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991.
Sarah L. Johnston Wendy L. Peacock Lynn M. Bell Michel Lonchampt John R. Speakman 《Obesity (Silver Spring, Md.)》2005,13(9):1558-1565
Objective: To validate GE PIXImus2 DXA fat mass (FM) estimates by chemical analysis, to compare previously published correction equations with an equation from our machine, and to determine intermachine variation. Research Methods and Procedures: C57BL/6J (n = 16) and Aston (n = 14) mice (including ob/ob), Siberian hamsters (Phodopus sungorus) (n = 15), and bank voles (Clethrionomys glareolus) (n = 37) were DXA scanned postmortem, dried, then fat extracted using a Soxhlet apparatus. We compared extracted FM with DXA‐predicted FM corrected using an equation designed using wild‐type animals from split‐sample validation and multiple regression and two previously published equations. Sixteen animals were scanned on both a GE PIXImus2 DXA in France and a second machine in the United Kingdom. Results: DXA underestimated FM of obese C57BL/6J by 1.4 ± 0.19 grams but overestimated FM for wild‐type C57BL/6J (2.0 ± 0.11 grams), bank voles (1.1 ± 0.09 grams), and hamsters (1.1 ± 0.13 grams). DXA‐predicted FM corrected using our equation accurately predicted extracted FM (accuracy 0.02 grams), but the other equations did not (accuracy, ?1.3 and ?1.8 grams; paired Student's t test, p < 0.001). Two similar DXA instruments gave the same FM for obese mutant but not lean wild‐type animals. Discussion: DXA using the same software could use the same correction equation to accurately predict FM for obese mutant but not lean wild‐type animals. PIXImus machines purchased with new software need validating to accurately predict FM. 相似文献
992.
Historical Ecology on Sandoy, Faroe Islands: Palaeoenvironmental and Archaeological Perspectives 总被引:1,自引:1,他引:0
Ian T. Lawson Mike J. Church Tom H. McGovern Símun V. Arge James Woollet Kevin J. Edwards Freddy J. Gathorne-Hardy Andrew J. Dugmore Gordon Cook Kerry-Anne Mairs Amanda M. Thomson Guðrún Sveinbjarnardótti 《Human ecology: an interdisciplinary journal》2005,33(5):651-684
We present palaeoenvironmental, geomorphological, archaeological, and place-name data which allow a holistic assessment of
the history of landscape change on Sandoy, Faroe Islands, especially in terms of the changes that occurred in response to
the colonization of the island by humans. In contrast to other situations in the North Atlantic region, there is considerable
continuity in the patterns and processes of landscape evolution across the initial settlement horizon. Many of the characteristic
features of post-settlement North Atlantic landscapes—absence of trees, widespread blanket mires, high rates of soil erosion—were
already in place when the first people arrived. Although human impact on Sandoy appears to have been light, conversely, the
unusual environment forced major alterations of the subsistence economy imported by the colonists. Settlement-era archaeological
records suggest that, from the start, patterns of resource use differed substantially from the regional norm, and these differences
became amplified over time as the Faroese economy created a locally sustainable cultural landscape. 相似文献
993.
Dorothea Bedigian Sebsebe Demissew Paul Gepts Daniel F. Austin Neil A. Harriman John Klock Sarah Walshaw John Richard Stepp Beverly J. Brown Julie Polley David Winston Barbara Pickersgill Patrick Van Damme Nina L. Etkin Beronda L. Montgomery Linda Perry Stephen E Siebert Robert J. Krueger Kathleen McConnell Wendy Applequist Mary Theresa Bonhage-Freund Karol Chandler-Ezell 《Economic botany》2005,59(4):395-412
994.
995.
Daniel F. Austin Richard Felger Karol Chandler-Ezell Michael J. Balick Kurt Allerslev Reynertson Alfredo Gomez-Beloz My Lien T. Nguyen Rob Dean Neil A. Harriman Dorothea Bedigian Mary Theresa Bonhage-Freund Wendy Applequist Linda M. Lyon John Klock My Lien T. Nguyen 《Economic botany》2005,59(2):197-209
996.
Rachael G Dean Leanne C Balding Riccardo Candido Wendy C Burns Zemin Cao Stephen M Twigg Louise M Burrell 《The journal of histochemistry and cytochemistry》2005,53(10):1245-1256
The temporal and spatial expression of transforming growth factor (TGF)-beta(1) and connective tissue growth factor (CTGF) was assessed in the left ventricle of a myocardial infarction (MI) model of injury with and without angiotensin-converting enzyme (ACE) inhibition. Coronary artery ligated rats were killed 1, 3, 7, 28, and 180 days after MI. TGF-beta(1), CTGF, and procollagen alpha1(I) mRNA were localized by in situ hybridization, and TGF-beta(1) and CTGF protein levels by immunohistochemistry. Collagen protein was measured using picrosirius red staining. In a separate group, rats were treated for 6 months with an ACE inhibitor. There were temporal and regional differences in the expression of TGF-beta(1), CTGF, and collagen after MI. Procollagen alpha1(I) mRNA expression increased in the border zone and scar peaking 1 week after MI, whereas collagen protein increased in all areas of the heart over the 180 days. Expression of TGF-beta(1) mRNA and protein showed major increases in the border zone and scar peaking 1 week after MI. The major increases in CTGF mRNA and protein occurred in the viable myocardium at 180 days after MI. Long-term ACE inhibition reduced left ventricular mass and decreased fibrosis in the viable myocardium, but had no effect on cardiac TGF-beta(1) or CTGF. TGF-beta(1) is involved in the initial, acute phase of inflammation and repair after MI, whereas CTGF is involved in the ongoing fibrosis of the heart. The antifibrotic benefits of captopril are not mediated through a reduction in CTGF. 相似文献
997.
Hennemuth W Rhoads LS Eichelberger H Watanabe M Van Bell KM Ke L Kim H Nguyen G Jonas JD Veith D Van Bell CT 《The Journal of eukaryotic microbiology》2008,55(1):44-50
Abiotic factors are thought to be primarily responsible for the loss of bacteriophages from the environment, but ingestion of phages by heterotrophs may also play a role in their elimination. Tetrahymena thermophila has been shown to ingest and inactivate bacteriophage T4 in co-incubation experiments. In this study, other Tetrahymena species were co-incubated with T4 with similar results. In addition, T. thermophila was shown to inactivate phages T5 and lambda in co-incubations. Several approaches, including direct visualization by electron microscopy, demonstrated that ingestion is required for T4 inactivation. Mucocysts were shown to have no role in the ingestion of T4. When (35)S-labeled T4 were fed to T. thermophila in a pulse-chase experiment, the degradation of two putative capsid proteins, gp23(*) and hoc, was observed. In addition, a polypeptide with the apparent molecular mass of 52 kDa was synthesized. This suggests that Tetrahymena can use phages as a minor nutrient source in the absence of bacteria. 相似文献
998.
999.
Thevelein JM Bonini BM Castermans D Haesendonckx S Kriel J Louwet W Thayumanavan P Popova Y Rubio-Texeira M Schepers W Vandormael P Van Zeebroeck G Verhaert P Versele M Voordeckers K 《Acta microbiologica et immunologica Hungarica》2008,55(2):75-89
In yeast the Protein Kinase A (PKA) pathway can be activated by a variety of nutrients. Fermentable sugars, like glucose and sucrose, trigger a spike in the cAMP level, followed by activation of PKA and phosphorylation of target proteins causing a.o. mobilization of reserve carbohydrates, repression of stress-related genes and induction of growth-related genes. Glucose and sucrose are sensed by a G-protein coupled receptor system that activates adenylate cyclase and also activates a bypass pathway causing direct activation of PKA. Addition of other essential nutrients, like nitrogen sources or phosphate, to glucose-repressed nitrogen- or phosphate-starved cells, also triggers rapid activation of the PKA pathway. In these cases cAMP is not involved as a second messenger. Amino acids are sensed by the Gap1 transceptor, previously considered only as an amino acid transporter. Recent results indicate that the amino acid ligand has to induce a specific conformational change for signaling. The same amino acid binding site is involved in transport and signaling. Similar results have been obtained for Pho84 which acts as a transceptor for phosphate activation of the PKA pathway. Ammonium activation of the PKA pathway in nitrogen-starved cells is mediated mainly by the Mep2 transceptor, which belongs to a different class of transporter proteins. Hence, different types of sensing systems are involved in control of the yeast PKA pathway by nutrients. 相似文献