4,912 research outputs found
Properties of the Higgs-like boson in the H → ZZ → 4 decay channel at CMS
The measurement of the properties of the new boson with mass
around 126 GeV are reported. The analysis uses pp collision data recorded by the
CMS detector at the LHC, corresponding to integrated luminosities of 5.1 fb−1 at
√s = 7 TeV and 19.6 fb−1 at √s = 8 TeV. The boson is observed in the H → ZZ →
4 channel ( = e, μ) with a local significance above the expected background of 6.8
standard deviations. The mass is measured to be 125.6±0.4(stat.)±0.2(syst.) GeV.
The spin-parity of the boson is studied and the pure scalar hypothesis is found to be
consistent with the observation, when compared to the other spin-parity hypotheses.
No other significant Standard Model Higgs-like excess is found in the search and
upper limits at 95% confidence level exclude the range 129.5–832.0 GeV
Recent results on the Higgs boson properties in the H→ZZ→4ℓ decay channel at CMS
The latest results on the measurement of the properties of the new
boson with mass around 125 GeV are reported. The analysis uses pp collision data
recorded by the CMS detector at the LHC, corresponding to integrated luminosities
of 5.1 fb−1 at √s = 7 TeV and 19.6 fb−1 at √s = 8 TeV. The boson is observed in
the H → ZZ → 4 channel ( = e, μ) and its mass is measured, giving the most
precise result ever achieved. Moreover, the first experimental constraint on Higgs
total width using H → ZZ → 4 events is presented, setting an upper limit of
33 MeV at 95% confidence level (42 MeV expected). The spin-parity of the boson is
studied and the pure scalar hypothesis is found to be consistent with the observation,
when compared to the other spin-parity hypotheses. No other significant Standard
Model Higgs-like excess is found in the search and upper limits at 95% confidence
level exclude the range 129.5–832.0 GeV
Asymptotic Expansion for the Wave Function in a one-dimensional Model of Inelastic Interaction
We consider a two-body quantum system in dimension one composed by a test
particle interacting with an harmonic oscillator placed at the position .
At time zero the test particle is concentrated around the position with
average velocity while the oscillator is in its ground state. In a
suitable scaling limit, corresponding for the test particle to a semi-classical
regime with small energy exchange with the oscillator, we give a complete
asymptotic expansion of the wave function of the system in both cases
and .Comment: 23 page
Well-posedness of the three-dimensional NLS equation with sphere-concentrated nonlinearity
We discuss strong local and global well-posedness for the three-dimensional NLS equation with nonlinearity concentrated on S2 . Precisely, local well-posedness is proved for any C 2 power-nonlinearity, while global well-posedness is obtained either for small data or in the defocusing case under some growth assumptions. With respect to point-concentrated NLS models, widely studied in the literature, here the dimension of the support of the nonlinearity does not allow a direct extension of the known techniques and calls for new ideas
Sex-specific Effects of Unpredictable Variable Prenatal Stress: Implications for Mammalian Developmental Programming During Spaceflight
During initial exposure and adaptation to the microgravity environment, adult mammals exhibit elevated stress, mediated by the Hypothalamic-Pituitary-Adrenal (HPA) axis. In our previous studies of pregnant rats exposed to 2-g hypergravity via continuous centrifugation, we reported changes in neuroendocrine profiles including decreased corticosterone and a concomitant increase in body mass and leptin in adult male offspring. Prenatally stressed adult offspring have been shown to exhibit an elevated stress response in adulthood, therefore we hypothesized that these changes resulted from stress exposure during fetal development. Future studies examining reproduction, gestation, and development on-orbit need to consider the unique stressors of vehicle launch, the space environment, and landing on the development of the HPA axis in animals born and raised in microgravity. In this study, we utilize Unpredictable Variable Prenatal Stress (UVPS) to simulate the stressors of spaceflight by exposing dams to three different stressors: (1) White Noise, (2) Strobe Light, and (3) Tube Restraint. Stressors were applied from Gestational Day 0 (G0), following an unpredictable schedule (morning [0600-1200hrs]; afternoon [1200-1800hrs]; evening [1800-2400hrs] in 15, 30, or 60 minute durations alongside non-stressed (NS) control dams. Following parturition, pups were fostered to non-manipulated, newly parturient dams to control for differential maternal care. On postnatal day 90 (P90), we harvested the hypothalamus, pituitary, and adrenal glands, and analyzed mRNA expression of the following genes via RT-qPCR: 1) melanocortin-2 receptor (MC2R), POMC, corticotropin-releasing hormone (CRH) in the pituitary; 2) glucocorticoid receptor (NR3C1), pro-opiomelanocortin (POMC), corticotropin-releasing hormone (CRH), brain-derived neurotropic factor (BDNF), in the hypothalamus; and 3) MC2R, tyrosine hydroxylase (TH), steroidogenic acute regulatory protein (STAR), cytochrome P450scc enzyme (CYP) in the adrenal. The identification of sex-specific fetal programming effects on adult stress response is a key step in determining potential animal behavior on-orbit, and will guide future multi-generational studies in microgravity
Characterisation of flow dynamics within and around an isolated forest, through measurements and numerical simulations
The case study of ‘Bosco Fontana’, a densely-vegetated forest located in the north of Italy, is analysed both
experimentally and numerically to characterise the internal ventilation of a finite forest with a vertically
non-homogeneous canopy. Measurements allow for the evaluation of the turbulent exchange across the forest
canopy. The case study is then reproduced numerically via a two-dimensional RANS simulation, successfully
validated against experimental data. The analysis of the internal ventilation leads to the identification of
seven regions of motion along the predominate-wind direction, for whose definition a new in-canopy stability
parameter was introduced. In the vertical direction, the non-homogeneity of the canopy leads to the separation
of the canopy layer into an upper foliage layer and a lower bush layer, characterised respectively by an
increasing streamwise velocity and turbulence intensity, and a weak backflow. The conclusions report an
improved description of the dynamic layer and regions of motion presented in the literature
The Effect of Statins on Mortality in Septic Patients: a Meta-Analysis of Randomized Controlled Trials
OBJECTIVE: Statins are among the most prescribed drugs worldwide and their recently discovered anti-inflammatory effect seems to have an important role in inhibiting proinflammatory cytokine production, chemokines expression and counteracting the harmful effects of sepsis on the coagulation system. We decided to perform a meta-analysis of all randomized controlled trials ever published on statin therapy in septic patients to evaluate their effect on survival and length of hospital stay.
DATA SOURCES AND STUDY SELECTION: Articles were assessed by four trained investigators, with divergences resolved by consensus. BioMedCentral, PubMed, Embase and the Cochrane Central Register of clinical trials were searched for pertinent studies. Inclusion criteria were random allocation to treatment and comparison of statins versus any comparator in septic patients.
DATA EXTRACTION AND SYNTHESIS: Data from 650 patients in 5 randomized controlled studies were analyzed. No difference in mortality between patients receiving statins versus control (44/322 [14%] in the statins group vs 50/328 [15%] in the control arm, RR = 0.90 [95% CI 0.65 to 1.26], p = 0.6) was observed. No differences in hospital stay (p = 0.7) were found.
CONCLUSIONS: Published data show that statin therapy has no effect on mortality in the overall population of adult septic patients. Scientific evidence on statins role in septic patients is still limited and larger randomized trials should be performed on this topic
Intrauterine Exposure to Maternal Stress Alters Bdnf IV DNA Methylation and Telomere Length in the Brain of Adult Rat Offspring
DNA methylation (addition of methyl groups to cytosines which normally represses gene transcription) and changes in telomere length (TTAGGG repeats on the ends of chromosomes) are two molecular modifications that result from stress and could contribute to the long-term effects of intrauterine exposure to maternal stress on offspring behavioral outcomes. Here, we measured methylation of Brain-derived neurotrophic factor (Bdnf), a gene important in development and plasticity, and telomere length in the brains of adult rat male and female offspring whose mothers were exposed to unpredictable and variable stressors throughout gestation. Males exposed to prenatal stress had greater methylation (Bdnf IV) in the medial prefrontal cortex (mPFC) compared to non-stressed controls. Further, prenatally-stressed males had shorter telomeres than controls in the mPFC. This study provides the first evidence in a rodent model of an association between prenatal stress exposure and subsequent shorter brain telomere length. Together findings indicate a long-term impact of prenatal stress on DNA methylation and telomere biology with relevance for behavioral and health outcomes, and contribute to a growing literature linking stress to intergenerational epigenetic alterations and changes in telomere length
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