The Centres for Disease Control Light Trap (CDC LT) and The Human Decoy Trap (HDT) Compared to The Human Landing Catch (HLC) for Measuring Anopheles Biting in Rural Tanzania

BackgroundThe intensity of vector mosquito biting is an important measure for malaria epidemiology and control. The human landing catch (HLC) is an effective entomological surveillance tool, but is labour-intensive, expensive and raises safety issues. The Centres for Disease Control light trap (CDC LT) and the human decoy trap (HDT) are less costly and exposure-free alternatives. This study compared the CDC LT and HDT against the HLC for measuring Anopheles (An.) biting in rural Tanzania and assessed their suitability as HLC proxies.MethodsIndoor mosquito surveys using HLC and CDC LT and outdoor surveys using HLC and HDT were conducted in 2017 and in 2019 in Ulanga, Tanzania in 19 villages, with one trap per house per night. Species composition, sporozoite rates and the numbers of mosquitoes caught by different trap types were compared. Aggregating the data by village and month, the Bland-Altman approach was used to assess agreement. ResultsOverall, 66,807 Anopheles funestus and 14,606 An. arabiensis adult females were caught from 6,013 CDC LT, 339 indoor HLC, 136 HDT and 195 outdoor HLC collections. Overall, the CDC LT caught fewer malaria vectors than indoor HLC: An. arabiensis (Adjusted rate ratio (Adj.RR) =0.35 (95% confidence interval (CI):0.27-0.46)) and An. funestus (Adj.RR=0.63(95%CI:0.51-0.79)). HDT caught fewer malaria vectors than outdoor HLC: An. arabiensis (Adj.RR=0.04(95%CI:0.01-0.14)) and An. funestus (Adj.RR=0.10(95%CI:0.07-0.15)). The bias and variability of the ratios of geometric mean mosquitoes caught by CDC LT and HDT relative to HLC collections for the same village-month were dependent on mosquito densities. The relative efficacies of both CDC LT and HDT declined with mosquito abundance. The variability in the ratios was substantial for low HLC counts and decreased as mosquito abundance increased. CDCLT caught a higher proportion of infected An. arabiensis and An. funestus than HLC, and HDT caught no infected mosquitoes.ConclusionsIf caution is taken in appreciation of its limitations, the CDC LT is suitable for use in routine entomological surveys and may be preferable for measuring sporozoite rates for Afrotropical mosquitoes. Use of HLC is useful to estimate human exposure to mosquitoes for estimating Entomological Inoculation Rate (EIR). The present design of the HDT is not amenable for use to conduct large-scale entomological surveys.

A proposal for wide range wavelength switching process using optical force

Optomechanical wavelength up-conversion based on optical force and core-shell scattering effects are used to control light coupling between two waveguides. This system consists of two parallel optical waveguides with 20 µm lengths suspended on a silica substrate embedded with Ag/Si/SiO2 core-shell nanoparticles. By mid-IR plane wave illumination with different intensities and different wavelengths on nanoparticles, scattering would increase and result in an improvement in attractive gradient optical force exerted on waveguides. Via bending waveguides toward each other, visible light propagating in the first waveguide would couple to another. PDMS as a polymer is used to reduce the required power for bending waveguides. Results reveal that when waveguides’ gap equilibrium is 400 nm and wavelengths of control and probe lights are 4.5 µm and 0.45 µm respectively, about 10.75 mW/µm2 power is needed to bend waveguides for total coupling of light between waveguides. The efficiency of the coupled waveguides system is %43.

Analytic Solution for Double Optical Metasurface Beam Scanners

Optical metasurfaces are researched more and more intensively for the possible realization of lightweight and compact optical devices with novel functionalities. In this paper, a new beam-steering system based on double metasurface lenses (metalenses) is proposed and developed. The proposed system is lightweight, small volume, low cost, and easy to integrate. The exact forward and inverse solutions are derived respectively using the generalized Snell’s law of refraction. Given the orientations of the double metalenses, the pointing position can be accurately determined. If the desired pointing position is given, the required metalenses’ orientations can be obtained by applied global optimization algorithms to solve nonlinear equations related to the inverse problem. The relationships of the scan region and blind zone with the system parameters are derived. The method to eliminate the blind zone is given. Comparison with double Risley-prism systems is also conducted. This work provides a new approach to control light beams.

Impact of Freshwater Discharge on the Carbon Uptake Rate of Phytoplankton During Summer (January–February 2019) in Marian Cove, King George Island, Antarctica

Rapidly changing conditions in high-latitude coastal systems can significantly impact biogeochemical cycles because these systems are strongly influenced by freshwater discharged from melting glaciers and streams on land. Generally, Antarctic coastal areas are considered high-productivity areas in which phytoplankton growth prevails under various environmental conditions (e.g., oceanographic and meteorological conditions). This study provides carbon uptake rates of phytoplankton in Marian Cove during summer (January-February 2019). Daily depth-integrated carbon uptake varied greatly and averaged 0.8 g C m–2 day–1, with a maximum of 4.52 mg g C m–2 day–1 recorded on 14 January. Similarly, the observed biomass standing stocks were very high (up to 19.5 mg m–3 chlorophyll a) and were dominated by microphytoplankton (20–200 μm), representing 84% of total chlorophyll a (chl-a). The depth-integrated chl-a and carbon uptake decreased from outer to inner areas (close to the glacial front) in the cove. As the austral summer progressed, the freshening of the surface waters coincided with high water stability and suspended material and with low productivity when nanophytoplankton were present (2–20 μm; >60%). These findings suggest that both photosynthetically active radiation penetrating the water column and enhanced turbidity control light availability for phytoplankton, as well as their community compositions.

Parametric atmospheres: An investigation of light, material and mass as the generator for design atmosphere

<p>Parametric design today is largely embedded within a traditional trajectory. Current use largely sees the role of computers in the design studio operate at a low level, fulfilling no more sophisticated tasks than which was formerly achieved by hand. What motivation there is for parametric design tools seems to be largely inspired by a visual aesthetic. Manipulating relationships between architectural elements to design atmosphere is a long established physical process. By utilising the computer to accurately simulate spatial qualities, I propose the genesis of something more novel. The quantification of atmosphere within a digital toolset allows the designer to accurately control light, material and mass through complex networks of parametric relationships. Simulating and researching architectural atmosphere from architects Peter Zumthor and Tadao Ando allows this thesis to demonstrate a methodology for accurately simulating architectural atmosphere through the generation of geometry in Grasshopper and simulation of real site specific lighting data in 3ds Max. This thesis presents a methodology for how digital parametric design techniques enable greater flexibility and control in designing atmospheric architecture.</p>

Parametric atmospheres: An investigation of light, material and mass as the generator for design atmosphere

<p>Parametric design today is largely embedded within a traditional trajectory. Current use largely sees the role of computers in the design studio operate at a low level, fulfilling no more sophisticated tasks than which was formerly achieved by hand. What motivation there is for parametric design tools seems to be largely inspired by a visual aesthetic. Manipulating relationships between architectural elements to design atmosphere is a long established physical process. By utilising the computer to accurately simulate spatial qualities, I propose the genesis of something more novel. The quantification of atmosphere within a digital toolset allows the designer to accurately control light, material and mass through complex networks of parametric relationships. Simulating and researching architectural atmosphere from architects Peter Zumthor and Tadao Ando allows this thesis to demonstrate a methodology for accurately simulating architectural atmosphere through the generation of geometry in Grasshopper and simulation of real site specific lighting data in 3ds Max. This thesis presents a methodology for how digital parametric design techniques enable greater flexibility and control in designing atmospheric architecture.</p>

Drosophila fabp is required for light-dependent Rhodopsin-1 clearance and photoreceptor survival

Rhodopsins are light-detecting proteins coupled with retinal chromophores essential for visual function. Coincidentally, dysfunctional rhodopsin homeostasis underlies retinal degeneration in humans and model organisms. Drosophila ninaEG69D mutant is one such example, where the encoded Rh1 protein imposes endoplasmic reticulum (ER) stress and causes light-dependent retinal degeneration. The underlying reason for such light-dependency remains unknown. Here, we report that Drosophila fatty acid binding protein (fabp) is a gene induced in ninaEG69D/+ photoreceptors, and regulates light-dependent Rhodopsin-1 (Rh1) protein clearance and photoreceptor survival. Specifically, our photoreceptor-specific gene expression profiling study in ninaEG69D/+ flies revealed increased expression of fabp together with other genes that control light-dependent Rh1 protein degradation. fabp induction in ninaEG69D photoreceptors required vitamin A and its transporter genes. In flies reared under light, loss of fabp caused an accumulation of Rh1 proteins in cytoplasmic vesicles. The increase in Rh1 levels under these conditions was dependent on Arrestin2 that mediates feedback inhibition of light-activated Rh1. fabp mutants exhibited light-dependent retinal degeneration, a phenotype also found in other mutants that block light-induced Rh1 degradation. These observations reveal a previously unrecognized link between light-dependent Rh1 proteostasis and the ER-stress imposing ninaEG69D mutant that cause retinal degeneration.

Toward a Connected System—Understanding the Contribution of Light from Different Sources on Occupants’ Circadian Rhythms

Light that enters humans’ eyes and impacts circadian rhythms may come from various sources, including the sun, electric lighting systems, and self-luminous displays. Occupants’ activities strongly impact the light entering their eyes, which is difficult to predict and not yet well understood. This study investigated the circadian contributions of light from different sources in real building environments to better understand the variables that influence the circadian health of occupants. Spectral irradiance distributions at a position equivalent to the front of an eye of a seated occupant in various interior office spaces were collected. Daylight and electric light were measured separately, and light emitted from displays was measured when a variety of different computer tasks was performed. Circadian stimulus (CS) and α-opic irradiance, defined by CIE DIS026/E:2018, were further calculated, and the circadian effects of light from different sources were compared. The results show that daylight has the greatest circadian effect, while electric light in spaces that were predominantly designed with conventional downward lighting has a very limited impact. The circadian effect of light from screens was considerably high. The outcomes suggest that, to optimise the circadian effects of light, connected lighting systems are needed to control light from different sources.

Influence of Indoor Residual Spay on An. Gambiae S.L. and An. Funestus Abundance, Resting Behavior and Community Perception on Irs Intervention In Kagera-Tanzania

Background: There has been a persistence of malaria transmission in Kagera Region despite consecutive phases of indoor residual spraying (IRS) targeting malaria vectors. In addition to that, there is limited information on the resting behaviors of An. gambiae s.l. and An. funestus and community perception on IRS in Kagera. Methods: The study was conducted in two districts; Missenyi and Karagwe. Missenyi was IRS sprayed with Pirimiphos methyl insecticide and Karagwe was unsprayed. Mosquito collections were conducted using bucket traps and CDC (Centre for Disease Control) light traps. Mosquitoes were identified morphologically using taxonomical key. Sibling species were identified by polymerase chain reaction (PCR). Interviews and focused group discussions (FGDs) were conducted in order to obtain information on community perception with regard to IRS interventions. Results: A total of 5,777 mosquitoes were collected indoors by CDC light traps. An. gambiae s.l. and An. funestus accounted for 13% (n=749) of all mosquitoes collected. Unexpectedly, large proportions of An. funestus were collected indoors in Missenyi district, despite the fact that, the area was sprayed. In Karagwe district, An. gambiae s.l. was collected in large proportion. Results have showed that, An. arabiensis was the dominant sibling species among the An. gambiae s.l. in Karagwe and Missenyi districts with 82.8% (n=24) and 98.8% (n=166), respectively. Study participants agreed that, IRS campaign is useful for control of malaria vectors. They also reported that, malaria transmission have declined by comparing before and after IRS. Challenges reported which the IRS campaign poses to them, including the emergence of other insects in their houses and increase of mosquitoes later after IRS. They also reported some mosquito resting places which are not a target during spray operations. Conclusion: The present study has revealed the abundance of malaria vectors and community perception on IRS intervention efficacy and sustainability. Surprisingly, large proportions of An. funestus were collected indoors, despite the fact that, Missenyi district was sprayed. This situation calls for further studies on An. funestus behaviors and possible reasons for tolerance in sprayed area. Community sensitization before, during and after IRS application needs to be strengthen for getting intended results.