Optogenetics and Light-Sheet Microscopy

Light-sheet microscopy is a powerful method for imaging small translucent samples in vivo, owing to its unique combination of fast imaging speeds, large field of view, and low phototoxicity. This chapter briefly reviews state-of-the-art technology for variations of light-sheet microscopy. We review recent examples of optogenetics in combination with light-sheet microscopy and discuss some current bottlenecks and horizons of light sheet in all-optical physiology. We describe how 3-dimensional optogenetics can be added to an home-built light-sheet microscope, including technical notes about choices in microscope configuration to consider depending on the time and length scales of interest

Cost-Effectiveness of Using HAART in Prevention of Mother-To-Child Transmission in the DREAM-Project Malawi

Introduction: Cost-effectiveness analysis are crucial in the management of the HIV/AIDS epidemic, particularly in resource-limited settings. Such analyses have not been performed in the use of highly active antiretroviral therapy (HAART) for prevention of mother-to-child transmission (PMTCT). Objective: Cost-effectiveness analysis of HAART approach in Malawi for PMTCT. Methods: In 2 health centres in Malawi 6500 pregnant women were tested; 1118 pregnant women completed the entire Drug Resource Enhancement against Aids and Malnutrition-Project Malawi (DREAM - PM) PMTCT protocol. The costs of the intervention were calculated using the ingredients method. Outcomes estimated were cost for infection averted and cost for DALY saved compared with no intervention. Results: From a private perspective cost for HIV infection averted was US $998 and cost per DALY saved was US$35.36. From a public perspective, the result became negative as follows: −261 and −16.55, respectively (lower cost than the cost of the therapy for an HIV+ child). The univariate sensitivity analysis showed that the cost for DALY saved always remained under the threshold of US $50, largely under the threshold given by the per capita yearly income in Malawi (US$667 PPD). Conclusions: Administration of HAART in a PMTCT programme in resource-limited settings is cost-effective. Drugs and laboratory tests are the most significant costs, but further reduction of these expenses is possible

Measurement of viral load by the automated Abbott real-time HIV-1 assay using dried blood spots collected and processed in Malawi and Mozambique

Background. The use of dried blood spots (DBS) for HIV-1 viral load quantification can greatly improve access to viral monitoring for HIV-infected patients receiving treatment in resource-limited settings.Objectives. To evaluate and validate HIV viral load measurement from DBS in sub-Saharan Africa, with a reliable, all-automated, standard commercial assay such as the Abbott m2000.Methods. A total of 277 DBS were collected in different health centres in Malawi and Mozambique and analysed for viral load determination using the Abbott m2000 assay with the corresponding plasma samples as gold standard. Samples were extracted using the m2000SP automatic extractor and then processed as the plasma samples using the specific 1.0 mL HIV-RNA DBS protocol.Results. Among samples with detectable HIV-RNA the correlation between viral load obtained from the paired 131 plasma and DBS samples was high (r=0.946). Overall, viral load values between DBS and plasma differed by less than 0.5 log unit in 90.1% of cases and by less than 1 log unit in 100% of cases. Using a threshold of 1 000 copies/mL (defining virological failure in resource-limited settings), sensitivity was 94.2% and specificity 98.6%, and both positive and negative predictive values were high (98.5% and 94.5%, respectively).Conclusion. DBS extracted and processed using the Abbott automated system can be reliably used in resource-limited setting to diagnose virological failure

Predicting trends in HIV-1 sexual transmission in sub-Saharan Africa through the Drug Resource Enhancement Against AIDS and Malnutrition model: antiretrovirals for 5 reduction of population infectivity, incidence and prevalence at the district level

The use of antiretrovirals to reduce the incidence of human immunodeficiency virus (HIV) infection has been evaluated in mathematical models as potential strategies for curtailing the epidemic. Cohort data from the Drug Resource Enhancement Against AIDS and Malnutrition (DREAM) Program was used to generate a realistic model for the HIV epidemic in sub-Saharan Africa

Studying and Optimizing the Take-Off Performance of Three-Surface Aircraft

In the quest for making aircraft more energy-efficient, configuration, and primarily the arrangement and quality of aerodynamic surfaces, play a relevant role. In a previous comparative study by the authors, it was shown how to obtain a significant increase in cruise performance by adopting a three-surface configuration instead of a classical pure back-tailed design. In this paper, an analysis of the same configurations in take-off is carried out, to assess through a fair comparison the potential effect of a three-surface one especially on take-off distance. Take-off is mathematically described by means of a sound analytic approach. Take-off distance is computed for a baseline two-surface aircraft, and in a later stage on a three-surface one. In addition to exploring the performance, a numerical optimization is also deployed, so as to find the best use of both configurations analyzed (i.e., baseline and three-surface) in take-off, and the corresponding top performance. The quality of the optimum, as well as the practical realization of a control link between the yoke and both control surfaces in the three-surface configuration, are analyzed in depth. The paper describes the advantage which can be attained by selecting a three-surface configuration, and proposes some remarks concerning the practical implementation of the maneuver to actually capture an optimal performance

Evaluation of reimplant total hip prostheses and resection arthroplasty.

Results of reimplanted total hip prostheses and resection arthroplasty were compared. Using the Iowa hip rating scale, the reimplanted prostheses population was rated higher for function, gait, and absence of deformity, however, the resection arthroplasty population rated better in freedom from pain. Radiographic findings in the reimplanted prostheses population included radiolucent lines around the cement, loosening, and cortex bone stock loss. These findings cause concern for the future of these implants. Repair and remodeling of the bone lesions were observed in resection arthroplasties. It was concluded that if healing of infection is achieved or if resection is performed for mechanical failure, the results may be considered permanent

Scan-less nonlinear optical microscope for image reconstruction and space-Time correlation analysis

Optical Microscopy has been applied to life science from its birth and reached widespread application due to its major advantages: limited perturbation of the biological tissue and the easy accessibility of the light sources. However, as the spatial and time resolution requirements and the time stability of the microscopes increase, researchers are struggling against some of its limitations: limited transparency and the refractivity of the living tissue to light and the field perturbations induced by the path in the tissue. We have developed a compact stand-Alone, completely scan-less, optical setup that allows to acquire non-linear excitation images and to measure the sample dynamics simultaneously on an ensemble of arbitrary chosen regions of interests. The image is obtained by shining a square array of spots on the sample obtained by a spatial light modulator and by shifting it (10 ms refresh time) on the sample. The final image is computed from the superposition of (100-1000) images. Filtering procedures can be applied to the raw images of the excitation array before building the image. We discuss results that show how this setup can be used for the correction of wave front aberrations induced by turbid samples (such as living tissues) and for the computation of space-Time cross-correlations in complex networks

Optogenetics and Light-Sheet Microscopy

Light-sheet microscopy is a powerful method for imaging small translucent samples in vivo, owing to its unique combination of fast imaging speeds, large field of view, and low phototoxicity. This chapter briefly reviews state-of-the-art technology for variations of light-sheet microscopy. We review recent examples of optogenetics in combination with light-sheet microscopy and discuss some current bottlenecks and horizons of light sheet in all-optical physiology. We describe how 3-dimensional optogenetics can be added to an home-built light-sheet microscope, including technical notes about choices in microscope configuration to consider depending on the time and length scales of interest.</p