Treatment of endobronchial metastases with intraluminal radiotherapy

AbstractMetastasis to the lung occurs quite commonly from certain types of extrapulmonary primary carcinoma. Spread to the bronchial lumen is relatively rare. When this does occur, symptoms resembling those of primary bronchial carcinoma are often present, in association with partial or complete obstruction of the bronchial lumen. Palliation of such symptoms is possible with the use of intraluminal radiotherapy (ILT). Between 1990 and 1998, 37 patients with endobronchial metastases were treated using this modality; a single fraction of radiation was delivered by the remote afterloading high dose rate microSelectron system. Data regarding these patients' characteristics and outcome are presented, following a retrospective review of case notes.The commonest symptoms were dyspnoea, cough and haemoptysis; the commonest primary tumour sites were breast, colorectum, oesophagus and kidney. Twenty-four (64·9%) patients had some improvement in symptoms following treatment. Mean overall survival was 280 days, range 9–1145 days. No serious adverse effects occurred. ILT is a relatively simple, safe and effective treatment in the palliation of symptoms due to endobronchial metastases

Invariant Homology on Standard Model Manifolds

Torus-fibered Calabi-Yau threefolds Z, with base dP_9 and fundamental group pi_1(Z)=Z_2 X Z_2, are reviewed. It is shown that Z=X/(Z_2 X Z_2), where X=B X_{P_1} B' are elliptically fibered Calabi-Yau threefolds that admit a freely acting Z_2 X Z_2 automorphism group. B and B' are rational elliptic surfaces, each with a Z_2 X Z_2 group of automorphisms. It is shown that the Z_2 X Z_2 invariant classes of curves of each surface have four generators which produce, via the fiber product, seven Z_2 X Z_2 invariant generators in H_4(X,Z). All invariant homology classes are computed explicitly. These descend to produce a rank seven homology group H_4(Z,Z) on Z. The existence of these homology classes on Z is essential to the construction of anomaly free, three family standard-like models with suppressed nucleon decay in both weakly and strongly coupled heterotic superstring theory.Comment: 57 pages, 13 figure

Next-generation sequencing of southern African Crimean-Congo haemorrhagic fever virus isolates reveals a high frequency of M segment reassortment

Crimean Congo haemorrhagic fever virus (CCHFV) is a bunyavirus with a single-stranded RNA genome consisting of three segments (S, M, L), coding for the nucleocapsid protein, envelope glycoproteins and RNA polymerase, respectively. To date only five complete genome sequences are available from southern African isolates. Complete genome sequences were generated for 10 southern African CCHFV isolates using next-generation sequencing techniques. The maximum-likelihood method was used to generate tree topologies for 15 southern African plus 26 geographically distinct complete sequences from GenBank. M segment reassortment was identified in 10/15 southern African isolates by incongruencies in grouping compared to the S and L segments. These reassortant M segments cluster with isolates from Asia/Middle East, while the S and L segments cluster with strains from South/West Africa. The CCHFV M segment shows a high level of genetic diversity, while the S and L segments appear to co-evolve. The reason for the high frequency of M segment reassortment is not known. It has previously been suggested that M segment reassortment results in a virus with high fitness but a clear role in increased pathogenicity has yet to be shown.The National Health Laboratory Service Research Trust, the Polio Research Foundation, South Africa, and University of the Free State Cluster funding.http://journals.cambridge.org/action/displayJournal?jid=HYG2015-05-30am201

Comparative analysis of the L, M, and S RNA segments of Crimean-Congo haemorrhagic fever virus isolates from southern Africa

Crimean–Congo haemorrhagic fever virus (CCHFV) is a member of the Bunyaviridae family with a tripartite, negative sense RNA genome. This study used predictive software to analyse the L (large), M (medium), and S (small) segments of 14 southern African CCHFV isolates. The OTU-like cysteine protease domain and the RdRp domain of the L segment are highly conserved among southern African CCHFV isolates. The M segment encodes the structural glycoproteins, GN and GC, and the non-structural glycoproteins which are post-translationally cleaved at highly conserved furin and subtilase SKI-1 cleavage sites. All of the sites previously identified were shown to be conserved among southern African CCHFV isolates. The heavily O-glycosylated N-terminal variable mucin-like domain of the M segment shows the highest sequence variability of the CCHFV proteins. Five transmembrane domains are predicted in the M segment polyprotein resulting in three regions internal to and three regions external to the membrane across the GN, NSM and GC glycoproteins. The corroboration of conserved genome domains and sequence identity among geographically diverse isolates may assist in the identification of protein function and pathogenic mechanisms, as well as the identification of potential targets for antiviral therapy and vaccine design. As detailed functional studies are lacking for many of the CCHFV proteins, identification of functional domains by prediction of protein structure, and identification of amino acid level similarity to functionally characterised proteins of related viruses or viruses with similar pathogenic mechanisms are a necessary step for selection of areas for further study.National Health Laboratory Service Research Trust, the Polio Research Foundation, South Africa and University of the Free State Cluster funding.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1096-90712016-05-31hb201

Barrier effects on the collective excitations of split Bose-Einstein condensates

We investigate the collective excitations of a single-species Bose gas at T=0 in a harmonic trap where the confinement undergoes some splitting along one spatial direction. We mostly consider onedimensional potentials consisting of two harmonic wells separated a distance 2 z_0, since they essentially contain all the barrier effects that one may visualize in the 3D situation. We find, within a hydrodynamic approximation, that regardless the dimensionality of the system, pairs of levels in the excitation spectrum, corresponding to neighbouring even and odd excitations, merge together as one increases the barrier height up to the current value of the chemical potential. The excitation spectra computed in the hydrodynamical or Thomas-Fermi limit are compared with the results of exactly solving the time-dependent Gross-Pitaevskii equation. We analyze as well the characteristics of the spatial pattern of excitations of threedimensional boson systems according to the amount of splitting of the condensate.Comment: RevTeX, 12 pages, 13 ps figure

Mean-field analysis of collapsing and exploding Bose-Einstein condensates

The dynamics of collapsing and exploding trapped Bose-Einstein condensat es caused by a sudden switch of interactions from repulsive to attractive a re studied by numerically integrating the Gross-Pitaevskii equation with atomic loss for an axially symmetric trap. We investigate the decay rate of condensates and the phenomena of bursts and jets of atoms, and compare our results with those of the experiments performed by E. A. Donley {\it et al.} [Nature {\bf 412}, 295 (2001)]. Our study suggests that the condensate decay and the burst production is due to local intermittent implosions in the condensate, and that atomic clouds of bursts and jets are coherent. We also predict nonlinear pattern formation caused by the density instability of attractive condensates.Comment: 7 pages, 8 figures, axi-symmetric results are adde

Dynamics in online social networks

An increasing number of today's social interactions occurs using online social media as communication channels. Some online social networks have become extremely popular in the last decade. They differ among themselves in the character of the service they provide to online users. For instance, Facebook can be seen mainly as a platform for keeping in touch with close friends and relatives, Twitter is used to propagate and receive news, LinkedIn facilitates the maintenance of professional contacts, Flickr gathers amateurs and professionals of photography, etc. Albeit different, all these online platforms share an ingredient that pervades all their applications. There exists an underlying social network that allows their users to keep in touch with each other and helps to engage them in common activities or interactions leading to a better fulfillment of the service's purposes. This is the reason why these platforms share a good number of functionalities, e.g., personal communication channels, broadcasted status updates, easy one-step information sharing, news feeds exposing broadcasted content, etc. As a result, online social networks are an interesting field to study an online social behavior that seems to be generic among the different online services. Since at the bottom of these services lays a network of declared relations and the basic interactions in these platforms tend to be pairwise, a natural methodology for studying these systems is provided by network science. In this chapter we describe some of the results of research studies on the structure, dynamics and social activity in online social networks. We present them in the interdisciplinary context of network science, sociological studies and computer science.Comment: 17 pages, 4 figures, book chapte

Mean-field description of collapsing and exploding Bose-Einstein condensates

We perform numerical simulation based on the time-dependent mean-field Gross-Pitaevskii equation to understand some aspects of a recent experiment by Donley et al. on the dynamics of collapsing and exploding Bose-Einstein condensates of $^{85}$Rb atoms. They manipulated the atomic interaction by an external magnetic field via a Feshbach resonance, thus changing the repulsive condensate into an attractive one and vice versa. In the actual experiment they changed suddenly the scattering length of atomic interaction from positive to a large negative value on a pre-formed condensate in an axially symmetric trap. Consequently, the condensate collapses and ejects atoms via explosion. We find that the present mean-field analysis can explain some aspects of the dynamics of the collapsing and exploding Bose-Einstein condensates.Comment: 9 Latex pages, 10 ps and eps files, version accepted in Physical Review A, minor changes mad

Atom lasers: production, properties and prospects for precision inertial measurement

We review experimental progress on atom lasers out-coupled from Bose-Einstein condensates, and consider the properties of such beams in the context of precision inertial sensing. The atom laser is the matter-wave analog of the optical laser. Both devices rely on Bose-enhanced scattering to produce a macroscopically populated trapped mode that is output-coupled to produce an intense beam. In both cases, the beams often display highly desirable properties such as low divergence, high spectral flux and a simple spatial mode that make them useful in practical applications, as well as the potential to perform measurements at or below the quantum projection noise limit. Both devices display similar second-order correlations that differ from thermal sources. Because of these properties, atom lasers are a promising source for application to precision inertial measurements.Comment: This is a review paper. It contains 40 pages, including references and figure