2,722 research outputs found

    Line Strengths of Rovibrational and Rotational Transitions in the X2Π^2\Pi Ground State of OH

    Get PDF
    A new line list including positions and absolute intensities (in the form of Einstein AA values and oscillator strengths) has been produced for the OH ground X\DP\ state rovibrational (Meinel system) and pure rotational transitions. All possible transitions are included with v\primed and v\Dprimed up to 13, and JJ up to between 9.5 and 59.5, depending on the band. An updated fit to determine molecular constants has been performed, which includes some new rotational data and a simultaneous fitting of all molecular constants. The absolute line intensities are based on a new dipole moment function, which is a combination of two high level ab initio calculations. The calculations show good agreement with an experimental v=1 lifetime, experimental μv\mu_\mathrm{v} values, and Δ\Deltav=2 line intensity ratios from an observed spectrum. To achieve this good agreement, an alteration in the method of converting matrix elements from Hund's case (b) to (a) was made. Partitions sums have been calculated using the new energy levels, for the temperature range 5-6000 K, which extends the previously available (in HITRAN) 70-3000 K range. The resulting absolute intensities have been used to calculate O abundances in the Sun, Arcturus, and two red giants in the Galactic open and globular clusters M67 and M71. Literature data based mainly on [O I] lines are available for the Sun and Arcturus, and excellent agreement is found.Comment: 17 pages, 8 figues. 7 supplementary files: dipole moment functions (OH-X-DMFs.txt), equilibrium constants (OH-X-Equilibrium_Constants.txt), partition function (OH-X-Q_5-6000K.dat), PGOPHER file with molecular constants and transition matric elements (OH-XX.pgo), vibrational Einstein A and f values (OH-XX-Avv_fvv.txt), line list (OH-XX-Line_list.txt), and OH-Transformation_Equation_Extra.doc

    The isolation, identification, and characterization of bacteria associated with the deep-sea coral Lophelia pertusa

    Get PDF
    Cold-water corals (CWC) form the structural basis of highly diverse and productive ecosystems in the deep, dark ocean, serving as important spawning, nursery, and breeding habitat for many fishes and invertebrates. As such, they play an important role in supporting fisheries that humans rely on, as well as general ocean health, which is of critical importance to Earth as the effects of climate change unfold. CWCs are heterotrophic filter feeders, and their ability to survive in dark, oligotrophic waters may be linked to partnerships with microbial symbionts that participate in nutrient cycling and conservation. While indirect methods–DNA sequencing, whole genome analysis, isotopic analysis–have been used to hypothesize the roles of these symbionts, few studies have grown cultures of associated microbes and directly observed the metabolic processes involved in carbon and nitrogen turnover. In this study, bacteria cultured from the globally distributed, deep-sea coral Lophelia pertusa were isolated and characterized according to morphological and physiological characteristics. Sanger sequencing of 16S rRNA from the isolates yielded a diversity of bacterial species in the phylum Proteobacteria. In culture, isolates demonstrate the ability to use a variety of organics as carbon, nitrogen, and energy sources, the most notable of which is chitin, a polymer containing both carbon and nitrogen that is abundant in marine systems. Additionally, preliminary evidence suggests the ability of one isolate to fix nitrogen. These findings corroborate evidence of nutrient cycling in CWCs and support the hypothesis that microbial associates of these corals are an important aspect of their ecophysiology and likely help fuel their productivity. Physical and physiological stress induced by changes in the environment resulting from human activities and climate change couldinfluence host-microbe interactions, altering the ability of CWCs to conserve and recycle limiting resources. Loss of CWC ecosystems would mean loss of critical habitat and a globally relevant carbon sink

    Middle school teacher attitudes toward the achievement of English language learners

    Get PDF
    The purpose of this study was to explore the attitudes of teachers who are responsible for teaching ELLs in an inclusion setting. In this study, inclusion refers to the integration of ELL students into mainstream classes with no ESL teacher to assist in the classroom. ELL students participate in traditional middle school language arts classes, but may be pulled out for ESL services. A survey developed by Reeves (2002) was modified and used to determine attitudes of middle school language arts teachers in North Carolina. This study occurred in one school district with a large ELL population in each of the eight regions. There were 740 teachers invited to participate in 68 schools, with a 51% response rate. Teachers indicated positive attitudes toward the inclusion of ELL students, however 89.6% expressed that ELL students needed to attain a minimum level of English proficiency prior to entering the mainstream classroom. A large percentage of teachers (89.3%) reported that ELL students require longer than two years to acquire English with 82.4% supporting legislation to make English the official language of the U.S. Responses on the Likert portion of the survey indicated that teachers felt they were supported, yet indicated support was a challenge when asked to write in their response. Recommendations for future research and implications for practice and policy include exploring the relationship between mainstream teachers and the ESL teacher, examining the role culture plays in the school setting and conducting qualitative research. Future policies should reflect research and best practice

    Optical assembly of far-field super-resolution imaging via optical gain

    Get PDF
    The performance of an optical imaging system is fundamentally limited by the wave nature of light. More specifically the lateral resolution of an image has traditionally been dictated by Abbe’s limit, to be approximately one-half of the wavelength. The pursuit of exceeding this limit is a growing interest in several research areas. The goal of these pursuits is to achieve super-resolution imaging, as in breaking what have long been thought of as insurmountable restrictions. There have been several methods proposed and demonstrated to overcome Abbe’s limits. Some of the aforementioned methods include the perfect lens made from negative refractive index materials and Structured Illumination Microscopy (SIM). This paper highlights a novel approach to achieving super-resolution imaging. In this case the means to obtaining super-resolution imaging will be through optical gain by using an active objective lens. This gain will allow for the retention of spatial frequencies beyond Abbes limit, by the conversion of evanescent waves into sustainable propagating waves. An optical assembly was constructed to verify the theory of optical gain assisted evanescent wave conversion. The experimental results show that for two specific situations, where one (Pump angle A) provides the possibility of optical gain assisted evanescent wave conversion and one (Pump angle C) does not, Pump angle A position allows for the detection of higher spatial frequency information than Pump angle C position in the far-field pattern. This confirms the hypothesis and the theory of evanescent wave conversion via optical gain, providing the potential for far-field super-resolution

    Note: Improved line strengths of rovibrational and rotational transitions within the X3Σ− ground state of NH

    Get PDF
    Recently, a line list including positions and transition strengths was published for the NH X3Σ− rovibrational and rotational transitions. The calculation of the transition strengths requires a conversion of transition matrix elements from Hund’s case (b) to (a). The method of this conversion has recently been improved during other work on the OH X2Π rovibrational transitions, by removing an approximation that was present previously. The adjusted method has been applied to the NH line list, resulting in more accurate transition strengths. An updated line list is presented that contains all possible transitions with v′ and v″ up to 6, and J up to between 25 and 44, depending on the band

    Aging is associated with an over-sensitivity of brain responses to sounds

    Get PDF
    Aging and hearing loss leads to increased neural responses to sounds in the auditory cortex compared to younger people. Enhanced neural activity to sound may be a physiological mechanism underlying the difficulty that older adults have with ignoring irrelevant sound information.https://ir.lib.uwo.ca/brainscanresearchsummaries/1002/thumbnail.jp

    Movement and habitat ecology of protected species in North Carolina

    Get PDF
    Reptiles and amphibians are declining worldwide, especially from global climate change and habitat loss and fragmentation. Conservation efforts for imperiled species usually involve habitat protection, but are only effective if biologists and land managers have a thorough understanding of a species’ habitat requirements. This prerequisite knowledge is complicated for many herpetofauna because they utilize different habitats throughout their lifetime, such as separate breeding and non breeding habitats. Thus, multiple habitats must be studied and protected for conservation to be successful. This research aimed to better understand the habitat ecology of two protected herpetofaunal species in North Carolina to enhance future conservation. The first species, mountain chorus frogs (Pseudacris brachyphona), are small, terrestrial frogs, and a state species of special concern. Like many amphibians their breeding habitat has been studied, but little is known about their post breeding habitat. Nineteen individuals from two breeding sites were tracked by radio telemetry for approximately 25 days as they left their breeding site to examine their post breeding habitat. Breeding pools were surrounded closely by field and orchard habitats, and more distantly by forest. Frogs traveled 11.4 475.6 m from their breeding site, and no macrohabitat selection was detected among available habitats. However, the majority of individuals from the breeding site nearest the forest entered the forest, and the farthest traveling individuals from the other breeding site did as well. Mountain chorus frogs likely continued moving after 25 days, and were selecting forest habitat. I measured percent cover of vegetation within 1 m2 plots in all habitats, and forest had significantly greater leaf litter and canopy cover than did field and orchard. Likewise, there were significantly more burrows available in the forest than in other habitats. These habitat characteristics would provide greater protection from predators and desiccation in the forest, which could explain preference for forest. The second species studied, the bog turtle (Glyptemys muhlenbergii), is a small freshwater species, that is both federally- and state threatened. The majority of its habitat in the southeastern United States is small wetlands in livestock pastures, dominated by emergent vegetation (rushes and sedges) and with little shrub and canopy cover. I followed the movements of six turtles using radio telemetry from May October 2015 in a unique bog turtle wetland. This site is in Nantahala National Forest, has likely had little human disturbance for 80 years, and approximately half of the wetland is shrub/scrub habitat. Resident turtles significantly preferred shrub/scrub habitat with 68% of locations within this habitat type. I located two nests, both in emergent habitat. Shrub/scrub had significantly greater abundance of deep mud, which could explain turtles’ preference for this habitat. Bog turtles frequently burrow down into mud, and deeper mud might be easier to move through. Females had greater mean daily movement rates and home ranges (8.3 m/day, 0.6064 ha) than males (5.0 m/day, 0.4458 ha), which might be due to nesting migrations to emergent habitat. Thus, bog turtles will utilize shrub/scrub habitat where available, but nest in emergent habitat, likely due to its better thermal environment for offspring development

    Monthly Planet, 1983, February

    Get PDF
    https://cedar.wwu.edu/planet/1115/thumbnail.jp

    Monthly Planet, 1982, November

    Get PDF
    https://cedar.wwu.edu/planet/1113/thumbnail.jp
    • …
    corecore