Chromidina spp. are enigmatic apostome ciliates (Oligohymenophorea, Opalinopsidae) that parasitise the renal and pancreatic appendages of cephalopods. Only four species have been described, among which only three have been formally named. No DNA sequence has been reported so far. To investigate Chromidina spp. diversity, we sampled cephalopods in the Mediterranean Sea off Tunis, Tunisia, and id...

The enzymatic conversion of phenylalanine to tyrosine requires a reduced pteridine cofactor (1, 2). This requirement can be met by a naturally occurring compound with structure closely related to biopterin and sepia pteridine (3) or by certain synthetic pteridines such as 2-amino-4-hydroxy-6,7-dimethyl5,6,7 ,%tetrahydropteridine (4). In the presence of the latter compound, the hydroxylation rea...

The world's oceans are three-dimensional habitats that support high diversity and biomass. Because the densities of most of the constituents of life are greater than that of seawater, planktonic and pelagic organisms had to evolve a host of mechanisms to occupy the third dimension. Some microscopic organisms survive at the surface by dividing rapidly in vertically well mixed zones, but most org...

Melanins are ubiquitous in nature but their biological activities and functions have been difficult to discern. Conventional approaches to determine material function start by resolving structure and then characterize relevant properties. These approaches have been less successful for melanins because of their complex structure and insolubility, and because their relevant properties are not rea...

Private set operations allow correlation of sensitive data from multiple data owners. Although intensely researched, current solutions still exhibit limited scalability in terms of the supported maximum set size and number of sets. To address these issues, we propose a new approach to private set operations based on a combination of efficient secure multiparty computation and bloom filters, a s...

The eyes of cuttlefish (Sepia officinalis) have a modified horizontal slit-pupil with a distinctive W-shape in bright light, while in darkness the pupil is circular. Two suggestions have previously been made for a function of the W-shape: (1) camouflaging the eye; (2) providing distance information. Since neither of these suggestions can fully explain the function of this pupil across the entir...

The fluorescence of eumelanin (from Sepia officinalis and black human hair) was activated and enhanced by almost three orders of magnitude by exposure to near-infrared radiation. No activation or enhanced emission was observed when the samples were heated up to 100°C. The near-infrared irradiation caused obvious changes to the eumelanin and could be seen by fluorescence and bright field imaging...

Biodegradable electronics represents an attractive and emerging paradigm in medical devices by harnessing simultaneous advantages afforded by electronically active systems and obviating issues with chronic implants. Integrating practical energy sources that are compatible with the envisioned operation of transient devices is an unmet challenge for biodegradable electronics. Although high-perfor...

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