Stability and BPS branes

We define the concept of Pi-stability, a generalization of mu-stability of vector bundles, and argue that it characterizes N=1 supersymmetric brane configurations and BPS states in very general string theory compactifications with N=2 supersymmetry in four dimensions.Comment: harvmac, 18 p

A Metabolomic Approach to Diagnosing Prosthetic Joint Infection

https://digitalcommons.dartmouth.edu/wetterhahnsymposium-2018/1000/thumbnail.jp

State-of-the-art treatment alternatives for base of skull meningiomas: complementing and controversial indications for neurosurgery, stereotactic and robotic based radiosurgery or modern fractionated radiation techniques

For skull base meningiomas, several treatment paradigms are available: Observation with serial imaging, surgical resection, stereotactic radiosurgery, radiation therapy or some combination of both. The choice depends on several factors. In this review we evaluate different treatment options, the outcome of modern irradiation techniques as well as the clinical results available, and establish recommendations for the treatment of patients with skull-base meningiomas

Nutrigenomic profiling of transcriptional processes affected in liver and distal intestine in response to a soybean meal-induced nutritional stress in Atlantic salmon (Salmo salar)

The aim of the present study was to generate an experimental model to characterize the nutrigenomic profile of a plant-derived nutritional stress. Atlantic salmon (Salmo salar) was used as the model species and the nutritional stress was induced by inclusion of dietary defatted soybean meal (SBM), as this ingredient had been previously demonstrated to induce enteropathy in the distal intestine and reduced growth performance in salmon. Triplicate groups of Atlantic salmon were fed increasing concentrations (0, 100, 200 and 300 g kg-1) of SBM for 12 weeks and reduced growth performance was used as the indicator of nutritional stress. The transcriptome was analysed in two tissues, distal intestine and liver, with the hypothesis being that intestinal gene expression would be dominated by specific responses to SBM whereas the liver transcriptome would include gene expression responses that could be more general and related to overall performance. Specifically, a set of 133 genes was differentially expressed in liver including 45 genes in common with the intestinal response. The liver specific response included genes involved in protein digestion and energy metabolism that were up-regulated, whereas genes in other pathways were generally anabolic and down-regulated. These responses may be more related to general nutritional stress than to SBM per se. This study provides a comprehensive report on the profiles of distal intestine and liver transcriptomes, highlighting the role of the latter tissue in fish undergoing SBM-induced nutritional stress

Does cytomegalovirus infection contribute to socioeconomic disparities in all-cause mortality?

The social patterning of cytomegalovirus (CMV) and its implication in aging suggest that the virus may partially contribute to socioeconomic disparities in mortality. We used Cox regression and inverse odds ratio weighting to quantify the proportion of the association between socioeconomic status (SES) and all-cause mortality that was attributable to mediation by CMV seropositivity. Data were from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994), with mortality follow-up through December 2011. SES was assessed as household income (income-to-poverty ratio ≤1.30; >1.30 to ≤1.85; >1.85 to ≤3.50; >3.50) and education (high school). We found strong associations between low SES and increased mortality: hazard ratio (HR) 1.80; 95% confidence interval (CI): 1.57, 2.06 comparing the lowest versus highest income groups and HR 1.29; 95% CI: 1.13, 1.48 comparing high school education. 65% of individuals were CMV seropositive, accounting for 6–15% of the SES-mortality associations. Age modified the associations between SES, CMV, and mortality, with CMV more strongly associated with mortality in older individuals. Our findings suggest that cytomegalovirus may partially contribute to persistent socioeconomic disparities in mortality, particularly among older individuals

The spectrum of BPS branes on a noncompact Calabi-Yau

We begin the study of the spectrum of BPS branes and its variation on lines of marginal stability on O_P^2(-3), a Calabi-Yau ALE space asymptotic to C^3/Z_3. We show how to get the complete spectrum near the large volume limit and near the orbifold point, and find a striking similarity between the descriptions of holomorphic bundles and BPS branes in these two limits. We use these results to develop a general picture of the spectrum. We also suggest a generalization of some of the ideas to the quintic Calabi-Yau.Comment: harvmac, 45 pp. (v2: added references

Sulfur disproportionating microbial communities in a dynamic, microoxic‐sulfidic karst system

Biogeochemical sulfur cycling in sulfidic karst systems is largely driven by abiotic and biological sulfide oxidation, but the fate of elemental sulfur (S0) that accumulates in these systems is not well understood. The Frasassi Cave system (Italy) is intersected by a sulfidic aquifer that mixes with small quantities of oxygen-rich meteoric water, creating Proterozoic-like conditions and supporting a prolific ecosystem driven by sulfur-based chemolithoautotrophy. To better understand the cycling of S0 in this environment, we examined the geochemistry and microbiology of sediments underlying widespread sulfide-oxidizing mats dominated by Beggiatoa. Sediment populations were dominated by uncultivated relatives of sulfur cycling chemolithoautotrophs related to Sulfurovum, Halothiobacillus, Thiofaba, Thiovirga, Thiobacillus, and Desulfocapsa, as well as diverse uncultivated anaerobic heterotrophs affiliated with Bacteroidota, Anaerolineaceae, Lentimicrobiaceae, and Prolixibacteraceae. Desulfocapsa and Sulfurovum populations accounted for 12%–26% of sediment 16S rRNA amplicon sequences and were closely related to isolates which carry out autotrophic S0 disproportionation in pure culture. Gibbs energy (∆Gr) calculations revealed that S0 disproportionation under in situ conditions is energy yielding. Microsensor profiles through the mat-sediment interface showed that Beggiatoa mats consume dissolved sulfide and oxygen, but a net increase in acidity was only observed in the sediments below. Together, these findings suggest that disproportionation is an important sink for S0 generated by microbial sulfide oxidation in this oxygen-limited system and may contribute to the weathering of carbonate rocks and sediments in sulfur-rich environments

Stromal cell derived factor-1: its influence on invasiveness and migration of breast cancer cells in vitro, and its association with prognosis and survival in human breast cancer

INTRODUCTION: Stromal cell-derived factor (SDF)-1 (CXC chemokine ligand-12) is a member of the CXC subfamily of chemokines, which, through its cognate receptor (CXC chemokine receptor [CXCR]4), plays an important role in chemotaxis of cancer cells and in tumour metastasis. We conducted the present study to evaluate the effect of SDF-1 on the invasiveness and migration of breast cancer cells, and we analyzed the expression of SDF-1 and its relation to clinicopathological features and clinical outcomes in human breast cancer. METHOD: Expression of SDF-1 mRNA in breast cancer, endothelial (HECV) and fibroblast (MRC5) cell lines and in human breast tissues were studied using RT-PCR. MDA-MB-231 cells were transfected with a SDF-1 expression vector, and their invasiveness and migration was tested in vitro. In addition, the expression of SDF-1 was investigated using immunohistochemistry and quantitative RT-PCR in samples of normal human mammary tissue (n = 32) and mammary tumour (n = 120). RESULTS: SDF-1 expression was identified in MRC5, MDA-MB-435s and MDA-MB-436 cell lines, but CXCR4 expression was detected in all cell lines and breast tissues. An autocrine loop was created following transfection of MDA-MB-231 (which was CXCR4 positive and SDF-1 negative) with a mammalian expression cassette encoding SDF-1 (MDA-MB-231SDF1(+/+)) or with control plasmid pcDNA4/GFP (MDA-MB-231(+/-)). MDA-MB-231SDF1(+/+ )cells exhibited significantly greater invasion and migration potential (in transfected cells versus in wild type and empty MDA-MB-231(+/-); P < 0.01). In mammary tissues SDF-1 staining was primarily seen in stromal cells and weakly in mammary epithelial cells. Significantly higher levels of SDF-1 were seen in node-positive than in node-negative tumours (P = 0.05), in tumours that metastasized (P = 0.05), and tumours from patients who died (P = 0.03) than in tumours from patients who were disease free. It was most notable that levels of SDF-1 correlated significantly with overall survival (P = 0.001) and incidence-free survival (P = 0.035). CONCLUSION: SDF-1 can increase the invasiveness and migration of breast cancer cells. Its levels correlated with node involvement and long-term survival in patients with breast cancer. SDF-1 may therefore have potential value in assessing clinical outcomes of patients with breast cancer