568 research outputs found
High temperature /800 to 1600 F/ magnetic materials
Tests of magnetic materials from 800 to 1600
Sedimentological characterization of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry
In glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across an moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2mm compared to control distributions derived from dry sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological
process interpretation and analysis
Voice Flows To And Around Leaders: Understanding When Units Are Helped Or Hurt By Employee Voice
In two studies, we develop and test theory about the relationship between speaking up, one type of organizational citizenship behavior, and unit performance by accounting for where employee voice is flowing. Results from a qualitative study of managers and professionals across a variety of industries suggest that voice to targets at different formal power levels (peers or superiors) and locations in the organization (inside or outside a focal unit) differs systematically in terms of its usefulness in generating actions to a unit's benefit on the issues raised and in the likely information value of the ideas expressed. We then theorize how distinct voice flows should be differentially related to unit performance based on these core characteristics and test our hypotheses using time-lagged field data from 801 employees and their managers in 93 units across nine North American credit unions. Results demonstrate that voice flows are positively related to a unit's effectiveness when they are targeted at the focal leader of that unitwho should be able to take actionwhether from that leader's own subordinates or those in other units, and negatively related to a unit's effectiveness when they are targeted at coworkers who have little power to effect change. Together, these studies provide a structural framework for studying the nature and impact of multiple voice flows, some along formal reporting lines and others that reflect the informal communication structure within organizations. This research demonstrates that understanding the potential performance benefits and costs of voice for leaders and their units requires attention to the structure and complexity of multiple voice flows rather than to an undifferentiated amount of voice.Business Administratio
Nanocoating with plant-derived pectins activates osteoblast response in vitro
Abstract: A new strategy to improve osseointegration of implants is to
stimulate adhesion of bone cells, bone matrix formation, and mineralization at
the implant surface by modifying surface coating on the nanoscale level.
Plant-derived pectins have been proposed as potential candidates for surface
nanocoating of orthopedic and dental titanium implants due to 1) their
osteogenic stimulation of osteoblasts to mineralize and 2) their ability to
control pectin structural changes. The aim of this study was to evaluate in
vitro the impact of the nanoscale plant-derived pectin Rhamnogalacturonan-I
(RG-I) from potato on the osteogenic response of murine osteoblasts. RG-I from
potato pulps was isolated, structurally modified, or left unmodified. Tissue
culture plates were either coated with modified RG-I or unmodified RG-I or –
as a control – left uncoated. The effect of nanocoating on mice osteoblast-
like cells MC3T3-E1 and primary murine osteoblast with regard to
proliferation, osteogenic response in terms of mineralization, and gene
expression of Runt-related transcription factor 2 (Runx2), alkaline phosphate
(Alpl), osteocalcin (Bglap), α-1 type I collagen (Col1a1), and receptor
activator of NF-κB ligand (Rankl) were analyzed after 3, 7, 14, and 21 days,
respectively. Nanocoating with pectin RG-Is increased proliferation and
mineralization of MC3T3-E1 and primary osteoblast as compared to osteoblasts
cultured without nanocoating. Moreover, osteogenic transcriptional response of
osteoblasts was induced by nanocoating in terms of gene induction of Runx2,
Alpl, Bglap, and Col1a1 in a time-dependent manner – of note – to the highest
extent under the PA-coating condition. In contrast, Rankl expression was
initially reduced by nanocoating in MC3T3-E1 or remained unaltered in primary
osteoblast as compared to the uncoated controls. Our results showed that
nanocoating of implants with modified RG-I beneficially 1) supports
osteogenesis, 2) has the capacity to improve osseointegration of implants, and
is therefore 3) a potential candidate for nanocoating of bone implants
Sustained improvements in MRI outcomes with abatacept following the withdrawal of all treatments in patients with early, progressive rheumatoid arthritis
Objectives: To assess structural damage progression with subcutaneous abatacept (ABA) in the Assessing Very Early Rheumatoid arthritis Treatment (AVERT) trial following abrupt withdrawal of all rheumatoid arthritis (RA) medication in patients achieving Disease Activity Score (DAS)-defined remission or low disease activity. Methods: Patients with early, active RA were randomised to ABA plus methotrexate (ABA/MTX) 125 mg/week, ABA 125 mg/week or MTX for 12 months. All RA treatments were withdrawn after 12 months in patients with DAS28 (C reactive protein (CRP)) <3.2. Adjusted mean changes from baseline in MRI-based synovitis, osteitis and erosion were calculated for the intention-to-treat population. Results: 351 patients were randomised and treated: ABA/MTX (n=119), ABA (n=116) or MTX (n=116). Synovitis and osteitis improved, and progression of erosion was statistically less with ABA/MTX versus MTX at month 12 (−2.35 vs −0.68, −2.58 vs −0.68, 0.19 vs 1.53, respectively; p<0.01 for each) and month 18 (−1.34 vs −0.49 −2.03 vs 0.34, 0.13 vs 2.0, respectively; p<0.01 for erosion); ABA benefits were numerically intermediate to those for ABA/MTX and MTX. Conclusions: Structural benefits with ABA/MTX or ABA may be maintained 6 months after withdrawal of all treatments in patients who have achieved remission or low disease activity
An Integrative Approach to Understanding Counterproductive Work Behavior: The Roles of Stressors, Negative Emotions, and Moral Disengagement
Several scholars have highlighted the importance of examining moral disengagement (MD) in understanding aggression and deviant conduct across different contexts. The present study investigates the role of MD as a specific social-cognitive construct that, in the organizational context, may intervene in the process leading from stressors to counterproductive work behavior (CWB). Assuming the theoretical framework of the stressor-emotion model of CWB, we hypothesized that MD mediates, at least partially, the relation between negative emotions in reaction to perceived stressors and CWB by promoting or justifying aggressive responses to frustrating situations or events. In a sample of 1,147 Italian workers, we tested a structural equations model. The results support our hypothesis: the more workers experienced negative emotions in response to stressors, the more they morally disengaged and, in turn, enacted CW
The usefulness of tenacity in spurring problem-focused voice : the moderating roles of workplace adversity
On ethically solvent leaders : the roles of pride and moral identity in predicting leader ethical behavior.
The popular media has repeatedly pointed to pride as one of the key factors motivating leaders to behave unethically. However, given the devastating consequences that leader unethical behavior may have, a more scientific account of the role of pride is warranted. The present study differentiates between authentic and hubristic pride and assesses its impact on leader ethical behavior, while taking into consideration the extent to which leaders find it important to their self-concept to be a moral person. In two experiments we found that with higher levels of moral identity, authentically proud leaders are more likely to engage in ethical behavior than hubristically proud leaders, and that this effect is mediated by leaders’ motivation to act selflessly. A field survey among organizational leaders corroborated that moral identity may bring the positive effect of authentic pride and the negative effect of hubristic pride on leader ethical behavior to the forefront
Periodic bouncing of a plasmonic bubble in a binary liquid by competing solutal and thermal Marangoni forces
The physicochemical hydrodynamics of bubbles and droplets out of equilibrium,
in particular with phase transitions, displays surprisingly rich and often
counterintuitive phenomena. Here we experimentally and theoretically study the
nucleation and early evolution of plasmonic bubbles in a binary liquid
consisting of water and ethanol. Remarkably, the submillimeter plasmonic bubble
is found to be periodically attracted to and repelled from the
nanoparticle-decorated substrate, with frequencies of around a few kHz. We
identify the competition between solutal and thermal Marangoni forces as origin
of the periodic bouncing. The former arises due to the selective vaporization
of ethanol at the substrate's side of the bubble, leading to a solutal
Marangoni flow towards the hot substrate, which pushes the bubble away. The
latter arises due to the temperature gradient across the bubble, leading to a
thermal Marangoni flow away from the substrate which sucks the bubble towards
it. We study the dependence of the frequency of the bouncing phenomenon from
the control parameters of the system, namely the ethanol fraction and the laser
power for the plasmonic heating. Our findings can be generalized to boiling and
electrolytically or catalytically generated bubbles in multicomponent liquids.Comment: 12 pages, 3 figure
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The influence of organizational culture and climate on entrepreneurial intentions among research scientists
Over the past decades, universities have increasingly become involved in entrepreneurial activities. Despite efforts to embrace their ‘third mission’, universities still demonstrate great heterogeneity in terms of their involvement in academic entrepreneurship. This papers adopts an institutional perspective to understand how organizational characteristics affect research scientists’ entrepreneurial intentions. Specifically, we study the impact of university culture and climate on entrepreneurial intentions, including intentions to spin off a company, to engage in patenting or licensing and to interact with industry through contract research or consulting. Using a sample of 437 research scientists from Swedish and German universities, our results reveal that the extent to which universities articulate entrepreneurship as a fundamental element of their mission fosters research scientists’ intentions to engage in spin-off creation and intellectual property rights, but not industry-science interaction. Furthermore, the presence of university role models positively affects research scientists’ propensity to engage in entrepreneurial activities, both directly and indirectly through entrepreneurial self-efficacy. Finally, research scientists working at universities which explicitly reward people for ‘third mission’ related output show higher levels of spin-off and patenting or licensing intentions. This study has implications for both academics and practitioners, including university managers and policy makers
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