Abstract: The invention resides in a method of determining a sequence of a target polymer, or part thereof, comprising polymer units comprising canonical and non-canonical polymer units. The method comprises taking a series of measurements of a signal relating to the target polymer wherein a measurement of the signal is dependent upon a plurality of polymer units, and wherein the polymer units of the target polymer modulate the signal, and wherein a non-canonical polymer unit modulates the signal differently from a corresponding canonical polymer unit. The series of measurements are analysed using a machine learning technique that attributes a measurement of a non-canonical polymer unit to being a measurement of a respective corresponding canonical polymer unit. The sequence of the target polymer, or part thereof, is determined from the analysed series of measurements. A non-canonical polymer unit identified from the analysis can be additionally or alternatively determined.

Abstract: An optical device comprises a metasurface including a plurality of nanostmctures. The nanostmctures convert an input light of an arbitrary spin state into an output light of an arbitrary total angular momentum state characterized by a superposition of two independent orbital angular momentum (OAM) states.

Abstract: Techniques for estimating a polymer sequence of a polymer based on a signal produced as a result of translocation of the polymer through a nanopore are described. The techniques may analyze portions of the signal to estimate whether there was a transition in the polymer sequence during each respective portion and which units of the sequence the transition was between. The techniques may comprise operation of one or more neural networks into which data from the signal may be input. The techniques may include generating a plurality of weights for a portion of the signal, wherein each weight is associated with a transition between labeled units of the polymer. The weights may be indicative of a likelihood that a transition occurred between a first of the labeled units to a second of the labeled units within the portion of the signal.

Abstract: An estimate of a target sequence of polymer units is generated from a series of measurements taken by a measurement system comprising nanopores during translocation of the polymer through a nanopore. A global model of the measurement system is stored, comprising transition weightings for possible transitions between k-mers on which successive measurements are dependent and emission weightings for possible values of measurements being observed when the measurement is dependent on possible identities of k-mer. The global model is adjusted, making reference to measurements taken using the measurement system such that the fit of the measurements to the adjusted model is improved. The estimate of a target sequence of polymer units is generated using the adjusted model. The adjustment of the model improves the quality of the estimation.