Near-Field Second-Harmonic Generation Induced by Local Field Enhancement

The field near a sharp metal tip can be strongly enhanced if irradiated with an optical field polarized along the tip axis. We demonstrate that the enhanced field gives rise to local second-harmonic (SH) generation at the tip surface thereby creating a highly confined photon source. A theoretical model for the excitation and emission of SH radiation at the tip is developed and it is found that this source can be represented by a single on-axis oscillating dipole. The model is experimentally verified by imaging the spatial field distribution of strongly focused laser modes

Spectral tunability of a plasmonic antenna with a dielectric nanocrystal

We show that the positioning of a nanometer length scale dielectric object, such as a diamond nanocrystal, in the vicinity of a gold bowtie nanoantenna can be used to tune the plasmonic mode spectrum on the order of a linewidth. We further show that the intrinsic luminescence of gold enhanced in the presence of nanometer-scale roughness couples efficiently to the plasmon mode and carries the same polarization anisotropy. Our findings have direct implications for cavity quantum electrodynamics related applications of hybrid antenna-emitter complexes.Comment: 10 pages, 3 figure

Values clarification and moral education

Moral education requires rigorous and extended thought, study, analysi

Thrasymachus’ Unerring Skill and the Arguments of Republic 1

In defending the view that justice is the advantage of the stronger, Thrasymachus puzzlingly claims that rulers never err and that any practitioner of a skill or expertise (τέχνη) is infallible. In what follows, Socrates offers a number of arguments directed against Thrasymachus’ views concerning the nature of skill, ruling, and justice. Commentators typically take a dim view of both Thrasymachus’ claims about skill (which are dismissed as an ungrounded and purely ad hoc response to Socrates’ initial criticisms) and Socrates’ latter arguments (which are deemed extremely weak). In this paper, I clarify Thrasymachus’ views (and those of several other ancients) concerning qua locutions and the nature of skill and ability and I reconstruct Socrates’ arguments against Thrasymachus’ views concerning skill and justice. I argue that Thrasymachus’ views are not ungrounded or ad hoc and that Socrates’ arguments are rather different (and significantly stronger) than often supposed

Characterizing the limited use of point-of-care ultrasound in Colombian emergency medicine residencies

Background: Emergency medicine (EM) is a growing specialty in Colombia with five residency programs in the country. EM leadership is interested in incorporating point-of-care (POC) ultrasound into a standardized national EM residency curriculum. This study is a nationwide survey of Colombian EM residents designed to explore the current state of POC ultrasound use within EM residencies and examine specific barriers preventing its expansion. Methods: We conducted a mix-methodology study of all available current EM residents in the five EM residencies in Colombia. The quantitative survey assessed previous ultrasound experience, current use of various applications, desire for further training, and perceived barriers to expanded use. Focus group discussions (FGDs) were conducted with current EM residents to gather additional qualitative insight into their practice patterns and perceived barriers to clinician-performed ultrasound. Results: Sixty-nine EM residents completed the quantitative survey, a response rate of 85% of all current EM residents in Colombia; 52% of resident respondents had previously used ultrasound during their training. Of these, 58% indicated that they had performed 40 scans. The most frequently used applications indicated by respondents were trauma, obstetrics, and procedures including vascular access. A quarter indicated they had previously received some ultrasound training, but almost all expressed an interest in learning more. Significant barriers included lack of trained teachers (indicated by 78% of respondents), absence of machines (57%), and limited time (41%). In FGDs, the barriers identified were inter-specialty conflicts over the control of ultrasonography, both institutionally and nationally, and program-specific curriculum decisions to include POC ultrasound. Conclusion: While currently limited in their access, EM residents in Colombia have a strong interest in integrating POC ultrasound into their training. Current barriers to expanded use include traditional barriers such as a lack of equipment seen in many developing countries, as well as inter-specialty conflicts typical of developed countries. Further collaboration is underway to help overcome these obstacles and integrate POC ultrasound into Colombian EM residency training

Characterizing the limited use of point-of-care ultrasound in Colombian emergency medicine residencies

Background: Emergency medicine (EM) is a growing specialty in Colombia with five residency programs in the country. EM leadership is interested in incorporating point-of-care (POC) ultrasound into a standardized national EM residency curriculum. This study is a nationwide survey of Colombian EM residents designed to explore the current state of POC ultrasound use within EM residencies and examine specific barriers preventing its expansion. Methods: We conducted a mix-methodology study of all available current EM residents in the five EM residencies in Colombia. The quantitative survey assessed previous ultrasound experience, current use of various applications, desire for further training, and perceived barriers to expanded use. Focus group discussions (FGDs) were conducted with current EM residents to gather additional qualitative insight into their practice patterns and perceived barriers to clinician-performed ultrasound. Results: Sixty-nine EM residents completed the quantitative survey, a response rate of 85% of all current EM residents in Colombia; 52% of resident respondents had previously used ultrasound during their training. Of these, 58% indicated that they had performed 40 scans. The most frequently used applications indicated by respondents were trauma, obstetrics, and procedures including vascular access. A quarter indicated they had previously received some ultrasound training, but almost all expressed an interest in learning more. Significant barriers included lack of trained teachers (indicated by 78% of respondents), absence of machines (57%), and limited time (41%). In FGDs, the barriers identified were inter-specialty conflicts over the control of ultrasonography, both institutionally and nationally, and program-specific curriculum decisions to include POC ultrasound. Conclusion: While currently limited in their access, EM residents in Colombia have a strong interest in integrating POC ultrasound into their training. Current barriers to expanded use include traditional barriers such as a lack of equipment seen in many developing countries, as well as inter-specialty conflicts typical of developed countries. Further collaboration is underway to help overcome these obstacles and integrate POC ultrasound into Colombian EM residency training

De micrografische identificatie van hout

The timber of dicotyledonous trees could not be classified on microscopic features in harmony with taxonomic practice because botanical systems were still faulty and not generally recognized, and because microscopic descriptions of timber were not uniform enough for compilation. To find whether timber features could be conformed with a botanic taxonomy, a scheme was drafted for the description of secondary wood of dicotyledonous trees based on definite, uniform and comparable characteristics.On this basis short descriptions were compiled of the timber of 93 species and a table was composed of species identical in microscopic structure. The 24 most important characteristics of the 42 families represented were described. Families and species were indexed.</p