1,368 research outputs found
The Indirect Search for Dark Matter from the centre of the Galaxy with the Fermi LAT
Dark matter (DM) constitutes around a 25% of the Universe, while baryons only
a 4%. DM can be reasonably assumed to be made of particles, and many theories
(Super-symmetry, Universal Extra Dimensions, etc.) predict Weakly Interacting
Massive Particles (WIMPs) as natural DM candidates at the weak scale.
Self-annihilation (or decay) of WIMPs might produce secondary gamma-rays, via
hadronization or as final state radiation. Since its launch in the 2008, the
Large Area Telescope on-board of the Fermi gamma-ray Space Telescope has
detected the largest amount of gamma-rays to date, in the 20MeV 300GeV energy
range, allowing to perform a very sensitive indirect experimental search for DM
(by means of high-energy gamma-rays). DM forms large gravitationally bounded
structures, the halos, which can host entire galaxies, such as the Milky Way.
The DM distribution in the central part of the halos is not experimentally
know, despite a very large density enhancement might be present. As secondary
gamma rays production is very sensitive to WIMP density, a very effective
search can be performed from the regions where the largest density is expected.
Therefore the information provided by the DM halo N-body simulations are
crucial. The largest gamma-ray signal from DM annihilation is expected from the
centre of the Galaxy. In the same region a large gamma-ray background is
produced by bright discrete sources and the cosmic-rays interacting with the
interstellar gas and the photons fields.
Here we report an update of the indirect search for DM from the Galactic
Center (GC).Comment: 6 pages, 2 figures. Invited talk presented at the Workshop "SciNeGHE
2010", September 8-10, 2010, Trieste, Italy. To appear in Il Nuovo Cimento C
- Colloquia on physic
Ocorrência de Butia lallemantii no município de Alegrete (RS) e ameaças às populações naturais.
Does regretting first vaginal intercourse have an effect on young adults' sexual behaviour?
Background The aims of this research were to determine personal differences depending on the reason for regretting or not first vaginal intercourse and its effects on sexual behaviour later on among young adults, and to assess the association between reasons for engaging in first vaginal intercourse and regretting it.
Data were drawn from the 2017 Swiss national survey on youth sexual behaviours among young adults (mean age 26 years) living in Switzerland. Out of the 7142 participants, 4793 (51% females) answered the question 'Looking back now to the first time you had vaginal intercourse, do you think that…' with five possible answers: (1) I should not have done it (6.7%); (2) I should have waited longer (7.7%); (3) I should have done it earlier (7.4%); (4) It was about the right time (67.9%); and (5) I don't know (10.3%). The five groups were compared on sociodemographic and sex behaviour-related variables, analysed separately by gender.
One-third of participants regretted their first experience. In the multivariate analysis, compared with the 'right time' group, all other groups were more likely to find their first experience unpleasant and to have done it with a casual partner. Those in the 'I should not have done it' and 'I should have waited longer' groups were also more likely to have done it because of external pressure, especially among females.
The study results underline the significance to choose the right time and the right partner for first vaginal intercourse and the importance of including partner respect and avoiding external pressure as part of sexual education
Indirect Search for Dark Matter from the Galactic Center with the Fermi Gamma Ray Satellite
High energy gamma ray observations can be used for the indirect search for annihilating Dark Matter. One of the possible observation strategy is the targeting of regions where high Dark Matter density is foreseen, such as the Galactic Center. This observation poses a challenge: to disentangle the possible Dark Matter signal from the bright gamma radiation of astrophysical sources. The Large Area Telescope on board of the GLAST satellite provides the best opportunity to date for such a study, because of its excellent sensitivity and angular resolution, as compared to the past satellite-borne detectors. A report of the GLAST LAT Dark Matter Group activities on this topic will be given
Does the Primary Resource of Sex Education Matter? A Swiss National Study.
Sex education (SE) remains a subject of debate, including controversies on resources. The purpose of this paper was to determine the main SE resource during adolescence and its associations with personal characteristics and sexual behaviors of youths. Data were obtained from a self-administrated Swiss national survey on sexuality among young adults (mean age 26.3). Participants (N = 4978) were divided into six groups according to their main SE resource during their adolescence: Friends (1939; 38.9%), Parents (1361; 27.3%), School (n = 949; 19.1%), The Internet (399; 8.0%), Nobody (172; 3.5%) and Other (157; 3.2%). Groups were compared on sociodemographic, first sexual experiences, pregnancy, risky sexual behaviors, and undesired sexual experiences data. Males and non-heterosexual participants were overrepresented in the Internet group while, females more often reported their parents as their main SE resource. Participants in the School group reported the lowest rates of sexually transmitted infections and Friends the highest. Compared to the School group, those in the Friends, Internet, Nobody, and Other groups were more likely to report undesired sexual experiences. Few differences appeared between parents and school. Even though some resources such as friends or the Internet presented negative outcomes when they were assessed individually, we cannot deny the important place that they occupy in the lives of some youths
Estudo da fauna edáfica em dois ecossistemas no município de Morro Redondo, RS, Brasil.
O solo é o habitat natural para uma grande variedade de organismos, tanto microorganismos quanto animais invertebrados. Estes organismos são altamente sensíveis a alterações ambientais e por isso vem sendo utilizados como indicador da qualidade do solo...Publicado também o resumo
Epigenetic Suppression of Transgenic T-cell Receptor Expression via Gamma-Retroviral Vector Methylation in Adoptive Cell Transfer Therapy
Transgenic T-cell receptor (TCR) adoptive cell therapies recognizing tumor antigens are associated with robust initial response rates, but frequent disease relapse. This usually occurs in the setting of poor long-term persistence of cells expressing the transgenic TCR, generated using murine stem cell virus (MSCV) y-retroviral vectors. Analysis of clinical transgenic adoptive cell therapy products in vivo revealed that despite strong persistence of the transgenic TCR DNA sequence over time, its expression was profoundly decreased over time at the RNA and protein levels. Patients with the greatest degrees of expression suppression displayed significant increases in DNA methylation over time within the MSCV promoter region, as well as progressive increases in DNA methylation within the entire MSCV vector over time. These increases in vector methylation occurred independently of its integration site within the host genomes. These results have significant implications for the design of future viral-vector gene engineered adoptive cell transfer therapies
An RNA Polymerase III General Transcription Factor Engages in Cell Type-Specific Chromatin Looping
Transcription factors (TFs) bind DNA in a sequence-specific manner and are generally cell type-specific factors and/or developmental master regulators. In contrast, general TFs (GTFs) are part of very large protein complexes and serve for RNA polymerases’ recruitment to promoter sequences, generally in a cell type-independent manner. Whereas, several TFs have been proven to serve as anchors for the 3D genome organization, the role of GTFs in genome architecture have not been carefully explored. Here, we used ChIP-seq and Hi-C data to depict the role of TFIIIC, one of the RNA polymerase III GTFs, in 3D genome organization. We find that TFIIIC genome occupancy mainly occurs at specific regions, which largely correspond to Alu elements; other characteristic classes of repetitive elements (REs) such as MIR, FLAM-C and ALR/alpha are also found depending on the cell’s developmental origin. The analysis also shows that TFIIIC-enriched regions are involved in cell type-specific DNA looping, which does not depend on colocalization with the master architectural protein CTCF. This work extends previous knowledge on the role of TFIIIC as a bona fide genome organizer whose action participates in cell type-dependent 3D genome looping via binding to REs
Enzymatic synthesis of structured lipids from liquid and fully hydrogenated high oleic sunflower oil
sem informaçãoStructured lipids (SL) were synthesized via enzymatic (EI) and chemical interesterification of high oleic sunflower oil (SO) and fully hydrogenated high oleic SO with Lipozyme TL IM (Thermomyces lanuginose) for 3 h at 70°C, 300 rpm. Reaction showed change211702716sem informaçãosem informaçãosem informaçã
Monitoramento do conteúdo de carbono orgânico em sistemas de manejo do solo na Serra do Sudeste, RS.
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