1,521 research outputs found
Probing the Supersymmetric Inflaton and Dark Matter link via the CMB, LHC and XENON1T experiments
The primordial inflation dilutes all matter except the quantum fluctuations
which we see in the cosmic microwave background (CMB) radiation. Therefore the
last phases of inflation must be embedded within a beyond the Standard Model
(SM) sector where the inflaton can directly excite the SM quarks and leptons.
In this paper we consider two inflaton candidates LLe and udd whose decay can
naturally excite all the relevant degrees of freedom besides thermalizing the
lightest supersymmetric particle (LSP) during and after reheating. In
particular, we present the regions of the parameter space which can yield
successful inflation with the right temperature anisotropy in the CMB, the
observed relic density for the neutralino LSP, and the recent Higgs mass
constraints from LHC within the MSSM with non-universal Higgs masses --
referred to as the NUHM2 model. We found that in most scenarios, the LSP seems
strongly mass degenerated with the next to lightest LSP (NLSP) and the
branching ratio B_s -> mu^+ mu^- very close to the present bound, thus leading
to falsifiable predictions. Also the dark matter interactions with XENON nuclei
would fall within the projected range for the XENON1T experiment. In the case
of a positive signal of low scale supersymmetry at the LHC, one would be able
to potentially pin down the inflaton mass by using the associated values for
the mass of the stau, the stop and the neutralino.Comment: 16 pages, 23 figures; v2: typos corrected; v3: version accepted by
PR
PAMELA and FERMI-LAT limits on the neutralino-chargino mass degeneracy
Searches for Dark Matter (DM) particles with indirect detection techniques
have reached important milestones with the precise measurements of the
anti-proton and gamma-ray spectra, notably by the PAMELA and FERMI-LAT
experiments. While the gamma-ray results have been used to test the thermal
Dark Matter hypothesis and constrain the Dark Matter annihilation cross section
into Standard Model (SM) particles, the anti-proton flux measured by the PAMELA
experiment remains relatively unexploited. Here we show that the latter can be
used to set a constraint on the neutralino-chargino mass difference. To
illustrate our point we use a Supersymmetric model in which the gauginos are
light, the sfermions are heavy and the Lightest Supersymmetric Particle (LSP)
is the neutralino. In this framework the W^+ W^- production is expected to be
significant, thus leading to large anti-proton and gamma-ray fluxes. After
determining a generic limit on the Dark Matter pair annihilation cross section
into W^+ W^- from the anti-proton data only, we show that one can constrain
scenarios in which the neutralino-chargino mass difference is as large as ~ 20
GeV for a mixed neutralino (and intermediate choices of the anti-proton
propagation scheme). This result is consistent with the limit obtained by using
the FERMI-LAT data. As a result, we can safely rule out the pure wino
neutralino hypothesis if it is lighter than 450 GeV and constitutes all the
Dark Matter.Comment: 22page
O processo de elaboração do livro didático de História na escola pública: uma análise no município de Itaipulândia (PR) (2010–2020)
Sabe-se que o Livro Didático (LD) é uma ferramenta amplamente utilizada no Brasil nas várias disciplinas que compõem a grade curricular da Educação Básica. Em vista disso, o LD de História destinado aos anos iniciais do Ensino Fundamental é o objeto desta investigação, que parte da seguinte problemática: Qual é a especificidade do LD para o ensino de História utilizado nos anos iniciais do Ensino Fundamental na rede pública de ensino do município de Itaipulândia (PR)? Metodologicamente, trata-se de uma pesquisa de abordagem qualitativa, a partir de uma revisão bibliográfica e de análise documental. O escopo central foi analisar o processo histórico de elaboração e de uso do LD para o ensino de História no referido município, nos anos de 2010 a 2020. As reflexões teóricas mobilizadas, que compreendem o processo histórico de produção e circulação do LD, as dimensões sociais, econômicas e políticas da constituição da História como disciplina escolar no Brasil e a elaboração e uso do LD de História para nos Anos Iniciais do Ensino Fundamental em Itaipulândia (PR), estão pautadas nos pressupostos da Pedagogia Histórico-Crítica (PHC). Como resultados, é possível constatar que o ato de produzir o LD advém do esforço coletivo dos educadores da rede pública de ensino no processo de implantação e implementação da PHC. Com relação ao ensino de História, o LD de apoio pedagógico é elaborado considerando a importância social e humana que tem esse campo do conhecimento. Assim, o material produzido no município de Itaipulândia (PR) constitui-se uma possibilidade para desenvolver um trabalho pedagógico na perspectiva da PHC, que é a proposta pedagógica institucionalizada nessa rede de ensino
Neutrinoless Double Beta Decay in Heavy Deformed Nuclei
The zero neutrino mode of the double beta decay in heavy deformed nuclei is
investigated in the framework of the pseudo SU(3) model, which has provided an
accurate description of collective nuclear structure and predicted half-lives
for the two neutrino mode in good agreement with experiments. In the case of
the calculated zero neutrino half-life is at least three orders of
magnitude greater than the two neutrino one, giving strong support of the
identification of the radiochemically determined half-life as being the two
neutrino double beta decay. For the zero neutrino matrix elements
are of the order of magnitude of, but lesser than, those evaluated using the
QRPA. This result confirms that different nuclear models produce similar zero
neutrino matrix elements, contrary to the two neutrino case. Using these pseudo
SU(3) results and the upper limit for the neutrino mass we estimate the
half-lives for six nuclei. An upper limit for majoron
coupling constant is extracted from the experimental data.Comment: 19 pages, LaTeX, 2 figures not included, availables as poscript files
upon reques
Synaptic Remodeling Depends on Signaling between Serotonin Receptors and the Extracellular Matrix
Rewiring of synaptic circuitry pertinent to memory formation has been associated with morphological changes in dendritic spines and with extracellular matrix (ECM) remodeling. Here, we mechanistically link these processes by uncovering a signaling pathway involving the serotonin 5-HT7 receptor (5-HT7R), matrix metalloproteinase 9 (MMP-9), the hyaluronan receptor CD44, and the small GTPase Cdc42. We highlight a physical interaction between 5-HT7R and CD44 (identified as an MMP-9 substrate in neurons) and find that 5-HT7R stimulation increases local MMP-9 activity, triggering dendritic spine remodeling, synaptic pruning, and impairment of long-term potentiation (LTP). The underlying molecular machinery involves 5-HT7R-mediated activation of MMP-9, which leads to CD44 cleavage followed by Cdc42 activation. One important physiological consequence of this interaction includes an increase in neuronal outgrowth and elongation of dendritic spines, which might have a positive effect on complex neuronal processes (e.g., reversal learning and neuronal regeneration)
Software engineering processes for self-adaptive systems
In this paper, we discuss how for self-adaptive systems some activities that traditionally occur at development-time are moved to run-time. Responsibilities for these activities shift from software engineers to the system itself, causing the traditional boundary between development-time and run-time to blur. As a consequence, we argue how the traditional software engineering process needs to be reconceptualized to distinguish both development-time and run-time activities, and to support designers in taking decisions on how to properly engineer such systems. Furthermore, we identify a number of challenges related to this required reconceptualization, and we propose initial ideas based on process modeling. We use the Software and Systems Process Engineering Meta-Model (SPEM) to specify which activities are meant to be performed off-line and on-line, and also the dependencies between them. The proposed models should capture information about the costs and benefits of shifting activities to run-time, since such models should support software engineers in their decisions when they are engineering self-adaptive systems
Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update
Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included
Two-photon Lithography for 3D Magnetic Nanostructure Fabrication
Ferromagnetic materials have been utilised as recording media within data
storage devices for many decades. Confinement of the material to a two
dimensional plane is a significant bottleneck in achieving ultra-high recording
densities and this has led to the proposition of three dimensional (3D)
racetrack memories that utilise domain wall propagation along nanowires.
However, the fabrication of 3D magnetic nanostructures of complex geometry is
highly challenging and not easily achievable with standard lithography
techniques. Here, by using a combination of two-photon lithography and
electrochemical deposition, we show a new approach to construct 3D magnetic
nanostructures of complex geometry. The magnetic properties are found to be
intimately related to the 3D geometry of the structure and magnetic imaging
experiments provide evidence of domain wall pinning at a 3D nanostructured
junction
Light neutralino dark matter in the MSSM and its implication for LHC searches for staus
It was shown in a previous study that a lightest neutralino with mass below
30 GeV was severely constrained in the minimal supersymmetric standard model
(MSSM), unless it annihilates via a light stau and thus yields the observed
dark matter abundance. In such a scenario, while the stau is the
next-to-lightest supersymmetric particle (NLSP), the charginos and the other
neutralinos as well as sleptons of the first two families are also likely to be
not too far above the mass bounds laid down by the Large Electron Positron
(LEP) collider. As the branching ratios of decays of the charginos and the
next-to-lightest neutralino into staus are rather large, one expects
significant rates of tau-rich final states in such a case. With this in view,
we investigate the same-sign ditau and tri-tau signals of this scenario at the
Large Hadron Collider (LHC) for two MSSM benchmark points corresponding to
light neutralino dark matter. The associated signal rates for these channels
are computed, for the centre-of-mass energy of 14 TeV. We find that both
channels lead to appreciable rates if the squarks and the gluino are not too
far above a TeV, thus allowing to probe scenarios with light neutralinos in the
14 TeV LHC run with 10-100 fb^{-1}.Comment: 19p, 4 Fig
Primary care follow up of patients discharged from the emergency department: a retrospective study
BACKGROUND: The visit to the emergency department (ED) constitutes a brief, yet an important point in the continuum of medical care. The aim of our study was to evaluate the continuity of care of adult ED visitors. METHODS: We retrospectively reviewed all ED discharge summaries for over a month 's period. The ED chart, referral letter and the patient's primary care file were reviewed. Data collected included: age, gender, date and hour of ED visit, documentation of ED referral and ED discharge letter in the primary care file. RESULTS: 359 visits were eligible for the study. 192 (53.5%) of the patients were women, average age 54.1 ± 18.7 years (mean ± SD). 214 (59.6%) of the visits were during working hours of primary care clinics ("working hours"), while the rest were "out of hours" visits. Only 196 (54.6%) of patients had a referral letter, usually from their family physician. A third (71/214) of "working hours" visits were self referrals, the rate rose to 63.5% (92/145) of "out of hours" visits (p < 0.0001). The ED discharge letter was found in 50% (179/359) of the primary care files. A follow-up visit was documented in only 31% (111/359). Neither follow up visit nor discharge letter were found in 43% of the files (153/359). CONCLUSIONS: We have found a high rate of ED self referrals throughout the day together with low documentation rates of ED visits in the primary care charts. Our findings point to a poor continuity of care of ED attendees
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