The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.

Internal sperm storage after mating is important for insect reproduction, because it permits delayed fertilisation, and post-copulatory mate choice in polyandrous females. The polyandry is common in many animal taxa including insects, because it increases female fitness by reducing the risk of infertility and providing opportunities for sperm competition and choice. The reproductive success of males, on the other hand, often depends upon avoidance of sperm competition by preventing mated females from copulating and receiving sperm from other male suitors. A widespread strategy used by males is the use of the male seminal fluid proteins (SFPs) that form the mating plug and alter female behaviors, for example by suppressing mating receptivity and elevating egg-laying. Under these circumstances, females are expected to evolve mechanism(s) to control exposure to the male SFPs in order to maximize fitness by balancing the positive and negative impacts of polyandry. Here, we discover that Drosophila melanogaster females eject male ejaculates 1-6 h after mating with a stereotypic behaviour, and that this is regulated by a brain neuropeptide pathway composed of diuretic hormone 44 (Dh44), and its receptor Dh44R1. We showed that suppressing Dh44 or Dh44R1 signals in the brain expedites sperm ejection, whereas enhancing Dh44 or Dh44R1 signals delays sperm ejection. This study uncovers a molecular mechanism by which females can influence sperm competition and selection, and counter actively the negative impact of polyandry.