7,245 research outputs found
Breadboard linear array scan imager using LSI solid-state technology
The performance of large scale integration photodiode arrays in a linear array scan (pushbroom) breadboard was evaluated for application to multispectral remote sensing of the earth's resources. The technical approach, implementation, and test results of the program are described. Several self scanned linear array visible photodetector focal plane arrays were fabricated and evaluated in an optical bench configuration. A 1728-detector array operating in four bands (0.5 - 1.1 micrometer) was evaluated for noise, spectral response, dynamic range, crosstalk, MTF, noise equivalent irradiance, linearity, and image quality. Other results include image artifact data, temporal characteristics, radiometric accuracy, calibration experience, chip alignment, and array fabrication experience. Special studies and experimentation were included in long array fabrication and real-time image processing for low-cost ground stations, including the use of computer image processing. High quality images were produced and all objectives of the program were attained
"Marginal pinching" in soap films
We discuss the behaviour of a thin soap film facing a frame element: the
pressure in the Plateau border around the frame is lower than the film
pressure, and the film thins out over a certain distance lambda(t), due to the
formation of a well-localized pinched region of thickness h(t) and extension
w(t). We construct a hydrodynamic theory for this thinning process, assuming a
constant surface tension: Marangoni effects are probably important only at late
stages, where instabilitites set in. We find lambda(t) ~ t^{1/4}, and for the
pinch dimensions h(t) ~ t^{-1/2}$ and w(t) ~ t^{-1/4}. These results may play a
useful role for the discussion of later instabilitites leading to a global film
thinning and drainage, as first discussed by K. Mysels under the name
``marginal regeneration''.Comment: 7 pages, 2 figure
Human prostate specific and shared differentiation antigens defined by monoclonal antibodies.
Genetic diversity of the rain tree (Albizia saman) in Colombian seasonally dry tropical forest for informing conservation and restoration interventions
Albizia saman is a multipurpose tree species of seasonally dry tropical forests (SDTFs) of Mesoamerica and northern South America typically cultivated in silvopastoral and other agroforestry systems around the world, a trend that is bound to increase in light of multimillion hectare commitments for forest and landscape restoration. The effective conservation and sustainable use of A. saman requires detailed knowledge of its genetic diversity across its native distribution range of which surprisingly little is known to date. We assessed the genetic diversity and structure of A.saman across twelve representative locations of SDTF in Colombia, and how they may have been shaped by past climatic changes and human influence. We found four different genetic groups which may be the result of differentiation due to isolation of populations in preglacial times. The current distribution and mixture of genetic groups across STDF fragments we observed might be the result of range expansion of SDTFs during the last glacial period followed by range contraction during the Holocene and humanâinfluenced movement of germplasm associated with cattle ranching. Despite the fragmented state of the presumed natural A. saman stands we sampled, we did not find any signs of inbreeding, suggesting that gene flow is not jeopardized in humanized landscapes. However, further research is needed to assess potential deleterious effects of fragmentation on progeny. Climate change is not expected to seriously threaten the in situ persistence of A. saman populations and might present opportunities for future range expansion. However, the sourcing of germplasm for tree planting activities needs to be aligned with the genetic affinity of reference populations across the distribution of Colombian SDTFs. We identify priority source populations for in situ conservation based on their high genetic diversity, lack or limited signs of admixture, and/or genetic uniqueness
Impact of a brief faculty training to improve patient-centered communication while using electronic health records
Objective
Despite rapid EHR adoption, few faculty receive training in how to implement patient-centered communication skills while using computers in exam rooms. We piloted a patient-centered EHR use training to address this issue.
Methods
Faculty received four hours of training at Cleveland Clinic and a condensed 90-minute version at the University of Chicago. Both included a lecture and a Group-Objective Structured Clinical Exam (GOSCE) experience. Direct observations of 10 faculty in their clinical practices were performed pre- and post-workshop.
Results
Thirty participants (94%) completed a post-workshop evaluation assessing knowledge, attitude, and skills. Faculty reported that training was important, relevant, and should be required for all providers; no differences were found between longer versus shorter training. Participants in the longer training reported higher GOSCE efficacy, however shorter workshop participants agreed more with the statement that they had gained new knowledge. Faculty improved their patient-centered EHR use skills in clinical practice on post- versus pre-workshop ratings using a validated direct-observation rating tool.
Conclusion
A brief lecture and GOSCE can be effective in training busy faculty on patient-centered EHR use skills.
Practice Implications
Faculty training on patient-centered EHR skills can enhance patient-doctor communication and promotes positive role modeling of these skills to learners
Comparing obstetricians' and neonatologists' approaches to periviable counseling
OBJECTIVE: To compare the management options, risks and thematic content that obstetricians and neonatologists discuss in periviable counseling.
STUDY DESIGN: Sixteen obstetricians and 15 neonatologists counseled simulated patients portraying a pregnant woman with ruptured membranes at 23 weeks of gestation. Transcripts from video-recorded encounters were qualitatively and quantitatively analyzed for informational content and decision-making themes.
RESULT: Obstetricians more frequently discussed antibiotics (P=0.005), maternal risks (<0.001) and cesarean risks (<0.005). Neonatologists more frequently discussed neonatal complications (P=0.044), resuscitation (P=0.015) and palliative options (P=0.023). Obstetricians and neonatologists often deferred questions about steroid administration to the other specialty. Both specialties organized decision making around medical information, survival, quality of life, time and support. Neonatologists also introduced themes of values, comfort or suffering, and uncertainty.
CONCLUSION: Obstetricians and neonatologists provided complementary counseling content to patients, yet neither specialty took ownership of steroid discussions. Joint counseling and/or family meetings may minimize observed redundancy and inconsistencies in counseling
Stress Drop Variation of DeepâFocus Earthquakes Based on Empirical Greenâs Functions
We analyze source characteristics of global, deepâfocus (>350Â km) earthquakes with moment magnitudes (Mw) larger than 6.0â8.2 using teleseismic Pâwave and Sâwave spectra and an empirical Greenâs functions approach. We estimate the corner frequency assuming Bruneâs source model and calculate stress drops assuming a circular crack model. Based on Pâwave and Sâwave spectra, the one standard deviation ranges are 3.5â369.8 and 8.2â328.9Â MPa, respectively. Based on the Pâwave analysis, the median of our stress drop estimates is about a factor of 10 higher than the median stress drop of shallow earthquakes with the same magnitude estimated by Allmann and Shearer (2009, https://doi.org/10.1029/2008JB005821). This suggests that, on average, the shear stress of deep faults in the mantle transition zone is an order of magnitude higher than the shear stress of faults in the crust. The wide range of stress drops implies coexistence of multiple physical mechanisms.Plain Language SummaryThe change of shear stress (i.e., stress drop) during an earthquake is thought to be larger for deeper earthquakes than shallow earthquakes because of higher overburden pressure. However, the observational evidence for stress drop dependence on depth is still inconclusive. We estimate stress drops of earthquakes deeper than 400Â km from recorded ground motion spectra. We find that the median stress drop of deep earthquakes is about one order of magnitude higher than the stress drop of shallow (<50Â km) earthquakes. This implies that the shear stress of deep faults is moderately higher than of faults in the crust. The wide range of our stress drop estimates suggests that various mechanisms producing deep earthquakes coexist.Key PointsEmpiricalGreenâs functions are applied to analyze stress drops of deepâfocus earthquakesOne standard deviation ranges are 3.5â369.8Â MPa for P waves and 8.2â328.9Â MPa for S wavesThe median stress drops suggest that fault shear stress is an order of magnitude higher in the mantle than in the crustPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154937/1/grl60493_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154937/2/grl60493.pd
PDGF controls contact inhibition of locomotion by regulating N-cadherin during neural crest migration
A fundamental property of neural crest (NC) migration is contact
inhibition of locomotion (CIL), a process by which cells change their
direction of migration upon cell contact. CIL has been proven to
be essential for NC migration in amphibians and zebrafish by
controlling cell polarity in a cell contact-dependent manner. Cell
contact during CIL requires the participation of the cell adhesion
molecule N-cadherin, which starts to be expressed by NC cells as a
consequence of the switch between E- and N-cadherins during
epithelial-to-mesenchymal transition (EMT). However, the mechanism
that controls the upregulation of N-cadherin remains unknown. Here,
we show that platelet-derived growth factor receptor alpha (PDGFRα)
and its ligand platelet-derived growth factor A (PDGF-A) are
co-expressed in migrating cranial NC. Inhibition of PDGF-A/PDGFRα
blocks NC migration by inhibiting N-cadherin and, consequently,
impairing CIL. Moreover, we identify phosphatidylinositol-3-kinase
(PI3K)/AKT as a downstream effector of the PDGFRα cellular
response during CIL. Our results lead us to propose PDGF-A/
PDGFRα signalling as a tissue-autonomous regulator of CIL by
controlling N-cadherin upregulation during EMT. Finally, we show that
once NC cells have undergone EMT, the same PDGF-A/PDGFRα
works as an NC chemoattractant, guiding their directional migration
International capital mobility in an era of globalisation: adding a political dimension to the 'FeldsteinâHorioka Puzzle'
The debate about the scope of feasible policy-making in an era of globalisation continues to be set within the context of an assumption that national capital markets are now perfectly integrated at the international level. However, the empirical evidence on international capital mobility contradicts such an assumption. As a consequence, a significant puzzle remains. Why is it, in a world in which the observed pattern of capital flows is indicative of a far from globalised reality, that public policy continues to be constructed in line with more extreme variants of the globalisation hypothesis? I attempt to solve this puzzle by arguing that ideas about global capital market integration have an independent causal impact on political outcomes which extends beyond that which can be attributed to the extent of their actual integration
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