83 research outputs found

    Effects of several abiotic and biotic factors and plant hormones on growth, morophology, and camptothecin accumulation in Camptotheca acuminata seedlings

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    This dissertation seeks to explore the effects of abiotic factors [nitrogen (N), sodium chloride (NaCl), and ultraviolet (UV) light], biotic factor [acetylsalicylic acid (ASA)], and plant hormones [benzyl adenine (BA) and naphthalene acetic acid (NAA)] on growth, morphology, and secondary metabolite, camptothecin (CPT, an anti-cancer compound) accumulation in Camptotheca acuminata. Five experiments were conducted with C. acuminata seedlings in a hydroponic system with commercial media and fluorescent lights and at 22-26 °C to investigate the effects of these five factors on height, weight, leaf number, leaf length, root to shoot ratio (RSR), specific leaf weight (SLW), CPT concentrations in leaves and/or roots, and final CPT yield in leaves which were collected in nondestructive harvestings. N deficiency decreased height, weight, leaf number, leaf length, and leaf chlorophyll concentration in comparison with N supplementation, but increased RSR, SLW, and CPT concentrations in leaves and roots. However, the CPT yield did not increase. NaCl addition reduced height, weight, leaf number, and leaf length, but increased SLW and CPT concentrations in leaves and roots. However, the CPT yield decreased. UV light short-term exposure had no effect on height, weight, leaf number, leaf length, RSR, and SLW, but increased leaf CPT concentration and yield after three weeks. ASA addition reduced plant height, weight, and leaf length, but increased SLW and leaf CPT concentration, and decreased CPT yield. BA application decreased height, but increased RSR and leaf CPT concentration, and had no effect on CPT yield. NAA application decreased height, weight, leaf number, leaf length, SLW, and CPT yield, but increased RSR, and had no effect on leaf CPT concentration. In conclusion, abiotic and biotic stresses reduced the growth and affected the morphology of C. acuminata seedlings in a hydroponic system. Abiotic stresses and biotic stress increased CPT concentration, but did not increase CPT yield (expect UV). Cytokinin up-regulated CPT concentration but had no effect on CPT yield, whereas auxin did not regulate CPT concentration but decreased CPT yield. A negative relationship between plant growth and CPT concentration existed under the treatments with N, NaCl, or ASA

    Poor recovery from a pulmonary exacerbation does not lead to accelerated FEV1 decline

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    BACKGROUND: Patients with CF treated for pulmonary exacerbations (PEx) may experience faster subsequent declines in FEV1. Additionally, incomplete recovery to baseline FEV1 occurs frequently following PEx treatment. Whether accelerated declines in FEV1 are preceded by poor PEx recovery has not been studied. METHODS: Using 2004 to 2011 CF Foundation Patient Registry data, we randomly selected one PEx among patients ≥6years of age with no organ transplantations, ≥12months of data before and after the PEx, and ≥1 FEV1 recorded within the 6months before and 3months after the PEx. We defined poor PEx recovery as the best FEV1 in the 3months after the PEx 5% predicted/year FEV1 decline and poor PEx recovery using multi-state Markov models. RESULTS: From 13,954 PEx, FEV1 declines of >5% predicted/year were more likely to precede poor spirometric recovery, HR 1.17 (1.08, 1.26), in Markov models adjusted for age and sex. Non-Responders were less likely to have a subsequent fast FEV1 decline, HR 0.41 (0.37, 0.46), than patients who recovered to >90% of baseline FEV1 following PEx treatment. CONCLUSIONS: Accelerated declines in FEV1 are more likely to precede a PEx with poor recovery than to occur in the following year. Preventing or halting declines in FEV1 may also have the benefit of preventing PEx episodes

    Poor recovery from cystic fibrosis pulmonary exacerbations is associated with poor long-term outcomes

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    RATIONALE: People with CF treated with IV antibiotics for a pulmonary exacerbation (PEx) frequently fail to recover to baseline FEV1 . The long-term impact of these events has not been studied. OBJECTIVES: To determine if a patient's spirometric recovery after a PEx is associated with time to next PEx within 1 year, the spirometric recovery after the next PEx, and/or the number of PEx episodes in the next 3 years. METHODS: We used data from the CF Foundation Patient Registry from 2004 to 2011. We randomly selected one PEx per patient that met inclusion/exclusion criteria. Patients were defined as Non-Responders if their best FEV1 (in liters) recorded in the 3 months after the PEx was <90% of the best FEV1 (in liters) in the 6 months before the PEx. We compared Responders and Non-Responders using multivariable regression models. RESULTS: We randomly chose 13 954 PEx episodes that met inclusion/exclusion criteria. A total of 2 762 (19.8%) patients were classified as Non-Responders. Non-Responders had a shorter median time to the next PEx, 235 (95%CI 218, 252) days, versus >365 days for Responders. Thirty-four percent of Non-Responders at the initial PEx were also Non-Reponders at the next PEx, versus 20% of Responders at the initial PEx. Non-Responders had more PEx episodes over the next 3 years, 4.99 (95%CI 4.84, 5.13), than Responders, 3.46 (95%CI 3.41, 3.51). CONCLUSIONS: Poor recovery after a PEx is associated with a shorter time to the next PEx, increased risk of poor recovery at a second PEx, and more frequent subsequent PEx treatments

    Opportunities for quality improvement in cystic fibrosis newborn screening

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    AbstractBackgroundWith the rapid implementation of cystic fibrosis (CF) newborn screening (NBS), quality improvement (QI) has become essential to identify and prevent errors. Using Process Failure Modes and Effects Analysis (PFMEA), we adapted this method to determine if it could be applied to discover and rank high priority QI opportunities.MethodsSite visits to three programmes were conducted, and PFMEA exercises were accomplished in Colorado, Massachusetts and Wisconsin with 23 experienced professionals. During each of these comprehensive sessions, participants identified and ranked potential failures based on severity, occurrence and detection to calculate risk priority number (RPN) values.ResultsA total of 96 failure modes were generated and ranked in a list of the 20 riskiest problems that show no significant discordances by site, although there were differences by profession of the rater, particularly nurses.ConclusionsOur results illustrate that the PFMEA method applies well to CF NBS and that steps requiring communication and information transfer are perceived to be the highest risks. The number of identified failures makes and their potential impact demonstrate considerable overall risk and a need for ongoing QI

    Ice concentration assimilation in a regional ice-ocean coupled model and its application in sea ice forecasting

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    A reasonable initial state of ice concentration is essential for accurate short-term forecasts of sea ice using ice-ocean coupled models. In this study, sea ice concentration data are assimilated into an operational ice forecast system based on a combined optimal interpolation and nudging scheme. The scheme produces a modeled sea ice concentration at every time step, based on the difference between observational and forecast data and on the ratio of observational error to modeled error. The impact and the effectiveness of data assimilation are investigated. Significant improvements to predictions of sea ice extent were obtained through the assimilation of ice concentration, and minor improvements through the adjustment of the upper ocean properties. The assimilation of ice thickness data did not significantly improve predictions. Forecast experiments show that the forecast accuracy is higher in summer, and that the errors on five-day forecasts occur mainly around the marginal ice zone

    Status of the Recent Declining of Arctic Sea Ice Studies

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    In the past 30 years, a large-scale change occurred in the Arctic climatic system, which had never been observed before 1980s. At the same time, the Arctic sea ice experienced a special evolution with more and more rapidly dramatic declining. In this circumstance, the Arctic sea ice became a new focus of the Arctic research. The recent advancements about abrupt change of the Arctic sea ice are reviewed in this paper. The previous analyses have demonstrated the accelerated declining trend of Arctic sea ice extent in the past 30 years, based on in-situ and satellite-based observations of atmosphere, as well as the results of global and regional climate simulations. Especially in summer, the rate of decrease for the ice extents was above 10% per decade. In present paper, the evolution characteristics of the arctic sea ice and its possible cause are discussed in three aspects, i.e. the sea ice physical properties, the interaction process of sea ice, ocean and atmosphere and its response and feedback mechanism to global and arctic climate system

    Thermodynamic processes of lake ice and landfast ice around Zhongshan Station, Antarctica

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    Thermodynamic processes of ice in three lakes and landfast ice around Zhongshan Station, Antarctica, were observed in 2006. The mass balance of lake ice was compared with that of landfast ice. The responses of lake ice and sea ice temperatures to the local surface air temperature are explored. Vertical conductive heat fluxes at varying depths of lake ice and sea ice were derived from vertical temperature profiles. The freeze up of lake ice and landfast ice occurred from late February to early March. Maximum lake ice thicknesses occurred from late September to early October, with values of 156{177 cm. The maximum sea ice thicknesses of 167{174 cm occurred relatively later, from late October to late November. Temporal variations of lake ice and landfast ice internal temperatures lagged those of air temperatures. High-frequency variations of air temperature were evidently attenuated by ice cover. The temporal lag and the high-frequency attenuation were greater for sea ice than for lake ice, and more distinct for the deeper ice layer than for the upper ice layer. This induced a smaller conductive heat flux through sea ice than lake ice, at the same depth and under the same atmospheric forcing, and a smoother fluctuation in the conductive heat flux for the deeper ice layer than for the upper ice layer. Enhanced desalination during the melt season increased the melting point temperature within sea ice, making it different from fresh lake ice

    Review of research on Arctic sea ice physics based on the Chinese National Arctic Research Expedition

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    China launched its Arctic research program and organized the first Chinese National Arctic Research Expedition (CHINARE-Arctic) in 1999. By 2016, six further expeditions had been conducted using the R/V Xuelong. The main region of the expeditions has focused on the Pacific sector of the Arctic Ocean for sea ice observations. The expeditions have used icebreaker, helicopter, boat, floe, and buoy platforms to perform these observations. Some new technologies have been developed, in particular, the underway auto-observing system for sea ice thickness using an electromagnetic instrument. The long-term measurement systems, e.g., the sea ice mass balance buoy, allow observations to extend from summer to winter. Some international cooperation projects have been involved in CHINARE-Arctic, especially the “Developing Arctic Modeling and Observing Capabilities for Long-Term Environmental Studies” project funded by the European Union during the International Polar Year. Arctic sea ice observations have been used to verify remote sensing products, identify changes in Arctic sea ice, optimize the parameterizations of sea ice physical processes, and assess the accessibility of ice-covered waters, especially around the Northeast Passage. Recommendations are provided as guidance to future CHINARE-Arctic projects. For example, a standardized operation system of sea ice observations should be contracted, and the observations of sea ice dynamics should be enhanced. The upcoming launch of a new Chinese icebreaker will allow increased ship time in support of future CHINARE Arctic oceanographic investigations

    The rise of sea ice research collaboration between China and Finland

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    Collaboration between China and Finland in marine sciences was commenced in winter 1988. The main topic was then short-term sea ice forecasting in the seasonal sea ice zone (SSIZ), particularly in the Bohai Sea in China and the Baltic Sea in Finland. The sea ice in SSIZ is thin and highly dynamic so that ice conditions may change rapidly. While the length scales of the Baltic Sea and the Bohai Sea are similar, the main difference between them is that the former is brackish and non-tidal while the latter is oceanic for the salinity and possesses a large tidal amplitude. The Bohai Sea is located at latitudes 37°N–41°N, and the Baltic Sea is located at latitudes 55°N–66°N. However, the same sea ice model is applicable for both. The main application field of sea ice forecasting was winter shipping in Finland and oil drilling in China. The collaboration was successful and in late 1990s the research was expanded to polar seas, lakes, and to climate change applications
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