Travel routes to remote ocean targets reveal the map sense resolution for a marine migrant

How animals navigate across the ocean to isolated targets remains perplexing greater than 150 years since this question was considered by Charles Darwin. To help solve this long-standing enigma, we considered the likely resolution of any map sense used in migration, based on the navigational performance across different scales (tens to thousands of kilometres). We assessed navigational performance using a unique high-resolution Fastloc-GPS tracking dataset for post-breeding hawksbill turtles (Eretmochelys imbricata) migrating relatively short distances to remote, isolated targets on submerged banks in the Indian Ocean. Individuals often followed circuitous paths (mean straightness index = 0.54, range 0.14-0.93, s.d. = 0.23, n = 22), when migrating short distances (mean beeline distance to target = 106 km, range 68.7-178.2 km). For example, one turtle travelled 1306.2 km when the beeline distance to the target was only 176.4 km. When off the beeline to their target, turtles sometimes corrected their course both in the open ocean and when encountering shallow water. Our results provide compelling evidence that hawksbill turtles only have a relatively crude map sense in the open ocean. The existence of widespread foraging and breeding areas on isolated oceanic sites points to target searching in the final stages of migration being common in sea turtles

Design agency:prototyping multi-agent systems in architecture

This paper presents research on the prototyping of multi-agent systems for architectural design. It proposes a design exploration methodology at the intersection of architecture, engineering, and computer science. The motivation of the work includes exploring bottom up generative methods coupled with optimizing performance criteria including for geometric complexity and objective functions for environmental, structural and fabrication parameters. The paper presents the development of a research framework and initial experiments to provide design solutions, which simultaneously satisfy complexly coupled and often contradicting objectives. The prototypical experiments and initial algorithms are described through a set of different design cases and agents within this framework; for the generation of façade panels for light control; for emergent design of shell structures; for actual construction of reciprocal frames; and for robotic fabrication. Initial results include multi-agent derived efficiencies for environmental and fabrication criteria and discussion of future steps for inclusion of human and structural factors

Synthesis of Spirobicyclic Pyrazoles by Intramolecular Dipolar Cycloadditions/[1s, 5s] Sigmatropic Rearrangements.

The formation of fused pyrazoles via intramolecular 1,3-dipolar cycloadditions of diazo intermediates with pendant alkynes is described. A subsequent thermal [1s, 5s] sigmatropic shift of these pyrazole systems resulted in a ring contraction, forming spirocyclic pyrazoles. The limitations of this rearrangement were explored by changing the substituents on the nonmigrating aromatic ring and by using substrates lacking an aromatic linkage to the propargyl group

Highly Sensitive and Selective Spiropyran-Based Sensor for Copper(II) Quantification.

The metal-binding capabilities of the spiropyran family of molecular switches have been explored for several purposes from sensing to optical circuits. Metal-selective sensing has been of great interest for applications ranging from environmental assays to industrial quality control, but sensitive metal detection for field-based assays has been elusive. In this work, we demonstrate colorimetric copper sensing at low micromolar levels. Dimethylamine-functionalized spiropyran (SP1) was synthesized and its metal-sensing properties were investigated using UV-vis spectrophotometry. The formation of a metal complex between SP1 and Cu2+ was associated with a color change that can be observed by the naked eye as low as ≈6 μM and the limit of detection was found to be 0.11 μM via UV-vis spectrometry. Colorimetric data showed linearity of response in a physiologically relevant range (0-20 μM Cu2+) with high selectivity for Cu2+ ions over biologically and environmentally relevant metals such as Na+, K+, Mn2+, Ca2+, Zn2+, Co2+, Mg2+, Ni2+, Fe3+, Cd2+, and Pb2+. Since the color change accompanying SP1-Cu2+ complex formation could be detected at low micromolar concentrations, SP1 could be viable for field testing of trace Cu2+ ions