I Want My Mamma

https://digitalcommons.library.umaine.edu/mmb-vp/6032/thumbnail.jp

Letter from Dot B. and Story Jackson to Hubert Creekmore

Dot B. and Story Jackson write from Cleveland, Ohio, to Creekmore in Jackson, Mississippi. Jackson states that Lindley at Harcourt said that they plan to publish Jackson\u27s novel. Jackson discusses Creekmore\u27s upcoming novel and their experiences living in Cleveland. Includes envelope.https://egrove.olemiss.edu/creekmore/1130/thumbnail.jp

I Long To See The Old Home Once Again

https://digitalcommons.library.umaine.edu/mmb-vp/3793/thumbnail.jp

Gender and vocal production mode discrimination using the high frequencies for speech and singing

Humans routinely produce acoustical energy at frequencies above 6 kHz during vocalization, but this frequency range is often not represented in communication devices and speech perception research. Recent advancements toward high-definition (HD) voice and extended bandwidth hearing aids have increased the interest in the high frequencies. The potential perceptual information provided by high-frequency energy (HFE) is not well characterized. We found that humans can accomplish tasks of gender discrimination and vocal production mode discrimination (speech vs. singing) when presented with acoustic stimuli containing only HFE at both amplified and normal levels. Performance in these tasks was robust in the presence of low-frequency masking noise. No substantial learning effect was observed. Listeners also were able to identify the sung and spoken text (excerpts from “The Star-Spangled Banner”) with very few exposures. These results add to the increasing evidence that the high frequencies provide at least redundant information about the vocal signal, suggesting that its representation in communication devices (e.g., cell phones, hearing aids, and cochlear implants) and speech/voice synthesizers could improve these devices and benefit normal-hearing and hearing-impaired listeners

The perceptual significance of high-frequency energy in the human voice

While human vocalizations generate acoustical energy at frequencies up to (and beyond) 20 kHz, the energy at frequencies above about 5 kHz has traditionally been neglected in speech perception research. The intent of this paper is to review (1) the historical reasons for this research trend and (2) the work that continues to elucidate the perceptual significance of high-frequency energy (HFE) in speech and singing. The historical and physical factors reveal that, while HFE was believed to be unnecessary and/or impractical for applications of interest, it was never shown to be perceptually insignificant. Rather, the main causes for focus on low-frequency energy appear to be because the low-frequency portion of the speech spectrum was seen to be sufficient (from a perceptual standpoint), or the difficulty of HFE research was too great to be justifiable (from a technological standpoint). The advancement of technology continues to overcome concerns stemming from the latter reason. Likewise, advances in our understanding of the perceptual effects of HFE now cast doubt on the first cause. Emerging evidence indicates that HFE plays a more significant role than previously believed, and should thus be considered in speech and voice perception research, especially in research involving children and the hearing impaired

Formulation and Testing of Paraffin-Based Solid Fuels Containing Energetic Additives for Hybrid Rockets

Many approaches have been considered in an effort to improve the regression rate of solid fuels for hybrid rocket applications. One promising method is to use a fuel with a fast burning rate such as paraffin wax; however, additional performance increases to the fuel regression rate are necessary to make the fuel a viable candidate to replace current launch propulsion systems. The addition of energetic and/or nano-sized particles is one way to increase mass-burning rates of the solid fuels and increase the overall performance of the hybrid rocket motor.1,2 Several paraffin-based fuel grains with various energetic additives (e.g., lithium aluminum hydride (LiAlH4) have been cast in an attempt to improve regression rates. There are two major advantages to introducing LiAlH4 additive into the solid fuel matrix: 1) the increased characteristic velocity, 2) decreased dependency of Isp on oxidizer-to-fuel ratio. The testing and characterization of these solid-fuel grains have shown that continued work is necessary to eliminate unburned/unreacted fuel in downstream sections of the test apparatus.3 Changes to the fuel matrix include higher melting point wax and smaller energetic additive particles. The reduction in particle size through various methods can result in more homogeneous grain structure. The higher melting point wax can serve to reduce the melt-layer thickness, allowing the LiAlH4 particles to react closer to the burning surface, thus increasing the heat feedback rate and fuel regression rate. In addition to the formulation of LiAlH4 and paraffin wax solid-fuel grains, liquid additives of triethylaluminum and diisobutylaluminum hydride will be included in this study. Another promising fuel formulation consideration is to incorporate a small percentage of RDX as an additive to paraffin. A novel casting technique will be used by dissolving RDX in a solvent to crystallize the energetic additive. After dissolving the RDX in a solvent chosen for its compatibility with both paraffin and RDX, the mixture will be combined with the melted paraffin. With the melting point of the paraffin far below the decomposition temperature of the RDX, the solvent will be boiled off, leaving the crystallized RDX embedded in the paraffin. At low percentages of RDX additive and with crystallized RDX surrounded by paraffin, the fuel grains will remain inert, maintaining a key benefit of hybrids in the safety of the solid fuel

Changes in Plasma Creatinine Concentration after Cardiac Anesthesia with Isoflurane, Propofol, or Sevoflurane A Randomized Clinical Trial

Background: Renal impairment often follows cardiac surgery. The authors investigated whether sevoflurane produces greater increases in plasma creatinine concentration than isoflurane or propofol after elective coronary artery surgery. Methods: As part of maintenance anesthesia, including during cardiopulmonary bypass, patients were randomly allocated to receive one of three agents: isoflurane (n ‫؍‬ 118), sevoflurane (n ‫؍‬ 118), or propofol (n ‫؍‬ 118). Results: The differences between the groups were small, clinically unimportant, and not statistically significant for the primary analysis and subgroups. The proportions of patients with creatinine increases greater than 44 M were 15% in the isoflurane group, 17% in the sevoflurane group, and 11% in the propofol group (P ‫؍‬ 0.45). The median increases were 8 M in the isoflurane group, 4 M in the sevoflurane group, and 6 M in the propofol group. The differences between the three median maximum increases were 1-4 M (P > 0.45). In the subgroup with preoperative renal impairment, the median increases were 10 M in the isoflurane group, 15 M in the sevoflurane group, and 5 M in the propofol group (P ‫؍‬ 0.72). Conclusions: Sevoflurane did not produce greater increases in creatinine than isoflurane or propofol after elective coronary artery surgery

Assessment of sweep net and suction sampling for evaluating pest insect populations in hay alfalfa

Insect populations in alfalfa grown for hay can be sampled using several methods. However, in a pest management program a relatively easy, quick, and reliable method of sampling is essential for making effective pest control decisions. A study was conducted to determine if two different sampling methods, sweepnet sampling and suction sampling, led to similar pest control decisions. Differences between sweepnet and D-Vac insect population estimates varied over sampling dates and years and were dependent on the insect species, their developmental stages, and abiotic factors. Our results indicate that, for many sampling dates, decisions on control of some pest insects would be similar for the two sampling methods.Keywords: Insecta; Medicago sativa; alfalfa weevil; pea aph