SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

In recent years, technological advances have greatly expanded the range of data types generated by life sciences researchers. These span domains such as molecular structures, nucleotide and protein sequences, metabolomics, and chemogenomics, resulting in hundreds of public resources holding diverse data sets for reuse in multiple formats [1]. Most resources focus on a specific data type, yet their value for researchers is enhanced once cross-referenced and combined with expert annotation and knowledge. Cross-referencing has increasingly been achieved by implementing website application programming interfaces (web APIs), providing programming-language−agnostic methods to access online resources. Web APIs enable dynamic data exchange between resources, augment websites with additional data, and can provide access to large data sets. Web APIs also enhance adherence to FAIR data principles by making data Findable, Accessible, Interoperable, and Reusable [2], thus increasing the value of those resources. Representational state transfer (REST) [3] is a popular method for providing interoperability between a client and server [4] using the hypertext transfer protocol (HTTP), the same building block as the world wide web, [5] and a common exchange format, e.g., JavaScript Object Notation (JSON) [6]. REST APIs are considered easier to develop than previous web-service standards, e.g., Simple Object Access Protocol (SOAP). However, REST specifies a set of requirements that any implementation of a REST API must address. Although well-known resources such as the World Wide Web Consortium (W3C) (https://www.w3.org) and the Internet Engineering Task Force (IETF) (https://www.ietf.org/) provide guidance on how to implement such a service, they can be difficult to understand and may have limited documentation. We present here 11 quick tips for creating and maintaining REST web APIs that were developed while implementing various web APIs (https://www.ebi.ac.uk/services) for European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI)’s data resources.

Analytic and computer models are presented that can provide an assessment of land-mobile and air-mobile communications performance in interference environments. The results obtained with these models, based on a communications region of operability criterion, include the effects of greater-than-free-space propagation path losses associated with low-elevation signal paths. The analytic models are used to examine the effects of higher order path loss on signal-to-interference contours for single and linearly distributed interference scenarios. The computer model can be used to investigate link performance for interference environments in which the link assets and each source of interference are arbitrarily located in three dimensions. A propagation submodel permits independent calculation of the loss over each link or interference signal path. Computer-generated plots are presented that illustrate the effect of antenna heights and frequency on the shape of the signal-to-interference (S/I) contours. Of particular interest is the effect on link region of operability when either the link transmitter or the sources of interference are at a higher altitude than the other.

A quantitative measure of the anti-intercept improvement (or margin) of a relay data net is described. It is assumed that the link relays are located to obtain the maximum anti-jam advantage against a line-of-sight jammer. The anti-intercept margin is defined as the ratio of the respective spatial power densities available to the intercept receiver when no relay and relays are used, and can be as large as 10-20 dB. It is shown that the relay anti-intercept (AI) margin for a spatially uniform jamming field intensity is lower than for a single jammer environment, and requires the same form of relay spacing needed to maximize the AI margin in the absence of jamming. It is also shown that operation in a lossy medium offers an opportunity for enhancing anti-intercept capability. A measure of overall AI performance that illustrates this enhancement is discussed.

The use of communications relays is examined as a means of improving the operation of line-sight-links in an interference or jamming environment. Expressions are derived that define optimum relay locations and the number of relays. These relationships are functions of the system and interference parameters, as well as of the link and interference source geometry. Bounds on flight path orbits of airborne relays are also defined. Backlink operation with and without relays is considered, and the condition for identical relay locations for both forward link and backlink data flow is derived. The results obtained can be used to evaluate tradeoffs among the different options for reducing vulnerability to external interference.