Enhancement of rare-earth--transition-metal exchange interaction in Pr2_{2}Fe17_{17} probed by inelastic neutron scattering

The fundamental magnetic interactions of Pr$_{2}$Fe$_{17}$ are studied by inelastic neutron scattering and anisotropy field measurements. Data analysis confirms the presence of three magnetically inequivalent sites, and reveals an exceptionally large value of the exchange field. The unexpected importance of $J$-mixing effects in the description of the ground-state properties of Pr$_{2}$Fe$_{17}$ is evidenced, and possible applications of related compounds are envisaged.Comment: 4 RevTeX pages, 4 EPS figures. Accepted for publication by Appl. Phys. Lett. (will be found at http://apl.aip.org

Regionalism and changing regional order in the Pacific Islands

Institutional developments in Pacific Islands regionalism have been dramatic in recent years. These include the changing role of the Parties to the Nauru Agreement, a grouping of eight ‘tuna-rich’ Pacific Island states that is transforming the dynamics of regional fisheries; the emergence of a more activist Melanesian Spearhead Group, which comprises the four largest economies of the Pacific Islands and is leading the process of regional economic integration; and the establishment of the Pacific Islands Development Forum, which promises a more inclusive ‘regionalism through partnerships’ approach in addressing climate change and sustainable development issues. This new dynamism is driven by the discontent of a growing number of island states with the established regional order,defined by prevailing institutions, power and ideas, and by a desire to assert greater control over their own futures. Against the backdrop of an increasingly dynamic geopolitical and geoeconomic landscape, Pacific Island states are using alternative regional frameworks to develop new approaches to the challenges facing them

Transmission of Information in Active Networks

Shannon's Capacity Theorem is the main concept behind the Theory of Communication. It says that if the amount of information contained in a signal is smaller than the channel capacity of a physical media of communication, it can be transmitted with arbitrarily small probability of error. This theorem is usually applicable to ideal channels of communication in which the information to be transmitted does not alter the passive characteristics of the channel that basically tries to reproduce the source of information. For an {\it active channel}, a network formed by elements that are dynamical systems (such as neurons, chaotic or periodic oscillators), it is unclear if such theorem is applicable, once an active channel can adapt to the input of a signal, altering its capacity. To shed light into this matter, we show, among other results, how to calculate the information capacity of an active channel of communication. Then, we show that the {\it channel capacity} depends on whether the active channel is self-excitable or not and that, contrary to a current belief, desynchronization can provide an environment in which large amounts of information can be transmitted in a channel that is self-excitable. An interesting case of a self-excitable active channel is a network of electrically connected Hindmarsh-Rose chaotic neurons.Comment: 15 pages, 5 figures. submitted for publication. to appear in Phys. Rev.

The activated torsion oscillation magnetometer

The activated torsion oscillation magnetometer exploits the mechanical resonance of a cantilever beam, driven by the torque exerted on the sample by an ac field applied perpendicularly to the film plane. We describe a model for the cantilever dynamics which leads to the calculation of the cantilever dynamic profile and allows the mechanical sensitivity of the instrument to be expressed in terms of the minimum electronically detectable displacement. We have developed a capacitance detector of small oscillations which is able to detect displacements of the order of 0.1 nm. We show that sensitivities of the order of 0.5(10-11 Am2 can be in principle achieved. We will subsequently describe the main features of the ATOM prototype which we have built and tested, with particular attention to the design solutions which have been adopted in order to reduce the effects of parasitic vibrations due either to acoustic noise, originating from the ac field coil, or to eddy currents in the capacitor electrodes. The instrument is mounted in a continuous flow cryostat and can work in the 4.2-300 K temperature range. Finally, we will show that our experimental set-up has a second mode of operation, named Torsion Induction Magnetometer (TIM).Comment: Invited Talk at the Moscow International Symposium on Magnetism, 2002 to appear in the J. Mag. Mag. Mat Revised versio

Phase diagram and magnetocaloric effect of CoMnGe_{1-x}Sn_{x} alloys

We propose the phase diagram of a new pseudo-ternary compound, CoMnGe_{1-x}Sn_{x}, in the range x less than or equal to 0.1. Our phase diagram is a result of magnetic and calometric measurements. We demonstrate the appearance of a hysteretic magnetostructural phase transition in the range x=0.04 to x=0.055, similar to that observed in CoMnGe under hydrostatic pressure. From magnetisation measurements, we show that the isothermal entropy change associated with the magnetostructural transition can be as high as 4.5 J/(K kg) in a field of 1 Tesla. However, the large thermal hysteresis in this transition (~20 K) will limit its straightforward use in a magnetocaloric device.Comment: 12 pages, 5 figure

Topical application of chlorhexidine gel with brush-on technique in the tailored treatment of plaque induced gingivitis

Aim: This study aimed to assess the action of a chlorhexidine-based brush-on gel application in the treatment of plaque-related gingivitis. Methods: The enrollment involved consecutive patients diagnosed with plaque-induced gingivitis. Each participant's full mouth plaque score and gingival index were recorded at the first appointment (t0) and at follow ups after 1 week (t1), 2 weeks (t2) and 3 weeks (t4). All patients were randomly sorted into two groups: A study group, who was given instruction to brush their gums daily with a chlorhexidine gel, and a control group who received a placebo gel. The two groups' data at baseline were compared using a chi-square test, while the t-Student and Mann-Whitney tests were employed to analyze the index's trends, both separately and compared. Results: In total, 30 patients were enrolled, 15 referring to the study group and 15 to the control group. The study group had an 87% decrease in their plaque score and an 84% decrease in their gingival index (p < 0.05). The control group displayed a reduction in plaque score and gingival index of 74% and 84%, respectively (p < 0.05). The plaque score decreased statistically more significantly in the study group than in the control group. Conclusion: Topical employment of a chlorhexidine-containing brush-on gel appears to be a useful home tool in the treatment of plaque-induced gingivitis, associated with professional debridement

Ancient Documents Denoising and Decomposition Using Aujol and Chambolle Algorithm

With the improvement of printing technology since the 15th century, there is a huge amount of printed documents published and distributed. These documents are degraded by the time and require to be preprocessed before being submitted to image indexing strategy, in order to enhance the quality of images. This paper proposes a new pre-processing that permits to denoise these documents, by using a Aujol and Chambolle algorithm. Aujol and Chambolle algorithm allows to extract meaningful components from image. In this case, we can extract shapes, textures and noise. Some examples of specific processings applied on each layer are illustrated in this paper

Bleeding from gastrointestinal angioectasias is not related to bleeding disorders - a case control study

n/aOriginal Publication:Charlotte M Hoog, Olle Brostrom, Tomas Lindahl, Andreas Hillarp, Gerd Larfars and Urban Sjoqvist, Bleeding from gastrointestinal angioectasias is not related to bleeding disorders - a case control study, 2010, BMC GASTROENTEROLOGY, (10), 113.http://dx.doi.org/10.1186/1471-230X-10-113Licensee: BioMed Centralhttp://www.biomedcentral.com