Development of new malaria diagnostics: matching performance and need.

Despite advances in diagnostic technology, significant gaps remain in access to malaria diagnosis. Accurate diagnosis and misdiagnosis leads to unnecessary waste of resources, poor disease management, and contributes to a cycle of poverty in low-resourced communities. Despite much effort and investment, few new technologies have reached the field in the last 30 years aside from lateral flow assays.

Limitations of haemozoin-based diagnosis of Plasmodium falciparum using dark-field microscopy.

Background: The haemozoin crystal continues to be investigated extensively for its potential as a biomarker for malaria diagnostics. In order for haemozoin to be a valuable biomarker, it must be present in detectable quantities in the peripheral blood and distinguishable from false positives. Here, dark-field microscopy coupled with sophisticated image processing algorithms is used to characterize the abundance of detectable haemozoin within infected erythrocytes from field samples in order to determine the window of detection in peripheral blood.

Detection of malarial byproduct hemozoin utilizing its unique scattering properties.

The scattering characteristics of the malaria byproduct hemozoin, including its scattering distribution and depolarization, are modeled using Discrete Dipole Approximation (DDA) and compared to those of healthy red blood cells. Scattering (or dark-field) spectroscopy and imaging are used to identify hemozoin in fresh rodent blood samples. A new detection method is proposed and demonstrated using dark-field in conjunction with cross-polarization imaging and spectroscopy.

Mixed external cavity mode dynamics in a semiconductor laser.

We observe experimentally and numerically novel mixed-mode dynamic states of a diode laser subject to two delayed optical feedbacks. These states have been proposed and analyzed within the framework of the Lang-Kobayashi single-feedback model. Such states are combinations of two distinct external cavity modes and can be identified through a characteristic sequence of a Hopf bifurcation followed by a secondary quasi-periodic bifurcation.