267 research outputs found

    Gestión de bosques mixtos de pino y roble en escenarios de incertidumbre climática

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    The process-based forest growth model 4C (FORESEE - FORESt Ecosystems in a Changing Environment) was used to analyze the growth of a mixed oak-pine stand [Quercus petraea (Mattuschka) Liebl., Pinus sylvestris L.]. The oak-pine stand is typical for the ongoing forest transformation in the north-eastern lowlands. The pine and the oak trees are 104 and 9 years old, respectively. Three different management scenarios (A, B, C) with different thinning grades and a thinning interval of five years were simulated. Every management scenario was simulated under three different climate scenarios (0K, 2K, 3K) compiled by the regional statistical climate model STAR 2.0 (PIK). For each climate scenario 100 different realisations were generated. The realisations of the climate scenarios encompass the period 2036-2060 and exhibit an increase of mean annual temperature of zero, two and three Kelvin until 2060, respectively. We selected 9 model outputs concerning biomass, growth and harvest which were aggregated to a single total performance index (TPI). The TPI was used to assess the management scenarios with regard to three management objectives (carbon sequestration, intermediate, timber yield) under climate change until 2060. We found out that management scenario A led to the highest TPI concerning the carbon sequestration objective and management scenario C performed best concerning the two other objectives. The analysis of variance in the growth related model outputs showed an increase of climate uncertainty with increasing climate warming. Interestingly, the increase of climate induced uncertainty is much higher from 2 to 3 K than from 0 to 2 K.Se ha utilizado un modelo forestal basado en procesos denominado 4C (FORESEE - FORESt Ecosystems in a Changing Environment) para analizar el crecimiento de un masa forestal con mezcla de Quercus petraea y Pinus sylvestris. Ésta es una mezcla típica en las áreas de transformación forestal en las zonas bajas del noreste de Alemania. Los pinos y los robles tienen una edad de 104 y 9 años respectivamente. Se simularon tres escenarios diferentes de manejo (A, B, C) con diferentes grados de claras e intervalos de clara de 5 años. Cada escenario de manejo fue simulado bajo tres escenarios climáticos (0K, 2K, 3K) los cuales se calcularon por el modelo regional climático estadístico STAR 2.0 (PIK). Se generaron 100 diferentes realizaciones para cada escenario climático. Las realizaciones incluyen el período 2036-2060 y presentan un aumento de la temperatura anual de cero, dos y tres grados Kelvin hasta el año 2060, respectivamente. Seleccionamos 9 salidas del modelo relacionadas con la biomasa, crecimiento y rendimiento que se combinaron en un único índice de rendimiento total (TPI, total performance index). El TPI fue analizado para investigar los escenarios de manejo con respecto a tres objetivos de manejo (secuestro de carbono, máximo rendimiento maderero, y un escenario intermedio a ambos) bajo la influencia de cambio climático hasta el año 2060. Nuestros resultados indican que el escenario A muestra el TPI más alto con respecto al secuestro de carbono, y el escenario C tuvo el mejor resultado respecto a los otros dos objetivos. El análisis de varianza en las salidas relativas al crecimiento mostró que mientras más evoluciona el calentamiento global, más crece la incertidumbre climática. Cabe destacar que el aumento de la incertidumbre inducida por el clima es mucho mayor al aumentar de 2 a 3 K que de 0 a 2 K

    Transforming the Professional Flight Program Curriculum: Justification, Process, and Future Development

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    According to the International Civil Aviation Organization (ICAO), by 2036 the aviation sector will need 620,000 new pilots, 125,000 new air traffic controllers, and 1.3 million aircraft maintenance personnel (ICAO, 2018); Pilots seeking a first officer position (a common entry-level position at Part 121 air carriers) are required to possess an Airline Transport Pilot (ATP) Certificate and 1,500 hours of total flight time; There are some exceptions! Support from administration Quantity vs Quality; How can flight faculty improve student learning and job readiness

    The Association between Critical Thinking and Scholastic Aptitude on First-time Pass Rate of the National Physical Therapy Examination

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    Objectives: 1) To investigate the relationships among critical thinking (CT) abilities, overall academic performance in the Doctorate of Physical Therapy (DPT) program as measured by cumulative grade point average (GPA), and National Physical Therapy Examination (NPTE) licensure scores, and 2) To determine if NPTE scores were significantly different between groups of students who were classified as having low, moderate or high CT abilities. Background: It is well-established that physical therapy practice requires good clinical reasoning skills. Passage of the NPTE is required for licensure. Research to date has been mixed as to whether CT abilities or GPA can predict success on national board licensure examinations such as the NPTE. The conflicting results may be partially due to weak research methodologies, uncontrolled confounders, and the use of non-standardized assessment instruments. Methods and Measures: A convenience sample of 91 DPT students completed a standard assessment of CT abilities three times. Repeated measure (RM) general linear model (GLM) tests were run to determine if mean California Critical Thinking Skills Test (CCTST) scores changed significantly over the course of the DPT program. A Pearson’s correlation matrix was constructed to investigate the relationships among NPTE scores, GPA, and CT. A univariate GLM test was run to determine if there was a statistically significant difference in mean NPTE scores between low, medium, and high CCTST groups. Results: Complete sets of the three CCTST scores were available for 69 students, and NPTE scores were available for 73 graduates. The strongest correlation with the first-time NPTE score was the GPA (r = 0.735, p = 0.001), followed by the CCTST score at Measurement 1 (r = 0.413, p = 0.0001). Graduates who were classified as having low CT abilities had a 100% failure rate on the first attempt for the NPTE, and scored significantly lower on the exam compared to graduates with moderate or high CT abilities (615.33, 634.6, and 652.43, respectively p = 0.0005). Conclusion: Implementing pedagogical practices that foster CT abilities and/or using a CCTST score of 18 or greater as DPT program entry criterion may equate to greater first-time NPTE pass rates for program graduates

    Comparison of the Host Ranges and Antigenicity of Cryptosporidium parvum and Cryptosporidium wrairi from Guinea Pigs

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    Oocysts of a Cryptosporidium isolate from guinea pigs were not infectious for adult mice, but were infectious for two of three newborn calves and for suckling mice. However, oocysts isolated from calves or mice infected with guinea pig Cryptosporidium were not infectious for guinea pigs. Four isolates of C. parvum from calves were incapable of infecting weanling guinea pigs. Microscopic examination of tissue from the colon and cecum of suckling guinea pigs inoculated with C. parvum revealed sparse infection of some pups. These host range studies and previously described differences in 125 I-labeled oocyst surface protein profiles between Cryptosporidium sp. from guinea pigs and C. parvum suggest they are distinct species. We propose the name Cryptosporidium wrairi be retained. Studies with monoclonal antibodies indicate that C. wrairi and C. parvum are antigenically related.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75184/1/j.1550-7408.1992.tb01471.x.pd

    Impacts of colonial waterbirds on vegetation and potential restoration of island habitats

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    Colonial waterbirds have impacted forested island ecosystems throughout their breeding range, changing vegetation, and soil characteristics and bird communities. Our objectives were to (1) determine effects of three levels of colonial waterbird exclusion on overall vegetation diversity and growth, and survival of a candidate restoration species (black elderberry; Sambucus nigra canadensis); (2) investigate effects of different planting techniques on survival and growth of black elderberry; and (3) determine effects of waterbird colonization on soil chemistry. In 2012, we investigated effects of three levels of waterbird exclusion (none control plots [CON]; partial, which excluded waterbirds larger than gulls [PEX]; and full which excluded all waterbirds [FEX]) on bird use, existing vegetation growth and diversity, and survival of planted black elderberry on three islands in Door County, WI, Lake Michigan. In 2013, we evaluated survival of black elderberry established with four planting treatments within three waterbird exclusion treatments on two islands in 2013.We also compared soil chemistry characteristics between islands with and without nesting waterbirds for 2 years. Overall plant growth was greater in exclosures, but elderberry survival was similar among treatments. Soil replacement and weed suppression planting treatments did not affect survival, but generally increased overall elderberry biomass. Soil from nesting islands was more acidic and had greater nutrient concentrations than reference islands. Exclusion or removal of colonial nesting waterbirds from islands may improve overall vegetation growth, but successful restoration of woody vegetation may require significant soil manipulation and planting

    "Wissenschaft fürs Wohnzimmer" – two years of interactive, scientific livestreams weekly on YouTube

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    Science communication is becoming increasingly important to connect academia and society, and to counteract fake news among climate change deniers. Online video platforms, such as YouTube, offer great potential for low-threshold communication of scientific knowledge to the general public. In April 2020 a diverse group of researchers from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research launched the YouTube channel "Wissenschaft fürs Wohnzimmer" (translated to "Sitting Room Science") to stream scientific talks about climate change and biodiversity every Thursday evening. Here we report on the numbers and diversity of content, viewers, and presenters from 2 years and 100 episodes of weekly livestreams. Presented topics encompass all areas of polar research, social issues related to climate change, and new technologies to deal with the changing world and climate ahead. We show that constant engagement by a group of co-hosts, and presenters from all topics, career stages, and genders enable a continuous growth of views and subscriptions, i.e. impact. After 783 days the channel gained 30,251 views and 828 subscribers and hosted well-known scientists while enabling especially early career researchers to improve their outreach and media skills. We show that interactive and science-related videos, both live and on-demand, within a pleasant atmosphere, can be produced voluntarily while maintaining high quality. We further discuss challenges and possible improvements for the future. Our experiences may help other researchers to conduct meaningful scientific outreach and to push borders of existing formats with the overall aim of developing a better understanding of climate change and our planet
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