23,074 research outputs found
Improving Statistical Language Model Performance with Automatically Generated Word Hierarchies
An automatic word classification system has been designed which processes
word unigram and bigram frequency statistics extracted from a corpus of natural
language utterances. The system implements a binary top-down form of word
clustering which employs an average class mutual information metric. Resulting
classifications are hierarchical, allowing variable class granularity. Words
are represented as structural tags --- unique -bit numbers the most
significant bit-patterns of which incorporate class information. Access to a
structural tag immediately provides access to all classification levels for the
corresponding word. The classification system has successfully revealed some of
the structure of English, from the phonemic to the semantic level. The system
has been compared --- directly and indirectly --- with other recent word
classification systems. Class based interpolated language models have been
constructed to exploit the extra information supplied by the classifications
and some experiments have shown that the new models improve model performance.Comment: 17 Page Paper. Self-extracting PostScript Fil
Material and Structural Aspects of Bone in Osteogenesis Imperfecta
Bone fragility is a fundamental problem in individuals with osteogenesis imperfecta (OI). The mechanisms behind this fragility, however, are not yet well understood. Multiple factors appear to contribute to the increased fracture risk in OI. At the structural level, bone mass deficiency can result in increased stress levels within bones. The underlying mineral and collagen abnormalities that define OI are also believed to result in compromised material-level properties. The variability of collagen biochemical irregularities causing OI and the corresponding heterogeneity of disease severity result in abnormalities that are not easily generalized within the OI population.
The aims of this chapter are to introduce basic mechanical notions pertaining to the strength of structures and materials, and to present a synthesis of existing literature regarding the mechanical properties of bones in OI
Economics of using rbsT
As new technologies such as rbST become available to dairy producers, evaluating the profitability of those technologies on individual farms is essential. Costs associated with rbST include purchase of product, feed, and labor. The costs of product and labor are independent of milk response. However, feed cost will increase as the milk production response to rbST increases. If the mailbox milk price is $10, approximately 7 lb more milk per day will be required to break even. It is essential that dairy producers have the management in place to achieve a profitable milk response to rbST.; Dairy Day, 1995, Kansas State University, Manhattan, KS, 1995
Planning a dairy expansion
Dairy farm size is increasing in all regions of the
United States. In two of the largest dairy states, California and Wisconsin, mean herd sizes have increased 950% and 250%, respectively, since 1950. Dairy herds of 500 cows are common in all areas of the United States, and herds over 1,500 cows are common in the West producand
Southeast. Many dairy operations are considering expansion of existing facilities or construction of new facilities to increase efficiencyor profitability. Before adding cows or facilities, dairy producers may want to answer the following questions: 1) How can I improve the efficiency of the present operation? 2) Can production per cow be increased? 3) Can the current herd be milked 3× per day? 4) Can I send the conheifers
to a contract raiser and expand the cow herd? 5) What are my financial goals? 6) Where do I want to be in 5 and 10 years? 7) What are investthe
expectations of other family members? 8)Do I have adequate acreage to expand the herd and manage the waste? 9) Do I want to manage employees? 10) Do I want to deal with regulatory agencies
Micro-CT Characterization of Human Trabecular Bone in Osteogenesis Imperfecta
Osteogenesis imperfecta (OI) is a genetic syndrome affecting collagen synthesis and assembly. Its symptoms vary widely but commonly include bone fragility, reduced stature, and bone deformity. Because of the small size and paucity of human specimens, there is a lack of biomechanical data for OI bone. Most literature has focused on histomorphometric analyses, which rely on assumptions to extrapolate 3-D properties. In this study, a micro-computed tomography (μCT) system was used to directly measure structural and mineral properties in pediatric OI bone collected during routine surgical procedures. Surface renderings suggested a poorly organized, plate-like orientation. Patients with a history of bone-augmenting drugs exhibited increased bone volume fraction (BV/TV), trabecular number (Tb.N), and connectivity density (Eu.Conn.D). The latter two parameters appeared to be related to OI severity. Structural results were consistently higher than those reported in a previous histomorphometric study, but these differences can be attributed to factors such as specimen collection site, drug therapy, and assumptions associated with histomorphometry. Mineral testing revealed strong correlations with several structural parameters, highlighting the importance of a dual approach in trabecular bone testing. This study reports some of the first quantitative μCT data of human OI bone, and it suggests compelling possibilities for the future of OI bone assessment
Recommended from our members
Chemistry and valency spectra of Chromite in SNC meteorites
Shergottite chromite core mantle sources were Al-poor, Fe-rich, low Fe^{3+}/Fe^{2+}, fO_{2} 1 to 4 unit
Role of Micro-CT in the Visualization, Measurement, and Quantification of Bone Structure in Osteogenesis Imperfecta
- …