2,535 research outputs found
Cylindrical surface profile and diameter measuring tool and method
A tool is shown having a cross beam assembly made of beams joined by a center box structure. The assembly is adapted to be mounted by brackets to the outer end of a cylindrical case. The center box structure has a vertical shaft rotatably mounted therein and extending beneath the assembly. Secured to the vertical shaft is a radius arm which is adapted to rotate with the shaft. On the longer end of the radius arm is a measuring tip which contacts the cylindrical surface to be measured and which provides an electric signal representing the radius of the cylindrical surface from the center of rotation of the radius arm. An electric servomotor rotates the vertical shaft and an electronic resolver provides an electric signal representing the angle of rotation of the shaft. The electric signals are provided to a computer station which has software for its computer to calculate and print out the continuous circumference profile of the cylindrical surface, and give its true diameter and the deviations from the ideal circle
Affinity of Arctomeles dimolodontus and other Old-World Badgers (Melinae: Mustelidae: Carnivora)
Mustelids, members of the weasel family, are the most species rich and ecologically diverse family within the order Carnivora. However, fossil mustelids are poorly understood due to their rarity in the fossil record. Fossils of “Eurasian” badgers in particular, subfamily Melinae, only include three stem and two crown genera: Arctomeles, Arctonyx, Ferinestrix, Meles, and Melodon. Today, melines are restricted to the Old World, but fossils of stem taxa have also been discovered in North America. Here, I discuss the occurrence of the fossil meline Arctomeles dimolodontus currently known only from the Gray Fossil Site of East Tennessee, USA, and its phylogenetic position within stem Melinae. A total of 34 dental characters across 8 taxa were selected because some taxa, such as Arctomeles sotnikovae and Ferinestrix vorax, are known only from teeth (or cranial fragments). A search of all possible trees using PAUP (set for maximum parsimony) yielded a single most parsimonious tree. Topology of that tree suggests that Ferinestrix is nested within crown group Melinae, rather than the stem group, and is the sister to extant Arctonyx, the hog badger. Results also suggest that Arctomeles sotnikovae does not group within the monophyletic clade formed by A. dimolodontus and A. pliocaenicus, but instead nests A. sotnikovae as a closely related, but separate, lineage to Melodon. Based on these findings, we propose that the ancestral stock of crown Melinae is more closely related to Arctomeles than Meles as previous research has suggested. Furthermore, the dental morphology within stem Melinae is relatively conservative for a generalized diet, although exceptions exist in some derived forms, such as Arctonyx and Ferinestrix, which may explain why PAUP nested the two as sister taxa. Arctonyx is an exclusively Old-World lineage, so it is likely that the Arctonyx-Ferinestrix clade had an Old-World origin, after which Ferinestrix migrated into North America and Arctonyx remained in the Old World. This begs the question: why do some melines migrate into North America while other contemporary forms do not? All stem meline genera have occurrences from Eurasia, yet only Arctomeles and Ferinestrix are known to have migrated into North America. This is likely because of the environmental constraints on where these different genera can live, but much remains unknown about the ecology of fossil melines to know for certain. Further study of this disparity can lead to a greater understanding of how the earth’s climate has changed since the Neogene and how this change impacts flora and fauna
Desorption of SVOCs from Heated Surfaces in the Form of Ultrafine Particles
Ultrafine
particles (UFP) produced by electric heating of stoves
and metal cooking pans, absent food, have been hypothesized to be
created from a surface film of semivolatile organic compounds (SVOCs)
sorbed from the surrounding air. This study tests that hypothesis
by size-resolved measurements extending the lower range of the UFP
studied from 10 to 2.3 nm, and including other surfaces (glass, aluminum,
and porcelain). Heating glass Petri dishes or squares of aluminum
foil to about 350–400 °C for 4–6 min removed all
sorbed organic substances completely. Subsequent exposure of these
“clean” Petri dishes and foil squares to indoor air
in two different residences for successively longer periods (1 h to
281 days), followed by heating the materials for 4–6 min, indicated
a strong relationship of the number, size distribution, and mass of
the UFP to the time exposed. Estimates of the accumulation rate of
SVOCs on surfaces were similar to those in studies of organic film
buildup on indoor windows. Transfer of skin oils by touching the glass
or foil surfaces, or after washing the glass surface with detergent
and bare hands, was also observed, with measured particle production
comparable with that produced by long-term exposure to indoor air
High-density rhesus macaque oligonucleotide microarray design using early-stage rhesus genome sequence information and human genome annotations
BACKGROUND: Until recently, few genomic reagents specific for non-human primate research have been available. To address this need, we have constructed a macaque-specific high-density oligonucleotide microarray by using highly fragmented low-pass sequence contigs from the rhesus genome project together with the detailed sequence and exon structure of the human genome. Using this method, we designed oligonucleotide probes to over 17,000 distinct rhesus/human gene orthologs and increased by four-fold the number of available genes relative to our first-generation expressed sequence tag (EST)-derived array. RESULTS: We constructed a database containing 248,000 exon sequences from 23,000 human RefSeq genes and compared each human exon with its best matching sequence in the January 2005 version of the rhesus genome project list of 486,000 DNA contigs. Best matching rhesus exon sequences for each of the 23,000 human genes were then concatenated in the proper order and orientation to produce a rhesus "virtual transcriptome." Microarray probes were designed, one per gene, to the region closest to the 3' untranslated region (UTR) of each rhesus virtual transcript. Each probe was compared to a composite rhesus/human transcript database to test for cross-hybridization potential yielding a final probe set representing 18,296 rhesus/human gene orthologs, including transcript variants, and over 17,000 distinct genes. We hybridized mRNA from rhesus brain and spleen to both the EST- and genome-derived microarrays. Besides four-fold greater gene coverage, the genome-derived array also showed greater mean signal intensities for genes present on both arrays. Genome-derived probes showed 99.4% identity when compared to 4,767 rhesus GenBank sequence tag site (STS) sequences indicating that early stage low-pass versions of complex genomes are of sufficient quality to yield valuable functional genomic information when combined with finished genome information from a closely related species. CONCLUSION: The number of different genes represented on microarrays for unfinished genomes can be greatly increased by matching known gene transcript annotations from a closely related species with sequence data from the unfinished genome. Signal intensity on both EST- and genome-derived arrays was highly correlated with probe distance from the 3' UTR, information often missing from ESTs yet present in early-stage genome projects
Comparative evaluation of [(99m)tc]tilmanocept for sentinel lymph node mapping in breast cancer patients: results of two phase 3 trials.
BackgroundSentinel lymph node (SLN) surgery is used worldwide for staging breast cancer patients and helps limit axillary lymph node dissection. [(99m)Tc]Tilmanocept is a novel receptor-targeted radiopharmaceutical evaluated in 2 open-label, nonrandomized, within-patient, phase 3 trials designed to assess the lymphatic mapping performance.MethodsA total of 13 centers contributed 148 patients with breast cancer. Each patient received [(99m)Tc]tilmanocept and vital blue dye (VBD). Lymph nodes identified intraoperatively as radioactive and/or blue stained were excised and histologically examined. The primary endpoint, concordance (lower boundary set point at 90 %), was the proportion of nodes detected by VBD and [(99m)Tc]tilmanocept.ResultsA total of 13 centers contributed 148 patients who were injected with both agents. Intraoperatively, 207 of 209 nodes detected by VBD were also detected by [(99m)Tc]tilmanocept for a concordance rate of 99.04 % (p < 0.0001). [(99m)Tc]tilmanocept detected a total of 320 nodes, of which 207 (64.7 %) were detected by VBD. [(99m)Tc]Tilmanocept detected at least 1 SLN in more patients (146) than did VBD (131, p < 0.0001). In 129 of 131 patients with ≥1 blue node, all blue nodes were radioactive. Of 33 pathology-positive nodes (18.2 % patient pathology rate), [(99m)Tc]tilmanocept detected 31 of 33, whereas VBD detected only 25 of 33 (p = 0.0312). No pathology-positive SLNs were detected exclusively by VBD. No serious adverse events were attributed to [(99m)Tc]tilmanocept.Conclusion[(99m)Tc]Tilmanocept demonstrated success in detecting a SLN while meeting the primary endpoint. Interestingly, [(99m)Tc]tilmanocept was additionally noted to identify more SLNs in more patients. This localization represented a higher number of metastatic breast cancer lymph nodes than that of VBD
How did the domestication of Fertile Crescent grain crops increase their yields?
The origins of agriculture, 10 000 years ago, led to profound changes in the biology of plants exploited as grain crops, through the process of domestication. This special case of evolution under cultivation led to domesticated cereals and pulses requiring humans for their dispersal, but the accompanying mechanisms causing higher productivity in these plants remain unknown. The classical view of crop domestication is narrow, focusing on reproductive and seed traits including the dispersal, dormancy and size of seeds, without considering whole-plant characteristics. However, the effects of initial domestication events can be inferred from consistent differences between traditional landraces and their wild progenitors.
We studied how domestication increased the yields of Fertile Crescent cereals and pulses using a greenhouse experiment to compare landraces with wild progenitors. We grew eight crops: barley, einkorn and emmer wheat, oat, rye, chickpea, lentil and pea. In each case, comparison of multiple landraces with their wild progenitors enabled us to quantify the effects of domestication rather than subsequent crop diversification. To reveal the mechanisms underpinning domestication-linked yield increases, we measured traits beyond those classically associated with domestication, including the rate and duration of growth, reproductive allocation, plant size and also seed mass and number.
Cereal and pulse crops had on average 50% higher yields than their wild progenitors, resulting from a 40% greater final plant size, 90% greater individual seed mass and 38% less chaff or pod material, although this varied between species. Cereal crops also had a higher seed number per spike compared with their wild ancestors. However, there were no differences in growth rate, total seed number, proportion of reproductive biomass or the duration of growth.
The domestication of Fertile Crescent crops resulted in larger seed size leading to a larger plant size, and also a reduction in chaff, with no decrease in seed number per individual, which proved a powerful package of traits for increasing yield. We propose that the important steps in the domestication process should be reconsidered, and the domestication syndrome broadened to include a wider range of traits
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