4,289 research outputs found

    Rare or threatened vascular plant species of Wollemi National Park, central eastern New South Wales

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    Wollemi National Park (c. 32o 20’– 33o 30’S, 150o– 151oE), approximately 100 km north-west of Sydney, conserves over 500 000 ha of the Triassic sandstone environments of the Central Coast and Tablelands of New South Wales, and occupies approximately 25% of the Sydney Basin biogeographical region. 94 taxa of conservation significance have been recorded and Wollemi is recognised as an important reservoir of rare and uncommon plant taxa, conserving more than 20% of all listed threatened species for the Central Coast, Central Tablelands and Central Western Slopes botanical divisions. For a land area occupying only 0.05% of these divisions, Wollemi is of paramount importance in regional conservation. Surveys within Wollemi National Park over the last decade have recorded several new populations of significant vascular plant species, including some sizeable range extensions. This paper summarises the current status of all rare or threatened taxa, describes habitat and associated species for many of these and proposes IUCN (2001) codes for all, as well as suggesting revisions to current conservation risk codes for some species. For Wollemi National Park 37 species are currently listed as Endangered (15 species) or Vulnerable (22 species) under the New South Wales Threatened Species Conservation Act 1995. An additional 50 species are currently listed as nationally rare under the Briggs and Leigh (1996) classification, or have been suggested as such by various workers. Seven species are awaiting further taxonomic investigation, including Eucalyptus sp. ‘Howes Swamp Creek’ (Doherty 26), known from a single location within the park, and Pultenaea sp. (Olinda) from Dunns Swamp – both these species remain undescribed, but are listed as endangered species. After applying IUCN criteria to the 94 taxa, 2 are considered Critically Endangered; 11 are considered Endangered; 23 are considered Vulnerable; 3 are considered Near Threatened; 19 are considered Data Deficient; and 36 are considered of Least Concern. It is likely that additional highly restricted plant taxa await discovery in remote locations

    Estimating Water Demand Schedules for Selected Industries in Arkansas

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    Water demand functions for the paper and chemical industries in the state of Arkansas were estimated utilizing data collected from individual plants throughout the state. Regression analysis was used to estimate demand functions from a data base which included information on intake and gross water use by source, recirculated water use, costs of acquiring, treating, and discharging water, plant output, employment, and level of technology. The demand for intake water was estimated as an exponential function of average water costs and the level of technology primarily. Price elasticities of demand were estimated as approximately equal to one for both industries. The results of this study could be used to determine the effects of various public policies on the withdrawal of water for industrial purposes

    UNDERSTANDING THE CHEMICAL GYMNASTICS OF ENZYME-CATALYZED 1’-1 AND 1’-3 TRITERPENE LINKAGES

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    Squalene synthase (SS) is an essential enzyme in eukaryotic systems responsible for an important branch point in isoprenoid metabolism that leads to sterol formation. The mechanistic complexity of SS has made it a difficult enzyme to study. The green alga Botryococcus braunii race B possesses several squalene synthase-like (SSL) enzymes that afford a unique opportunity to study the complex mechanism of triterpene biosynthesis. SSL-1 catalyzes presqualene diphosphate (PSPP) formation, which can either be converted to squalene by SSL-2 or botryococcene by SSL-3. A rationally designed mutant study of B. braunii squalene synthase (BbSS) and SSL-3 was conducted to understand structure-function relations among these enzymes. These studies revealed two amino acid positions in SSL-3 (N171, G207) that appeared to control 1’-3 versus 1’-1 linkages. The reciprocal mutations in the corresponding positions of BbSS did not convert this enzyme into a botryococcene synthase. Next, a genetic selection was developed to evolve SSL enzymes towards a fully functional SS. Previous studies have shown that Saccharomyces cerevisiae squalene synthase (ScSS) can be knocked out and although lethal, growth can be restored by providing an exogenous source of ergosterol. Additional studies have shown that successful complementation of the ScSS knockout with a non-fungal SS is possible but requires a fungal SS carboxy- terminus region. Given these observations, proof-of-principle experiments were conducted to demonstrate that SSL-SSL fusion enzymes could complement the ScSS knockout followed by construction of a mutant SSL-SSL fusion enzyme library that was screened in the ScSS knockout yeast line. From this library, mutant SSL-SSL fusion enzymes were identified that were able to complement, which demonstrated the feasibility of this approach as a genetic selection for mutant SSL enzymes. Squalene and botryococcene have valuable industrial applications in vaccine adjuvant formations, cosmetic products, and renewable energy feedstock material. Limitations in natural sources of these molecules have made heterologous production of them an important research target. Algae represent a desirable group of organisms that could be engineered to produce these metabolites because they are photosynthetic and capable of using non-arable farmland. The feasibility, approach, and progress for engineering green algae to produce squalene and botryococcene are discussed

    Paid Consulting in Ontario Colleges of Applied Arts and Technology

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    A survey of faculty participation in paid consulting arrangements in Ontario Colleges of Applied Arts and Technology reveals that 34% were involved in at least one project during a specified one-year period. There was significant variation in participation by division of academic appointment and by gender. The authors suggest that further research should be undertaken concerning the nature and role of paid consulting in community colleges. A number of basic questions are raised in an attempt to induce further study on this important topic.Cette étude porte sur le niveau de consultation rémunérée effectuée par les membres du corps professoral des Collèges des arts appliqués et de la tech-nologie de l'Ontario. Elle révèle que 34% d'entre eux ont été impliqués dans au moins un projet au cours d'une même année; on note que cette participation variait de façon significative selon le genre et la position académiques en ques-tion. Les auteurs suggèrent que des études plus poussées soient entreprises quant à la nature et au rôle de la consultation rémunérée dans les collèges communautaires; ils soulèvent également des questions fondamentales voulant inciter à d'autres recherches sur ce sujet d'importance

    Observers can always generate nonlocal correlations without aligning measurements by covering all their bases

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    Quantum theory allows for correlations between the outcomes of distant measurements that are inconsistent with any locally causal theory, as demonstrated by the violation of a Bell inequality. Typical demonstrations of these correlations require careful alignment between the measurements, which requires distant parties to share a reference frame. Here, we prove, following a numerical observation by Shadbolt et al., that if two parties share a Bell state and each party randomly chooses three orthogonal measurements, then the parties will always violate a Bell inequality. Furthermore, we prove that this probability is highly robust against local depolarizing noise, in that small levels of noise only decrease the probability of violating a Bell inequality by a small amount. We also show that generalizing to N parties increases the robustness against noise. These results improve on previous ones that only allowed a high probability of violating a Bell inequality for large numbers of parties.Comment: 4 pages, 2 figures. v2: updated reference. v3: published versio

    Trans-Excision-Splicing Ribozyme and Methods of Use

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    A group I intron-derived ribozyme which binds RNA in trans, excises an internal segment from within the RNA, and splices the remaining 5′ and 3′ ends of the RNA back together (the trans-excision-splicing reaction) is disclosed. The excised segment can be as long as 28 nucleotides, or more, and as little as one nucleotide. The ribozymes of the invention are easily modified to alter their sequence specificity. Such ribozymes represent a new and potentially powerful class of generally adaptable genetic therapeutics

    Trans-Excision-Splicing Ribozyme and Methods of Use

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    A group I intron-derived ribozyme which binds RNA in trans, excises an internal segment from within the RNA, and splices the remaining 5′ and 3′ ends of the RNA back together (the trans-excision-splicing reaction) is disclosed. The excised segment can be as long as 28 nucleotides, or more, and as little as one nucleotide. The ribozymes of the invention are easily modified to alter their sequence specificity. Such ribozymes represent a new and potentially powerful class of generally adaptable genetic therapeutics

    Generating nonclassical correlations without fully aligning measurements

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    We investigate the scenario where spatially separated parties perform measurements in randomly chosen bases on an N-partite Greenberger-Horne-Zeilinger state. We show that without any alignment of the measurements, the observers will obtain correlations that violate a Bell inequality with a probability that rapidly approaches 1 as N increases and that this probability is robust against noise. We also prove that restricting these randomly chosen measurements to a plane perpendicular to a common direction will always generate correlations that violate some Bell inequality. Specifically, if each observer chooses their two measurements to be locally orthogonal, then the N observers will violate one of two Bell inequalities by an amount that increases exponentially with N. These results are also robust against noise and perturbations of each observer's reference direction from the common direction.Comment: v2: Essentially published version (with typos fixed, results updated in Table 2 and Figure 4 replaced); v1: 16 pages, 5 figures, 2 tables, comments welcom

    Designing Reliable Impact Evaluations

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    Resiliency and quality of life trajectories after injury

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    Injury can greatly impact patients' long-term quality of life. Resilience refers to an individual's ability to positively adapt after facing stress or trauma. The objective of this study was to examine the relationship between preinjury resiliency scores and quality of life after injury. METHODS: Two hundred twenty-five adults admitted with an Injury Severity Score greater than 10 but without neurologic injury were included. The 36-item Short Form was administered at the time of admission and repeated at 1 month, 2 months, 4 months, and 12 months after injury. The Connor-Davidson Resilience Scale was completed at admission and scores were categorized into high resiliency or not high resiliency. Group-based trajectory modeling was used to identify distinct recovery trajectories for physical component scores (PCS) and mental component scores (MCS) of the 36-item Short Form. Multinomial logistic regression was used to determine whether baseline resiliency scores were predictive of PCS and MCS recovery trajectories. RESULTS: Age, race, sex, mechanism of injury, Charlson Comorbidity Index, Injury Severity Score, presence of hypotension on admission, and insurance status were not associated with high resiliency. Compared with those who made less than US 10,000peryear,thosewhomademorethanUS10,000 per year, those who made more than US 50,000 per year had higher odds of being in the high resilience group (odds ratio, 10.92; 95% confidence interval, 2.58-46.32). Three PCS and 5 MCS trajectories were identified. There was no relationship between resilience and PCS trajectory. However, patients with high resiliency scores were 85% less likely to belong to trajectory 1, the trajectory that had the lowest mental health scores over the course of the study. Follow-up for the study was 93.8% for month 1, 82.7% for month 2, 69.4% for month 4, and 63.6% for month 12. CONCLUSION: Patient resiliency predicts quality of life after injury in regards to mental health with over 25% of patients suffering poor mental health outcome trajectories. Efforts to teach resiliency skills to injured patients could improve long-term mental health for injured patients. Trauma centers are well positioned to carry out such interventions. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III
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