56 research outputs found
Highly deformed Ca configurations in Si + C
The possible occurrence of highly deformed configurations in the Ca
di-nuclear system formed in the Si + C reaction is investigated
by analyzing the spectra of emitted light charged particles. Both inclusive and
exclusive measurements of the heavy fragments (A 10) and their
associated light charged particles (protons and particles) have been
made at the IReS Strasbourg {\sc VIVITRON} Tandem facility at bombarding
energies of Si) = 112 MeV and 180 MeV by using the {\sc ICARE}
charged particle multidetector array. The energy spectra, velocity
distributions, and both in-plane and out-of-plane angular correlations of light
charged particles are compared to statistical-model calculations using a
consistent set of parameters with spin-dependent level densities. The analysis
suggests the onset of large nuclear deformation in Ca at high spin.Comment: 33 pages, 11 figure
Effect of the dry matter intake level on the sanguine profile of glucose, insulin, urea, estrogen and progesterone and concentration of IGF-I in the follicular liquid of crossbred heifers
Hypertensive Disorders of Pregnancy and DNA Methylation in Newborns
Hypertensive disorders of pregnancy (HDP) are associated with low birth weight, shorter gestational age, and increased risk of maternal and offspring cardiovascular diseases later in life. The mechanisms involved are poorly understood, but epigenetic regulation of gene expression may play a part. We performed meta-analyses in the Pregnancy and Childhood Epigenetics Consortium to test the association between either maternal HDP (10 cohorts; n=5242 [cases=476]) or preeclampsia (3 cohorts; n=2219 [cases=135]) and epigenome-wide DNA methylation in cord blood using the Illumina HumanMethylation450 BeadChip. In models adjusted for confounders, and with Bonferroni correction, HDP and preeclampsia were associated with DNA methylation at 43 and 26 CpG sites, respectively. HDP was associated with higher methylation at 27 (63%) of the 43 sites, and across all 43 sites, the mean absolute difference in methylation was between 0.6% and 2.6%. Epigenome-wide associations of HDP with offspring DNA methylation were modestly consistent with the equivalent epigenome-wide associations of preeclampsia with offspring DNA methylation (R2=0.26). In longitudinal analyses conducted in 1 study (n=108 HDP cases; 550 controls), there were similar changes in DNA methylation in offspring of those with and without HDP up to adolescence. Pathway analysis suggested that genes located at/near HDP-associated sites may be involved in developmental, embryogenesis, or neurological pathways. HDP is associated with offspring DNA methylation with potential relevance to development
Apoptosis: Its significance in cancer and cancer therapy
Apoptosis is a distinct mode of cell death that is responsible for deletion of cells in normal tissues; it also occurs in specific pathologic contexts. Morphologically, it involves rapid condensation and budding of the cell, with the formation of membrane‐enclosed apoptotic bodies containing well‐preserved organelles, which are phagocytosed and digested by nearby resident cells. There is no associated inflammation. A characteristic biochemical feature of the process is double‐strand cleavage of nuclear DNA at the linker regions between nucleosomes leading to the production of oligonucleosomal fragments. In many, although not all of the circumstances in which apoptosis occurs, it is suppressed by inhibitors of messenger RNA and protein synthesis. Apoptosis occurs spontaneously in malignant tumors, often markedly retarding their growth, and it is increased in tumors responding to irradiation, cytotoxic chemotherapy, heating and hormone ablation. However, much of the current interest in the process stems from the discovery that it can be regulated by certain proto‐oncogenes and the p53 tumor suppressor gene. Thus, c‐myc expression has been shown to be involved in the initiation of apoptosis in some situations, and bcl‐2 has emerged as a new type of proto‐oncogene that inhibits apoptosis, rather than stimulating mitosis. In p53‐negative tumor‐derived cell lines transfected with wild‐type p53, induction of the gene has, in rare cases, been found to cause extensive apoptosis, instead of growth arrest. Finally, the demonstration that antibodies against a cell‐surface protein designated APO‐1 or Fas can enhance apoptosis in some human lymphoid cell lines may have therapeutic implications
Assessment of grid-based whole-rock delta D surveys in exploration: Boulder County epithermal tungsten deposit, Colorado
Important epithermal tungsten mineralization in the Boulder County district is mainly hosted by quartz-ferberite (FeWO4) veins. Isotopic studies based on an extensive grid (deltaD) and individual samples of wall-rock alteration and mineralization (deltaD, deltaO) have demonstrated the dominance of meteoric fluids during alteration processes. However, the involvement of magmatic fluids during the deposition of the ferberite veins cannot be ruled out. The fluids responsible for alteration exchanged with the country rocks to produce a large deltaD anomaly but no concomitant delta O-18 anomaly, indicating that water/rock ratios were small. The deltaD anomaly coincides closely with those produced by H2O+ and Rb/Sz used as a proxy for hydrothermal alteration, but does not correlate closely with either lithochemical W anomalies or areas of greatest W production. It is concluded that the fluids responsible for district-wide hydrothermal alteration are distinct from those that produced the W mineralization and that ED anomalies, while a sensitive technique for highlighting areas of significant fluid-rock interact ion, must be used with caution for identifying drilling targets. The study has provided an estimate of the stable isotope composition of early Tertiary meteoric water in the Front Range (ca. deltaD = -140%, deltaO = 18.7%)
Hollows in living trees develop slowly but considerably influence the estimate of forest biomass
Activation energy for skeletal aragonite deposited by the hermatypic coral Platygyra spp.
CHALK AND FLUID INOCULATION METHODS IN STUDYING THE PERCENT RECOVERY OF CLOSTRIDIUM PERFRINGENS, ESCHERICHIA COLI AND ENTEROCOCCUS FAECALIS FROM RAW GROUND BEEF
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