ECONOMIC IMPACT OF BRUSH ENCROACHMENT IN TEXAS

Resource /Energy Economics and Policy,

Properties and characterization of ALD grown dielectric oxides for MIS structures

We report on an extensive structural and electrical characterization of under-gate dielectric oxide insulators Al2O3 and HfO2 grown by Atomic Layer Deposition (ALD). We elaborate the ALD growth window for these oxides, finding that the 40-100 nm thick layers of both oxides exhibit fine surface flatness and required amorphous structure. These layers constitute a base for further metallic gate evaporation to complete the Metal-Insulator-Semiconductor structure. Our best devices survive energizing up to ~3 MV/cm at 77 K with the leakage current staying below the state-of-the-art level of 1 nA. At these conditions the displaced charge corresponds to a change of the sheet carrier density of 3 \times 1013 cm-2, what promises an effective modulation of the micromagnetic properties in diluted ferromagnetic semiconductors.Comment: 8 pages, 5 figures, 14 reference

Ovariectomy Induces Early Changes in Cardiac Fibrosis and Angiotensin II Gene Expression

Postmenopausal women have an increased risk for heart disease. Ovariectomized mouse models show changes in body weight, adipose tissue, and systemic inflammation within 8-12 weeks following ovariectomy. These pathological changes may contribute to cardiac dysfunction after menopause. However, early changes in cardiac markers that may lead to dysfunction and disease remain unclear. Objective: To evaluate differences in cardiac gene expression between 8-week post-ovariectomy and control mice. Methods: Myocardial RNA was isolated from ovariectomized (OVX, n=10) and sham surgery (SHAM, n=10) adult mice 8 weeks following surgery. Fetal gene program, fibrosis, and angiotensin II gene expression were determined via RT-PCR. Differences between groups were analyzed using two sample t-tests. Results: Compared to SHAM, OVX mice exhibited a fetal gene expression pattern similar to that observed in failing hearts including increased B-type natriuretic peptide (p=0.02), atrial natriuretic peptide (p=0.06) and alpha skeletal actin (p=0.01) and decreased alpha and beta myosin heavy chain isoform expression (p=0.05, p=0.02, respectively). Expression of fibrotic genes vimentin (p=0.01), fibronectin (p=0.02), collagen1 (p=0.04), and collagen3 (p=0.03) were greater in OVX compared with SHAM. Lastly, angiotensin II was also significantly greater in OVX (p=0.001). Conclusion: Ovariectomized mice begin to exhibit maladaptive gene expression within 8 weeks after surgery, indicating that ovarian hormone loss initiates a pathological response in the heart at early time points that may be related to angiotensin II-induced cardiac fibrosis

Pericyte NF-κB Activation Enhances Endothelial Cell Proliferation and Proangiogenic Cytokine Secretion

Pericytes are skeletal muscle resident, multipotent stem cells that are localized to capillaries. They respond to damage through activation of nuclear-factor kappa-B (NF-κB), a transcription factor that regulates many cellular processes including inflammation. Research has shown that pericyte NF-κB activation positively affects myoblast proliferation. It is unknown how pericyte NF-κB affects signaling and proliferation of endothelial cells, an important component of muscle tissue microcirculation. PURPOSE: To determine the effects of altered pericyte NF-κB activity on endothelial cell proliferation and identify inflammatory factors involved in this cell-cell signaling. METHODS: Human primary pericytes were transfected with vectors designed to increase or decrease NF-κB activity (or empty vector control). Transfected pericytes were co-cultured with human microvascular endothelial cells (HMVECs) using transwell inserts. HMVEC proliferation was assessed via cell counting at 24 and 48 hr. Secreted cytokines in cell culture supernatants were screened using a Luminex multiplex assay. RESULTS: HMVEC proliferation was greater in the increased pericyte NF-κB activity condition compared to the decreased NF-κB condition at 24 and 48 hr (1.3 fold, p=0.002). At 24 hr, cytokine secretion was greater in the increased NF-κB condition compared to control and decreased NF-κB conditions for 14 cytokines, including interleukin-8 (IL-8; 6.4 fold, p CONCLUSION: NF-κB activation in pericytes caused increased HMVEC proliferation, which may have been mediated by proinflammatory and proangiogenic cytokines known to be under the transcriptional regulation of NF-κB

High-Frequency Electrically Stimulated Skeletal Muscle Contractions Increase p70\u3csup\u3es6k\u3c/sup\u3e Phosphorylation Independent of Known IGF-I Sensitive Signaling Pathways

Insulin-like growth factor (IGF-I) is hypothesized to be a critical upstream regulator of mammalian target of rapamycin (mTOR)-regulated protein synthesis with muscle contraction. We utilized a mouse model that expresses a skeletal muscle specific dominant-negative IGF-I receptor to investigate the role of IGF-I signaling of protein synthesis in response to unilateral lengthening contractions (10 sets, 6 repetitions, 100. Hz) at 0 and 3. h following the stimulus. Our results indicate that one session of high frequency muscle contractions can activate mTOR signaling independent of signaling components directly downstream of the receptor

Two unusual silicoflagellate double skeletons

A study of silicoflagellate double skeletons revealed two unusual doublets that are illustrated and discussed here. One of these comprises two ten-sided Octactis skeletons that appear to form a doublet, but both in the same (apical) orientation. The other specimen is a double skeleton of Dictyocha that is slightly disarticulated, with a third, less robust skeleton in between. These unusual double skeletons suggest that there is much more to be learned about the formation of silicoflagellate skeletons and the reproductive processes in this protist grou

Cytoprotective effect of lithium against spontaneous and induced apoptosis of lymphoid cell line MOLT-4.

Lithium (Li) is still useful in the treatment of bipolar disorder. Cellular mechanisms of Li action are not fully understood and include some cytoprotective properties. Data concerning Li effect on the apoptotic mechanisms in cells other than neurons are fragmentary and contradictory. We have investigated anti-apoptotic activity of Li in a lymphoid derived MOLT-4 cell line. Spontaneous and camptothecin-induced apoptosis was analyzed in cells treated with 0-20 mM Li carbonate. Early apoptosis was identified as significant mitochondrial depolarization (JC-1 staining). Later stages of apoptosis were estimated with annexin V binding and by the proportion of cells containing sub-G1 amounts of DNA (PI staining). We have observed a biphasic effect of Li on the proportion of spontaneously apoptotic cells;namely, low (therapeutic) concentrations of Li had a significant effect stabilizing the mitochondrial membrane polarization, while 10 and 20mM Li increased apoptosis. The latter could be seen both as mitochondrial depolarization as well as an increased proportion of sub-G1 cells, accompanied by reduced proportion of S phase cells. Li at concentrations above 2 mM had a significant, dose-dependent, anti-apoptotic effect on the cells undergoing camptothecin induced apoptosis. In conclusion, demonstrated cytoprotective effect of Li is at least partially related to stabilization of mitochondrial membrane potential and to the reduction of DNA damaging effects in proliferating cells; both may form part of the mechanism through which Li is useful in therapy of bipolar disorder, but may have more general consequences