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Highly Specialized (highly + specialized)

Distribution by Scientific Domains

Life Sciences	40%

Selected Abstracts

Injectable Biomaterials for Regenerating Complex Craniofacial Tissues,

ADVANCED MATERIALS, Issue 32-33 2009
James D. Kretlow
Abstract Engineering complex tissues requires a precisely formulated combination of cells, spatiotemporally released bioactive factors, and a specialized scaffold support system. Injectable materials, particularly those delivered in aqueous solution, are considered ideal delivery vehicles for cells and bioactive factors and can also be delivered through minimally invasive methods and fill complex 3D shapes. In this review, we examine injectable materials that form scaffolds or networks capable of both replacing tissue function early after delivery and supporting tissue regeneration over a time period of weeks to months. The use of these materials for tissue engineering within the craniofacial complex is challenging but ideal as many highly specialized and functional tissues reside within a small volume in the craniofacial structures and the need for minimally invasive interventions is desirable due to aesthetic considerations. Current biomaterials and strategies used to treat craniofacial defects are examined, followed by a review of craniofacial tissue engineering, and finally an examination of current technologies used for injectable scaffold development and drug and cell delivery using these materials. [source]

The ovarian morphology of Scorpaena notata shows a specialized mode of oviparity

JOURNAL OF FISH BIOLOGY, Issue 4 2002
M. Muñoz
Scorpaena notata is an oviparous species with external fertilization that deposits its eggs in a gelatinous matrix. The internal epithelium of the ovarian wall is chiefly responsible for the production of this matrix, which is particularly abundant and viscous during the spawning period. The oocytes lack lipid droplets, so flotation and transport of the eggs is probably accomplished by means of the matrix that surrounds them. The ovarian stroma is situated along the centre of the gonad and the developing oocytes are connected to it by peduncles. The paucity and small size of the cortical alveoli of the oocytes are notable, as is the thinness of the zona radiata. These are characteristics that would be typical of viviparous species. The histological and ultrastructural observations lead to the conclusion that this species presents a type of oviparity more highly specialized than that of the majority of teleosts. [source]

Digital Scholarship, Economics, and the American Literary Canon

LITERATURE COMPASS (ELECTRONIC), Issue 2 2009
Kenneth M. Price
This article explores the nature of the newly emerging digital canon of American literature, a canon that is developing partly by design and partly by chance. Whether in mass-digitization projects or in electronic scholarly editing, there is a strong predominance of electronic projects devoted to the study of literatures and cultures from the nineteenth century or earlier (copyright restrictions limit work on later periods). In addition, though some of the material needed for American literary study is publicly accessible, a significant amount of material is available only via subscription. Yet only some libraries can afford electronic access and only some users have university affiliations , thus the availability of information is limited significantly. Problems are especially acute for independent scholars and those at smaller or under-funded institutions who often lack access to fee-based resources. Ventures like Google Book Search admirably make massive numbers of books widely available to readers, but such projects lack the structures useful for advanced work. When scholars attempt to create a digital scholarly edition (sometimes called an ,archive' or a ,digital thematic research collection'), and insist on rigor and a full critical apparatus, we trade Google's equalizing treatment of texts for a highly specialized and inevitably expensive treatment of a limited number of texts. [source]

A genome map of divergent artificial selection between Bos taurus dairy cattle and Bos taurus beef cattle

ANIMAL GENETICS, Issue 2 2009
B. J. Hayes
Summary A number of cattle breeds have become highly specialized for milk or beef production, following strong artificial selection for these traits. In this paper, we compare allele frequencies from 9323 single nucleotide polymorphism (SNP) markers genotyped in dairy and beef cattle breeds averaged in sliding windows across the genome, with the aim of identifying divergently selected regions of the genome between the production types. The value of the method for identifying selection signatures was validated by four sources of evidence. First, differences in allele frequencies between dairy and beef cattle at individual SNPs were correlated with the effects of those SNPs on production traits. Secondly, large differences in allele frequencies generally occurred in the same location for two independent data sets (correlation 0.45) between sliding window averages. Thirdly, the largest differences in sliding window average difference in allele frequencies were found on chromosome 20 in the region of the growth hormone receptor gene, which carries a mutation known to have an effect on milk production traits in a number of dairy populations. Finally, for the chromosome tested, the location of selection signatures between dairy and beef cattle was correlated with the location of selection signatures within dairy cattle. [source]

How to become a yucca moth: minimal trait evolution needed to establish the obligate pollination mutualism

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010
JEREMY B. YODER
The origins of obligate pollination mutualisms, such as the classic yucca,yucca moth association, appear to require extensive trait evolution and specialization. To understand the extent to which traits truly evolved as part of establishing the mutualistic relationship, rather than being pre-adaptations, we used an expanded phylogenetic estimate with improved sampling of deeply-diverged groups to perform the first formal reconstruction of trait evolution in pollinating yucca moths and their nonpollinating relatives. Our analysis demonstrates that key life-history traits of yucca moths, including larval feeding in the floral ovary and the associated specialized cutting ovipositor, as well as colonization of woody monocots in xeric habitats, may have been established before the obligate mutualism with yuccas. Given these pre-existing traits, novel traits in the mutualist moths are limited to the active pollination behaviours and the tentacular appendages that facilitate pollen collection and deposition. These results suggest that a highly specialized obligate mutualism was built on the foundation of pre-existing interactions between early Prodoxidae and their host plants, and arose with minimal trait evolution. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 847,855. [source]