Ophiuroidea is the largest class among extant echinoderms, with over 2000 described species assigned to 33 families. Here, first identification key recently revised classification was developed, and morphological descriptions were derived from it, expanding previous short diagnoses. The built by analyzing internal external skeletal characters of predominantly type each family, including at leas...

Bioluminescence relies on the oxidation of a luciferin substrate catalysed by a luciferase enzyme. Luciferins and luciferases are generic terms used to describe a large variety of substrates and enzymes. Whereas luciferins can be shared by phylogenetically distant organisms which feed on organisms producing them, luciferases have been thought to be lineage-specific enzymes. Numerous light emiss...

In this work, additional input is provided into the ongoing discussion on the mechanisms, causes and remedies of brittle fracture failures of composite (non-ceramic) insulators. This has been done partially to complement the recently published article on this topic entitled “ IEEE Task Force Report: Brittle Fracture in Non-Ceramic Insulators” [1]. At first, the most important characteristics of...

BACKGROUND Previous authors have claimed that dehydration of the nail plate causes brittle nails. Some experts claim that normal nails contain 18% water, and brittle nails contain less than 16%. OBJECTIVE We sought to test the hypothesis that brittle nails contain 2% less water than normal nails. We also examined the relationship between a number of health and behavioral variables and brittle...

let $d$ be an integral domain and $star$ a semistar operation stable and of finite type on it. we define the semistar dimension (inequality) formula and discover their relations with $star$-universally catenarian domains and $star$-stably strong s-domains. as an application, we give new characterizations of $star$-quasi-pr"{u}fer domains and um$t$ domains in terms of dimension ine...

This paper presents an investigation of the mechanism of the brittle–ductile cutting mode transition from the perspective of the mechanics. A mechanistic model is proposed to analyze the relationship between undeformed chip thickness, deformation, and stress levels in the elastic stage of the periodic chip formation process, regarding whether brittle or ductile mode deformation is to follow the...

Three ganglioside molecular species, OSG-0 (1), OSG-1 (2), and OSG-2 (3) have been obtained from the polar lipid fraction of the chloroform/methanol extract of the brittle star Ophiocoma scolopendrina. The structures of these gangliosides have been determined on the basis of chemical and spectroscopic evidence as 1-O-[(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (1)...

The first morphological observation of a euryalid brittle star, Asteronyx loveni, using non-destructive X-ray micro-computed tomography (µCT) was performed. The body of euryalids is covered by thick skin, and it is very difficult to observe the ossicles without dissolving the skin. Computed tomography with micrometer resolution (approximately 4.5-15.4 µm) was used to construct 3D images of skel...