Fs-laser ablation of teeth is temperature limited and provides information about the ablated components.

The goal of this work is to investigate the thermal effects of femtosecond laser (fs-laser) ablation for the removal of carious dental tissue. Additional studies identify different tooth tissues through femtosecond laser induced breakdown spectroscopy (fsLIBS) for the development of a feedback loop that could be utilized during ablation in a clinical setting. Scanning Election Microscope (SEM) images reveal that minimal morphological damages are incurred at repetition rates below the carbonization threshold of each tooth tissue. Thermal studies measure the temperature distribution and temperature decay during laser ablation and after laser cessation, and demonstrate that repetition rates at or below 10kHz with a laser fluence of 40 J/cm2 would inflict minimal thermal damage on the surrounding nerve tissues and provide acceptable clinical removal rates. Spectral analysis of the different tooth tissues is also conducted and differences between the visible wavelength fsLIBS spectra are evident, though more robust classification studies are needed for clinical translation. These results have initiated a set of precautionary recommendations that would enable the clinician to utilize femtosecond laser ablation for the removal of carious lesions while ensuring that the solidity and utility of the tooth remain intact.

Moving beyond behaviour: advancing HIV risk prevention epistemologies and interventions (A report on the state of the literature).

This paper is based on an extensive literature review of academic, policy and 'grey' literatures on the intersections of culture and the global HIV/AIDS pandemic commissioned by UNESCO. It highlights that the review exposed a dominant conceptual perspective that poorly captures structures of vulnerability, particularly structures that expose entire populations to risk in relatively uniform ways. Stemming from this, the review revealed a series of specific topical areas in need of further research including masculinities, transactional sex, infrastructural deficits in health and education, fragile states and global governance. For each of these topical areas the authors demonstrate the relationship to the conceptual limitation, summarise relevant research in this area, and provide evidence of applicability to public health interventions. In pursuit of more effective interventions, this paper draws attention to some of the conceptual limitations of current approaches to understanding the pandemic, and calls for interventions that move beyond individual behaviours to address structures that shape individual behaviour and make entire populations more vulnerable to HIV.