Demospongiae is a class of marine sponges that mineralize skeletal elements, the glass spicules, made of amorphous silica. The spicules exhibit a diversity of highly regular three-dimensional branched morphologies that are a paradigm example of symmetry in biological systems. Current glass shaping technology requires treatment at high temperatures. In this context, the mechanism by which glass ...

We present a new model of unsupervised competitive neural network, based on spicules. This model is capable of detecting topological information of an input space, determining its orientation and, in most case, its skeleton.

Silica deposition is a fundamental process in sponges. Most sponges in the Classes Demospongiae and Hexactinellida secrete siliceous elements, which can subsequently fuse, interlock with each other, or form three-dimensional structures connected by spongin. The resulting skeletal frameworks allow sponges to grow upwards and facilitate water exchange with minimal metabolic cost. Several studies ...

Two species of Acuaria were collected from passerine birds from the Area de Conservacion Guanacaste, Costa Rica. Acuaria mayori Lent, Freitas and Proenca, 1945, was collected from Myiarchus nuttingi. Specimens from Costa Rica differ from the original description by having a spicule ratio of 1:1.5-1.7 versus 1:1.43-1.47, as well as shorter spicules and female tails. Acuaria wangi n. sp. in Hylop...

The goal of this study was to assess the reliability of measurements of the physical characteristics of spiculated masses on mammography. The images used in this study were obtained from the Digital Database for Screening Mammography. Two experienced radiologists measured the properties of 21 images of spiculated masses. The length and width of all spicules and the major axis of the mass were m...

Calcium-based matrices serve predominantly as inorganic, hard skeletal systems in Metazoa from calcareous sponges [phylum Porifera; class Calcarea] to proto- and deuterostomian multicellular animals. The calcareous sponges form their skeletal elements, the spicules, from amorphous calcium carbonate (ACC). Treatment of spicules from Sycon raphanus with sodium hypochlorite (NaOCl) results in the ...

The skeletal elements (spicules) of the demosponge Lubomirskia baicalensis were analyzed; they are composed of amorphous, non-crystalline silica, and contain in a central axial canal the axial filament which consists of the enzyme silicatein. The axial filament, that orients the spicule in its longitudinal axis exists also in the center of the spines which decorate the spicule. During growth of...

Four new Paramphimonhystrella species are described from the continental slope of New Zealand. P. glossalga n. sp. is characterised by presence of twelve lips, large buccal cavity, males with short, heavily cuticularised spicules joined distally, and females with large postvulvar sac and hammer-shaped cuticularised piece immediately posterior to vagina. P. barbula n. sp. is characterised by nar...

Motivated by recent observations of spicules and macrospicules in the far-ultraviolet (FUV) wavelength range with the Solar Ultraviolet Measurements of Emitted Radiation spectrograph (SUMER) on the Solar and Heliospheric Observatory (SOHO), a generation mechanism for spicules and macrospicules is outlined which deviates significantly from most of the previous concepts. The important aspect is t...