On cohomological dimension and depth under linkage

Some relations between cohomological dimensions and depths of linked ideals are investigated and discussed by various examples.Comment: 7 page

Improved Energy Detector for Wideband Spectrum Sensing in Cognitive Radio Networks

In this paper, an improved energy detector for a wideband spectrum sensing is proposed. For a better detection of the spectrum holes the overall band is divided into equal non-overlapping sub-bands. The main objective is to determine the detection thresholds for each of these subbands jointly. By defining the problem as an optimization problem, we aim to find the maximum aggregated opportunistic throughput of cognitive radio networks. Introducing practical constraints to this optimization problem will change the problem into a convex and solvable one. The results of this paper show that the proposed improved energy detector will increase the aggregated throughput considerably

Cooling of a Nanomechanical Resonator in the Presence of a Single Diatomic Molecule

We propose a theoretical scheme for coupling a nanomechanical resonator to a single diatomic molecule via microwave cavity mode of a driven LC resonator. We describe the diatomic molecule by a Morse potential and find the corresponding equations of motion of the hybrid system by using Fokker-Planck formalism. Analytical expressions for the effective frequency and the effective damping of the nanomechanical resonator are obtained. We analyze the ground state cooling of the nanomechanical resonator in presence of the diatomic molecule. The results confirm that presence of the molecule improves the cooling process of the mechanical resonator. Finally, the effect of molecule's parameters on the cooling mechanism is studied.Comment: 10 pages, 8 figure

String cosmology from Poisson-Lie T-dual sigma models on supermanifolds

We generalize the formulation of Poisson-Lie T-dual sigma models on manifolds to supermanifolds. In this respect, we formulate 1+1 dimensional string cosmological models on the Lie supergroup C^3 and its dual (A_1,1 + 2A)^0_(1,0,0), which are coupled to two fermionic fields. Then, we solve the equations of motion of the models and show that there is a essential singularity for the metric of the original model and its dual.Comment: 17 pages, Appendix and three references have adde

Generating quantum discord between two distant Bose-Einstein condensates with Bell-like detection

We propose a technique that enables the creation of quantum discord between two distant nodes, each containing a cavity consist of the Bose-Einstein condensate, by applying a non-ideal Bell-like detection on the output modes of optical cavities. We find the covariance matrix of the system after the non-ideal Bell-like detection, showing explicitly that one enables manipulation of the quantum correlations, and particularly quantum discord, between remote Bose-Einstein condensates. We also find that the non-ideal Bell-like detection can create entanglement between distant Bose-Einstein condensates at the two remote site

Mothers’ experience of having children with diabetes

Abstract Background: Diabetes is a major health problem, which has a wide prevalence in the world. There is no sign of its stopping, but it is increasing. Diabetes in children is three to four times more common than other childhood diseases. Diagnosis of diabetes for children causes emotional responses in parents and family members. Interventions for children with diabetes involve the family, child, and professionals including physicians, nurses, and nutritionist. Self-care is difficult without direct parents’ participation. According to studies, burden of diabetes for mothers is more than for fathers. This study aimed to explore mothers’ experience of children with diabetes. Materials and Methods: This is a qualitative content analysis. Study population was recruited through purposeful sampling. Eleven mothers who have a child with diabetes and referring to the “Glands and Metabolism Research Center” and “Al-Zahra Hospital” were selected. Participants were aged 28 to 42 years. Data gathering was done through deep interviews with participants in 2007 that was tape-recorded. Mean average of interviews was 45 minutes. Data analysis was done using conventional qualitative content analysis. Results: Participants’ experience was classified in the two main concepts including reaction at the time of diagnosis and disease consequences for mothers. Conclusion: Mothers of children with diabetes expressed some reactions at the time of diagnosis, which was mainly due to lack of information, and lack of attention to their needs at the time of diagnosis, especially it was due to the sudden diagnosis and lack of enough opportunities for mothers to accept the disease. The disease causes some consequences for mothers that affect their lives. Therefore, it is necessary to consider the needs of families of children with diabetes and to provide support and sufficient information about their child’s illness for them

Mutual information as an order parameter for quantum synchronization

Spontaneous synchronization is a fundamental phenomenon, important in many theoretical studies and applications. Recently this effect has been analyzed and observed in a number of physical systems close to the quantum mechanical regime. In this work we propose the mutual information as a useful order parameter which can capture the emergence of synchronization in very different contexts, ranging from semi-classical to intrinsically quantum mechanical systems. Specifically we first study the synchronization of two coupled Van der Pol oscillators in both classical and quantum regimes and later we consider the synchronization of two qubits inside two coupled optical cavities. In all these contexts, we find that mutual information can be used as an appropriate figure of merit for determining the synchronization phases, independently of the specific details of the system