For the last decades, manifold learning has shown its advantage of efficient non-linear dimensionality reduction in data analysis. Based on the assumption that informative and discriminative representation of the data lies on a low-dimensional smooth manifold which implicitly embedded in the original high-dimensional space, manifold learning aims to learn the low-dimensional representation foll...

Introduction: Extraosseous Ewing’s sarcoma (EES) of the head and neck region is a rare occurrence, and Ewing’s sarcoma of the parapharyngeal space is even rarer. To the best of our knowledge, only three cases of EES of the parapharyngeal space have been reported in the literature.   Case Report: We report a rare case of EES of the parapharyngeal space in an 8-year-old girl. She presented with c...

This paper describes the fine structure of the spermatozoan apex and its morphological changes during the process of fertilization in Ciona intestinalis. At the apex of the head an acrosome is present in the form of a flattened vesicle containing moderately electron-dense material with an electron-dense plate in its centre. Contiguous to the acrosome, an apical substance is located in the anter...

Investigation of eye movement strategies often requires the measurement of gaze orientation without restraining the head. However, most commercial eye-trackers have low tolerance for head movements. Here we present a novel geometry-based method to estimate gaze orientation in space in unrestricted head conditions. The method combines the measurement of eye-in-head orientation-provided by a head...

What is head stabilization in birds? When the body of a bird is held in the hand and rotated or moved in different directions the head often appears ‘locked in space’ or glued to the spot, and does not move with the rest of the body. To maintain this stable position the bird has, of course, to make complex compensatory movements of the neck. This can be seen clearly in chickens, pigeons, owls a...

An important prerequisite for effective motor action is the discrimination between active and passive body movements. Passive movements often require immediate reflexes, whereas active movements may demand suppression of the latter. The vestibular system maintains correct body and head posture in space through reflexes. Since vestibular inputs have been reported to be largely suppressed in the ...

Solitary fibrous tumor (SFT) is a well-known tumor composed of spindle cells found most commonly in the pleura. Recently, accounts of their rare occurrence at other sites, including the head and neck area, have been reported. The parapharyngeal space is a rare location even for head and neck SFTs, and thus, could be confused with a variety of other tumors that can originate in this area. Here, ...

We develop a framework on multi-head nite automata that allows us to study the relation of parallel logarithmic time and sequential logarithmic space in a uniform and nonuniform setting in more detail. In both settings it turns out that NC 1 requires data-independent computations|the movement of the input-heads only depends on the length of the input|whereas logarithmic space is caught with dat...

INTRODUCTION As the head provides a reference frame for detecting and controlling motion via the visual and vestibular systems, it is desirable to keep it stable in space. While much is known about reflex and mechanical factors, little is known about predictive control. To determine the contribution of prediction to head stability in space (HSS) we asked two question. First, is HSS better for a...