 |
 |
|
 |
||
 |
 |
|
|
|
|
||
|
|
Aalto
Clarence
King's Geology in the Context of His EraAfter completing a geology degree at Yale and serving as a volunteer for Whitney's Geological Survey of California, Clarence King organized and directed the Fortieth Parallel Survey [1867-72] from the Sierra Nevada (SN) across the Rocky Mountains, topographically and geologically mapping 87,000 sq. mi. His interpretations presented in "Systematic Geology" [1878] and later papers reflect both his training at Yale, strongly influenced by J. D. Dana, and personal field and laboratory observations. Some of these interpretations have proven to be incorrect, but when viewed in context of his times they reflect superb critical thinking by King. For example, his requirement of a western sediment source and uniform gradual subsidence due to loading in the Great Basin (GB) during the Paleozoic reflected a consensus that granitic and most metamorphic rocks were Archean, and that facies indicated a Paleozoic strand line east of SN. Post-Jurassic catastrophic tectonism resulted in sudden depression of the SN Archean land and uplift of GB Paleozoics, accompanied by extensive folding reflecting chiefly east-west crustal shortening, with deformation lessening eastward and fold locations strongly influenced by a high relief, largely buried Archean topography. Complex high angle Tertiary faulting accompanying catastrophic rhyolitic volcanism resulted in dislocation of old folds, and ranges were broken into irregular blocks with thousands of feet of relative vertical displacement. Tertiary basalts succeeded rhyolites, and finally, extensive pluvial lakes formed contemporaneously with extensive alpine glaciation. King rejected strict Lyellian uniformitarianism and related Darwinian evolution to episodes of selection pressure engendered by natural catastrophes, for which he found evidence in his field area. King's [1893] refinement [to 24 my] of Kelvin's earth age estimate from terrestrial refrigeration reinforced his conception that inadequate time existed to explain the Fortieth Parallel geologic record by radical uniformitarianism, and that higher energy, accelerated geologic processes best accounted for episodes of uplift/subsidence, faulting, volcanism and landscape degradation. King thus stands out as an early "actualist", in some ways quite modern in his approach to event stratigraphy.
Aberson et al.
An Interactive Tutorial for Teaching Regression
Variance ComponentsThe Web Interface for Statistics Education (WISE) provides Internet-based tutorials that supplement the teaching of core statistical concepts. This paper focuses on an interactive tutorial that provides instruction on correlation and regression. The correlation/regression tutorial (<http://wise.cgu.edu>, choose tutorials, then correlation and regression) includes an interactive JAVA applet, guided demonstrations, multiple-choice questions with feedback, and thought questions to test student understanding. We include a complete assignment that instructors or students may freely download.
Forty-one students from introductory (n = 22), intermediate (n = 12), and advanced (n = 7) psychological statistics courses used the tutorial as a laboratory assignment. Following tutorial completion, students rated ease of use, clarity of explanation of concepts, and comfort with topics. Most students found the materials easy to understand (90%) and rated statistical explanations as "clear" (80%). Students indicated that they were more comfortable with the material after using the tutorial (3% not at all comfortable, 56% somewhat, 41% very) than they were prior to completing the assignment (15% not at all, 73% somewhat, 12% very), Wilcoxon T = 3.8, p < .001.
Poster presentation: American Psychological Association, Chicago, Illinois, 2002.
Aberson et al.
One hundred forty-eight White college students participated in an examination of the influence of intergroup anxiety, perspective taking, contact quality, contact quantity, and salience of outgroup identity on implicit and explicit attitudes towards African Americans. Consistent with previous research, negative explicit attitudes were associated with greater intergroup anxiety and negative stereotyping. Contact quality and intergroup aspects of contact related to anxiety, perspective taking, and negative stereotyping. Only the interaction between quantity and quality of contact predicted implicit bias. Additional analyses, using a latent variable approach, revealed a relationship between intergroup anxiety and implicit biases. We discuss results in terms of integrated threat theory and models of intergroup bias proposed by Hewstone and Brown (1986).
Poster Presentation: Society for Personality and Social Psychology, Los Angeles, California, 2003.
Ambrose
Concern that declining returns of Pacific salmon have resulted in a loss of nutrients that historically enriched nutrient-poor streams of the Pacific Northwest has prompted recent efforts to introduce salmon carcasses as a recovery technique. While some studies have reported increased periphyton response to nutrient enrichment from carcasses or other sources, other evidence suggests that light may serve as a primary limitation on stream productivity. This study examined periphyton response to simultaneous manipulations of light and salmon carcass enrichment. Chlorophyll a, biofilm ash-free dry mass (AFDM), gross primary production (GPP), and periphyton taxonomic structure were measured in six tributary streams in the Smith and Klamath River basins in northern California that received varying treatments of increased light and salmon carcass introductions. In each stream, red alder (Alnum rubra) and other hardwoods were felled from the riparian zone to increase light along a 100 m stretch of stream, and another 100 m reach was established that had an intact riparian canopy. In three streams, salmon carcasses were introduced in both open and canopy-closed sections. Carcass enrichment provided a significant influx of phosphorus, but not nitrogen, into study streams. Results of an experiment using nutrient diffusing clay saucers to evaluate nutrient limitation, conducted in open and closed sections of a carcass-fertilized and a non-fertilized stream, implicated nitrogen as a limiting nutrient, and established a strong canopy effect on periphyton accrual, measured as AFDM. Canopy and carcass treatments did not detectably affect biomass of periphyton on natural substrates. The taxonomic composition of the periphyton assemblage was dominated by diatoms in all stream reaches on all dates, but diatom coverage was significantly reduced in open stream sections in August 2002 with a concomitant increase in green algae. Gross primary production, which was estimated by measuring changes in oxygen concentration in light and dark respiration chambers in early summer, did not differ among treatments. Collectively, results suggest that stream productivity, as indexed by attributes of the periphyton assemblage, may be enhanced to a greater extent by opening of the riparian canopy than by salmon carcass enrichment.
Bohannon and O'Gara
Copper, a heavy metal, is a cheap and commonly used molluscicide (Babu and Rao, 1985). In this study, the lethal and sub-lethal effects of copper on freshwater oligochaete, Lumbriculus variegatus were examined. The median lethal concentration (LC50) at 24 hr after copper exposure was 0.132 ppm. Sub-lethal endpoints focused on a few stimulus-evoked locomotor behaviors: escape reflexes controlled by giant interneuron pathways, swimming and reversal. Helical swimming and reversal behaviors are controlled by non-giant interneural pathways. Copper exposure (8 hr) produces concentration-dependent impairment of helical swimming and reversal behaviors. Copper exposure (24 hr) produces a reduction in giant fiber conduction velocity.
Boyle and Metz
Marine invertebrates that reproduce by spawning rely upon gamete surface proteins to recognize conspecific gametes for fertilization. By mediating species-specific fertilization, these proteins define reproductive compatibility. Gamete recognition proteins (GRPs) and their genes have previously been studied in echinoderms [E. C. Metz; S. R. Palumbi; Mol. Biol. 13, 397-406, 1996] and mollusks [V. D. Vacquier; Science 281, 1995-1998, 1998]. We have begun characterization of GRPs from marine polychaete annelids, opening this diverse group (~10,000 species) for the first time to comparative studies on the molecular evolution of fertilization.
Gametes were surgically removed from worms. Brief sonication was used to separate components of whole sperm. Centrifugation was utilized for component enrichment. The nucleic acid label DAPI and fluorescamine (a free amino group label) were used for labeling sperm components. Sperm proteins were separated by SDS-PAGE. Urea and SDS were used to dissolve acrosomal proteins.
Eudistylia sperm contain large acrosomal vesicles. Sperm nuclei and acrosomes were physically separated by sonication. Enrichment of acrosomes was not accomplished by centrifugation. Sperm nuclei were distinctly labeled with DAPI, and acrosomes were distinctly labeled with fluorescamine. Hypo-osmotic sperm treatment produced characteristic "ring" structures that labeled with fluorescamine on whole sperm. Acrosomal protein was solubilized in 4-8 M urea or 10% SDS. Highly insoluble acrosomal "gum-like" material labeled weakly with DAPI.
We found that the major component of Eudistylia acrosomes is a highly insoluble, basic protein. These proteins could not be resolved using SDS-PAGE, and we plan to isolate and characterize the acrosomal "gum" using acid-urea gels. Edistylia is an ideal model system for research on GRPs and a variety of techniques will be used to access the gene(s) and studies of its molecular evolution.
Funding for this project has been provided by HHMI.
Brown, Zoellner, and Golden
A
Computational Investigation of Conformer DistributionStable conformations of a series of perfluoroalkanes and their hydrocarbon analogs were analyzed using semi-empirical calculations at the PM3 level (PC Spartan ProÔ ). It was found that perfluoroalkanes exhibit helical structures as a significant percentage of their total stable conformations, whereas their hydrocarbon analogs do not. Two basic helical structures are present, a 5-carbon pitch helix and a 16-carbon pitch helix. Other stable conformations appear to be combinations of the two different helices. This effect is not observed in the analogous saturated alkanes. Higher level calculations are underway.
Clark, et al.
A
Thermal Desorption Spectrometer for Use in Undergraduate Research
and Laboratory CurriculumConstruction of a thermal desorption spectrometer has been undertaken. The instrument, upon its completion, is to be used in the undergraduate physical chemistry laboratory as well as to study the behavior of fluorocarbons adsorbed on Pt (111) surface.
Thermal desorption spectroscopy (TDS) is relatively simple in its theory and yet provides information fundamental in understanding the surface chemistry of the adsorbed molecules. Furthermore, even though TDS is one of the earliest methods used in investigating the state of adsorbates on surface, it is still extensively used in accurately determining the desorption parameters. Thus, the TDS would give future students the opportunities to be exposed to an important analytical technique in surface chemistry: an avenue of physical chemistry that tends to be underrepresented in current undergraduate physical chemistry courses.
Duckworth, van Horn, and Zoellner
Methylphenidate (Ritalin®) is a commonly prescribed pharmaceutical used to minimize the symptoms of attention deficit hyperactivity disorder (ADHD). The primary mode of action of this medication is thought to be through binding to an active site on the dopamine transporter. When abused, methylphenidate exhibits physiological effects similar to those of cocaine, most notably dopamine re-uptake inhibition. Because both methylphenidate and cocaine appear to bind to similar sites on the dopamine transporter, and because methylphenidate is a cocaine antagonist, it is may be feasible to use derivatives of methylphenidate to treat cocaine abuse. Semi-empirical (PM3) methods have been used to calculate the structures and properties of approximately fifty derivatives of methylphenidate and fifty derivatives of cocaine in order to establish correlations between experimental binding affinities and calculated electronic and molecular orbital properties. Calculated properties that appear to correlate strongly with binding affinities will be discussed and methods to enhance binding affinity will be inferred for both methylphenidate and cocaine.
Dupree, et al.
The
Development of a Questionnaire to Measure Sleep Disturbance in AdultsThere are a multiple number of questionnaires that explore a variety of sleep concepts. Most are extensive surveys of sleep disorders used in epidemiological studies. Others are a series of questions more typically written for an individual clinical interview. Most have no reports on any psychometric properties.
For the purposes of our ongoing research, we developed a questionnaire that explored Primary Insomnia, Restless Legs Syndrome, Nocturnal Micturition, Night Sweats, and Depression. The questionnaire contains 32 items, including two demographic questions and ten items that reflect the "exclusionary" criteria for Primary Insomnia such as physical and mental illness, medication use, substance use, or another sleep disorder. The remaining 20 items are scored on a five-point, Likert-type scale. Six of these explore Criteria A of Primary Insomnia, which identifies symptoms such as difficulty initiating or maintaining sleep and non-restorative sleep. Six items explored the Criteria B requirements of significant distress or impairment in functioning. Two items each explored the other four variables. All items were paired with a similar item to improve reliability.
Two analyses were conducted to measure the psychometric properties of this questionnaire. For this purpose all 363 respondents were used; 228 females and 135 males. Internal reliability was measured based on correlations of the paired items. Values ranged from 0.710 to 0.819 for the items related to Primary Insomnia. The other paired items ranged from 0.612 to 0.820. All of the correlations were significant at the 0.001 level.
Construct validity was measured through a principle-components factor analysis with Varimax rotation. The eigenvalues ranged from 5.196 for the first factor to 1.775 for the sixth factor, accounting for a cumulative percentage of 80.2% of the variance of the entire set. Loading on the sleep symptom items ranged from 0.546 to 0.770. Loadings on the functioning items ranged from 0.797 to 0.823. Loadings on each of the other subsets ranged from 0.827 to 0.907 for each variable. The Kaiser-Meyer-Olkin (KMO) measure of adequacy of item sampling was 0.907, which Kaiser labels as "marvelous." Also, Bartlett's Test of Sphericity suggests appropriate normality of distribution, with p<0.001.
In conclusion, these analyses strongly support the description and distinction of the original six variables, making this questionnaire a useful, brief, and psychometrically sound tool in exploring such sleep disturbances.
Edinger-Marshall, et al.
Many publicly owned rangelands are remote, with agricultural techniques limited or prohibited (e.g., cultivation and herbicides). This poster will document the first phase of an integrated approach to managing yellow starthistle (YST) (Centaurea solstitialis) using manual treatments (simulated grazing) and revegetation with transplants. Transplantation of perennial plugs does not require seedbed preparation and decreases risks associated with seed predation and weed competition. The objective of this long-term project is to restore a YST-infested homestead site with perennial native grasses and forbs. Blue wildrye (Elymus glaucus) and broad-leaved lotus (Lotus crassifolius) seed was gathered on the Six Rivers National Forest and sown in plugs at Tsemeta Nursery in Hoopa, California. In preparation for Fall 2002 transplantation, we did a baseline study to determine existing competitive species, their phenology, and concurrent environmental factors, including precipitation, air and soil temperature, and soil moisture. Results will be presented using digital imagery recorded starting March 2002. One specific objective will be to identify the optimal time for YST control by weed whacking (simulated grazing). Future studies will focus on herbivory and seedbank dynamics, the potential for herbivore grazing for weed control, and quantifying the role of existing biocontrol insects on YST.
Ettlin, Aberson, and Lawrence
This study examines whether minority targets receive more favorable ratings than majority targets. We extend research on the aversive racism paradigm through examination of reactions to minorities when normative behaviors and expressions of attitude are clear rather than ambiguous. To address this issue, we conducted a meta-analysis of 17 studies including more than 2000 participants. We found, as predicted, that minority targets are treated more positively (in terms of evaluation or behavior) than majority targets when norms proscribed positive treatment. When norms were ambiguous, majority targets received worse treatment than majority group members. We discuss results in terms of the aversive bias perspective, motivations to appear non-prejudiced (e.g., evaluative differences result from desire to appear egalitarian), and the flexible correction model.
Poster presentation: Western Psychological Association, Irvine, California, 2002. Paper based on presentation by Aberson and Ettlin, Social Justice Research, under review.
Giraldes and Cook
Umpolung
Indium- and Palladium-mediated Allylations of AldehydesThe reaction of indium and palladium with five-membered allylic benzoate substrates has shown regio- and stereo-specific allylations to various aldehydes resulting in a single homoallylic alcohol product. Some of these products are known to serve as important precursors for many biologically active molecules such as macrolides, polyhydroxylated natural products, and polyether antibiotics (polyketides). Postulates regarding the full mechanism are currently being investigated. It has been determined, so far, that an electrophilic -allylpalladium complex results just before the addition umpolung of the indium(I). Current investigations with six-membered allylic benzoate substrates are in progress to determine if the same regio- and stereo-selectivity will result. The results of this study will be presented.
Giraldes and Smith
An investigation into the study of h6-benzyne metal complexes was undertaken. Attempts to synthesize h6-benzyne coordinated metal compounds have been performed, but to date no prudent methods have proved useful. The instability of benzyne compounds causes one to have to undertake indirect methods of verification, e.g., Diels-Alder reactions with furan solvent. The method attempted here involved generating benzyne from benzenediazonium-2-carboxylate in the presence of a metal carbonyl. The benzyne may complex, dimerize, or do something entirely different. The results obtained in this study will be presented.
Haag, Smith, and Aberson
Two hundred seventy-three White undergraduates participated in an investigation how beliefs relate to support for affirmative action (AA) policies. Beliefs included fairness of AA, belief in merit, and value of diversity. Analyses predicted support for a general affirmative action policy, a tiebreak policy, and a policy using banding from beliefs and individual-level variables such as future benefit from AA and demographics. For the general policy, each belief predicted support for AA. Fairness and value of diversity predicted support for tiebreak. Value of diversity predicted support for aptitude testing. Individual characteristics improved prediction for AA in general but not for tiebreak or aptitude testing. We discuss predictions and results in terms of procedural and distributive justice, fairness heuristic theory, and models of support for AA.
Poster presentation: Western Psychological Association, Irvine, California, 2003.
Paper based on presentation by Aberson and Haag, Analyses of Social Issues and Public Policy, in press.
Haddad, Mola, and Hill
Angle dependant torque magnetization measurements have been carried out on the organic superconductor, k
-(ET)2Cu(NCS)2 at extremely low temperatures (~25 mK). Magneto-thermal instabilities are observed in the form of abrupt magnetization (flux) jumps for magnetic field sweeps of 0-20 Tesla. An initial analysis of these measurements only addressed the magnitude of the flux jumps without a detailed analysis of their structure. In this work we address the fine structure of the flux jumps, in particular examining the self-similarity displayed by the flux jumps at increasingly greater magnification. As scale invariance is a signature of fractal geometry, we have used a simple "box counting" method to determine the fractal dimension of the observed magneto-thermal instabilities within the superconducting mixed state as a function of the angle between the superconducting sample and applied magnetic field. From such an analysis we have determined that the magnetization of this organic superconductor does in fact show fractal behavior with a box counting dimension of DB ~ 1.2-1.4, similar to many other well known mathematical and naturally occurring fractals.
Higdon and Zoellner
Anti-oxidants have been identified as important biological agents in the prevention of heart disease and arteriosclerosis as well as some of the effects of aging. In particular, flavonoids such as catechin, epicatechin, and quercetin, found in wines, teas, and fruits have been cited in this respect. Computational methods have been applied to the analysis of the structures and properties of these or similar molecules; less work is extant concerning the determination of the relative anti-oxidant capabilities of anti-oxidants. In the present study, computational methods at the semi-empirical (PM3) and Hartree-Fock (3-21G(*) and 6-31G*) levels have been used to establish a reference set of stepwise oxidations by the stable free radical TMPO (2,2,6,6-tetramethylpiperidine-N-oxide of the simple phenols catechol, resorcinol, and hydroquinone. (For example, catechol is stepwise oxidized first to the semiquinone mono-radical and then to the quinone while two molecules of TMPO are reduced from the N-oxide to the N-hydroxide. Because the TMPO is the oxidizing agent in all reactions, direct comparisons between widely differing compounds becomes possible.) Establishment of this reference set of oxidation reactions then has allowed the investigation and comparison of more complex polyphenolic compounds for their anti-oxidant capabilities. The structural and electronic properties that give rise to the anti-oxidant capabilities of these polyphenolic compounds will be discussed in detail.
Howe and MacPhee
A
Meta-Analytical Evaluation of the Effects of ParentingThis meta-analysis examines over 400 studies (some unpublished) examining parental practices and their effects (if any) on children's social developmental outcomes. Prior research has suggested that parenting does affect children's adjustment in the peer domain, but it is unclear which parenting practices exert the strongest effects and on which types of social behaviors. Some examples of the parenting variables examined in the literature are: warmth/nurturance, open communication, and maltreatment. Child outcomes consist of variables such as loneliness, associating with deviant peers, and social competence. Preliminary results, using unweighted effect sizes, are shown in Table 1. Parental warmth/nurturance and attachment showed the strongest effects (on children's loneliness particularly). Surprisingly, some parenting practices, such as emotional communication, had relatively few important effects, across the studies, for children's outcomes in any domain measured. This study helps us determine the most salient parental behaviors and particularly informs future intervention/prevention efforts with parents, aimed at improving children's social adjustment.
Hu and Daugherty
Skin
Conductance Correlates to Symptoms of Motion SicknessIn the present study, we used optokinetic drum rotation to provoke symptoms of motion sickness. Electrical dermal activities were indexed by recording tonic and phasic skin conductance from the sites of finger palmar and forehead. The experimental results showed that subjects' subjective ratings of motion sickness (SRMS) were gradually increased during the 12 minutes of drum rotation period. Both phasic and tonic skin conductance levels were also gradually increased during the 12 minutes of drum rotation period for all subjects. Pearson's correlation coefficient analysis of 50 subjects indicated that subjects' rating of SRMS during the drum rotation period was significantly correlated to ratios of phasic skin conductance recorded in the finger palmar site between drum rotation and baseline periods (r = 0.432, p < 0.02), ratios of tonic skin conductance recorded in the finger palmar site between drum rotation and baseline periods (r =
0.476, p < 0.01), ratios of phasic skin conductance recorded in the forehead site between drum rotation and baseline periods (r = 0.624, p < 0.0001), and ratios of tonic skin conductance recorded in the forehead site between drum rotation and baseline periods (r = 0.388, p < 0.05). In conclusion, the phasic skin conductance responses recorded at forehead site was the most sensitive physiological correlate of motion sickness.
Julian and Howard
Concern over the decline of amphibian populations has prompted studies of the effects of pesticides on amphibians. Because many amphibians breed in water associated with agricultural areas, testing the sublethal effects of pesticide exposure throughout larval development may be especially relevant. We investigated the effects of pulsed exposure to three insecticides (carbaryl, chlorpyrifos, and imidacloprid on survival, growth, and time to metamorphosis of three amphibian species (Pseudacris triseriata, Bufo americanus, and Rana sphenocephala). Tadpoles were raised from two weeks post-hatching to metamorphosis in 20-gallon aquaria containing one of three dosages of a pesticide. Survival to metamorphosis of tadpoles in high concentrations of all three pesticides was significantly decreased for all species. As a result, subsequent analysis on sublethal effects was only performed on medium, low, and control concentrations. Growth of R. sphenocephala tadpoles was significantly decreased by exposure to medium concentrations of all three pesticides; however, growth of B. americanus tadpoles was decreased by medium concentrations of carbaryl and chlorpyrifos only. Growth of P. triseriata in all pesticide treatments was not significantly different from controls. Time to metamorphosis of tadpoles of all three species was significantly increased by medium concentrations of all three pesticides. Sublethal effects on time to metamorphosis and growth would be expected to have negative impacts on population persistence.
Keller and Zoellner
A
Computational Investigation of the Structures and Properties of
Möbius-twisted Molecules: Coronene and the Kekulenes RevisitedPrevious computational investigations [Frisch and Zoellner, Proc. Eleventh Nat. Conf. Undergrad. Res. 1997, V, 1760; Zoellner, Krebs, and Browne, J. Chem. Inf. Comp. Sci. 1994, 34(2), 252] strongly indicated that two independent isomeric molecules containing a single Möbius half-twist are derivable from the planar aromatic molecule coronene, and that four independent molecules containing a Möbius half-twist could be derived from [12]-kekulene. Recent studies at higher levels of theory supported the possibility of the existence of two Möbius-twisted coronenes, but demonstrated that only three independent Möbius-twisted [12]-kekulene isomers actually exist. Further, these calculations also indicated that fewer than the six predicted Möbius-twisted [18]-kekulenes are actually independent isomers. The experimental and calculated structures and properties of coronene and the kekulenes will be compared to and contrasted with the structures and properties of the Möbius-twisted isomers as calculated at Hartree-Fock levels of theory. Based upon molecular orbital energies, electron densities, and other calculated properties, reactivity trends for the Möbius-twisted isomers will be inferred.
Largent, et al.
Indole and 3-chloroindole: The Source of the Disagreeable
Odor of the Mushroom,
Hygrophorus paupertinusThe odor emanating from the mushroom, Hygrophorus paupertinus, is disagreeable and fecal-like. Solid phase microextraction (SPME) and analysis by gas chromatography-mass spectrometry (GC-MS) showed 1-octen-3-ol, indole and 3-chloroindole were responsible for the odor (structures below). This is the first case where 3-chloroindole has been identified from a terrestrial organism. Indole and 3-chloroindole are responsible for the fecal-like odor of this mushroom.
Lincoln and Smith
Alternate Pathways to (Cyclobutadiene)tricarbonyliron(0)(Cyclobutadiene)iron(0) tricarbonyl has been synthesized via many pathways. The "standard" Organic Syntheses method is reliable, but it requires cyclooctatetraene, which is expensive (~$40/g). We are investigating two alternate pathways to (cyclobutadiene)iron(0) tricarbonyl. Both involve a photochemical [2+2] cyclization in the initial step: the dimerization of crystalline maleic anhydride and the [2+2] cyclization of 1,2-dichloroethylene with maleic anhydride. These pathways are being pursued with the intention of synthesizing simple cyclobutadiene derivatives, (fluorocyclobutadiene)tricarbonyliron(0) and (hydroxycyclobutadiene)tricarbonyliron(0).
Madej, et al.
Using
Dynamic Programming and Genetic AlgorithmsMany anadromous fisheries streams in the Pacific Northwest have been damaged by various land use activities, including timber harvest and road construction. Unpaved forest roads can cause erosion and downstream sedimentation damage in anadromous fish-bearing streams. Although road decommissioning and road upgrading activities have been conducted on many of these roads, these activities have usually been implemented and evaluated on a site-specific basis without the benefit of a watershed perspective. Land managers still struggle with designing the most effective road treatment plan to minimize erosion while keeping costs reasonable across a large land base. Trade-offs between costs of different levels of treatment and the net effect on reducing sediment risks to streams need to be quantified. For example, which problems should be treated first, and by what treatment method? Is it better to fix one large problem or 100 small problems? If sediment reduction to anadromous fish-bearing streams is the desired outcome of road treatment activities, a more rigorous evaluation of risks and optimization of treatments is needed. Two approaches, Dynamic Programming (DP) and Genetic Algorithms (GA), were successfully used to determine the most effective treatment levels for roads and stream crossings in a pilot study basin with approximately 200 road segments and stream crossings and in an actual watershed with approximately 600 road segments and crossings. The optimization models determine the treatment levels for roads and crossings that maximize the total sediment saved within a watershed while maintaining the total treatment cost within the specified budget. The optimization models import GIS data on roads and crossings and export the optimal treatment level for each road and crossing to the GIS watershed model.
Moriarty
Historically, wolverines were distributed throughout the continent, including Alaska, the northwestern part of America, and south along the Rocky Mountains to Arizona and New Mexico. Although wolverines were present, they were never abundant in California. In the state there have been no confirmed documented wolverine sightings since the 1940s. In order to access the likelihood of this species’ continued existence, habitat analysis was preformed. Using ArcView, the total areas of preserved wilderness lands were intersected with the total area of suitable habitat. Suitable habitat was obtained by combining all high elevation vegetation/substrate types that were described amongst the consulted literature. Home ranges from various studies were compared. The lowest documented value of home range size was 40 km2 and with the calculated available area, 68 individuals could exist within the isolated habitat. Conversely, the largest home range for wolverine was 800 km2 and only four individuals with this requirement could exist. These numbers are overestimates, as roads, human use, corridor connectivity, and other essential variables were not considered.
Nachem
Pediatric Nursing Research and the Human Subjects
CommitteeOne of the most daunting aspects of doing nursing research can be the process of receiving approval from a committee for protection of human subjects in research, or Institutional Review Board (IRB). The process may be even more complex for research with children, because federal guidelines require specific protections for minors. Gaining IRB approval need not be a barrier to research. This poster provides guidelines and tips for preparing a research proposal for IRB review. The focus will be on psychosocial and behavioral research with children and their families, but the information will also apply to other types of research.
References:
Informed Consent Checklist (9/98); <http://ohrp.osophs.dhhs.gov/humansubjects/assurance/consentckls.htm>.
Nachem, B.; "Successfully negotiating the IRB process"; Journal of Child and Family Nursing (2001), 4, (1).
Nachem, B.; "Getting human subjects committee approval for research"; Home Health Care Management and Practice (2000), 13, (1).
National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research; "The Belmont Report: Ethical Principles and Guidelines for the Protection of Human Subjects of Research"; Office of Protection from Research Risks Reports (April 18, 1979);
<http://ohrp.osophs.dhhs.gov/humansubjects/guidance/belmont.htm#xethical>.
U.S. Department of Health and Human Services, National Institutes of Health, Office for Protection from Research Risks; Title 45, Public Welfare, Part 46, C.F.R.; Protection of Human Subjects; Subpart A, Federal Policy for the Protection of Human Subjects; Federal Register 56, 28003, (June 18, 1991); <http://ohrp.osophs.dhhs.gov/humansubjects/guidance/45cfr46.htm>.
Nielson
Elucidation of Doxorubicin Metabolism Using CE-LIFCapillary Electrophoresis with Laser Induced Fluorescence Detection (CE-LIF) was used in the separation and determination of the anti-caner drug doxorubicin (DOX) and its metabolites in cells treated with the drug. Cellular and matrix concentrations of DOX and its primary metabolite doxorubicinol were monitored over an 8 hr period to determine the rate of drug efflux. In addition, an attempt was made to gain structural information about unidentified doxorubicin metabolites through derivitization with a commercial fluorescent probe.
Parks, et al.
Regulation
of Protein Expression in Escherichia coli by Autoinducer-2
Escherichia
coli regulates the expression
of specific genes in response to signal molecules present in their
environment. These signal molecules, termed autoinducers, increase
in concentration proportionally with cell density during growth.
In this study, we used two methods to observe the changes that
take place in the proteome of E. coli following induction
by autoinducer-2 (AI-2). Both Isotope Coded Affinity Tags (ICAT)
and two-dimensional polyacrylamide gel electrophoresis (2D-PAGE)
were used in conjunction with mass spectrometry to identify proteins
from bulk E. coli cell lysates. The differentially expressed
proteins that we observed indicate a shift in nutrient utilization,
conservation of existing resources, and preparation for stressful
conditions. These changes lead us to believe that AI-2 is used
as an indicator of metabolic stress in populations that have depleted
levels of available nutrients.
Smith
Propellanes are a class of compounds in which three rings are fused to a central bond; a [2.2.2]propellane has three fused four-membered rings. The central bond of a [2.2.2]propellane is easily broken, thus only one other example is known, and it has a half-life of 28 minutes at 25°C. Fluorine is known to stabilize four membered rings, so to stabilize the central bond a fluorinated [2.2.2]propellane was synthesized.
Wayman and Sammakia
We have developed two amino-alcohol systems as nucleophilic oxygen catalysts for acyl transfer reactions. These molecules bear an alcohol and a base in close proximity to facilitate the acylation and subsequent deacylation of the catalyst oxygen. Initial studies focused on 4-dialkylaminopyridines as the basic unit, with substitution at both the 2- and 6-positions in order to sterically deactivate the nucleophilic pyridine nitrogen. A second system was based on an ortho-disubstituted benzene, consisting of a pyrrolidinomethyl substituent at one site and a hydroxyalkyl group at the other. A variety of catalysts of these types were prepared with varying acidities due to the presence of electron-withdrawing and electron-donating alkyl groups geminal to the hydroxyl group.
The importance of the hydroxyl group for catalytic activity has been established by blocking the hydroxyl group as the methyl ether. The methyl ethers of both the pyridine-derived and benzene-derived systems were found to be 94 and 930 times less active than the corresponding alcohol derivatives, respectively.
The inductive effect of the alkyl group plays a significant role in the reactivity of this class of catalysts. An electron-withdrawing group renders the hydroxyl group more acidic, more readily deprotonated and more reactive towards acylation, and a better leaving group for deacylation. As a result, trifluoromethyl substituted catalysts were found to proceed 4 and 40 times faster than the methyl substituted derivatives of the pyridine and benzene-derived systems, respectively.
The mechanism of this process is further revealed by the following observations. Immediately after the reaction is initiated, the NMR spectra (used to monitor the reaction progress) show the rapid decrease in the concentration of the catalyst and the appearance of a new set of signals corresponding to the acylated catalyst. The acylated catalyst remains as the predominant species until the reaction nears completion and the catalyst reverts to its original unacylated state. The system displays zero order kinetics with respect to the p-nitrophenyl methoxyacetate throughout the majority of the reaction, suggesting a rate-limiting deacylation of a steady state concentration of the acyl-catalyst intermediate. The reaction is first order in catalyst, as expected. We are confident that the dominant catalytic pathway proceeds via acylation-deacylation of the catalyst oxygen.
White
Phylogenetic
Pattern of Rarity in the Argophyllean CladeMost studies of rarity have been conducted from ecological and population genetic frameworks, while evolutionary history (phylogeny) has been largely ignored. Macro-evolutionary dynamics and underlying genealogical processes may significantly contribute to explanations about the positions and rates of rarity within some groups. Work presented here is a case study of rarity from a phylogenetic framework and utilizes several new methods of analysis. The study was framed around the hypothesis that high rates of diversification coupled with local speciation generate phylogenetic clusters of rare species. Evidence for this hypothesis was sought by addressing three testable questions: 1) Do diversification rates vary within the group? 2) Do rare species cluster in the phylogeny? 3) Are newly derived rare species more frequent than expected?
This study is based on the results of a morphological cladistic analysis of 47 species of Astragalus - 17 of which are rare. Species range sizes, based upon published distributional-dot maps, were quantified using ArcView GIS and the program "Minimum Cell Count" written for this analysis. Significant evidence was found that diversification rates vary within the group (Asymmetry Test, p < 0.05). Evidence of phylogenetic clustering of rare species was found but not at a significant level (Mantel procedure, p = 0.09). Rare species do not appear more derived that would be expected by chance (Monte Carlo simulation, p = 0.32). Taken together, these results provide equivocal support for the study hypothesis and may be due to a variety of reasons. One possibility is that the phylogenetic scale (number of taxa in this case) of the study system was not large enough. Other evidence is presented which supports this conclusion. Overall, this work demonstrates a number of new methods for the study of rarity with respect to phylogeny and the utility of this general approach.
Wood and Weldon
The giraffe (Giraffa camelopardalis) emits a scent that can be detected by humans over considerable distances. Dichloromethane extracts of hair samples from adult male and female reticulated giraffes (G. c. reticulata) were analyzed by gas chromatography-mass spectrometry. Two highly odoriferous compounds, indole and 3-methylindole (aromatic compounds), identified in these extracts appear to be primarily responsible for the giraffe's strong scent. Another major compound was the alkane, octane. Several aldehydes were found, benzaldehyde, heptanal, octanal and nonanal, as well as the aromatic, p-cresol. The fatty acids tetradecanoic acid and hexadecanoic acid were on the skin secretion, and finally the steroid, 3,5-androstadien-17-one. These compounds may deter microorganisms or ectoparasitic arthropods. Most of these compounds are known to possess bacteriostatic or fungistatic properties against mammalian skin pathogens or other microorganisms. The levels of p-cresol in giraffe hair are sufficient to repel some ticks. Structures of the volatile compounds from the giraffe are given below:
Last modified 2 May 2003