A study of laser plasmas as X-ray sources in the 1-10 keV spectral region

An experimental investigation on X-ray emission from laser-produced plasmas is presented and the properties of such an emission of interest for application purposes are examined. Plasmas were generated by focusing 1 μm, 3 ns Nd laser pulses onto Al and Cu targets at an intensity of 1013 W/cm2. The temporal evolution of the emission and its spectral features were investigated by using an X-ray streak-camera and an X-ray photodiode. In the case of Cu targets, the analysis of the emission showed two spectral components. The main component was centered at ≈ 1.2 keV and a minor component, whose intensity was measured to be 10-3 of the previous component, was observed at ≈7 keV. The X-ray conversion efficiency, in the investigated spectral region, was measured to be 1% for Cu targets and 0.3% for Al targets

UAV Thermal Infrared Remote Sensing of an Italian Mud Volcano

Extreme environments like active volcanoes exhibit many difficulties in being studied by in situ techniques. For exam-ple, during eruptions, summit areas are very hard to be accessed because of logistics problems and/or volcanic hazards. The use of remote sensing techniques in the last 20 years by satellite or airborne platforms has proven their capabilities in mapping and monitoring the evolution of volcanic activity. This approach has become increasingly important, as much interest is actually focused on understanding precursory signals to volcanic eruptions. In this work we verify the use of cutting-edge technology like unmanned flying system thermally equipped for volcanic applications. We present the results of a flight test performed by INGV in collaboration with the University of Bologna (Aerospace Division) by using a multi-rotor aircraft in a hexacopter configuration. The experiment was realized in radio controlled mode to overcome many regulation problems which, especially in Italy, limit the use of this system in autonomous mode. The overall goal was not only qualitative but also quantitative oriented. The system flew above an Italian mud volcano, named Le Salinelle, located on the lower South West flank of Mt. Etna volcano, which was chosen as representative site, providing not only a discrimination between hot and cold areas, but also the corresponding temperature values. The in-flight measurements have been cross-validated with contemporaneous in-situ acquisition of thermal data and from independent measurements of mud/water temperature

Ray-tracing simulations of a bent crystal X-ray optics for imaging using laser-plasma X-ray sources

Ray-tracing simulations of an optical X-ray system based on a spherically bent crystal operating in Bragg configuration for monochromatic projection imaging of thin samples are presented, obtained using a code developed for that purpose. The code is particularly suited for characterizing experimental arrangements routinely used with laser-produced plasma X-ray sources. In particular, the spatial resolution of the imaging system was investigated and a careful study of the complex pattern of the X-ray backlighting beam was performed

Soft laser-plasma X-ray source for differential absorption imaging of tracing elements in thin samples

The differential imaging technique is particularly suitable for the detection of small concentrations of contrasts agents for biological and medical applications in samples using X-ray radiography. In this paper, we present an application of this technique using a laser-plasma soft X-ray source combined with a bent crystal. Using a Fresnel plate as a test object, we were able to obtain spatial resolutions of the order of a few tens of microns. The use of our configuration to perform differential imaging of a test-sample at the L2 edge of Br at 1,596 eV is finally demonstrated

Differences in gene expression profiles of seven target proteins in third-stage larvae of anisakis simplex (Sensu stricto) by sites of infection in blue whiting (micromesistius poutassou)

The third-stage larvae of the parasitic nematode genus Anisakis tend to encapsulate in different tissues including the musculature of fish. Host tissue penetration and degradation involve both mechanic processes and the production of proteins encoded by an array of genes. Investigating larval gene profiles during the fish infection has relevance in understanding biological traits in the parasite’s adaptive ability to cope with the fish hosts’ defense responses. The present study aimed to investigate the gene expression levels of some proteins in L3 of A. simplex (s.s.) infecting different tissues of blue whiting Micromesistius poutassou, a common fish host of the parasite in the NE Atlantic. The following genes encoding for Anisakis spp. proteins were studied: Kunitz-type trypsin inhibitor (TI), hemoglobin (hb), glycoprotein (GP), trehalase (treh), zinc metallopeptidase 13 (nas 13), ubiquitin-protein ligase (hyd) and sideroflexin 2 (sfxn 2). Significant differences in gene transcripts (by quantitative real-time PCR, qPCR) were observed in larvae located in various tissues of the fish host, with respect to the control. ANOVA analysis showed that relative gene expression levels of the seven target genes in the larvae are linked to the infection site in the fish host. Genes encoding some of the target proteins seem to be involved in the host tissue migration and survival of the parasite in the hostile target tissues of the fish host

Revisão de Trimezia Salisb. ex Herb. (Iridaceae) para o Brasil

The genus Trimezia is characterized by having herbs with low or medium size, plane or terete leaves with underground system in the form of a corm covered by spireled fibrous cataphylls. The floral morphology is vey distinctive, showing revolute internal tepal densely covered by stipes and trifide or bifide styles. The genus has a present 18 valid species and is distributed in tropical or subtropical regions of the American continent, especially in central Brazil. In this country, 13 species occur, 10 of them being endemic to Brazil and three occuring also in parts of Central America, Venezuela, Peru, Colombia, Argentina and Paraguay. Trimezia has its genetic diversity in “campos rupestres” vegetation of Minas Gerais, were nine species occur, seven of them occuring on more than one mountain, but Trimezia fistulosa is endemic of Serra do Cipó and T. plicatifolia is endemic to Serra do Cabral.O gênero Trimezia caracteriza-se por ser formado por ervas perenes de pequeno a mediano porte, com folhas planas ou cilíndricas e sistema subterrâneo na forma de um cormo alongado e coberto por catáfilos fibrosos. A morfologia floral é bastante característica por apresentar tépalas internas revolutas e densamente estriadas e estiletes cilíndricos, bífidos ou trífidos nos ápices. O gênero conta atualmente com 18 espécies validamente descritas e está distribuído nas regiões tropical e subtropical do continente americano, notadamente no Brasil Central. No Brasil, constatou-se a ocorrência de 13 espécies, sendo 10 restritas ao país e três que estendem sua área de ocorrência em parte da América Central, Venezuela, Peru, Colômbia, Argentina e Paraguai. O gênero está bem representado nas regiões Centro-Oeste e Sudeste, especialmente nos Estados de Minas Gerais, Goiás, Mato Grosso e Mato Grosso do Sul, com algumas espécies ocorrendo em São Paulo, Paraná, Rio de Janeiro, Bahia e Maranhão. Trimezia tem centro de diversidade genética nos campos rupestres de Minas Gerais, com nove espécies, com sete espécies ocorrendo em duas ou mais serras, porém T. fistulosa é endêmica da Serra do Cipó e T. plicatifolia da Serra do Cabral

Space- and time-resolved observation of extreme laser frequency upshifting during ultrafast-ionization

A 65-fs, 800-nm, 2-TW laser pulse propagating through a nitrogen gas jet has been experimentally studied by 90 Thomson scattering. Time-integrated spectra of scattered light show unprecedented broadening towards the blue which exceeds 300 nm. Images of the scattering region provide for the first time a space- and time-resolved description of the process leading quite regularly to such a large upshift. The mean shifting rate was as high as dk/dt3A ̊/fs, never observed before. Interferometry shows that it occurs after partial laser defocusing. Numerical simulations prove that such an upshift is consistent with a laser-gas late interaction, when laser intensity has decreased well below relativistic values (a0 1) and ionization process involves most of the laser pulse. This kind of interaction makes spectral tuning of ultrashort intense laser pulses possible in a large spectral range. VC 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4818602

Real-time optical manipulation of cardiac conduction in intact hearts

Optogenetics has provided new insights in cardiovascular research, leading to new methods for cardiac pacing, resynchronization therapy and cardioversion. Although these interventions have clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies do not take into account cardiac wave dynamics in real time. Here, we developed an all‐optical platform complemented by integrated, newly developed software to monitor and control electrical activity in intact mouse hearts. The system combined a wide‐field mesoscope with a digital projector for optogenetic activation. Cardiac functionality could be manipulated either in free‐run mode with submillisecond temporal resolution or in a closed‐loop fashion: a tailored hardware and software platform allowed real‐time intervention capable of reacting within 2 ms. The methodology was applied to restore normal electrical activity after atrioventricular block, by triggering the ventricle in response to optically mapped atrial activity with appropriate timing. Real‐time intraventricular manipulation of the propagating electrical wavefront was also demonstrated, opening the prospect for real‐time resynchronization therapy and cardiac defibrillation. Furthermore, the closed‐loop approach was applied to simulate a re‐entrant circuit across the ventricle demonstrating the capability of our system to manipulate heart conduction with high versatility even in arrhythmogenic conditions. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time optically based stimulation can control cardiac rhythm in normal and abnormal conditions, promising a new approach for the investigation of the (patho)physiology of the heart

Multi-GeV Electron Spectrometer

The advance in laser plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1pC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction of such a device. We will present the design considerations for this spectrometer and the first results from a prototype.Comment: 7 pages, 6 figures, submitted to NIM