656 research outputs found

    Fixing Advising: A Model for Faculty Advising

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    This paper addresses mandates to fix the advising process with a focus on faculty advising systems. Measures of student success and satisfaction, administrative issues, and faculty concerns are among the many factors discussed. Regression analysis is used to explore long-voiced faculty complaints that students do not follow advice. A case study is used to illustrate changes in one department’s advising process and measures of student satisfaction are reported. A model of advising components is offered to illustrate practices suggested to realize the full potential of the advising process

    Open- and closed-system characteristics of a tilted plutonic system, Klamath Mountains, California

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    The Wooley Creek batholith and Slinkard pluton are adjacent plutons with identical U-Pb zircon ages of 161 +4/−2 Ma. The plutons dip toward each other, which suggests that they are connected in the subsurface. Geologic and thermochemical evidence shows that the Slinkard pluton is the structurally lowest part of the system and the Wooley Creek batholith the structurally highest, with a total structural relief of at least 15 km. The wall rocks adjacent to the highest level of the Wooley Creek batholith are intruded by mafic to felsic dikes derived from the subjacent pluton. The Slinkard pluton is predominantly quartz diorite but grades from two-pyroxene diorite to sparse muscovite-biotite granite and shows little evidence of contamination except near contacts. The Wooley Creek batholith grades upward from two-pyroxene gabbro to biotite-hornblende granite and has a central zone in which injected mafic magma was trapped and mixed. Major and trace element data are consistent with closed-system fractionation of the Slinkard pluton and lower (adjacent) Wooley Creek batholith, but with open-system differentiation of the upper Wooley Creek batholith and roof-zone dikes. Andesitic roof-zone dikes show trace element enrichment similar to the central mixed zone of the Wooley Creek batholith and may have differentiated at that central level of the system

    Internet Use for Health Information among American Indians: Facilitators and Inhibitors

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    Our research team explored Internet use among a heterogeneous American Indian (AI) population to determine Internet use in relation to health information seeking behaviors. Participants examined an AI culturally-tailored tobacco website as an example to explain what they wanted in an AI Internet health site. Using community-based participatory research, we conducted 10 focus groups with non-college AI men and women (N=96), stratified by age (18-29, 30-49, and 50 and over) to better understand their perceptions of Internet use and health information needs. We found that Internet use varied greatly among all strata. Participants referenced WebMD© more than any other website, but participants were not pleased with the design and navigation. When examining the sample website, participants across strata stressed that recreational and traditional tobacco use should be discussed. Participants in all strata desired a simple website design with easy to read text accompanied by images. In order to gain and maintain cultural respect, participants stated that web designers should be aware that some images hold cultural meaning, particularly tobacco. Baseline data are needed for AI’s use of the Internet to obtain health information; this research is helpful to address health inequalities among AI, particularly access to web-based health information

    Possible obsidian sources for artifacts from Timor: narrowing the options using chemical data

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    Measurements made at the Australian National University using laser ablation ICPMS show that none of the 88 analyzed obsidian artifacts from East Timor match either the known Papua New Guinea or the five Island SE Asian source samples in our ANU collections. There is a coastal journey of more than 3000 km between the occurrence of obsidians from the Bismarck Archipelago volcanic province of Papua New Guinea and the Sunda-Banda Arc volcanic chain, yet obsidian artifacts from the two important PNG sources of Talasea and Lou Island are found at coastal Bukit Tengkorak in eastern Sabah at a similar distance along with material that has no known source. Timor lies south of the eastern section of the active volcanic Banda Arc island chain but it is within range of possible rhyolite sources from there. Although there is a continuous chain of around 60 active volcanoes stretching from west Sumatra to the Moluccas most are basaltic to andesitic with few areas likely to produce high silica dacite-rhyolite deposits. This does not exclude the possibility that the volcanic landscapes may contain obsidian, but without detailed survey and chemical analysis of sources from the Sunda-Banda Arc the attribution of the Timor obsidian artifacts remains to be demonstrated. Timor may seem to be an unlikely source for the presence of obsidians as it lacks reports of the silica-rich rhyolite volcanic centers necessary to produce this material. Despite the absence of detailed survey and analysis of Indonesian obsidian sources, especially from the volcanically active Banda Arc, this paper presents evidence that one of two obsidian sources is clearly from Timor while the other, with less certainty, is also from an unknown local source

    Channel incision into a submarine landslide on a Carboniferous basin margin, San Juan, Argentina: Evidence for the role of knickpoints

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    Emplacement of submarine landslides, or mass-transport deposits, can radically reshape the physiography of continental margins, and strongly influence subsequent sedimentary processes and dispersal patterns. Typically, progressive healing of the complicated relief generated by the submarine landslide occurs prior to progradation of sedimentary systems. However, subsurface and seabed examples show that submarine channels can incise directly into submarine landslides. Here, the evolution of a unique exhumed example of two adjacent, and partially contemporaneous, submarine channel-fills is documented. The channels show deep incision (>75 m), and steep lateral margins (up to 70°), cut into a >200 m thick submarine landslide. The stepped basal erosion surface, and multiple terrace surfaces, are mantled by clasts (gravels to cobbles) reflecting periods of bedload-derived sedimentation, punctuated by phases of downcutting and sediment bypass. The formation of multiple terrace surfaces in a low aspect ratio confinement is consistent with the episodic migration of knickpoints during entrenchment on the dip slope of the underlying submarine landslide. Overlying sandstone-rich channel-fills mark a change to aggradation. Laterally stacked channel bodies coincide with steps in the original large-scale erosion surface, recording widening of the conduit; this is followed by tabular, highly aggradational fill. The upper fill, above a younger erosional surface, shows an abrupt change to partially confined tabular sandstones with normally graded caps, interpreted as lobe fringe deposits, which formed due to down-dip confinement, followed by prograding lobe deposits. Overlying this, an up-dip avulsion induced lobe switching and back-stepping, and subsequent failure of a sandstone body up-dip led to emplacement of a sandstone-rich submarine landslide within the conduit. Collectively, this outcrop represents episodic knickpoint-generated incision, and later infill, of a slope adjusting to equilibrium. The depositional signature of knickpoints is very different from existing models, but is probably reflective of other highly erosional settings undergoing large-scale slope adjustment.Fil: Allen, Charlotte. University of Leeds; Reino UnidoFil: Gomis Cartesio, Luz E.. No especifíca;Fil: Hodgson, David M.. University of Leeds; Reino UnidoFil: Peakall, Jeff. University of Leeds; Reino UnidoFil: Milana, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

    Provenance of Eocene river sediments from the central northern Sierra Nevada and implications for paleotopography

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    Geochronology of fluvial deposits can be used to characterize provenance, the paleotopography of sediment source regions, and the development of regional drainage systems. We present U-Pb and (U-Th)/He ages of detrital zircon grains from Eocene gravels preserved in several paleoriver systems along the western flank of the central and northern Sierra Nevada. These ages allow us to trace the sourcing of detritus in paleorivers and to constrain the evolution of the Sierra Nevada range front. U-Pb zircon age distributions are bimodal, with a dominant peak between 110 and 95 Ma and smaller but significant peaks in the Middle to Late Jurassic, matching the predominant ages of the Sierra Nevada batholith. A small fraction (<6%) of grains has pre-Mesozoic ages, which consistently match ages from prebatholithic assemblages within the northern part of the range. (U-Th)/He ages of a subset of double-dated zircons cluster between 114 and 74 Ma and are consistent with batholithic (U-Th)/He cooling ages in the northern Sierra. Our results indicate that the Eocene river systems in the central northern Sierra Nevada likely had proximal headwaters and had relatively steep axial gradients, draining smaller areas than was commonly thought. This also suggests that the northern Sierra Nevada would have had an established drainage divide and would have acted as a major topographic barrier during the early to mid-Cenozoic. The data presented here support a model of the Eocene northern Sierra Nevada characterized by a western slope with a gradient broadly similar to that of today

    Spatial tethering of kinases to their substrates relaxes evolutionary constraints on specificity

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    Signal transduction proteins are often multi-domain proteins that arose through the fusion of previously independent proteins. How such a change in the spatial arrangement of proteins impacts their evolution and the selective pressures acting on individual residues is largely unknown. We explored this problem in the context of bacterial two-component signalling pathways, which typically involve a sensor histidine kinase that specifically phosphorylates a single cognate response regulator. Although usually found as separate proteins, these proteins are sometimes fused into a so-called hybrid histidine kinase. Here, we demonstrate that the isolated kinase domains of hybrid kinases exhibit a dramatic reduction in phosphotransfer specificity in vitro relative to canonical histidine kinases. However, hybrid kinases phosphotransfer almost exclusively to their covalently attached response regulator domain, whose effective concentration exceeds that of all soluble response regulators. These findings indicate that the fused response regulator in a hybrid kinase normally prevents detrimental cross-talk between pathways. More generally, our results shed light on how the spatial properties of signalling pathways can significantly affect their evolution, with additional implications for the design of synthetic signalling systems.National Science Foundation (U.S.) (CAREER Award)National Science Foundation (U.S.). Graduate Research Fellowship Progra

    Timing of sedimentation, metamorphism, and plutonism in the Helgeland Nappe Complex, north-central Norwegian Caledonides

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    The Helgeland Nappe Complex consists of a sequence of imbricated east-dipping nappes that record a history of Neoproterozoic- Ordovician, sedimentary, metamorphic, and magmatic events. A combination of U-Pb dating of zircon and titanite by laser-ablation- inductively coupled plasma-mass spectrometry plus chemostratigraphic data on marbles places tight constraints on the sedimentary, tectonic, and thermal events of the complex. Strontium and carbon isotope data have identifi ed Neoproterozoic marbles in the Lower Nappe, the Horta nappe, and Scandian-aged infolds in the Vikna region. The environment of deposition of these rocks was a continental shelf, presumably of Laurentia. Detrital zircon ages from the Lower Nappe are nearly identical to those of Dalradian sedimentary rocks in Scotland. Cambrian rifting caused development of one or more ophiolitefl oored basins, into which thick sequences of Early Ordovician clastic and carbonate sediments were deposited. On the basis of ages of the youngest zircons, deposition ended after ca. 481 Ma. These basin units are now seen as the Skei Group, Sauren-Torghatten Nappe, and Middle Nappe, as well as the stratigraphically highest part of the Horta nappe and possibly of the Upper Nappe. The provenance of these sediments was partly from the Lower Nappe, on the basis of detrital zircon age populations in metasandstones and cobbles from proximal conglomerates. However, the source of Cambrian-Ordovician zircons in all of the Early Ordovician basins is enigmatic. Crustal anatexis of the Lower and Upper Nappes occurred ca. 480 Ma, followed by imbrication of the entire nappe sequence. By ca. 478 Ma, the Horta nappe was overturned and was at the structural base of the nappe sequence, where it underwent migmatization and was the source of S-type magmas. Diverse magmatic activity followed ca. 465 Ma, 450-445 Ma, and 439-424 Ma. Several plutons in the youngest age range contain inherited 460-450 Ma zircons. These zircons are interpreted to refl ect a deep crustal zone in which mafi c magmas caused melting, mixing, and hybridization from 460 to 450 Ma. Magmatic reheating of this zone, possibly associated with crustal thickening, resulted in voluminous, predominantly tonalitic magmatism from 439 to 424 Ma

    CamAPS FX hybrid closed-loop with ultra-rapid lispro compared with standard lispro in adults with type 1 diabetes: a double-blind, randomized, crossover study.

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    INTRODUCTION To evaluate hybrid closed-loop with ultra-rapid insulin lispro (Lyumjev) compared with hybrid closed-loop with standard insulin lispro in adults with type 1 diabetes. MATERIALS AND METHODS In a single-center, double-blind, randomized, crossover study, 28 adults with type 1 diabetes (mean±SD: age 44.5±10.7, HbA1c 7.1±0.9% [54±10mmol/mol]) underwent two 8-week periods comparing hybrid closed-loop with ultra-rapid insulin lispro and hybrid closed-loop with standard insulin lispro in random order. CamAPS FX closed-loop system was used in both periods. RESULTS In an intention-to-treat analysis, the proportion of time sensor glucose was in target range (3.9 to 10mmol/L; primary endpoint) was greater with ultra-rapid lispro compared with standard insulin lispro (mean±SD: 78.7±9.8% vs. 76.2±9.6%; mean difference 2.5 percentage points [95%CI 0.8 to 4.2]; p=0.005). Mean sensor glucose was lower with ultra-rapid lispro compared with standard insulin lispro (7.9±0.8mmol/L vs. 8.1±0.9mmol/L; p=0.048). The proportion of time with sensor glucose <3.9mmol/L was similar between interventions (median [IQR] ultra-rapid lispro 2.3% [1.3-2.7%] vs. standard insulin lispro 2.1% [1.4-3.3%]; p=0.33). No severe hypoglycemia or ketoacidosis occurred. CONCLUSIONS The use of ultra-rapid lispro with CamAPS FX hybrid closed-loop increases time in range and reduces mean glucose with no difference in hypoglycemia compared with standard insulin lispro in adults with type 1 diabetes

    Rethinking PowerPoint slide design for multimedia learning

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    This analysis investigates two differential PowerPoint slide designs—presentation and teleprompter—for multimedia learning. Eye tracking measures assessed differences in fixations. Participants demonstrated greater fixation counts for teleprompter slides, measures of aesthetic liking evidenced that slides incorporating imagery resulted in more pleasurable learning experiences, and visually-based slides influenced more reflective learning and greater activation of information processing. The results offer practical advice for instructors wishing to increase the slide design effectiveness for improved multimedia learning
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