2,293 research outputs found

    Effects of Mosquito Control Chemicals on Aquatic Fauna

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    No mosquito abatement districts have ever been organized in Arkansas. Mosquito control efforts have been largely adulticiding operations by either aerial application or ground thermal fogging machines. Practically no chemical applications have been directed at the larval stage in residual water in ditches and depressions from which adult populations arise. Some larviciding with ethyl parathion has been done in ricefields. Although the treatment is very effective in mosquito reduction, voluntary treatment has not been completely successful. Because relatively little insecticide has been used as a larvicide in Arkansas, it was possible to evaluate the effect of recommended larvicides on non-target organisms in the aquatic environment. A developing mosquito control demonstration program in the rice-producing area provided the study site

    House Fly Problem

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    Interview with Ralph Lancaster by Mike Hastings

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    Biographical NoteRalph I. Lancaster, Jr. was born on May 5, 1930, in Bangor, Maine, to Ralph I. Lancaster, Sr. and Mary Kelleher Lancaster. He was reared in Bangor by Bridget and Charles Mylan. He attended high school at John Bapst and went on to the College of the Holy Cross in Worcester, Massachusetts, being graduated in 1952 with a degree in English and a minor in history. He earned his law degree from Harvard Law School, then was drafted and spent two years in the Army. He returned to Maine to clerk for Judge Gignoux and remained in that position for two years. Then he was offered a position at the law firm Hutchinson Pierce, where he remained at the time of this interview (now Pierce Atwood) as a trial lawyer. SummaryInterview includes discussion of: growing up in Bangor; Holy Cross and Harvard Law School; Lancaster’s experience in the Army; clerkship with Judge Gignoux; the University of Maine Law School and the overabundance of lawyers in parts of Maine; how Lancaster came to work for Hutchinson Pierce (now Pierce Atwood); being a trial lawyer and a Maine lawyer; how Judge Gignoux was selected, his attributes, and occasions when he would sit in other locations around the country; George Mitchell’s appointment to the federal judgeship in Maine; Lancaster’s reaction to Mitchell’s appointment to Muskie’s U.S. Senate seat; Supreme Court consideration; how the practice of law has changed in Maine; the degree to which education prepares a lawyer for his or her work and the need for hands-on experience; and Lancaster’s views on lawyers advertising

    THE USE OF NEAR INFRARED REFLECTANCE FOR EVALUATING COTTON FINENESS AND MATURITY

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    The U.S. Department of Agriculture has proposed to develop Ii new high speed, high volume technique to assess cotton quality. This goal has led us to investigate the feasibility of near infrared reflectance spectroscopy as a technique for evaluating cotton fiber perimeter size and wall thickness, two of the physical characteristics used in the evaluation of cotton fineness and maturity. In order to isolate the effects of perimeter size and wall thickness, nineteen cotton samples were selected on the basis of their having a nonsignificant correlation between these 2 measurements. The reflectance spectra from 1100 to 2500 nanometers was recorded at every other wavelength. The 700 independent variables were transformed by log (1/ reflectance). Due to the multicollinearity of the independent variables, the principle components were used in a multiple regression with data obtained from the reference method (arealometer) for the two dependent variables, perimeter size and wall thickness. The regression analysis of perimeter size and wall thickness on the principle components gave R2\u27S of 0.229 and 0.943 respectively

    Implementation of the page fault frequency replacement algorithm.

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    This paper investigates the implementation of the page fault frequency (PFF) replacement algorithm as the mechanism for selecting and replacing pages of programs loaded into the main memory of a multiprocessing, multiprogrammed computer system. The frequency at which an executing program requires a page of virtual memory, the PFF, provides a basis for judging the real memory requirements of the program. Operating difficulties of PFF that reduce its usefulness in a time-shared computer system (Michigan Terminal System) are discussed, and a means of implementing the algorithm is proposed.http://archive.org/details/implementationof00lancCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

    Toward autism recognition using hidden Markov models

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    Master of ScienceDepartment of Computing and Information SciencesDavid A. GustafsonThe use of hidden Markov models in autism recognition and analysis is investigated. More specifically, we would like to be able to determine a person's level of autism (AS, HFA, MFA, LFA) using hidden Markov models trained on observations taken from a subject's behavior in an experiment. A preliminary model is described that includes the three mental states self-absorbed, attentive, and join-attentive. Futhermore, observations are included that are more or less indicative of each of these states. Two experiments are described, the first on a single subject and the second on two subjects. Data was collected from one individual in the second experiment and observations were prepared for input to hidden Markov models and the resulting hidden Markov models were studied. Several questions subsequently arose and tests, written in Java using the JaHMM hidden Markov model tool- kit, were conducted to learn more about the hidden Markov models being used as autism recognizers and the training algorithms being used to train them. The tests are described along with the corresponding results and implications. Finally, suggestions are made for future work. It turns out that we aren't yet able to produce hidden Markov models that are indicative of a persons level of autism and the problems encountered are discussed and the suggested future work is intended to further investigate the use of hidden Markov models in autism recognition

    Predicting the behavior of robotic swarms in discrete simulation

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    Doctor of PhilosophyDepartment of Computing and Information SciencesDavid GustafsonWe use probabilistic graphs to predict the location of swarms over 100 steps in simulations in grid worlds. One graph can be used to make predictions for worlds of different dimensions. The worlds are constructed from a single 5x5 square pattern, each square of which may be either unoccupied or occupied by an obstacle or a target. Simulated robots move through the worlds avoiding the obstacles and tagging the targets. The interactions between the robots and the robots and the environment lead to behavior that, even in deterministic simulations, can be difficult to anticipate. The graphs capture the local rate and direction of swarm movement through the pattern. The graphs are used to create a transition matrix, which along with an occupancy matrix, can be used to predict the occupancy in the patterns in the 100 steps using 100 matrix multiplications. In the future, the graphs could be used to predict the movement of physical swarms though patterned environments such as city blocks in applications such as disaster response search and rescue. The predictions could assist in the design and deployment of such swarms and help rule out undesirable behavior

    Ultrafast Excited-State Dynamics of Rhenium(I) Photosensitizers [Re(Cl)(CO)_(3)(N,N)] and [Re(imidazole)(CO)_(3)(N,N)]^+: Diimine Effects

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    Femto- to picosecond excited-state dynamics of the complexes [Re(L)(CO)_(3)(N,N)]^n (N,N = bpy, phen, 4,7-dimethyl-phen (dmp); L = Cl, n = 0; L = imidazole, n = 1+) were investigated using fluorescence up-conversion, transient absorption in the 650−285 nm range (using broad-band UV probe pulses around 300 nm) and picosecond time-resolved IR (TRIR) spectroscopy in the region of CO stretching vibrations. Optically populated singlet charge-transfer (CT) state(s) undergo femtosecond intersystem crossing to at least two hot triplet states with a rate that is faster in Cl (~100 fs)^(−1) than in imidazole (~150 fs)^(−1) complexes but essentially independent of the N,N ligand. TRIR spectra indicate the presence of two long-lived triplet states that are populated simultaneously and equilibrate in a few picoseconds. The minor state accounts for less than 20% of the relaxed excited population. UV−vis transient spectra were assigned using open-shell time-dependent density functional theory calculations on the lowest triplet CT state. Visible excited-state absorption originates mostly from mixed L;N,N^(•−) → Re^(II) ligand-to-metal CT transitions. Excited bpy complexes show the characteristic sharp near-UV band (Cl, 373 nm; imH, 365 nm) due to two predominantly ππ*(bpy^(•−)) transitions. For phen and dmp, the UV excited-state absorption occurs at 305 nm, originating from a series of mixed ππ* and Re → CO;N,N•− MLCT transitions. UV−vis transient absorption features exhibit small intensity- and band-shape changes occurring with several lifetimes in the 1−5 ps range, while TRIR bands show small intensity changes (≤5 ps) and shifts (~1 and 6−10 ps) to higher wavenumbers. These spectral changes are attributable to convoluted electronic and vibrational relaxation steps and equilibration between the two lowest triplets. Still slower changes (≥15 ps), manifested mostly by the excited-state UV band, probably involve local-solvent restructuring. Implications of the observed excited-state behavior for the development and use of Re-based sensitizers and probes are discussed

    Ground State Entropy of Potts Antiferromagnets: Bounds, Series, and Monte Carlo Measurements

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    We report several results concerning W(Λ,q)=exp(S0/kB)W(\Lambda,q)=\exp(S_0/k_B), the exponent of the ground state entropy of the Potts antiferromagnet on a lattice Λ\Lambda. First, we improve our previous rigorous lower bound on W(hc,q)W(hc,q) for the honeycomb (hc) lattice and find that it is extremely accurate; it agrees to the first eleven terms with the large-qq series for W(hc,q)W(hc,q). Second, we investigate the heteropolygonal Archimedean 4824 \cdot 8^2 lattice, derive a rigorous lower bound, on W(482,q)W(4 \cdot 8^2,q), and calculate the large-qq series for this function to O(y12)O(y^{12}) where y=1/(q1)y=1/(q-1). Remarkably, these agree exactly to all thirteen terms calculated. We also report Monte Carlo measurements, and find that these are very close to our lower bound and series. Third, we study the effect of non-nearest-neighbor couplings, focusing on the square lattice with next-nearest-neighbor bonds.Comment: 13 pages, Latex, to appear in Phys. Rev.
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