Dark matter effective field theory scattering in direct detection experiments

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMWe examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter spaceThe authors gratefully acknowledge Liam Fitzpatrick, Wick Haxton, and Tim Tait for helpful conversations. This work is supported in part by the National Science Foundation, by the United States Department of Energy, by NSERC Canada, and by MultiDark (Spanish MINECO). Fermilab is operated by the Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. SLAC is operated under Contract No. DE-AC02- 76SF00515 with the United States Department of Energ

First direct limits on lightly ionizing particles with electric charge less than e/6

Artículo escrito por muchos autores, sólo se referencian el primero, los autores que firman como Universidad Autónoma de Madrid y el grupo de colaboración en el caso de que aparezca en el artículoWhile the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200This work is supported in part by the National Science Foundation, by the U.S. Department of Energy, by NSERC Canada, and by MultiDark (Spanish MINECO). Fermilab is operated by the Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. SLAC is operated under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energ

Maximum likelihood analysis of low energy CDMS II germanium data

Artículo escrito por un elevado número de autores, sólo se referencian el primero, los autores que firman como Universidad Autónoma de Madrid y el grupo de colaboración en el caso de que aparezca en el artículoWe report on the results of a search for a Weakly Interacting Massive Particle (WIMP) signal in low-energy data of the Cryogenic Dark Matter Search experiment using a maximum likelihood analysis. A background model is constructed using geant4 to simulate the surface-event background from Pb210 decay-chain events, while using independent calibration data to model the gamma background. Fitting this background model to the data results in no statistically significant WIMP component. In addition, we perform fits using an analytic ad hoc background model proposed by Collar and Fields, who claimed to find a large excess of signal-like events in our data. We confirm the strong preference for a signal hypothesis in their analysis under these assumptions, but excesses are observed in both single- and multiple-scatter events, which implies the signal is not caused by WIMPs, but rather reflects the inadequacy of their background modelThis work is supported in part by the National Science Foundation, by the United States Department of Energy, by NSERC Canada, and by MultiDark (Spanish MINECO). Fermilab is operated by the Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. SLAC is operated under Contract No. DE-AC02-76SF00515 with the United States Department of Energ

Population variability in some genes involving the haemostatic system: data on the general population of Corsica (France), Sardinia and Sicily (Italy)

Three different population samples from Corsica (France), Sardinia and Sicily (Italy) were studied using nine genetic markers. For the first time, allele distributions of FGA TaqI, FGB Bcl I, FGB Hind III, PAI-1 Hind III, PLAT TPA-25, GPIIIa Taq I, GPIIb I/D 9bp, FVII HVR4 and FVII -323 10 bp markers, which are thought to be associated with cardiovascular disease risk, were studied in the general population of the three islands. The frequencies of the markers analysed in the present work show some peculiarities: the locus FVII HVR4 is characterized by the presence of a rare allele (H5), found in Corsicans and in Sardinians; the locus FBG BcII shows a low frequency of the B1 allele and the absence of the B1B1 genotype. The frequencies of some alleles have a distribution that is in agreement with the low risk for cardiovascular diseases in south European countries. The results highlight a genetic differentiation between the three Mediterranean islands and the other European populations

Immunomodulation induced by synthetic peptides derived from Staphylococcus aureus protein A

Peptides from 10 to 22 amino acids containing sequences encompassed by Staphylococcus aureus protein A were synthesized. Some of these peptides, when present in cultures of lymphomononuclear cells from healthy donors or from cancer patients (melanoma, breast carcinoma, non-Hodgkin lymphoma and renal cell carcinoma) promoted: (i) changes in the phenotype of the lymphomononuclear population, (ii) stimulation of monocytes (release of IL-1 and TNF-alpha), and (iii) an increase in cytotoxicity against K562, Daudi and HT-29 cells. Isolated monocytes responded also to those peptides with a release of IL-1 and TNF alpha and an increase of cytotoxicity against HT-29 cells. It was found that the active peptides had the following structural pattern: a length of at least 15 amino-acid residues with a proline at position 6, valine, leucine, isoleucine, glycine, alanine or lysine at position 2, and glutamic or aspartic acid at position 11. Replacement of Pro at position 6 with any other residue turned the peptide inactive. Replacement of residues at positions 2 and 11 with amino-acid residues other than those required for activity resulted in compounds with a marked decrease in the immunomodulating properties described, or lacking these properties altogether

Potential benefits of melatonin in organ transplantation: a review

Organ transplantation is a useful therapeutic tool for patients with end-stage organ failure; however, graft rejection is a major obstacle in terms of a successful treatment. Rejection is usually a consequence of a complex immunological and nonimmunological antigen-independent cascade of events, including free radical-mediated ischemia-reperfusion injury (IRI). To reduce the frequency of this outcome, continuing improvements in the efficacy of antirejection drugs are a top priority to enhance the long-term survival of transplant recipients. Melatonin (N-acetyl-5-methoxytryptamine) is a powerful antioxidant and ant-inflammatory agent synthesized from the essential amino acid L-tryptophan; it is produced by the pineal gland as well as by many other organs including ovary, testes, bone marrow, gut, placenta, and liver. Melatonin has proven to be a potentially useful therapeutic tool in the reduction of graft rejection. Its benefits are based on its direct actions as a free radical scavenger as well as its indirect antioxidative actions in the stimulation of the cellular antioxidant defense system. Moreover, it has significant anti-inflammatory activity. Melatonin has been found to improve the beneficial effects of preservation fluids when they are enriched with the indoleamine. This article reviews the experimental evidence that melatonin is useful in reducing graft failure, especially in cardiac, bone, otolaryngology, ovarian, testicular, lung, pancreas, kidney, and liver transplantation

Co-expression of inducible nitric oxide synthase and arginases in different human monocyte subsets. Apoptosis regulated by endogenous NO

Human monocyte subsets, isolated from cultures of mononuclear cells, or freshly obtained from patients with multiple sclerosis, Graves' disease or pemphigus vulgaris, differed in phenotype, apoptotic features, mRNA levels of arginase II (A-II) and the inducible form of nitric oxide synthase (iNOS). Liver-type arginase I mRNA was present in all subsets. Apoptosis was followed by the expression of T cell intracellular antigen (TIA) and the simultaneous detection of DNA stainability by propidium iodine and annexin V binding. Apoptosis was practically absent both in activated CD14(++)CD33(++)DR(++)CD25(++)CD69(++)CD71(++/+) CD16(-) cells, expressing A-II mRNA and having arginase activity, but not iNOS mRNA, and in not fully mature large CD14(++)CD16(+)CD23(+)DR(++) monocytes, expressing simultaneously both mRNAs and having both enzyme activities. However, differentiated small CD14(+/++)CD16(+)CD69(+)CD25(+/-)CD71(++)CD23(+) DR(++) monocytes, expressing high levels of iNOS mRNA, exhibited apoptotic signs. Amounts of NO synthesised by monocytes co-expressing iNOS and arginase changed with the addition of arginine or an iNOS inhibitor; in that case a correlation of NO production and apoptotic features was observed. Data suggest a regulatory role for endogenous NO in apoptosis of stimulated and differentiated monocytes, and also that iNOS and A-II, when simultaneously present, could control the production of NO as a consequence of their competition for arginine