Strong Parameterized Deletion: Bipartite Graphs

The purpose of this article is two fold: (a) to formally introduce a stronger version of graph deletion problems; and (b) to study this version in the context of bipartite graphs. Given a family of graphs F, a typical instance of parameterized graph deletion problem consists of an undirected graph G and a positive integer k and the objective is to check whether we can delete at most k vertices (or k edges) such that the resulting graph belongs to F. Another version that has been recently studied is the one where the input contains two integers k and l and the objective is to check whether we can delete at most k vertices and l edges such that the resulting graph belongs to F. In this paper, we propose and initiate the study of a more general version which we call strong deletion. In this problem, given an undirected graph G and positive integers k and l, the objective is to check whether there exists a vertex subset S of size at most k such that each connected component of G-S can be transformed into a graph in F by deleting at most l edges. In this paper we study this stronger version of deletion problems for the class of bipartite graphs. In particular, we study Strong Bipartite Deletion, where given an undirected graph G and positive integers k and l, the objective is to check whether there exists a vertex subset S of size at most k such that each connected component of G-S can be made bipartite by deleting at most l edges. While fixed-parameter tractability when parameterizing by k or l alone is unlikely, we show that this problem is fixed-parameter tractable (FPT) when parameterized by both k and l

Comparison of reliability of lateral cephalogram and computed tomography for assessment of airway space

Background and Aims: The oropharyngeal (OP) and nasopharyngeal structures seems to play roles in the development of the dentofacial complex. Soft palate as a part of nasopharyngeal and OP apparatus has an important role in phonation, deglutition and respiration. The aim of this study was to find whether any correlation exists between the three typesof malocclusion and airway space using lateral cephalogram and computed tomography (CT) and to compare its reliability. To obtain important information on the morphology of the soft palate on lateral cephalogram and to determine its etiopathogenesis in obstructive sleep apnea (OSA).Materials and Methods: Lateral cephalogram of 45 subjects were used to measure the pharyngeal airway. The subjects were divided into three groups (each group included 15 subjects) according to ANB angle: Class I (ANB angle 2-4‹), Class II (ANB angle >4‹), Class III (ANB angle .2‹).Results: The result showed a significant reduction in pharyngeal airway in ANB Class II. Type I soft palate, leaf-shape was found in maximum subjects. The volume of airway size showed higher statistical significance with the greater coefficient of variation on CT in relation to corresponding cephalometric airway area.Conclusion: The sagittal skeletal pattern is a contributory factor in  variations in the upper airway dimensions. The measurements acquired from both the modalities are reliable and reproducible, but CT gives the better assessment of cross.sectional dimensions of airway space. Morphology of the soft palate can be used as references for etiologicalresearch of OSA.Key words: Airway space, computed tomography, lateral cephalogram, malocclusion, obstructive sleep apnea, soft tissue are

Single Production of Doubly Charged Higgsinos at linear e-e- colliders

Several extended supersymmetric models, motivated by either grand unification, or by neutrino mass generation, predict light doubly charged higgsinos. We study the production of a single doubly charged higgsino and its decay channels at the International Linear Collider (ILC) operating in the e-e- mode. We analyze the production cross section for e-e- --> tilde{Delta}^{--}_{L,R} chi^0_1 as a function of different kinematic variables, followed by the decay, through several channels, of the doubly charged higgsino into a final state of two leptons plus missing energy. We include the standard model background and discuss how kinematic cuts could be used effectively to limit this background. Single production of these exotics could provide a spectacular signal for a new underlying symmetry and for physics beyond the minimal supersymmetric standard model.Comment: Typos corrected, Journal Versio

Specific detection of Aspergillus fumigatus in sputum sample of pulmonary tuberculosis patients by two-step PCR

The incidence of life-threatening systemic fungal infections has been increasing in recent years, and the increasing incidence has been correlated with increasing numbers of immunocompromisedpatients. We developed a two-step PCR assay that specifically amplifies a region of the 18S rRNA gene that is highly conserved in Aspergillus fumigatus. This assay allows direct and rapid detection of down to 10 fg of Aspergillus fumigatus DNA corresponding to 1 to 5 colony forming unit (CFU) per ml of sputum sample of pulmonary tuberculosis patients. The two primer pairs that produced PCR productswith the highest sensitivity and species specificity were the Aspergillus fumigatus primers AFU7S and AFU7AS, which amplified a fragment of 405 bp, followed by AFU5S and AFU5AS, which produced aninternal fragment of 236 bp. PCR has been shown to be a highly sensitive diagnostic tool for the detection of infectious fungi specimens. Our point to the considerable potential clinical value of thissimple, specific, rapid, and inexpensive PCR assay is for improving the means of early diagnosis of systemic aspergillosis tuberculosis patients

Some entanglement features of three-atoms Tavis-Cummings model: Cooperative case

In this paper we consider a system of identical three two-level atoms interacting at resonance with a single-mode of the quantized field in a lossless cavity. The initial cavity field is prepared in the coherent state while the atoms are taken initially to be either in the uppermost excited state "$|eee>$" or The $\textmd{GHZ}$-state or the $\textmd{W}$-state. For this system we investigate different kinds of atomic inversion and entanglement, which arise between the different parts of the system due to the interaction. Also the relationship, between entanglement and some other nonclassical effects in the statistical properties, such as collapses and revivals in the atomic inversion where superharmonic effects appear, is discussed. The $Q$-functions for different cases are discussed. Most remarkably it is found that the $\textmd{GHZ}$-state is more robust against energy losses, showing almost coherent trapping and Schr\"odinger-cat states can not be produced from such state. Also the entanglement of $\textmd{GHZ}$-state is more robust than the $\textmd{W}$-state. Another interesting feature found is that the state which has no pairwise entanglement initially will have a much improvement of such pairwise entanglement through the evolution. Sudden death and sudden revival of atoms-pairwise entanglement are produced with the $\textmd{W}$-state.Comment: 14 pages, 7 figure

How delicate are the f(R) gravity models with a disappearing cosmological constant?

We consider stability of spherically symmetric solutions in f(R) gravity model proposed by Starobinsky. We find that the model suffers from a severe fine-tuning problem when applied to compact objects like neutron stars. The problem can be remedied by introducing a cutoff on the mass of the scalar degree of freedom present in the model. A new mass scale associated with neutron stars density is then required for the stabilities of f(R) gravity solutions inside relativistic stars

Signatures for doubly-charged Higgsinos at colliders

Several supersymmetric models with extended gauge structures predict light doubly-charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying their production and decay characteristics.Comment: 3 pages, 4 figures, Latex. Submitted for SUSY 2008 proceeding