1,125 research outputs found
Where form and substance meet: using the narrative approach of re-storying to generate research findings and community rapprochement in (university) mathematics education
Storytelling is an engaging way through which lived experience can be shared and reflected upon, and a tool through which difference, diversityâand even conflictâcan be acknowledged and elaborated upon. Narrative approaches to research bring the richness and vibrancy of storytelling into how data is collected and interpretations of it shared. In this paper, I demonstrate the potency of the narrative approach of re-storying for a certain type of university mathematics education research (non-deficit, non-prescriptive, context-specific, example-centred and mathematically focused) conducted at the interface of two communities: mathematics education and mathematics. I do so through reference to Amongst Mathematicians (Nardi, 2008), a study carried out in collaboration with 20 university mathematicians from six UK mathematics departments. The study deployed re-storying to present data and analyses in the form of a dialogue between two fictional, yet entirely data-grounded, charactersâM, mathematician, and RME, researcher in mathematics education. In the dialogues, the typically conflicting epistemologiesâand mutual perceptions of such epistemologiesâof the two communities come to the fore as do the feasibility-of, benefits-from, obstacles-in and conditions-for collaboration between these communities. First, I outline the use of narrative approaches in mathematics education research. Then, I introduce the study and its use of re-storying, illustrating this with an example: the construction of a dialogue from interview data in which the participating mathematicians discuss the potentialities and pitfalls of visualisation in university mathematics teaching. I conclude by outlining re-storying as a vehicle for community rapprochement achieved through generating and sharing research findingsâthe substance of researchâin forms that reflect the fundamental principles and aims that underpin this research. My conclusions resonate with sociocultural constructs that view mathematics teacher education as contemporary praxis and the aforementioned inter-community discussion as taking place within a third space
Consumer perceptions of co-branding alliances: Organizational dissimilarity signals and brand fit
This study explores how consumers evaluate co-branding alliances between dissimilar partner firms. Customers are well aware that different firms are behind a co-branded product and observe the partner firmsâ characteristics. Drawing on signaling theory, we assert that consumers use organizational characteristics as signals in their assessment of brand fit and for their purchasing decisions. Some organizational signals are beyond the control of the co-branding partners or at least they cannot alter them on short notice. We use a quasi-experimental design and test how co-branding partner dissimilarity affects brand fit perception. The results show that co-branding partner dissimilarity in terms of firm size, industry scope, and country-of-origin image negatively affects brand fit perception. Firm age dissimilarity does not exert significant influence. Because brand fit generally fosters a benevolent consumer attitude towards a co-branding alliance, the findings suggest that high partner dissimilarity may reduce overall co-branding alliance performance
Identifying and Prioritizing Greater Sage-Grouse Nesting and Brood-Rearing Habitat for Conservation in Human-Modified Landscapes
BACKGROUND: Balancing animal conservation and human use of the landscape is an ongoing scientific and practical challenge throughout the world. We investigated reproductive success in female greater sage-grouse (Centrocercus urophasianus) relative to seasonal patterns of resource selection, with the larger goal of developing a spatially-explicit framework for managing human activity and sage-grouse conservation at the landscape level. METHODOLOGY/PRINCIPAL FINDINGS: We integrated field-observation, Global Positioning Systems telemetry, and statistical modeling to quantify the spatial pattern of occurrence and risk during nesting and brood-rearing. We linked occurrence and risk models to provide spatially-explicit indices of habitat-performance relationships. As part of the analysis, we offer novel biological information on resource selection during egg-laying, incubation, and night. The spatial pattern of occurrence during all reproductive phases was driven largely by selection or avoidance of terrain features and vegetation, with little variation explained by anthropogenic features. Specifically, sage-grouse consistently avoided rough terrain, selected for moderate shrub cover at the patch level (within 90 m(2)), and selected for mesic habitat in mid and late brood-rearing phases. In contrast, risk of nest and brood failure was structured by proximity to anthropogenic features including natural gas wells and human-created mesic areas, as well as vegetation features such as shrub cover. CONCLUSIONS/SIGNIFICANCE: Risk in this and perhaps other human-modified landscapes is a top-down (i.e., human-mediated) process that would most effectively be minimized by developing a better understanding of specific mechanisms (e.g., predator subsidization) driving observed patterns, and using habitat-performance indices such as those developed herein for spatially-explicit guidance of conservation intervention. Working under the hypothesis that industrial activity structures risk by enhancing predator abundance or effectiveness, we offer specific recommendations for maintaining high-performance habitat and reducing low-performance habitat, particularly relative to the nesting phase, by managing key high-risk anthropogenic features such as industrial infrastructure and water developments
Observation of Nuclear Scaling in the Reaction at 1
The ratios of inclusive electron scattering cross sections of He,
C, and Fe to He have been measured for the first time. It is
shown that these ratios are independent of at Q1.4 (GeV/c) for
1.5 where the inclusive cross section depends primarily on the
high-momentum components of the nuclear wave function. The observed scaling
shows that the momentum distributions at high-momenta have the same shape for
all nuclei and differ only by a scale factor. The observed onset of the scaling
at Q1.4 and 1.5 is consistent with the kinematical expectation that
two nucleon short range correlations (SRC) are dominate the nuclear wave
function at 300 MeV/c. The values of these ratios in the scaling
region can be related to the relative probabilities of SRC in nuclei with
A3. Our data demonstrate that for nuclei with A12 these
probabilities are 5-5.5 times larger than in deuterium, while for He it is
larger by a factor of about 3.5.Comment: 11 pages, 10 figure
Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton
The reaction was studied at Jefferson Lab using a
tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state
with strangeness S=+1 and mass MeV/c was observed in the
invariant mass spectrum. The peak's width is consistent with the CLAS
resolution (FWHM=26 MeV/c), and its statistical significance is 7.8
1.0 ~. A baryon with positive strangeness has exotic structure and
cannot be described in the framework of the naive constituent quark model. The
mass of the observed state is consistent with the mass predicted by a chiral
soliton model for the baryon. In addition, the invariant mass
distribution was analyzed in the reaction with high
statistics in search of doubly-charged exotic baryon states. No resonance
structures were found in this spectrum.Comment: 5 pages, 5 figures, add reference
Exclusive Photoproduction of the Cascade (Xi) Hyperons
We report on the first measurement of exclusive Xi-(1321) hyperon
photoproduction in gamma p --> K+ K+ Xi- for 3.2 < E(gamma) < 3.9 GeV. The
final state is identified by the missing mass in p(gamma,K+ K+)X measured with
the CLAS detector at Jefferson Laboratory. We have detected a significant
number of the ground-state Xi-(1321)1/2+, and have estimated the total cross
section for its production. We have also observed the first excited state
Xi-(1530)3/2+. Photoproduction provides a copious source of Xi's. We discuss
the possibilities of a search for the recently proposed Xi5-- and Xi5+
pentaquarks.Comment: submitted to Phys. Rev.
Metadherin Mediates Lipopolysaccharide-Induced Migration and Invasion of Breast Cancer Cells
BACKGROUND: Breast cancer is the most prevalent cancer in women worldwide and metastatic breast cancer has very poor prognosis. Inflammation has been implicated in migration and metastasis of breast cancer, although the exact molecular mechanism remains elusive. PRINCIPAL FINDINGS: We show that the pro-inflammatory endotoxin Lipopolysaccharide (LPS) upregulates the expression of Metadherin (MTDH), a recently identified oncogene, in a number of breast cancer lines. Stable knockdown of MTDH by shRNA in human breast MDA-MB-231 cells abolishes LPS-induced cell migration and invasion as determined by several in vitro assays. In addition, knockdown of MTDH diminishes Nuclear Factor-kappa B (NF-ÎșB) activation by LPS and inhibited LPS-induced IL-8 and MMP-9 production. CONCLUSIONS: These results strongly suggest that MTDH is a pivotal molecule in inflammation-mediated tumor metastasis. Since NF-ÎșB, IL-8 and MMP-9 play roles in LPS-induced invasion or metastasis, the mechanism of MTDH-promoted invasion and metastasis may be through the activation of NF-ÎșB, IL-8 and MMP-9, also suggesting a role of MTDH in regulating both inflammatory responses and inflammation-associated tumor invasion. These findings indicate that MTDH is involved in inflammation-induced tumor progression, and support that MTDH targeting therapy may hold promising prospects in treating breast cancer
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at sâ=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fbâ1 of protonâproton collision data at âs = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via tËâtÏË01 or tËâ bÏ˱1 âbW(â)ÏË01 , where ÏË01 (Ï˱1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of tË â tÏË01 . For a branching fraction of 100%, top squark masses in the range 270â645 GeV are excluded for ÏË01 masses below 30 GeV. For a branching fraction of 50% to either tË â tÏË01 or tË â bÏ˱1 , and assuming the Ï˱1 mass to be twice the ÏË01 mass, top squark masses in the range 250â550 GeV are excluded for ÏË01 masses below 60 GeV
Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at âs = 7 TeV with the ATLAS detector
This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of âs = 7 TeV;{\rm Te}{\rm V}4.6\;{\rm f}{{{\rm b}}^{-1}}{{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}|\eta |\lt 1.9{{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques
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