Marrow space star volume can reveal change of trabecular connectivity

Bone ◽  
1992 ◽  
Vol 13 (5) ◽  
pp. A36-A36
Author(s):  
A. Vesterby
Keyword(s):  
Marrow Space ◽  
Trabecular Connectivity ◽  
Space Star

scholarly journals The interplay of osteogenesis and hematopoiesis

2004 ◽  
Vol 167 (6) ◽  
pp. 1113-1122 ◽  
Author(s):  
Sergei A. Kuznetsov ◽  
Mara Riminucci ◽  
Navid Ziran ◽  
Takeo W. Tsutsui ◽  
Alessandro Corsi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Parathyroid Hormone ◽  
Ex Vivo ◽  
Cell Types ◽  
Heterotopic Bone ◽  
Stromal Compartment ◽  
Marrow Space ◽  
Stromal Tissue

The ontogeny of bone marrow and its stromal compartment, which is generated from skeletal stem/progenitor cells, was investigated in vivo and ex vivo in mice expressing constitutively active parathyroid hormone/parathyroid hormone–related peptide receptor (PTH/PTHrP; caPPR) under the control of the 2.3-kb bone-specific mouse Col1A1 promoter/enhancer. The transgene promoted increased bone formation within prospective marrow space, but delayed the transition from bone to bone marrow during growth, the formation of marrow cavities, and the appearance of stromal cell types such as marrow adipocytes and cells supporting hematopoiesis. This phenotype resolved spontaneously over time, leading to the establishment of marrow containing a greatly reduced number of clonogenic stromal cells. Proliferative osteoprogenitors, but not multipotent skeletal stem cells (mesenchymal stem cells), capable of generating a complete heterotopic bone organ upon in vivo transplantation were assayable in the bone marrow of caPPR mice. Thus, PTH/PTHrP signaling is a major regulator of the ontogeny of the bone marrow and its stromal tissue, and of the skeletal stem cell compartment.

A Novel Two-Step Validation Algorithm for Lost-in-Space Star Identification

2020 ◽  
Vol 56 (3) ◽  
pp. 2272-2279 ◽  
Author(s):  
Xiaochu Wang ◽  
Changhao Sun ◽  
Ting Sun
Keyword(s):  
Star Identification ◽  
Space Star

scholarly journals Three-dimensional model of bone marrow

Blood ◽  
1978 ◽  
Vol 51 (4) ◽  
pp. 633-643 ◽  
Author(s):  
N Mohandas ◽  
M Prenant
Keyword(s):  
Bone Marrow ◽  
Close Association ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Scale Models ◽  
Marrow Space ◽  
Normal Rat

Abstract Three-dimensional scale models of bone marrow from a hypertransfused and a normal rat were constructed. The model of marrow from the hypertransfused rat demonstrated the existence of distinct erythroblastic islands in situ in which the erythroblasts underwent sychronous maturation. Macrophages were found in close association with the developing erythroblasts. The immature erythroblasts were tightly grouped, but as they matured they began to move apart. Erythroblasts in individual clusters were found to be at the same stage of morphologic maturation. In contrast, the model of marrow from the normal rat showed a majority of clusters containing erythroblasts at various stages of maturation. Erythropoiesis was not spatially restricted to the area proximal to the sinuses but was found to occur over the entire marrow space. Thrombopoiesis, however, was found to take place exclusively in the immediate vicinity of the marrow sinuses.

Snacking in Space: Star Dines on Planet

Science News ◽  
2001 ◽  
Vol 159 (20) ◽  
pp. 310
Author(s):  
Ron Cowen
Keyword(s):  
Space Star

scholarly journals Variation in primary and culture-expanded cells derived from connective tissue progenitors in human bone marrow space, bone trabecular surface and adipose tissue

Cytotherapy ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 343-360 ◽  
Author(s):  
Maha A. Qadan ◽  
Nicolas S. Piuzzi ◽  
Cynthia Boehm ◽  
Wesley Bova ◽  
Malcolm Moos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Adipose Tissue ◽  
Connective Tissue ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Marrow Space ◽  
Trabecular Surface

scholarly journals Efficient Star Identification Using a Neural Network

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3684
Author(s):  
David Rijlaarsdam ◽  
Hamza Yous ◽  
Jonathan Byrne ◽  
Davide Oddenino ◽  
Gianluca Furano ◽  
...  
Keyword(s):  
Neural Network ◽  
Attitude Determination ◽  
Lightweight Design ◽  
A Priori ◽  
Search Time ◽  
Identification Algorithm ◽  
Star Sensor ◽  
Feature Extraction Method ◽  
Star Identification ◽  
Space Star

The required precision for attitude determination in spacecraft is increasing, providing a need for more accurate attitude determination sensors. The star sensor or star tracker provides unmatched arc-second precision and with the rise of micro satellites these sensors are becoming smaller, faster and more efficient. The most critical component in the star sensor system is the lost-in-space star identification algorithm which identifies stars in a scene without a priori attitude information. In this paper, we present an efficient lost-in-space star identification algorithm using a neural network and a robust and novel feature extraction method. Since a neural network implicitly stores the patterns associated with a guide star, a database lookup is eliminated from the matching process. The search time is therefore not influenced by the number of patterns stored in the network, making it constant (O(1)). This search time is unrivalled by other star identification algorithms. The presented algorithm provides excellent performance in a simple and lightweight design, making neural networks the preferred choice for star identification algorithms.

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