR

...reports, and records; falsification, reproduction, or alteration. 63.20 Section...reports, and records; falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2013-01-01

385

14 CFR 65.20 - Applications, certificates, logbooks, reports, and records: Falsification, reproduction, or...  

Code of Federal Regulations, 2013 CFR

...reports, and records: Falsification, reproduction, or alteration. 65.20 Section...reports, and records: Falsification, reproduction, or alteration. (a) No person...rating under this part; (3) Any reproduction, for fraudulent purpose, of any...

2013-01-01

386

High-rate carburizing in a glow discharge methane plasma  

Microsoft Academic Search

Carburizing at high temperature (1040?C) in a glow-discharge methane plasma signifi-cantly reduces carburizing time. Sufficient\\u000a carbon to produce a 1.0 mm case on conven-tional carburizing steels can be introduced in 10 min at methane pressures in the\\u000a range of 1.3 to 2.7 kPa (10 to 20 Torr). To reduce the carbon concentration at the surface to an acceptable level (007E1.0

William L. Grube; Jack G. Gay

1978-01-01

387

Global warming and reproductive health.  

PubMed

The largest absolute numbers of maternal deaths occur among the 40-50 million women who deliver annually without a skilled birth attendant. Most of these deaths occur in countries with a total fertility rate of greater than 4. The combination of global warming and rapid population growth in the Sahel and parts of the Middle East poses a serious threat to reproductive health and to food security. Poverty, lack of resources, and rapid population growth make it unlikely that most women in these countries will have access to skilled birth attendants or emergency obstetric care in the foreseeable future. Three strategies can be implemented to improve women's health and reproductive rights in high-fertility, low-resource settings: (1) make family planning accessible and remove non-evidenced-based barriers to contraception; (2) scale up community distribution of misoprostol for prevention of postpartum hemorrhage and, where it is legal, for medical abortion; and (3) eliminate child marriage and invest in girls and young women, thereby reducing early childbearing. PMID:22883918

Potts, Malcolm; Henderson, Courtney E

2012-10-01

388

Male reproductive effort and breeding system in an hermaphroditic plant  

Microsoft Academic Search

Male reproductive effort was estimated from flower, seed and fruit biomass data in populations of the self-compatible plant Gilia achilleifolia that differ in genetically estimated selfing rate. Male reproductive effort decreases with increased rate of selfing, a finding that is consistent with theoretical arguments pertaining to the allocation of resources to male and female reproductive functions in hermaphroditic organisms.

Daniel J. Schoen

1982-01-01

389

Magnetic accretion in high-accretion rate polars  

NASA Astrophysics Data System (ADS)

The spectral components of polars strongly magnetic CVs were barely disentangled by previous X-ray missions. The physics of accretion in a strongly magnetic, non-relativistic environment is therefore still puzzling. XMM-Newton can solve the riddle, but the frequent low states of the brightest members prevented systematic studies. We thus began TOO-like XMM-Newton observations of the brightest systems in their high states. We are in the process creating a synoptic view on the HARPs and propose to continue in AO12 with one further trigger. We will investigate the physics of the hard X-ray emitting shock, the heated accretion pole cap, the atmosphere of the white dwarf, the absorption in the shock and in the flow, the lines in the accretion flow and the reflection from the white dwarf.

Schwope, Axel

2012-10-01

390

Learning rate and temperament in a high predation risk environment.  

PubMed

Living in challenging environments can influence the behavior of animals in a number of ways. For instance, populations of prey fish that experience frequent, nonlethal interactions with predators have a high proportion of individuals that express greater reaction to risk and increased activity and exploration-collectively known as temperament traits. Temperament traits are often correlated, such that individuals that are risk-prone also tend to be active and explore more. Spatial learning, which requires the integration of many sensory cues, has also been shown to vary in fish exposed to different levels of predation threat. Fish from areas of low predation risk learn to solve spatial tasks faster than fish from high predation areas. However, it is not yet known whether simpler forms of learning, such as learning associations between two events, are similarly influenced. Simple forms of associative learning are likely to be affected by temperament because a willingness to approach and explore novel situations could provide animals with a learning advantage. However, it is possible that routine-forming and inflexible traits associated with risk-prone and increased exploratory behavior may act in the opposite way and make risk-prone individuals poorer at learning associations. To investigate this, we measured temperament in Panamanian bishop fish (Brachyrhaphis episcopi) sampled from a site known to contain many predators. The B. episcopi were then tested with an associative learning task. Within this population, fish that explored more were faster at learning a cue that predicted access to food, indicating a link between temperament and basic learning abilities. PMID:25270336

DePasquale, C; Wagner, T; Archard, G A; Ferguson, B; Braithwaite, V A

2014-11-01

391

Ctenophore population recruits entirely through larval reproduction in the central Baltic Sea.  

PubMed

The comb jelly Mertensia ovum, widely distributed in Arctic regions, has recently been discovered in the northern Baltic Sea. We show that M. ovum also exists in the central Baltic but that the population consists solely of small-sized larvae (less than 1.6 mm). Despite the absence of adults, eggs were abundant. Experiments revealed that the larvae were reproductively active. Egg production and anticipated mortality rates suggest a self-sustaining population. This is the first account of a ctenophore population entirely recruiting through larval reproduction (paedogenesis). We hypothesize that early reproduction is favoured over growth to compensate for high predation pressure. PMID:22535640

Jaspers, Cornelia; Haraldsson, Matilda; Bolte, Sören; Reusch, Thorsten B H; Thygesen, Uffe H; Kiørboe, Thomas

2012-10-23

392

Ctenophore population recruits entirely through larval reproduction in the central Baltic Sea  

PubMed Central

The comb jelly Mertensia ovum, widely distributed in Arctic regions, has recently been discovered in the northern Baltic Sea. We show that M. ovum also exists in the central Baltic but that the population consists solely of small-sized larvae (less than 1.6 mm). Despite the absence of adults, eggs were abundant. Experiments revealed that the larvae were reproductively active. Egg production and anticipated mortality rates suggest a self-sustaining population. This is the first account of a ctenophore population entirely recruiting through larval reproduction (paedogenesis). We hypothesize that early reproduction is favoured over growth to compensate for high predation pressure. PMID:22535640

Jaspers, Cornelia; Haraldsson, Matilda; Bolte, Sören; Reusch, Thorsten B. H.; Thygesen, Uffe H.; Kiørboe, Thomas

2012-01-01

393

High-rate deposition of high-quality CdTe films for high-efficiency solar cells  

Microsoft Academic Search

CdTe\\/CdS heterojunction solar cells of 11% efficiency have been produced by close-spaced sublimation of highly oriented large-grain p-CdTe films at a deposition-rate of above 5 ?m\\/min in a nitrogen-ambient at a pressure of 10-1 mbar, using a very thin evaporated n-CdS film. Internal quantum efficiencies are close to 100% over a broad spectral range. A realistic potential of >15% is

Dieter Bonnet; Beate Henrichs; Hilmar Richter

1991-01-01

394

A tensile impact apparatus for characterization of fibrous composites at high strain rates  

Microsoft Academic Search

A high rate tensile testing apparatus called “flying wedge” for testing fibrous composites at strain rates up to 103s?1 has been described. R2000 glass\\/epoxy composite has been tested at a very low strain rate of 10?3s?1 using the universal Instron tensile testing machine, and at high strain rates up to nearly 850s?1 using flying wedge. The results show significant increase

G. H. Majzoobi; F. Fereshteh Saniee; M. Bahrami

2005-01-01

395

Growth or reproduction? Resource allocation by female frogs Rana temporaria.  

PubMed

The decision how to allocate marginal resources to reproduction and growth can have important effects on associated life-history parameters as well as on population dynamics. In addition to showing variation among individuals in a population, such allocation rules may be either condition-dependent or fixed in different individuals. While many studies on anuran amphibians have focused on egg numbers and egg sizes in females of different sizes, virtually no data exist on the relative allocation of marginal resources to growth versus reproduction. In the laboratory, we therefore offered female common frogs ( Rana temporaria) low versus high food rations for a full reproductive cycle, and monitored their growth and later reproductive investment (egg number and egg size the following breeding season). Feeding rates had an effect both on female growth and on egg number and size. There was no trade-off found between the two forms of investment. A flexible allocation rule could not be supported as there was no significant effect of feeding rate on the relative allocation of resources to growth versus reproduction. PMID:14505030

Lardner, Björn; Loman, Jon

2003-12-01

396

Original article Reproductive biotechnologies  

E-print Network

Original article Reproductive biotechnologies for endangered mammalian species Pierre COMIZZOLIa, France b INRA, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France (Received 2 June 2000; accepted 16 August 2000) Abstract -- Assisted reproductive techniques (gamete

Paris-Sud XI, Université de

397

Female Reproductive System  

MedlinePLUS

... and female reproductive systems. Continue What Is the Female Reproductive System? Most species have two sexes: male ... some reason other than pregnancy. Infections of the Female Reproductive System Sexually transmitted diseases (STDs) . Also called ...

398

Reproductive strategy, sexual development and attraction to facial characteristics.  

PubMed

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics. PMID:17118929

Cornwell, R Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-12-29

399

Reproductive strategy, sexual development and attraction to facial characteristics  

PubMed Central

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics. PMID:17118929

Cornwell, R. Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-01-01

400

High School Principals' Rating of Success in Implementation of 21st Century Skills  

ERIC Educational Resources Information Center

The purpose of this quantitative study was to investigate how Rhode Island high school principals rate success in implementing 21st century skills in their schools. Secondly, this study investigated how high school principals rate the influence of implementing of 21st century skills in curriculum and instruction in their schools. The high

Sam, Sonn

2011-01-01

401

A comparative study of high strain rate behavior of three martensitic steels  

NASA Astrophysics Data System (ADS)

This paper describes the high strain rate response of HY100, HY130 and AF1410 steels determined from the split Hopkinson bar and quasi-static experiments under room and high temperatures. Differences in the macroscopic high strain rate response of these steels were observed. Metallurgical fracture surface analysis provided insight into the microstructural response and the observed macroscopic behavior of each steel.

Last, H. R.; Garrett, R. K.; Rajendran, A. M.

1996-05-01

402

Reproduction of radiologic images on plain paper.  

PubMed

Skyrocketing health care costs and pressures from managed care have combined to promote cost-cutting strategies in radiology and radiation oncology departments. A study was conducted to evaluate the use of a high-resolution laser printer for printing plain-paper images as substitutes for both original and duplicate radiologic film images. A variety of radiologic images were used to evaluate the image reproduction capabilities of the printer in terms of linearity, detail, and contrast. In many cases, printed images had a quality comparable to that of the original images. Six computed tomographic (CT) scans and six radiation therapy simulator radiographs were compared with printed reproductions by each of seven board-certified radiation oncologists, who rated the reproductions as acceptable for documentation, acceptable for diagnostic purposes (CT scans only), or unacceptable. Ninety-five percent of printed CT images and 90% of printed simulation images were rated acceptable for documentation. The quality of printed images of radiation therapy port films was not quantitatively measured but was improved by adjusting image contrast and brightness and using various image enhancement techniques. The use of printed images is less expensive than that of processed film and eliminates the environmental, time, storage, and delivery problems associated with film. Technologic advances in imaging, networking, and printing have made possible the inexpensive duplication of medical images. PMID:9599396

Ibbott, G S; Zhang, Y; Mohiuddin, M; Adams, E

1998-01-01

403

Poor owner knowledge of feline reproduction contributes to the high proportion of accidental litters born to UK pet cats.  

PubMed

'Accidental' litters contribute to population growth and the number of unwanted animals entering animal welfare organisations. Assessing the problem's extent and determining risk factors enables identification of education targets. Data were obtained from 715 cat-owning households in a cross-sectional telephone survey. Demographic and lifestyle factors were assessed for their association with accidental litters and with owner knowledge of cat reproduction. A total of 128 litters were reported from 552 female cats, and the proportion of accidental litters reported by owners was 80 per cent. Multivariable analysis identified that respondents were more likely to report an accidental litter of kittens if they believed a female cat should have a litter prior to being neutered, if they had more than one cat and if they rented rather than owned their home. Misconceptions relating to cat reproduction were common. The opinion that the youngest age a cat could get pregnant was five months of age (or older) was held by 83.5 per cent of cat-owning respondents, with over a quarter (26.4 per cent; 174/659) believing a queen is unable to conceive until at least a year of age. Almost half the respondents (49.0 per cent; 334/682) believed a female cat should have a litter before being neutered or were not sure; 38.8 per cent (264/681) thought that un-neutered, related cats would not mate or were not sure. This study suggests that improving cat-owner knowledge of the reproductive capacity of cats is likely to have a significant impact on the numbers of accidental litters born. PMID:24343905

Welsh, C P; Gruffydd-Jones, T J; Roberts, M A; Murray, J K

2014-02-01

404

High-Throughput Sequencing to Reveal Genes Involved in Reproduction and Development in Bactrocera dorsalis (Diptera: Tephritidae)  

PubMed Central

Background Tephritid fruit flies in the genus Bactrocera are of major economic significance in agriculture causing considerable loss to the fruit and vegetable industry. Currently, there is no ideal control program. Molecular means is an effective method for pest control at present, but genomic or transcriptomic data for members of this genus remains limited. To facilitate molecular research into reproduction and development mechanisms, and finally effective control on these pests, an extensive transcriptome for the oriental fruit fly Bactrocera dorsalis was produced using the Roche 454-FLX platform. Results We obtained over 350 million bases of cDNA derived from the whole body of B. dorsalis at different developmental stages. In a single run, 747,206 sequencing reads with a mean read length of 382 bp were obtained. These reads were assembled into 28,782 contigs and 169,966 singletons. The mean contig size was 750 bp and many nearly full-length transcripts were assembled. Additionally, we identified a great number of genes that are involved in reproduction and development as well as genes that represent nearly all major conserved metazoan signal transduction pathways, such as insulin signal transduction. Furthermore, transcriptome changes during development were analyzed. A total of 2,977 differentially expressed genes (DEGs) were detected between larvae and pupae libraries, while there were 1,621 DEGs between adults and larvae, and 2,002 between adults and pupae. These DEGs were functionally annotated with KEGG pathway annotation and 9 genes were validated by qRT-PCR. Conclusion Our data represent the extensive sequence resources available for B. dorsalis and provide for the first time access to the genetic architecture of reproduction and development as well as major signal transduction pathways in the Tephritid fruit fly pests, allowing us to elucidate the molecular mechanisms underlying courtship, ovipositing, development and detailed analyses of the signal transduction pathways. PMID:22570719

Zheng, Weiwei; Peng, Tao; He, Wei; Zhang, Hongyu

2012-01-01

405

High Humidity in the Honey Bee (Apis mellifera L.) Brood Nest Limits Reproduction of the Parasitic Mite Varroa jacobsoni Oud  

Microsoft Academic Search

Factors influencing reproduction of\\u000athe parasitic mite Varroa jacobsoni\\u000ahave become a central theme of honey\\u000abee pathology. In large parts of the\\u000aworld the mite has made it impossible\\u000afor colonies of the honey bee Apis\\u000amellifera to survive if no measures of\\u000atreatment are applied [1]. Originally a\\u000aparasite of the Eastern honey bee A.\\u000acerana, the mite

B. Kraus; H. H. W. Velthuis

1997-01-01

406

ASSESSING ADOLESCENT REPRODUCTIVE HEALTH: A GUIDE FOR OUT-OF-SCHOOL TIME PRACTITIONERS  

Microsoft Academic Search

BACKGROUND The reproductive health of American adolescents has been, and continues to be, a matter of serious concern. America's teen birth rate - already one of the highest among developed nations - is again on the rise. Also, rates of sexually-transmitted infection (STI) among teens remain disconcertingly high,1 with one-quarter of the 19 million new cases of STIs each year

Meghan O'Toole; Kristin Anderson Moore; Victoria N. Ball

2008-01-01

407

Female reproductive disorders: the roles of endocrine-disrupting compounds and developmental timing  

PubMed Central

Objective To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disruptions warrant evaluation of the impact of EDCs on female reproductive health. Design Publications related to the contribution of EDCs to disorders of the ovary (aneuploidy, polycystic ovary syndrome, and altered cyclicity), uterus (endometriosis, uterine fibroids, fetal growth restriction, and pregnancy loss), breast (breast cancer, reduced duration of lactation), and pubertal timing were identified, reviewed, and summarized at a workshop. Conclusion(s) The data reviewed illustrate that EDCs contribute to numerous human female reproductive disorders and emphasize the sensitivity of early life-stage exposures. Many research gaps are identified that limit full understanding of the contribution of EDCs to female reproductive problems. Moreover, there is an urgent need to reduce the incidence of these reproductive disorders, which can be addressed by correlative studies on early life exposure and adult reproductive dysfunction together with tools to assess the specific exposures and methods to block their effects. This review of the EDC literature as it relates to female health provides an important platform on which women’s health can be improved. PMID:18929049

Crain, D. Andrew; Janssen, Sarah J.; Edwards, Thea M.; Heindel, Jerrold; Ho, Shuk-mei; Hunt, Patricia; Iguchi, Taisen; Juul, Anders; McLachlan, John A.; Schwartz, Jackie; Skakkebaek, Niels; Soto, Ana M.; Swan, Shanna; Walker, Cheryl; Woodruff, Teresa K.; Woodruff, Tracey J.; Giudice, Linda C.; Guillette, Louis J.

2014-01-01

408

Ettlia sp. YC001 showing high growth rate and lipid content under high CO2.  

PubMed

Over 100 green-colored colonies were isolated from environmental samples when cultivating on a BG11 agar medium, and 4 strains showing different morphologies were selected based on light microscopic observation. Among these strains, the microalgal species with the highest growth rate under 10% CO(2) was identified as Ettlia sp. YC001 using an 18S rDNA-based phylogenetic analysis and morphological comparison. The highest cell density of 3.10 g/L (based on dry cell weight) and biomass productivity of 0.19 g/L/d were obtained under 5% CO(2) after 16 days. The lipid content and productivity were also up to 42% of the dry cell weight and 80.0mg/L/d, respectively. The color of the Ettlia sp. YC001 culture changed from green to red after a month due to the accumulation of certain carotenoids. Therefore, it would seem that Ettlia sp. YC001 is appropriate for mitigating CO(2) due to its high biomass productivity, and a suitable candidate for producing biodiesel and high-value products. PMID:23147124

Yoo, Chan; Choi, Gang-Guk; Kim, Sun-Chang; Oh, Hee-Mock

2013-01-01

409

Weak Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-line Regions?  

NASA Astrophysics Data System (ADS)

We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and SDSS J123743.08+630144.9 at z = 3.49. In both sources, we detect an unusually weak broad H? line and place tight upper limits on the strengths of their [O III] lines. Virial, H?-based black hole mass determinations indicate normalized accretion rates of L/L Edd=0.4 for these sources, which is well within the range observed for typical quasars with similar luminosities and redshifts. We also present high-quality XMM-Newton imaging spectroscopy of SDSS J114153.34+021924.3 and find a hard-X-ray photon index of ? = 1.91+0.24 -0.22, which supports the virial L/L Edd determination in this source. Our results suggest that the weakness of the broad emission lines in WLQs is not a consequence of an extreme continuum-emission source but instead due to abnormal broad emission line region properties.

Shemmer, Ohad; Trakhtenbrot, Benny; Anderson, Scott F.; Brandt, W. N.; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Lira, Paulina; Netzer, Hagai; Plotkin, Richard M.; Richards, Gordon T.; Schneider, Donald P.; Strauss, Michael A.

2010-10-01

410

Ka-Band TWT High-Efficiency Power Combiner for High-Rate Data Transmission  

NASA Technical Reports Server (NTRS)

A four-port magic-T hybrid waveguide junction serves as the central component of a high-efficiency two-way power combiner circuit for transmitting a high-rate phase-modulated digital signal at a carrier frequency in the Ka-band (between 27 and 40 GHz). This power combiner was developed to satisfy a specific requirement to efficiently combine the coherent outputs of two traveling-wavetube (TWT) amplifiers that are typically characterized by power levels on the order of 100 W or more. In this application, the use of a waveguide-based power combiner (instead of a coaxial-cable- or microstrip-based power combiner, for example) is dictated by requirements for low loss, high power-handling capability, and broadband response. Combiner efficiencies were typically 90 percent or more over both the linear and saturated output power regions of operation of the TWTs . Figure 1 depicts the basic configuration of the magic-T hybrid junction. The coherent outputs of the two TWTs enter through ports 1 and 4. As a result of the orientations of the electromagnetic fields, which also provides a needed high port-to-port isolation, of these two input signals and the interior design of the magic-T junction, the input powers are divided so as to add in phase at one output port (port 2), and to be opposite in phase and hence cancel each other at the opposite coplanar output port (port 3). The net result is that the output power at port 2 is essentially double that of the output of one TWT, minus the power lost in the magic-T hybrid junction. Optimum performance as a high-efficiency power combiner thus requires a balance of both power and phase at the input ports of the magic-T. Replicas of this two-way combiner can be arranged in a binary configuration to obtain a 2n-way (where n is an integer) combiner. For example, Figure 2 illustrates the use of three two-way combiners to combine the outputs of four TWTs.

Wintucky, Edwin G.; Simons, Rainee; Vaden, Karl R.; Lesny, Gary G.; Glass, Jeffrey L.

2007-01-01

411

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.  

PubMed

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence. PMID:17251099

Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

2007-04-01

412

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans  

PubMed Central

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence. PMID:17251099

Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

2007-01-01

413

The evolution of senescence and post-reproductive lifespan in guppies (Poecilia reticulata).  

PubMed

The study of post-reproductive lifespan has been of interest primarily with regard to the extended post-menopausal lifespan seen in humans. This unusual feature of human demography has been hypothesized to have evolved because of the "grandmother" effect, or the contributions that post-reproductive females make to the fitness of their children and grandchildren. While some correlative analyses of human populations support this hypothesis, few formal, experimental studies have addressed the evolution of post-reproductive lifespan. As part of an ongoing study of life history evolution in guppies, we compared lifespans of individual guppies derived from populations that differ in their extrinsic mortality rates. Some of these populations co-occur with predators that increase mortality rate, whereas other nearby populations above barrier waterfalls are relatively free from predation. Theory predicts that such differences in extrinsic mortality will select for differences in the age at maturity, allocation of resources to reproduction, and patterns of senescence, including reproductive declines. As part of our evaluation of these predictions, we quantified differences among populations in post-reproductive lifespan. We present here the first formal, comparative study of the evolution of post-reproductive lifespan as a component of the evolution of the entire life history. Guppies that evolved with predators and that experienced high extrinsic mortality mature at an earlier age but also have longer lifespans. We divided the lifespan into three non-overlapping components: birth to age at first reproduction, age at first reproduction to age at last reproduction (reproductive lifespan), and age at last reproduction to age at death (post-reproductive lifespan). Guppies from high-predation environments live longer because they have a longer reproductive lifespan, which is the component of the life history that can make a direct contribution to individual fitness. We found no differences among populations in post-reproductive lifespan, which is as predicted since there can be no contribution of this segment of the life history to an individual's fitness. Prior work on the evolution of post-reproductive lifespan has been dominated by speculation and correlative analyses. We show here that this component of the life history is accessible to formal study as part of experiments that quantify the different segments of an individual's life history. Populations of guppies subject to different mortality pressures from predation evolved differences in total lifespan, but not in post-reproductive lifespan. Rather than showing the direct effects of selection characterizing other life-history traits, post-reproductive lifespan in these fish appears to be a random add-on at the end of the life history. These findings support the hypothesis that differences in lifespan evolving in response to selection are confined to the reproductive lifespan, or those segments of the life history that make a direct contribution to fitness. We also show, for the first time, that fish can have reproductive senescence and extended post-reproductive lifespans despite the general observation that they are capable of producing new primary oocytes throughout their lives. PMID:16363919

Reznick, David; Bryant, Michael; Holmes, Donna

2006-01-01

414

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Remote sensing of the upper tropospheric state of storms using space-borne high spectral resoluti...  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without of Wisconsin at Madison pg. n/a #12;Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. #12;Reproduced with permission of the copyright owner. Further reproduction

Wisconsin at Madison, University of

415

The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate  

Microsoft Academic Search

Background and Purpose: Indications of the existence of long repair half-times on the order of 2–4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of

Peter Sminia; Christoph J. Schneider; Jack F. Fowler

2002-01-01

416

Signal simulator model A-111. [signal source for Doppler tracking high data rate receivers  

NASA Technical Reports Server (NTRS)

A signal simulator designed to function as a signal source for Doppler tracking high data rate receivers is described. The simulator produces modulated signals whose carrier frequency can be varied between 200 and 900 MHz at rates greater than 20 MHz/sec. The modulation is phase shift keying with data rate up to 300 megabits per second.

Flattau, T.; Mellars, J.

1974-01-01

417

Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities  

ERIC Educational Resources Information Center

This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

2008-01-01

418

Overhead Rates for Federal Research Are as High as Ever, Survey Finds.  

ERIC Educational Resources Information Center

Despite pressure from Congress and faculty, and a series of revisions in federal regulations, the average rate charged the government by universities for overhead for federally financed research appears remains high. Average rate for the top 100 research institutions is over 50%; most of the highest rates are at private institutions; all the…

Cordes, Colleen

1998-01-01

419

The Effect of Transition Grade to High School, Gender, and Grade Level upon Dropout Rates.  

ERIC Educational Resources Information Center

Compares high-school dropout rates for boys versus girls in 45 schools with grade spans of 7-12, 9-12, or 10-12. For all three grade spans, boys had higher dropout rates than girls. Highest rates were in the 10-12 grade span; the lowest were in 7-12 districts. (Contains 13 references.) (MLH)

Alspaugh, John W.

2000-01-01

420

An Integrated Epidemiological and Economic Analysis of Vaccination against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (PRRS) in Thua Thien Hue Province, Vietnam.  

PubMed

The purposes of this study are to assess pig farmers' preference for highly pathogenic porcine reproductive and respiratory syndrome (PRRS) vaccine, and estimate the cost and benefit of PRRS vaccination in Vietnam. This study employed an integrated epidemiological and economic analysis which combined susceptible-infectious-recovered (SIR) model, choice experiment (CE) and cost-benefit analysis (CBA) together. The result of SIR model showed the basic reproduction number (R0) of PRRS transmission in this study is 1.3, consequently, the optimal vaccination percentage is 26%. The results of CE in this study indicate that Vietnam pig farmers are showing a high preference for the PRRS vaccine. However, their mean willingness to pay is lower than the potential cost of PRRS vaccine. It can be considered to be one of the reasons that the PRRS vaccination ratio is still low in Vietnam. The results of CBA specified from the whole society's point of view (Social perspective), the benefits of PRRS vaccination are 2.3 to 4.5 times larger than the costs. To support policy making for increasing the PRRS vaccination proportion, this study indicates two ways to increase the vaccination proportion: i) decrease vaccine price by providing a subsidy, ii) provide compensation of culling only for PRRS vaccinated pigs. PMID:25178303

Zhang, Haifeng; Kono, Hiroichi; Kubota, Satoko

2014-10-01

421

An Integrated Epidemiological and Economic Analysis of Vaccination against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (PRRS) in Thua Thien Hue Province, Vietnam  

PubMed Central

The purposes of this study are to assess pig farmers’ preference for highly pathogenic porcine reproductive and respiratory syndrome (PRRS) vaccine, and estimate the cost and benefit of PRRS vaccination in Vietnam. This study employed an integrated epidemiological and economic analysis which combined susceptible-infectious-recovered (SIR) model, choice experiment (CE) and cost-benefit analysis (CBA) together. The result of SIR model showed the basic reproduction number (R0) of PRRS transmission in this study is 1.3, consequently, the optimal vaccination percentage is 26%. The results of CE in this study indicate that Vietnam pig farmers are showing a high preference for the PRRS vaccine. However, their mean willingness to pay is lower than the potential cost of PRRS vaccine. It can be considered to be one of the reasons that the PRRS vaccination ratio is still low in Vietnam. The results of CBA specified from the whole society’s point of view (Social perspective), the benefits of PRRS vaccination are 2.3 to 4.5 times larger than the costs. To support policy making for increasing the PRRS vaccination proportion, this study indicates two ways to increase the vaccination proportion: i) decrease vaccine price by providing a subsidy, ii) provide compensation of culling only for PRRS vaccinated pigs. PMID:25178303

Zhang, Haifeng; Kono, Hiroichi; Kubota, Satoko

2014-01-01

422

Interactions for pollinator visitation and their consequences for reproduction in a plant community  

NASA Astrophysics Data System (ADS)

Competition and facilitation in species interactions attract much attention in ecology, but their relative importance has seldom been evaluated in a community context. We assessed competitive and facilitative interactions for pollinator visitation among co-flowering species in a plant community, investigated the subsequent consequences for plant reproduction, and investigated whether effects could be trait-based. We removed the flowers of two species attractive to pollinators, in two separate experiments and assessed the effects on pollinator visitation rates and components of reproductive success in 11 co-flowering focal herb species. Overall, most focal species appear not to interact with the removal species with respect to pollinator visitation and subsequent reproduction (neutral interactions). Three focal species in the community had significantly higher reproductive responses (fruit production and seed weight) in the presence of the attractive removal species (facilitative interactions), but species interaction effects were less pronounced in species' flower visitation rates. A community-wide meta-analysis demonstrated that the two experiments did not have a significant effect on either facilitation or competition, and that there was no overall correlation between effect sizes for visitation and reproduction. Based on species-specific responses, it seems likely that floral traits such as similar flower colors contribute to interspecific facilitation of pollinator visitation and, in particular, that high pollinator dependence for plant reproduction, and associated pollen limitation, may contribute to subsequent interaction effects on reproduction in the focal species.

Hegland, Stein Joar; Totland, Ørjan

2012-08-01

423

High-Rate Disinfection Techniques for Combined Sewer Overflow (Proceedings Paper)  

EPA Science Inventory

This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH ), a...

424

High rate deposition of ?c-Si with plasma gun CVD  

Microsoft Academic Search

High rate deposition of microcrystalline silicon using direct current are plasma gun chemical vapor deposition was investigated. A sheet like plasma was produced using a DC are plasma gun and a magnetic field. An important feature of this plasma was that it was produced using high current and low voltage. By increasing the plasma density and flow rate of feed

Nobuhiko Imajyo

1996-01-01

425

Photonic millimeter-wave generation and its applications in high data rate wireless access  

Microsoft Academic Search

Microwave Photonics is widely considered as a disruptive technology for high data rate wireless communications. This paper discusses technological trends in enabling photonic solutions for high data rate wireless access systems operating in the millimeter-wave regime. Besides technical achievements, a focus is also put on worldwide regulations for wireless communications in the E-band (60-90 GHz).

Andreas Stöhr

2010-01-01

426

Develop High Charge and Discharge Rate Lead/Acid Battery Technology.  

National Technical Information Service (NTIS)

The objective of this program was to develop a high charge rate, high discharge rate lead-acid battery compatible with the requirements of a hybrid heat-engine/electric vehicle. Because the power requirements and charge-discharge profiles for a hybrid-veh...

H. P. Silverman

1972-01-01

427

Blood Pressure and Heart Rate Responses to Anticipated High-stress Dental Treatment  

Microsoft Academic Search

Twenty-four healthy adults participated in a study to determine the effects of anticipated high-stress dental treatment on blood pressure and heart rate. Blood pressure, heart rate, and state anxiety were assessed prior to four consecutive dental appointments. Appointments 1, 2, and 4 were of relatively low stress and appointment 3 was of relatively high stress. Blood pressure was unaffected while

Frank M. Beck; Joël M. Weaver

1981-01-01

428

Words high and low in pleasantness as rated by male and female college students  

Microsoft Academic Search

No catalog of words currently available contains normative data for large numbers of words rated low or high in affect. A preliminary sample of 1,545 words was rated for pleasantness by 26-33 college students. Of these words, 274 were selected on the basis of their high or low rat- ings. These words, along with 125 others (Rubin, 19811, were then

FRANCIS S. BELLEZZA; ANTHONY G. GREENWALD; MAHZARIN R. BANAJZ

1986-01-01

429

Facile synthesized nanorod structured vanadium pentoxide for high-rate lithium batteries  

E-print Network

Facile synthesized nanorod structured vanadium pentoxide for high-rate lithium batteries Anqiang cathode material for high-rate lithium battery applications. 1. Introduction Lithium ion batteries have a challenge. Mohan et al.17 fabricated V2O5 nanotubes as cathode material for lithium battery by hydrothermal

Cao, Guozhong

430

Chromosomal alterations cause the high rates and wide ranges of drug resistance in cancer cells  

E-print Network

Chromosomal alterations cause the high rates and wide ranges of drug resistance in cancer cells, aneuploidy is the primary cause of the high rates and wide ranges of drug resistance in cancer cells. Ã? 2005 to answer four critical sets of questions about drug resistance in cancer cells. First: How do cancer cells

Duesberg, Peter

431

Rate effects of standard and high-strip-current microchannel plate image intensifiers  

Microsoft Academic Search

The gains of gated MCPIIs at high repetition rate (up to 10 kHz) were measured. Comparisons were made between the gain behavior of a standard ITT type F4111 MCPII and similar device incorporating a high strip current microchannel plate. The most notable effect observed for the standard MCPII is a decline in luminous gain with increasing gate repetition rate and

George J. Yates; Kevin L. Albright; Paul A. Zagarino; Matthew C. Thomas

1992-01-01

432

Improving High School Graduation Rates. Education Policy Brief. Volume 6, Number 7, Summer 2008  

ERIC Educational Resources Information Center

In May 2008, the Center for Evaluation & Education Policy (CEEP) issued the Education Policy Brief, "Calculating High School Graduation Rates," which discussed the importance of accurate and reliable high school graduation data, various graduation rate calculation methods, the history behind the use of particular methodologies, and the nationwide…

Stanley, Kylie R.; Plucker, Jonathan A.

2008-01-01

433

Theoretical analysis of the high-rate vector quantization of LPC parameters  

Microsoft Academic Search

The paper presents a theoretical analysis of high-rate vector quantization (VQ) systems that use suboptimal, mismatched distortion measures, and describes the application of the analysis to the problem of quantizing the linear predictive coding (LPC) parameters in speech coding systems. First, it is shown that in many high-rate VQ systems the quantization distortion approaches a simple quadratically weighted error measure,

William R. Gardner; Bhaskar D. Rao

1995-01-01

434

High School Dropout, Graduation, and Completion Rates: Better Data, Better Measures, Better Decisions  

ERIC Educational Resources Information Center

High school graduation and dropout rates have long been used as indicators of educational system productivity and effectiveness and of social and economic well being. While determining these rates may seem like a straightforward task, their calculation is in fact quite complicated. How does one count a student who leaves a regular high school but…

Hauser, Robert M., Ed.; Koenig, Judith Anderson, Ed.

2011-01-01

435

The Effect of Selected Nonmusical Factors on Adjudicators' Ratings of High School Solo Vocal Performances  

ERIC Educational Resources Information Center

The purpose of this study was to examine the effect of differentiated performance attire and stage deportment on adjudicators' ratings of high school solo vocal performances. High school choral students (n = 153) and undergraduate (n = 97) and graduate music majors (n = 32) served as adjudicators (N = 282). Adjudicators rated recorded solo vocal…

Howard, Sandra A.

2012-01-01

436

High-rate laser-direct-write dry etching of titanium  

Microsoft Academic Search

Titanium surfaces can be etched spatially selective in a chlorine atmosphere under 488 nm cw Ar+-laser irradiation focused to 3 µm with well-controlled etch depth and high etch rate. By scanning the substrate, patterns can be generated by laser direct writing with high scan speed. The dependence of the etch rate on various parameters, such as laser power, scan speed

O. Lehmann; M. Stuke

1996-01-01