Visually driven analysis of movement data by progressive clustering

The paper investigates the possibilities of using clustering techniques in visual exploration and analysis of large numbers of trajectories, that is, sequences of time-stamped locations of some moving entities. Trajectories are complex spatio-temporal constructs characterized by diverse non-trivial properties. To assess the degree of (dis)similarity between trajectories, specific methods (distance functions) are required. A single distance function accounting for all properties of trajectories, (1) is difficult to build, (2) would require much time to compute, and (3) might be difficult to understand and to use. We suggest the procedure of progressive clustering where a simple distance function with a clear meaning is applied on each step, which leads to easily interpretable outcomes. Successive application of several different functions enables sophisticated analyses through gradual refinement of earlier obtained results. Besides the advantages from the sense-making perspective, progressive clustering enables a rational work organization where time-consuming computations are applied to relatively small potentially interesting subsets obtained by means of ‘cheap’ distance functions producing quick results. We introduce the concept of progressive clustering by an example of analyzing a large real data set. We also review the existing clustering methods, describe the method OPTICS suitable for progressive clustering of trajectories, and briefly present several distance functions for trajectories

Magnetic Helicity Generation from the Cosmic Axion Field

The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about |H_B| \simeq (10^{-20} G)^2 kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.Comment: 6 pages, 2 figures. Accepted for publication in Phys. Rev. D. Minor revisions and new references adde

Foundation Pattern, Productivity and Colony Success of the Paper Wasp, Polistes versicolor

Polistes versicolor (Olivier) (Hymenoptera: Vespidae) colonies are easily found in anthropic environments; however there is little information available on biological, ecological and behavioral interactions of this species under these environmental conditions. The objective of this work was to characterize the foundation pattern, the productivity, and the success of colonies of P. versicolor in anthropic environments. From August 2003 to December 2004, several colonies were studied in the municipal district of Juiz de Fora, Southeastern Brazil. It was possible to determine that before the beginning of nest construction the foundress accomplishes recognition flights in the selected area, and later begins the construction of the peduncle and the first cell. As soon as new cells are built, the hexagonal outlines appear and the peduncle is reinforced. Foundation of nests on gypsum plaster was significantly larger (p < 0.0001; χ2 test) in relation to the other types of substrate, revealing the synantropism of the species. On average, the P. versicolor nest presents 244.2 ± 89.5 (100–493) cells and a medium production of 171.67 ± 109.94 (37–660) adults. Cells that produced six individuals were verified. Usually, new colonies were founded by an association of females, responsible for the success of 51.5%. Although these results enlarge knowledge on the foundation pattern of P. versicolor in anthropic environments, other aspects of the foundation process require further investigation

A Note on the Cosmic Evolution of the Axion in a Strong Magnetic Field

It has been pointed out in the literature that in the presence of an external magnetic field the axion mass receives an electromagnetic contribution. We show that if a magnetic field with energy density larger than ~10^{-8} times the energy density of the Universe existed at temperatures of a few GeV, that contribution would be dominant and consequently the cosmic evolution of the axion field would change substantially. In particular, the expected axion relic abundance would be lowered, allowing a small relaxation of the present cosmological bound on the Peccei-Quinn constant.Comment: 2 pages, no figures. Minor changes. References added. Accepted for publication in JCA

The quantum cryptographic switch

We illustrate using a quantum system the principle of a cryptographic switch, in which a third party (Charlie) can control to a continuously varying degree the amount of information the receiver (Bob) receives, after the sender (Alice) has sent her information. Suppose Charlie transmits a Bell state to Alice and Bob. Alice uses dense coding to transmit two bits to Bob. Only if the 2-bit information corresponding to choice of Bell state is made available by Charlie to Bob can the latter recover Alice's information. By varying the information he gives, Charlie can continuously vary the information recovered by Bob. The performance of the protocol subjected to the squeezed generalized amplitude damping channel is considered. We also present a number of practical situations where a cryptographic switch would be of use.Comment: 7 pages, 4 Figure

A combination of celecoxib and glucosamine sulfate has anti-inflammatory and chondroprotective effects: results from an in vitro study on human osteoarthritic chondrocytes

This study investigated the possible anti-inflammatory and chondroprotective effects of a combination of celecoxib and prescription-grade glucosamine sulfate (GS) in human osteoarthritic (OA) chondrocytes and their possible mechanism of action. Chondrocytes were treated with celecoxib (1.85 M) and GS (9 M), alone or in combination with IL-1b (10 ng/mL) and a specific nuclear factor (NF)- B inhibitor (BAY-11-7082, 1 M). Gene expression and release of some pro-inflammatory mediators, metalloproteinases (MMPs), and type II collagen (Col2a1) were evaluated by qRT-PCR and ELISA; apoptosis and mitochondrial superoxide anion production were assessed by cytometry; B-cell lymphoma (BCL)2, antioxidant enzymes, and p50 and p65 NF- B subunits were analyzed by qRT-PCR. Celecoxib and GS alone or co-incubated with IL-1b significantly reduced expression and release of cyclooxygenase (COX)-2, prostaglandin (PG)E2, IL-1b, IL-6, tumor necrosis factor (TNF)-a, and MMPs, while it increased Col2a1, compared to baseline or IL-1b. Both drugs reduced apoptosis and superoxide production; reduced the expression of superoxide dismutase, catalase, and nuclear factor erythroid; increased BCL2; and limited p50 and p65. Celecoxib and GS combination demonstrated an increased inhibitory effect on IL-1b than that observed by each single treatment. Drugs effects were potentiated by pre-incubation with BAY-11-7082. Our results demonstrated the synergistic effect of celecoxib and GS on OA chondrocyte metabolism, apoptosis, and oxidative stress through the modulation of the NF- B pathway, supporting their combined use for the treatment of OA

Vector Bosons in the Randall-Sundrum 2 and Lykken-Randall models and unparticles

Unparticle behavior is shown to be realized in the Randall-Sundrum 2 (RS 2) and the Lykken-Randall (LR) brane scenarios when brane-localized Standard Model currents are coupled to a massive vector field living in the five-dimensional warped background of the RS 2 model. By the AdS/CFT dictionary these backgrounds exhibit certain properties of the unparticle CFT at large N_c and strong 't Hooft coupling. Within the RS 2 model we also examine and contrast in detail the scalar and vector position-space correlators at intermediate and large distances. Unitarity of brane-to-brane scattering amplitudes is seen to imply a necessary and sufficient condition on the positivity of the bulk mass, which leads to the well-known unitarity bound on vector operators in a CFT.Comment: 60 pages, 8 figure

Analysis of CGF biomolecules, structure and cell population: Characterization of the stemness features of CGF cells and osteogenic potential

Concentrated Growth Factors (CGF) represent new autologous (blood-derived biomaterial), attracting growing interest in the field of regenerative medicine. In this study, the chemical, structural, and biological characterization of CGF was carried out. CGF molecular characterization was performed by GC/MS to quantify small metabolites and by ELISA to measure growth factors and matrix metalloproteinases (MMPs) release; structural CGF characterization was carried out by SEM analysis and immunohistochemistry; CGF has been cultured, and its primary cells were isolated for the identification of their surface markers by flow cytometry, Western blot, and real-time PCR; finally, the osteogenic differentiation of CGF primary cells was evaluated through matrix mineralization by alizarin red staining and through mRNA quantification of osteogenic differentiation markers by real-time PCR. We found that CGF has a complex inner structure capable of influencing the release of growth factors, metabolites, and cells. These cells, which could regulate the production and release of the CGF growth factors, show stem features and are able to differentiate into osteoblasts producing a mineralized matrix. These data, taken together, highlight interesting new perspectives for the use of CGF in regenerative medicine

The Future of Our Seas: Marine scientists and creative professionals collaborate for science communication

To increase awareness of the current challenges facing the marine environment, the Future of Our Seas (FOOS) project brought together the expertise of scientists, public engagement experts and creatives to train and support a group of marine scientists in effective science communication and innovative public engagement. This case study aims to inspire scientists and artists to use the FOOS approach in training, activity design and development support (hereafter called the ‘FOOS programme’) to collaboratively deliver novel and creative engagement activities. The authors reflect on the experiences of the marine scientists: (1) attending the FOOS communication and engagement training; (2) creating and delivering public engagement activities; (3) understanding our audience; and (4) collaborating with artists. The authors also share what the artists and audiences learned from participating in the FOOS public engagement activities. These different perspectives provide new insights for the field with respect to designing collaborative training which maximizes the impact of the training on participants, creative collaborators and the public. Long-term benefits of taking part in the FOOS programme, such as initiating future collaborative engagement activities and positively impacting the scientists’ research processes, are also highlighted