1,090 research outputs found
Seed dormancy and germination of a panel of New Zealand plant species : Carex trifida, Corposma robusta, Cyperus ustulatus, Hebe stricta, Muehlenbeckia australis, Myrsine australis, Phormium tenax and Sophora prostrata : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University
Literature was reviewed on the germination and possible uses for revegetation of the New Zealand indigenous species selected. Seeds of Carex trifida, Coprosma robusta, Cyperus ustulatus, Hebe stricta, Leptospermum scoparium, Muehlenbeckia australis, Myrsine australis, Phormium tenax, Phormium 'Yellow Wave' and Sophora prostrata were assessed for germination rates, percentage germination, dormancy and the effects that temperature has on germination. Seeds of Carex, Cyperus and Myrsine showed no germination in light or dark at 20°C. In contrast, 12 weeks of low temperature stratification resulted in a high percentage of seed germinating for Carex and Cyperus. There was no germination of Myrsine despite high viability in the initial germination experiment and the stratification experiment. Removal of the endocarp and a period of stratification increased germination percentage of Myrsine to 91%. Germination was low for Muehlenbeckia in the light at 20°C, but 4 weeks of low temperature stratification increased germination rate. After 2 years, 80% of Coprosma seeds germinated but germination rate increased after subjecting the seed to 8 weeks or more of stratification. No seeds of Coprosma or Muehlenbeckia germinated in the dark. Rapid germination of Hebe seeds was obtained, with 100% of the seed germinating in the light while only 7% germinated in the dark. Leptospermum had rapid germination, with 100% germinating in the light, while only 3% germinated in the dark. A low percentage of Phormium seed germinated in both the light and dark in the first month and no further germination was observed. In contrast, 8 weeks or more of low temperature stratification resulted in almost complete germination. There was rapid germination of Sophora seeds with 100% of the seed germinating in the light and dark. Carex seed had a limited temperature range at which it germinated (22°C to 26°C), while Cyperus had a wider range (18°C to 32°C) but did not germinate at low temperatures (6°C to 14°C). The optimum germination range for Cyperus was 24°C to 30°C. Hebe did not germinate at high temperatures (30°C to 32°C) but successfully germinated at all other temperatures with the optimum germination range being 6°C to 24°C. Leptospermum did not germinate at 6°C but had maximum germination at most other temperatures. Muehlenbeckia and Phormium germinated at all temperatures tested (6°C to 32°C) with the most seed germinating at 20°C for Muehlenbeckia and between 14°C to 22°C for Phormium. Sophora did not germinate at the low temperatures (6°C to 10°C). The germination rate increased with temperature for Cyperus, Hebe, Leptospermum, Muehlenbeckia, and Phormium. Generally, for Carex and Sophora as temperature increased germination rate slowed. It appeared that light is required for Hebe and Leptospermum to germinate. Sophora required scarification but not light. Coprosma and Muehlenbeckia required light and a period of chilling to increase the rate of germination. A small percentage of the Phormium population is not dormant but a period of chilling increased the germination percentage for that portion of the population that is dormant. Carex and Cyperus required a period of chilling in order to break dormancy. Myrsine required removal of endocarp and a period of chilling to germinate. A list of cleaning descriptions and the equipment that was used for each species studied is reported. Preliminary results of a hydroseeding trail using the species studied were also reported
Groundwater fate of aromatic hydrocarbons at industrial sites : a coal tar site case study
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.Includes bibliographical references.by Allison Ann MacKay.Ph.D
Increased annexin A1 and A2 levels in bronchoalveolar lavage fluid are associated with resistance to respiratory disease in beef calves
Technology Probes: Inspiring Design for and with Families
We describe a new methodology for designing technologies for and with families
called technology probes. Technology probes are simple, flexible, adaptable
technologies introduced into families' homes with three interdisciplinary goals:
the social science goal of collecting data about the use of the technology in a
real-world setting, the engineering goal of field-testing the technology, and
the design goal of inspiring users and designers to think about new
technologies. We present the results of designing and deploying two technology
probes, the MessageProbe and the VideoProbe, with families in France, Sweden,
and the U.S. We conclude with our plans for creating new technologies based on
our experiences.
Keywords
Design Methods, Computer Mediated Communication, Computer Supported Cooperative
Work (CSCW), Home,
Ethnography, Participatory Design and Cooperative Design, User Studies and
Fieldwork
(UMIACS-TR-2002-87)
(HCIL-TR-2002-16
Discrete Survival Time Constructions for Studying Marital Formation and Dissolution in Rural South Africa
Introduction: Marriage formation and dissolution are important life-course events which impact psychological well-being and health of adults and children experiencing the events. Family studies have usually concentrated on analyzing single transitions including Never Married to Married and Married to Divorced. This does not allow understanding and interrogation of dynamics of these life changing events and their effects on individuals and their families. The objective of this study was to assess determinants associated with transitions between and within marital states in South Africa.
Methods: The population-based data available for this study consists of over 55, 000 subjects representing over 340, 000 person-years exposure from the Africa Health Research Institute (AHRI) in rural KwaZulu-Natal, South Africa. It was collected from 1 January 2004 to 31 December 2016. Multilevel multinomial, binary and competing risks regression models were used to model marital state occupation, transitions between marital states as well as investigate determinants of marital dissolution, respectively.
Results: Between the years 2006 and 2007, a subject was more likely to be married than never married when compared to years 2004 − 2005. After 2007, subjects were less likely to be married than never married and the trend reduced over the years up to 2016 [with OR=0.86, CI=(0.78; 0.94), OR=0.71, CI=(0.64; 0.78), OR=0.60, CI=(0.54; 0.67), OR=0.50, CI=(0.44; 0.56), and OR = 0.43, CI = (0.38; 0.48)] for periods 2008 − 2009, 2010 − 2011, 2012 − 2013, 2014 − 2015, and 2016, respectively. In 2008 − 2009, subjects were more likely to experience a marital dissolution than in the period 2004 − 2005 and the trend slightly reduces from 2010 until 2013 [OR=24.49, CI=(5.53; 108.37)]. Raising age at first sexual debut was found to be inversely associated with a marital dissolution [OR = 0.97;CI = (0.95; 0.99)]. Highly educated subjects were more likely to stay in one marital state than those who never went to school [OR=6.43, CI=(4.89; 8.47), OR=18.86, CI=(1.14; 53.31), and OR=2.96, CI=(1.96; 4.46) for being married, separated and widowed, respectively, among subjects with tertiary education]. As the age at first marriage increased, subjects became less likely to experience a marital separation [OR = 0.06, CI = (0.00; 1.11), OR = 0.05, CI = (0.00; 0.91), and OR = 0.04, CI = (0.00; 0.76) for subjects who entered a first marriage at ages 18 − 22, 23 − 29, and 30 − 40, respectively].
Conclusion: The study found that marrying at later ages is associated with a lower rate of marital dissolution while more educated subjects tend to stay longer in one marital state. Sexual debut at later ages was associated with a lower likelihood of experiencing a marital dissolution. There could, however, be some factors that are not accounted for in the model that may lead to heterogeneity in these dynamics in our model specification which are captured by the random effects in the model. Nonetheless, we may postulate that existing programs that encourage delay in onset of sexual activity for HIV risk reduction for example, may also have a positive impact on lowering rates of marital dissolution, thus ultimately improving psychological and physical health
No change in neurodevelopment at 11 years after extremely preterm birth.
OBJECTIVE: To determine whether improvements in school age outcomes had occurred between two cohorts of births at 22-25 weeks of gestation to women residents in England in 1995 and 2006. DESIGN: Longitudinal national cohort studies. SETTING: School-based or home-based assessments at 11 years of age. PARTICIPANTS: EPICure2 cohort of births at 22-26 weeks of gestation in England during 2006: a sample of 200 of 1031 survivors were evaluated; outcomes for 112 children born at 22-25 weeks of gestation were compared with those of 176 born in England during 1995 from the EPICure cohort. Classroom controls for each group acted as a reference population. MAIN OUTCOME MEASURES: Standardised measures of cognition and academic attainment were combined with parent report of other impairments to estimate overall neurodevelopmental status. RESULTS: At 11 years in EPICure2, 18% had severe and 20% moderate impairments. Comparing births at 22-25 weeks in EPICure2 (n=112), 26% had severe and 21% moderate impairment compared with 18% and 32%, respectively, in EPICure. After adjustment, the OR of moderate or severe neurodevelopmental impairment in 2006 compared with 1995 was 0.76 (95% CI 0.45 to 1.31, p=0.32). IQ scores were similar in 1995 (mean 82.7, SD 18.4) and 2006 (81.4, SD 19.2), adjusted difference in mean z-scores 0.2 SD (95% CI -0.2 to 0.6), as were attainment test scores. The use of multiple imputation did not alter these findings. CONCLUSION: Improvements in care and survival between 1995 and 2006 are not paralleled by improved cognitive or educational outcomes or a reduced rate of neurodevelopmental impairment
Genetic relationships between spring emergence, canopy phenology and biomass yield increase the accuracy of genomic prediction in Miscanthus
Miscanthus has potential as a bioenergy crop but the rapid development of high-yielding varieties is challenging. Previous studies have suggested that phenology and canopy height are important determinants of biomass yield. Furthermore, while genome-wide prediction was effective for a broad range of traits, the predictive ability for yield was very low. We therefore developed models clarifying the genetic associations between spring emergence, consequent canopy phenology and dry biomass yield. The timing of emergence was a moderately strong predictor of early-season elongation growth (genetic correlation >0.5), but less so for growth later in the season and for the final yield (genetic correlation <0.1). In contrast, early-season canopy height was consistently more informative than emergence for predicting biomass yield across datasets for two species in Miscanthus and two growing seasons. We used the associations uncovered through these models to develop selection indices that are expected to increase the response to selection for yield by as much as 21% and improve the performance of genome-wide prediction by an order of magnitude. This multivariate approach could have an immediate impact in operational breeding programmes, as well as enable the integration of crop growth models and genome-wide predictionpublishersversionPeer reviewe
Empirical Analysis of Factors Affecting Confirmation Bias Levels of Software Engineers
Confirmation bias is defined as the tendency of people to seek evidence that verifies a hypothesis rather than seeking evidence to falsify it. Due to the confirmation bias, defects may be introduced in a software product during requirements analysis, design, implementation and/or testing phases. For instance, testers may exhibit confirmatory behavior in the form of a tendency to make the code run rather than employing a strategic approach to make it fail. As a result, most of the defects that have been introduced in the earlier phases of software development may be overlooked leading to an increase in software defect density. In this paper, we quantify confirmation bias levels in terms of a single derived metric. However, the main focus of this paper is the analysis of factors affecting confirmation bias levels of software engineers. Identification of these factors can guide project managers to circumvent negative effects of confirmation bias, as well as providing guidance for the recruitment and effective allocation of software engineers. In this empirical study, we observed low confirmation bias levels among participants with logical reasoning and hypothesis testing skills
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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