13,681 research outputs found
Relation of Magnetic and Gravity Field Data to Selected Structural Elements of the Central Portion of the Arkoma Basin
In order to acquire a greater understanding of some of the major basement structural features characteristic of the Arkoma basin, magnetic and gravity data have been collected and analyzed for a selected area. Several anomalies exist and are found to be associated with faulting or major fracturing in the Precambrian basement. Modelling of source bodies based on magnetic and gravity values provides quantitative estimates of the depth as well as the geometry of basement structural geology
The Diverse Structure and Organization of U.S. Beef Cow-Calf Farms
Beef cow-calf production in the United States is widespread, occurring in every State. Nearly 765,000 farms, about 35 percent of the 2.2 million farms in the United States, had a beef cow inventory in 2007. Most of these were small, part-time operations. About a third of farms that raise beef animals had a beef cow inventory of less than 10 cows, more than half had fewer than 20 cows, and nearly 80 percent had fewer than 50 cows. In this study, ERS uses data from USDAās 2008 Agricultural Resource Management Survey for U.S. beef cow-calf operations to examine the structure, costs, and characteristics of beef cow-calf producers. Many small operations are ārural residence farmsā that specialize in beef cow-calf production, but their income from off-farm sources exceeds that from the farm. Most beef cow-calf production occurs on large farms, but cow-calf production is not the primary enterprise on many of these farms. Findings suggest that operators of beef cow-calf farms have a diverse set of goals for the cattle enterprise.Beef cow-calf production, farm income, animal traceability, Agricultural Resource Management Survey (ARMS), National Animal Identification System (NAIS), Agribusiness, Agricultural and Food Policy, Farm Management, Livestock Production/Industries,
Canonical transforming growth factor-Ī² signaling regulates disintegrin metalloprotease expression in experimental renal fibrosis via miR-29
Fibrosis pathophysiology is critically regulated by Smad 2ā and Smad 3āmediated transforming growth factor-Ī² (TGF-Ī²) signaling. Disintegrin metalloproteases (Adam) can manipulate the signaling environment, however, the role and regulation of ADAMs in renal fibrosis remain unclear. TGF-Ī² stimulation of renal cells results in a significant up-regulation of Adams 10, 17, 12, and 19. The selective Smad2/3 inhibitor SB 525334 reversed these TGF-Ī²āinduced changes. InĀ vivo, using ureteral obstruction to model renal fibrosis, we observed increased Adams gene expression that was blocked by oral administration of SB 525334. Similar increases in Adam gene expression also occurred in preclinical models of hypertension-induced renal damage and glomerulonephritis. miRNAs are a recently discovered second level of regulation of gene expression. Analysis of 3ā² untranslated regions of Adam12 and Adam19 mRNAs showed multiple binding sites for miR-29a, miR-29b, and miR-29c. We show that miR-29 family expression is decreased after unilateral ureter obstruction and this significant decrease in miR-29 family expression was observed consistently in preclinical models of renal dysfunction and correlated with an increase in Adam12 and Adam19 expression. Exogenous overexpression of the miR-29 family blocked TGF-Ī²āmediated up-regulation of Adam12 and Adam19 gene expression. This study shows that Adams are involved in renal fibrosis and are regulated by canonical TGF-Ī² signaling and miR-29. Therefore, both Adams and the miR-29 family represent therapeutic targets for renal fibrosis
Beef Cow-Calf Producer Participation in the National Animal Identification System
Farm Management, Livestock Production/Industries, Production Economics,
The Environment as an Argument
Context-awareness as defined in the setting of Ubiquitous Computing [3] is all about expressing the dependency of a specific computation upon some implicit piece of information. The manipulation and expression of such dependencies may thus be neatly encapsulated in a language where computations are first-class values. Perhaps surprisingly however, context-aware programming has not been explored in a functional setting, where first-class computations and higher-order functions are commonplace. In this paper we present an embedded domain-specific language (EDSL) for constructing context-aware applications in the functional programming language Haskell. Ā© 2012 Springer-Verlag
Characterization of Metastatic Tumor Formation by the Colony Size Distribution
Knowledge regarding the kinetics of metastatic tumor formation, as related to
the growth of the primary tumor, represents a fundamental issue in cancer
biology. Using an in vivo mammalian model, we show here that one can obtain
useful information from the frequency distribution of the sizes of metastatic
colonies in distant organs after serial sectioning and image reconstruction. To
explain the experimental findings, we constructed a biophysical model based on
the respective growth patterns of the primary tumor and metastases and a
stochastic process of metastatic colony formation. Heterogeneous distributions
of various biological parameters were considered. We found that the elementary
assumption of exponential forms of growth for the primary tumor and metastatic
colonies predicts a linear relation on a log-log plot of a metastatic colony
size distribution, which was consistent with the experimental results.
Furthermore, the slope of the curve signifies the ratio of growth rates of the
primary and the metastases. Non-exponential (Gompertzian and logistic) tumor
growth patterns were also incorporated into the theory to explain possible
deviation from the log-log linear relation. The observed metastasis-free
probability also supported the assumption of a time-dependent Poisson process.
With this approach, we determined the mechanistic parameters governing the
process of metastatogenesis in the lungs for two murine tumor cell lines (KHT
and MCaK). Since biological parameters specified in the model could be obtained
in the laboratory, a workable metastatic "assay" may be established for various
malignancies and in turn contribute in formulating rational treatment regimens
for subclinical metastases.Comment: 14 pages, 6 figure
Letter from J. H. McBride to John Muir, 1913 Sep 24.
Board of EducationDr. J. H. McBRIDE, PRESIDENTI.N. SMITH, VICE-PRESIDENTMRS. CLARA M. ODELLFRANK MAYWILLIAM S. GRASSIENORVAL G. FELKER, CLERKPasadena City SchoolsOFFICES:521-526: 527, 529 CHAMBER OF COMMERCE BUILDINGTELEPHONE COLORADO 2805Administrative DepartmentJEREMIAH M. RHODESSUPERINTENDENTNORVAL G. FELKERBUSINESS MANAGERLEONA C. CARVERSUPERINTENDENT\u27S SECRETARYSept. 24,1913.Mr. John Muir,Martinez, California.My dear Mr. Muir:-Pasadena, in developing its splendid school system, has always tried to hold before the young people of the community for their emulation and encouragement the highest types of American citizenship. With this object in view and in common with other communities of our State and Nation, our Schools have been named in honor of those who have taken a conspicuous part in public affairs as statesmen, scientists, and men of letters.It is with no small degree of pride that the Board of Education of the Pasadena City School District has recently caused the name of John Muir to be given to one of our best schools, believing that in so doing the honor will be Pasadena\u27s, and the inspiration which comes from familiarity with a name which stands for the best things in the life and literature of our State and Nation will be a constant incentive to high scholarship and true citizenship on the part of the boys and girls of Pasadena.Yours very truly,[illegible] president[illegible] ClerkBoard of Education of thePasadena City School District.0555
Dosage compensation in birds
AbstractThe Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess ādosage compensationā systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mammals, insects, and nematodes, although the mechanisms involved differ profoundly [2]. In birds, however, it is widely accepted that dosage compensation does not occur [3ā5], and the differential expression of Z-linked genes has been suggested to underlie the avian sex-determination mechanism [6]. Here we show equivalent expression of at least six of nine Z chromosome genes in male and female chick embryos by using real-time quantitative PCR [7]. Only the Z-linked ScII gene, whose ortholog in Caenorhabditis elegans plays a crucial role in dosage compensation [8], escapes compensation by this assay. Our results imply that the majority of Z-linked genes in the chicken are dosage compensated
- ā¦