406 research outputs found
Antimatter signals of singlet scalar dark matter
We consider the singlet scalar model of dark matter and study the expected
antiproton and positron signals from dark matter annihilations. The regions of
the viable parameter space of the model that are excluded by present data are
determined, as well as those regions that will be probed by the forthcoming
experiment AMS-02. In all cases, different propagation models are investigated,
and the possible enhancement due to dark matter substructures is analyzed. We
find that the antiproton signal is more easily detectable than the positron one
over the whole parameter space. For a typical propagation model and without any
boost factor, AMS-02 will be able to probe --via antiprotons-- the singlet
model of dark matter up to masses of 600 GeV. Antiprotons constitute,
therefore, a promising signal to constraint or detect the singlet scalar model.Comment: 24 pages, 8 figures. v2: minor improvements. Accepted for publication
in JCA
Comparison of ensemble simple feed forward neural network and deep learning neural network on Phishing Detection
Phishing attack is one of wide spread cybercrimes due to the advancement of the Internet. There are many forms of phishing attack and the most common one is through email. The attacker tries to pretend by sending email from an official organization or body to deceive the user in giving in their credential user name and password. The username and password are then used for malicious purpose. Many methods have been used to detect these phishing attacks; however, the attack evolved too quickly to be solved by manual approach. Therefore, automated phishing detection through artificial intelligence approach would be more feasible. In this paper, a comparison study for phishing detection between two neural networks which are the feedforward neural network and the deep learning neural network is carried out. The result is empirically evaluated to determine which method performs better in phishing detection
Dynamical Breakdown of Symmetry in a (2+1) Dimensional Model Containing the Chern-Simons Field
We study the vacuum stability of a model of massless scalar and fermionic
fields minimally coupled to a Chern-Simons field. The classical Lagrangian only
involves dimensionless parameters, and the model can be thought as a (2+1)
dimensional analog of the Coleman-Weinberg model. By calculating the effective
potential, we show that dynamical symmetry breakdown occurs in the two-loop
approximation. The vacuum becomes asymmetric and mass generation, for the boson
and fermion fields takes place. Renormalization group arguments are used to
clarify some aspects of the solution.Comment: Minor modifications in the text and figure
LRRK2 A419V is not associated with Parkinson's disease in different Chinese populations
10.1371/journal.pone.0036123PLoS ONE77
MTHFR C677T polymorphism as a risk factor of neural tube defects in Malay_a case control study
Major congenital malformations occur in about 3% of newborn. Several studies have suggested that homozygosity for the C677T methylenetetrahydrofolate reductase (MTHFR) variant is a potential risk factor for neural tube defects (NTDs). It has been hypothesized that the maternal folic acid supplementation prevents NTDs by partially correcting reduced MTHFR activity associated with the variant form of the enzyme. This association has not been found in some ethnic groups. In this study, we attempted to assess the association between NTDs and MTHFR C677T in Malaysian Malay population. Results show that MTHFR 677TT genotype was absent in both patient and control groups
Antiproton constraints on dark matter annihilations from internal electroweak bremsstrahlung
If the dark matter particle is a Majorana fermion, annihilations into two
fermions and one gauge boson could have, for some choices of the parameters of
the model, a non-negligible cross-section. Using a toy model of leptophilic
dark matter, we calculate the constraints on the annihilation cross-section
into two electrons and one weak gauge boson from the PAMELA measurements of the
cosmic antiproton-to-proton flux ratio. Furthermore, we calculate the maximal
astrophysical boost factor allowed in the Milky Way under the assumption that
the leptophilic dark matter particle is the dominant component of dark matter
in our Universe. These constraints constitute very conservative estimates on
the boost factor for more realistic models where the dark matter particle also
couples to quarks and weak gauge bosons, such as the lightest neutralino which
we also analyze for some concrete benchmark points. The limits on the
astrophysical boost factors presented here could be used to evaluate the
prospects to detect a gamma-ray signal from dark matter annihilations at
currently operating IACTs as well as in the projected CTA.Comment: 32 pages; 13 figure
Plasmodium knowlesi reinfection in human
To the Editor: In 2004, a large number of patients infected with Plasmodium knowlesi (simian malarial species) were reported in Sarawak, Malaysia (1). P. knowlesi infection was also reported in Peninsular Malaysia (2). Here we report a case of human P. knowlesi reinfection. Phylogenetic sequence analysis shows that the first and second infections were caused by different strains of P. knowlesi
Sharp Trace Hardy-Sobolev-Maz'ya Inequalities and the Fractional Laplacian
In this work we establish trace Hardy and trace Hardy-Sobolev-Maz'ya
inequalities with best Hardy constants, for domains satisfying suitable
geometric assumptions such as mean convexity or convexity. We then use them to
produce fractional Hardy-Sobolev-Maz'ya inequalities with best Hardy constants
for various fractional Laplacians. In the case where the domain is the half
space our results cover the full range of the exponent of the
fractional Laplacians. We answer in particular an open problem raised by Frank
and Seiringer \cite{FS}.Comment: 42 page
Examining health-related quality of life patterns in women with breast cancer
Purpose: We aimed to identify subgroups of women with breast cancer who experience different health-related quality of life (HRQOL) patterns during active treatment and survivorship and determine characteristics associated with subgroup membership. Methods: We used data from the third phase of the population-based Carolina Breast Cancer Study and included 2142 women diagnosed with breast cancer from 2008 to 2013. HRQOL was measured, on average, 5 and 25 months post diagnosis. Latent profile analysis was used to identify HRQOL latent profiles (LPs) at each time point. Latent transition analysis was used to determine probabilities of women transitioning profiles from 5 to 25 months. Multinomial logit models estimated adjusted odds ratios (aORs) and 95% confidence intervals for associations between patient characteristics and LP membership at each time point. Results: We identified four HRQOL LPs at 5 and 25 months. LP1 had the poorest HRQOL and LP4 the best. Membership in the poorest profile at 5 months was associated with younger age aOR 0.95; 0.93–0.96, White race aOR 1.48; 1.25–1.65, being unmarried aOR 1.50; 1.28–1.65 and having public aOR 3.09; 1.96–4.83 or no insurance aOR 6.51; 2.12–20.10. At 25 months, Black race aOR 1.75; 1.18–1.82 was associated with the poorest profile membership. Black race and smoking were predictors of deteriorating to a worse profile from 5 to 25 months. Conclusions: Our results suggest patient-level characteristics including age at diagnosis and race may identify women at risk for experiencing poor HRQOL patterns. If women are identified and offered targeted HRQOL support, we may see improvements in long-term HRQOL and better breast cancer outcomes
Modelling of patient-specific femur with osteogenesis imperfecta to determine the fracture risk under various loads
Osteogenesis imperfecta (OI) is a fragile bone disease characterized by easy fractures. The femur consists of cortical and cancellous bone, each with different mechanical properties. Bone fractures often occur throughout patients’ lifetime. However, doctors still have no quantitative method to predict fractures. Therefore, this project’s purpose is to investigate the OI femoral fracture risk to help prevent fractures. The project consists of three sections; cortical and cancellous segmentation, reconstruction of 3D OI femoral model and finite element analysis (FEA) of the OI femur to obtain fracture risk. The fracture risk in daily activities and the fracture load were examined. All the stress values were judged by the fracture criteria, assumed as 115 MPa. The exercises that exerted force more than 6 times of body weight can cause fractures. In addition, the optimal compressive force and tensile force were 919.7 N and 912.1 N, respectively, while medial and lateral impact were 230.8 N. Cancellous bone was not affected even a fracture happen. Based on these findings, we can conclude that when the OI femur is subjected to lateral or medial forces, the femur breaks easily. The bone can be reconstructed into a solid body without having to separate bone into cortical and cancellous
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