2,720 research outputs found
Direct detection of neutralino dark matter in the NMSSM
We address the direct detection of neutralino dark matter in the framework of
the Next-to-Minimal Supersymmetric Standard Model. We conduct a detailed
analysis of the parameter space, taking into account all the available
constraints from LEPII, and compute the neutralino-nucleon cross section. We
find that sizable values for the detection cross section, within the reach of
dark matter detectors, are attainable in this framework, and are associated
with the exchange of very light Higgses, GeV, the latter
exhibiting a significant singlet composition.Comment: LaTex, 6 pages, 4 figures. Talk given at the 5th International
Workshop on the Identification of Dark Matter (IDM2004), Edinburgh, 6-10
September 200
NMSSM with a singlino LSP: possible challenges for searches for supersymmetry at the LHC
A light singlino in the NMSSM can reduce considerably the missing transverse
energy at the end of sparticle decay cascades; instead, light NMSSM-specific
Higgs bosons can be produced. Such scenarios can be consistent with present
constraints from the LHC with all sparticle masses below ~1 TeV. We discuss
search strategies, which do not rely on missing transverse energy, for such
scenarios at the next run of the LHC near 14 TeV.Comment: 20 pages, 9 Figures. References and experimental constraints added;
slight change of benchmark point, conclusions unchange
LHC constraints on M_1/2 and m_0 in the semi-constrained NMSSM
Constraints from searches for squarks and gluinos at the LHC at sqrt{s}=8 TeV
are applied to the parameter space of the NMSSM with universal squark/slepton
and gaugino masses at the GUT scale, but allowing for non-universal soft Higgs
mass parameters (the sNMSSM). We confine ourselves to regions of the parameter
space compatible with a 125 GeV Higgs boson with diphoton signal rates at least
as large as the Standard Model ones, and a dark matter candidate compatible
with WMAP and XENON100 constraints. Following the simulation of numerous points
in the m_0-M_{1/2} plane, we compare the constraints on the sNMSSM from 3-5
jets + missing E_T channels as well as from multijet + missing E_T channels
with the corresponding cMSSM constraints. Due to the longer squark decay
cascades, lower bounds on M_{1/2} are alleviated by up to 50 GeV. For heavy
squarks at large m_0, the dominant constraints originate from multijet +
missing E_T channels due to gluino decays via stop pairs.Comment: 18 pages, 2 Tables, 3 Figure
NMSSM neutralino dark matter
We study the viability of the lightest neutralino as a dark matter candidate
in the Next-to-Minimal Supersymmetric Standard Model. Taking into account
accelerator constraints as well as bounds on low-energy observables, and
imposing consistency with present bounds on the neutralino relic density, we
address the prospects for the direct detection of neutralino dark matter. We
find regions of the allowed parameter space where the neutralino detection
cross section is within the reach of dark matter detectors, essentially owing
to the presence of very light singlet-like Higgses, and to either singlino
dominated or very light neutralinos.Comment: 4 pages, 2 figures. Presented at 13th International Symposium on
Particles, Strings and Cosmology (PASCOS 07), London, England, 2-7 Jul 200
Mucosal Immunity, Stress, Cognition and Functional Fitness in Sedentary and Active Elderly Men
Physical activity in the elderly has been shown to have positive effects on several chronic diseases and to improve immunity, mental health and cognition. Chronic stress as also been shown to have immuno-suppressive effects and to accelerate immunosenescence. Recently it as also been found that different types of exercise may affect cognition and dementia risk to different extents.
This cross-sectional study compared a group of 16 sedentary men with a mean age of 74,5+10,17 years old and a group of 17 men engaged in moderate regular exercise, mean age 69,99+6,36 years old, and aimed to identifying markers involved in maintaining immune and mental health in the elderly. Immune and physiological markers of stress (salivary IgA, CRP, cortisol, alpha-amylase, testosterone and DHEA), psychological variables (perceived stress, self-esteem, physical self, satisfaction with life) and functional fitness (using the Rikli and Jones test battery) were evaluated. A smaller sample of subjects (8 sedentary and 10 active) was also evaluated for cognitive function using the Vienna Test System Software (Schuhfried, Austria). Four different tests were used: evaluation of reaction time to a visual stimulus, evaluation of reaction time to sound, evaluation of different components of cognitive speed and evaluation of complex and multiple reactions to different stimuli. Statistical analysis was performed using the independent samples T-test and the bivariate Pearson’s correlation for the association between variables. For the cognition tests variables the Mann-Whitney and Spearman tests were used.
Results showed that the active group had significantly better results in all components of functional fitness, including upper and lower strength and flexibility, agility and balance as well as aerobic resistance. Saliva levels of CRP and IgA concentration, but not IgA secretion rates, were lower in the active group. In the psychological variables, differences between groups were only found for Physical Self in the Physical Function domain. The active group performed better for cognitive speed and for complex and multiple reactions test. Correlations were found for the navel perimeter and salivary flow rate (r=-0.32, p=0.02) and CRP (r=0.34, p=0.012) and mean reaction time to sound (r=-0.47, p=0.049); for salivary cortisol and total perceived stress (r=0.29, p=0.034). Two components of the cognitive speed test (reaction time to choose and reaction time to visual search) negatively correlated with saliva flow rate (r=-0.64, p=0.003; r=-0.52, p=0.02). Several correlations were also found for aerobic resistance and the complex and multiple reactions test.
Inflammation and cognition were improved in active groups
Asbestose pulmonar: mecanismos celulares da sua patogenia
A asbestose pulmonar continua a ser uma das doenças ocupacionais mais graves do nosso
tempo. Apesar de clÃnica e epidemiologicamente bem caracterizada pouco se sabe ainda dos
mecanismos celulares responsáveis pela sua ocorrência. Assim, a partir da informação até ao
momento disponÃvel sobre este assunto, tentámos delinear os vários mecanismos envolvidos na
resposta do pulmão profundo à inalação de fibras de asbesto.
Numa primeira parte caracterizam-se os vários tipos de fibras de asbesto existentes bem como
os seus diferentes padrões de deposição e transporte.
Numa segunda parte descrevem-se os possÃveis mecanismos celulares envolvidos na patogenia
da asbestose pulmonar, nomeadamente a acção dos macrófagos alveolares, dos neutrófilos e dos
respectivos mediadores.
A análise do perfil linfocitário de lavados bronco-alveolares de pacientes com asbestose é
também descrita, salientando-se um acentuado aumento na relação CD4/CD8.Pulmonary asbestosis is still one serious occupational disease ofour times. Although the clinical
and epidemiological featu res ofthe disease are well caracterized, the cellular mechanisms involved
are still poorly understood.
Taking advantage ofall the information available on this subject, we tried to depict the several
mechanisms involved in the answer ofthe deep lung to the inhalation ofasbestos jibers.
ln the jirst part ofthis article we characterized the diferent kinds ofasbestos jibers as well as their
patterns oftransport and deposition in the deep lung.ln the second part we discribed the possible cellular mechanisms underlying the pathogeny of
pulmonary asbestosis. The e.fJect ofthe alveolar macrophages, polinuclear neuthrophils and the action
oftheir mediators is discribed.
Analysis of the bronco alveolar lavage jluid lynphocitary profile of pacients with pulmonary
asbestosis is also discribed, revealing significant increase in the CD4/CD8 ratio
Excessive Higgs pair production with little MET from squarks and gluinos in the NMSSM
In the presence of a light singlino-like LSP in the NMSSM, the missing
transverse energy - MET - signature of squark/gluino production can be
considerably reduced. Instead, a pair of Higgs bosons is produced in each
event. We propose benchmark points for such scenarios, which differ in the
squark and gluino masses, and in their decay cascades. Events for these points
are simulated for the run II of the LHC at 13 TeV centre of mass energy. After
cuts on the transverse momenta of at least four jets, and requiring two
tau-leptons from one Higgs decay, we find that the invariant mass of two b-jets
from the other Higgs decay shows clear peaks above the background. Despite the
reduced MET, this search strategy allows to see signals for sufficiently large
integrated luminosities, depending on the squark/gluino masses.Comment: 16 pages, 10 figure
- …