2,316 research outputs found
Motivating learners through information literacy
This paper is included in the Information Literacy: Key to an Inclusive Society, the proceedings of the European Conference on Information Literacy, 2016. The paper introduces a model for creating information literacy learning activities that motivate students. The model draws from informed learning, an approach to information literacy that emphasizes the role that information plays in fostering learning about a subject. Self-determination theory, a motivational theory that focuses on enabling self-determined learners, is applied within the informed learning framework. The results of the investigation outline characteristics of motivating learning activities that enable learning subject content through engagement with information. The model is intended to be used by librarians when working with classroom teachers to foster greater student learning gains through creative and reflective engagement with information
Detecting a decline in serial homicide : have we banished the devil from the details?
The current research provides perspective regarding the true prevalence of serial murderers in modern society and addresses the conflict between the evidenced decline in serial homicide and the viewpoint that the phenomenon is increasing. The likelihood that serial murderers are responsible for most unresolved homicides and missing persons is examined in the context of a declining prevalence. A mixed methods approach was used, consisting of a review of a sample of unresolved homicides, a comparative analysis of the frequency of known serial homicide series and unresolved serial homicide series, and semi-structured interviews of experts. In failing to become serial killers, aspiring and probable serial killers and spree killers have impacted the rate of serial murder by not reaching their potential. The past decade contained almost half the cases (13%) that existed at the 1980s peak of serial homicide (27%). Only 282 (1.3%) strangled females made up the 22,444 unresolved homicides reviewed. Most expert respondents thought it unreasonable that any meaningful proportion of missing persons cases are victims of serial homicide. Technology, shifts in offending behavior, proactive law enforcement action, and vigilance of society have transformed serial killing and aids in viewing offenders as people impacted by societal shifts and cultural norms. The absence of narrative details inhibited some aspects of the review. An exhaustive list of known unresolved serial homicide series remained elusive as some missing persons are never reported. Future research should incorporate those intending to murder serially, but whose efforts were stalled by arrest, imprisonment, or death
Portuguese validation of the Bergen Facebook Addiction Scale: an Empirical Study
Previous research on Social Networking Sites (SNSs) addiction have suggest the need to improve assessment of this behavioral addiction. The present study aimed at validating a Portuguese version of the Bergen Facebook Addiction Scale (BFAS), a widely used instrument to assess addiction to Facebook. A study was conducted in a sample of 509 Portuguese adolescent using an online survey. The psychometric properties (construct validity, criterion validity, and reliability) of the Portuguese BFAS was scrutinized. The results from the psychometric analyses suggested that the new validated instrument had excellent psychometric properties. The CFA confirmed the original one-factor solution of the BFAS and criterion validity was warranted. The reliability of the BFAS was supported by satisfactory levels of internal consistency as measured by the Cronbach’s alpha (α = .83), composite reliability (CR = .82), and factor determinacy (FD = .91). Overall, the results provided empirical support for the validity and reliability of the Portuguese BFAS. Moreover, the results were highly comparable with the findings of the original development study of the BFAS and cross-cultural support for the scale was obtained
The pivotal role of effort beliefs in mediating implicit theories of intelligence and achievement goals & academic motivations
Empirical studies into meaning systems surrounding implicit theories of intelligence typically entail two stringent assumptions: that different implicit theories and different effort beliefs represent opposite poles on a single scale, and that implicit theories directly impact the constructs as achievement goals and academic motivations. Through an empirical study based on a large sample of university students, we aim to demonstrate that relaxing these stringent assumptions, and thereby using the meaning system framework to its full potential, will provide strong benefits: effort beliefs are crucial mediators of relationships between implicit theories and achievement goals and academic motivations, and the different poles of implicit theories and effort beliefs do expose different relationships with goal setting behaviour and academic motivations. A structural equation model, cross-validated by demonstrating gender-invariance of path coefficients, demonstrates that incremental and entity theory views have less predictive power than positive and negative effort beliefs in explaining achievement goals and motivations
Three-dimensional scapular morphology is associated with rotator cuff tears and alters the abduction moment arm of the supraspinatus.
BACKGROUND: Numerous studies have reported an association between rotator cuff injury and two-dimensional measures of scapular morphology. However, the mechanical underpinnings explaining how these shape features affect glenohumeral joint function and lead to injury are poorly understood. We hypothesized that three-dimensional features of scapular morphology differentiate asymptomatic shoulders from those with rotator cuff tears, and that these features would alter the mechanical advantage of the supraspinatus.
METHODS: Twenty-four individuals with supraspinatus tears and twenty-seven age-matched controls were recruited. A statistical shape analysis identified scapular features distinguishing symptomatic patients from asymptomatic controls. We examined the effect of injury-associated morphology on mechanics by developing a morphable model driven by six degree-of-freedom biplanar videoradiography data. We used the model to simulate abduction for a range of shapes and computed the supraspinatus moment arm.
FINDINGS: Rotator cuff injury was associated with a cranial orientation of the glenoid and scapular spine (P = .011, d = 0.75) and/or decreased subacromial space (P = .001, d = 0.94). The shape analysis also identified previously undocumented features associated with superior inclination and subacromial narrowing. In our computational model, warping the scapula from a cranial to a lateral orientation increased the supraspinatus moment arm at 20° of abduction and decreased the moment arm at 160° of abduction.
INTERPRETATIONS: Three-dimensional analysis of scapular morphology indicates a stronger relationship between morphology and cuff tears than two-dimensional measures. Insight into how morphological features affect rotator cuff mechanics may improve patient-specific strategies for prevention and treatment of cuff tears
Invasion speeds for structured populations in fluctuating environments
We live in a time where climate models predict future increases in
environmental variability and biological invasions are becoming increasingly
frequent. A key to developing effective responses to biological invasions in
increasingly variable environments will be estimates of their rates of spatial
spread and the associated uncertainty of these estimates. Using stochastic,
stage-structured, integro-difference equation models, we show analytically that
invasion speeds are asymptotically normally distributed with a variance that
decreases in time. We apply our methods to a simple juvenile-adult model with
stochastic variation in reproduction and an illustrative example with published
data for the perennial herb, \emph{Calathea ovandensis}. These examples
buttressed by additional analysis reveal that increased variability in vital
rates simultaneously slow down invasions yet generate greater uncertainty about
rates of spatial spread. Moreover, while temporal autocorrelations in vital
rates inflate variability in invasion speeds, the effect of these
autocorrelations on the average invasion speed can be positive or negative
depending on life history traits and how well vital rates ``remember'' the
past
Ethanol Oxidation and Toxicity: Role of Alcohol P-450 Oxygenase
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66172/1/j.1530-0277.1986.tb05179.x.pd
Asteroid Confusions with Extremely Large Telescopes
Asteroids can be considered as sources of contamination of point sources and
also sources of confusion noise, depending whether their presence is detected
in the image or their flux is under the detection limit. We estimate that at
low ecliptic latitudes, ~10,000--20,000 asteroids/sq. degree will be detected
with an E-ELT like telescope, while by the end of Spitzer and Herschel
missions, infrared space observatories will provide ~100,000 serendipitous
asteroid detections. The detection and identification of asteroids is therefore
an important step in survey astronomy.Comment: 8 pages, 4 figures, accepted by Earth, Moon and Planets, ELT
Conference (Elba, 2009 Sept.) S
CD4 Depletion in SIV-Infected Macaques Results in Macrophage and Microglia Infection with Rapid Turnover of Infected Cells
In rhesus macaques (RMs), experimental depletion of CD4+ T-cells prior to SIV infection results in higher viremia and emergence of CD4-independent SIV-envelopes. In this study we used the rhesus recombinant anti-CD4 antibody CD4R1 to deplete RM CD4+ T-cells prior to SIVmac251 infection and investigate the sources of the increased viral burden and the lifespan of productively infected cells. CD4-depleted animals showed (i) set-point viral load two-logs higher than controls; (ii) macrophages constituting 80% of all SIV vRNA+ cells in lymph node and mucosal tissues; (iii) substantial expansion of pro-inflammatory monocytes; (iv) aberrant activation and infection of microglial cells; and (v) lifespan of productively infected cells significantly longer in comparison to controls, but markedly shorter than previously estimated for macrophages. The net effect of CD4+ T-cell depletion is an inability to control SIV replication and a shift in the tropism of infected cells to macrophages, microglia, and, potentially, other CD4-low cells which all appear to have a shortened in vivo lifespan. We believe these findings have important implications for HIV eradication studies
Non-Fermi-liquid d-wave metal phase of strongly interacting electrons
Developing a theoretical framework for conducting electronic fluids
qualitatively distinct from those described by Landau's Fermi-liquid theory is
of central importance to many outstanding problems in condensed matter physics.
One such problem is that, above the transition temperature and near optimal
doping, high-transition-temperature copper-oxide superconductors exhibit
`strange metal' behaviour that is inconsistent with being a traditional Landau
Fermi liquid. Indeed, a microscopic theory of a strange-metal quantum phase
could shed new light on the interesting low-temperature behaviour in the
pseudogap regime and on the d-wave superconductor itself. Here we present a
theory for a specific example of a strange metal---the 'd-wave metal'. Using
variational wavefunctions, gauge theoretic arguments, and ultimately
large-scale density matrix renormalization group calculations, we show that
this remarkable quantum phase is the ground state of a reasonable microscopic
Hamiltonian---the usual t-J model with electron kinetic energy and two-spin
exchange supplemented with a frustrated electron `ring-exchange' term,
which we here examine extensively on the square lattice two-leg ladder. These
findings constitute an explicit theoretical example of a genuine
non-Fermi-liquid metal existing as the ground state of a realistic model.Comment: 22 pages, 12 figures: 6 pages, 7 figures of main text + 16 pages, 5
figures of Supplementary Information; this is approximately the version
published in Nature, minus various subedits in the main tex
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