Reflection terahertz time-domain spectroscopy for imaging and identifying concealed interfaces in insulated systems.

Polarization-resolved reflection spectroscopy enabled by a custom ultrahigh molecular weight polymer dove prism is used to identify spectral characteristics that manifest in the time domain at terahertz frequencies, which shows promise in combination with terahertz time-domain reference-free reflection imaging at a concealed interface. The method is used to produce 100×100 pixel images of an interface concealed by an ultrahigh molecular weight polymer using TE and TM polarized terahertz fields. The construction of material-specific image filters is guided by a theoretical reflection model by identifying reflection pulse characteristics unique to an interface. Application of these filters to the collected terahertz images distinguishes materials at the interface including the concealing plastic, water, air, glass, and metal that are correctly identified and imaged.

A qualitative review of cannabis stigmas at the twilight of prohibition.

BACKGROUND: As laws change and cannabis use increases, it is worthwhile to take a rich account of cannabis stigmas in society, and this review identifies a disjunction between quantitative investigations on cannabis users and qualitative investigations on the same population. This is also the first attempt to explicate cannabis stigmas as they manifest on multiple analytical levels. Following brief explanations of the normalization hypothesis and the concept of stigma, this review is organized between structural (macro) stigmas, social (meso) stigmas, and personal (micro) stigmas. Furthermore, since cannabis stigmas are similar to the stigmas faced by sexual minorities in that each is physically concealable, the two groups are compared here because the literature base is more extensive with the latter. METHODS: This qualitative review synthesizes the body of empirical studies on both medical and nonmedical cannabis use with attention to stigma, stereotypes, and other social consequences. Studies considered for the review mostly come from the social sciences, particularly sociology. The information presented here is primarily drawn from peer-reviewed articles on cannabis users in the USA, though research from similar national contexts is cited as well. RESULTS: This review suggests claims of normalization may be premature. While stigmas surrounding cannabis appear to have diminished, there is little evidence that such stigmas have entirely disappeared. It is possible that sweeping claims of cannabis normalization may be symptomatic of unchecked social privileges or social distance from cannabis users. Such claims may also be the product of valuing quantitative data over the nuanced accounts uncovered through qualitative investigations. CONCLUSION: This substantial coverage of the literature indicates the lived experience of a post-prohibition society is not the same as a one where cannabis is normalized. Individuals working with those who use cannabis should not assume stigmas have disappeared, especially since cannabis stigmas often intersect with other sources of social inequality. While a comprehensive discussion of ways to combat lingering social stigmas is beyond the scope of this review, it concludes by highlighting some of the strategies identified through research which help users resist or mitigate these oppressive forces. Future research would be wise to prioritize the experiences of people of color, women, and adult populations if the hope is to identify ways to further normalize the plant in American society.

THz pulse shaping and improved optical-to-THz conversion efficiency using a binary phase mask.

We demonstrate improved optical-to-terahertz (THz) conversion efficiency and THz pulse shaping from an interdigitated GaAs large area photoconductive antenna by using a binary phase mask. The binary phase mask results in a time-delayed excitation of the adjacent antennas, which allows subsequent antennas to produce an additive field, thus resulting in a quasi-single-cycle THz pulse. We demonstrate control over the temporal profile of the THz waveform to maximize optical-to-THz conversion efficiency.

Evaluating of veterinarians' and veterinary students' knowledge and clinical use of pulse oximetry.

RATIONALE FOR THE STUDY: We hypothesized that veterinarians and veterinary students may lack key knowledge about pulse oximetry, which may result in this type of patient monitor not being used on appropriate patient populations or to its full capabilities. METHODOLOGY: A questionnaire was developed to assess an individual's knowledge and understanding of pulse oximetry. Residents and specialists in anesthesiology and critical care at several academic institutions were surveyed first to assess the questionnaire for clarity and to serve as a control group. General veterinary practitioners (GPs) attending continuing education courses at the University of Georgia were surveyed over a 24-month period. Students entering their senior-year anesthesiology rotation at the University of Georgia were also surveyed. RESULTS: Residents and specialists (69% correct responses) scored significantly higher than senior students (46%), who scored significantly higher than GPs (34%). Only 15% of GPs and 21% of senior students reported that they had received training in pulse oximetry in school. Those who had received training scored significantly higher than those who had not. Many GPs did not report using a pulse oximeter on their critical patients under anesthesia, a group that would be expected to benefit from its use. CONCLUSIONS: Veterinarians have a poor understanding of how pulse oximetry works, the information it provides, and how best to apply it to their patients. Furthermore, the respondents did not use pulse oximeters in a manner that would yield the most information and result in the greatest benefit to the patient relative to the cost of the instrument. Didactic training in veterinary curricula and during continuing education opportunities continues to be necessary in order to produce veterinarians who have an understanding of the technologies available to improve patient care.