An effective high-efficiency LED headlamp system for automotive low-beam lighting which consists of parabolic reflector, compound lenses and combined prisms, is introduced in this paper. Using a single, high-brightness LED, the illumination requirements for a headlamp low beam specified by UNECE regulation 'Addendum 111: Regulation No. 112 Revision 2' can be achieved. On the test screen at a distance of 25 m, simulation results as well as testing results for the prototype meet the requirements of the UNECE regulation for all specified regions and key points.

In this paper, we propose a composite optical system for automotive headlamps. The system is composed of a paraboloid collimating reflector, an off-axis paraboloid reflector, a baffle and an imaging len. By using a LED as the light source, precise light distribution can be achieved. When making ray-tracing simulation for the composite optical system in TracePro, a clear cut-off line can be seen on the measuring screen, as well as a hotspot at the centre. The power consumption for the LED light sources in this system is less than 10 W, resulting in an energy efficiency of more than 58% and a maximum illumination of 26.76 lux at the centre hotspot.

The influence of microbiota on mosquito physiology and vector competence is becoming increasingly clear but our understanding of interactions between microbiota and mosquitoes still remains incomplete. Here we show that gut microbiota of Anopheles stephensi, a competent malaria vector, participates mosquito tryptophan metabolism. Elimination of microbiota by antibiotics treatment leads to the accumulation of tryptophan (Trp) and its metabolites, kynurenine (Kyn), 3-hydroxykynurenine (3-HK) and xanthurenic acid (XA). Of these, 3-HK impairs the structure of peritrophic matrix (PM), thereby promoting Plasmodium berghei infection. Among the major gut microbiota in An. stephensi, Pseudomonas alcaligenes plays a role in catabolizing 3-HK as revealed by whole genome sequencing and LC-MS metabolic analysis. The genome of P. alcaligenes encodes kynureninase (KynU) that is responsible for the conversion of 3-HK to 3-Hydroxyanthranilic acid (3-HAA). Mutation of this gene abrogates the ability of P. alcaligenes to metabolize 3-HK, which in turn abolishes its role on PM protection. Colonization of An. stephensi with KynU mutated P. alcaligenes fails to protect mosquitoes against parasite infection as effectively as those with wild type bacterium. In summary, we identify an unexpected function of gut microbiota in controlling mosquito tryptophan metabolism with the major consequences on vector competence.

Dietary sugar is the major energy source for mosquitoes, but its influence on mosquitoes' capability to transmit malaria parasite remains unclear. Here we show that Plasmodium berghei infection changes global metabolism of Anopheles stephensi with the most significant impact on glucose metabolism. Supplementation of glucose or trehalose (the main hemolymph sugar) to mosquito increases Plasmodium infection by alkalizing the mosquito midgut. The glucose/trehalose diets promote rapid growth of a commensal bacterium, Asaia bogorensis, which remodels glucose metabolism and consequently increases midgut pH. The pH increase in turn promotes Plasmodium gametogenesis. We also demonstrate the sugar composition from different natural plants influences A. bogorensis growth and Plasmodium infection is associated with their capability to expand A. bogorensis. Altogether, our results demonstrate that dietary glucose is an important factor that determines mosquito's competency to transmit Plasmodium and further highlight a key role for mosquito-microbiota metabolic interactions in regulating development of malaria parasite.

The use of LEDs is increasing rapidly in both the commercial and residential markets. Nowadays, the main way to measure the luminous intensity distribution of a LED is by using a goniophotometer. This takes a long time which means its test efficiency is low. In this paper, we will propose a new way to measure the luminous intensity distribution of LEDs based on the Luneburg lens, which is a kind of dielectric lens with continuously changed index of refraction, with high efficiency and low cost. We also develop a complete test system and give the result of a simulation of the test system.