Fourmis d'Espagne et autres espèces paléarctiques (Hymenopt.)

Les fourmis qui font le principal objet de cette étude ont été récoltées en Espagne et en Portugal par M. Dusmet, de 1919 à 1922, étude que d'autres occupations m'ont empêché d'entreprendre plus tôt. J' y ai ajouté la description d'autres fourmis paléarctiques qui me paraissent nouvelles. Sauf indications spéciales, toutes les espèces citées ici sont donc dues à M. Dusmet à qui j'adresse ici mes meilleurs remerciernents 1, ainsi qu'à mes autres correspondants dont les envois m'ont permis le présent travail.Peer reviewe

How to prevent overdiagnosis

Overdiagnosis is the diagnosis of an abnormality that is not associated with a substantial health hazard and that patients have no benefit to be aware of. It is neither a misdiagnosis (diagnostic error), nor a false positive result (positive test in the absence of a real abnormality). It mainly results from screening, use of increasingly sensitive diagnostic tests, incidental findings on routine examinations, and widening diagnostic criteria to define a condition requiring an intervention. The blurring boundaries between risk and disease, physicians' fear of missing a diagnosis and patients' need for reassurance are further causes of overdiagnosis. Overdiagnosis often implies procedures to confirm or exclude the presence of the condition and is by definition associated with useless treatments and interventions, generating harm and costs without any benefit. Overdiagnosis also diverts healthcare professionals from caring about other health issues. Preventing overdiagnosis requires increasing awareness of healthcare professionals and patients about its occurrence, the avoidance of unnecessary and untargeted diagnostic tests, and the avoidance of screening without demonstrated benefits. Furthermore, accounting systematically for the harms and benefits of screening and diagnostic tests and determining risk factor thresholds based on the expected absolute risk reduction would also help prevent overdiagnosis

Surface-to-volume ratio controls the radiation of stratified plasmonic antennas

Surface plasmons are excited at a metal/dielectric interface, through the coupling between conduction electrons and incident photons. The surface plasmon generation is therefore strongly determined by the accessibility of the surface to the incoming electromagnetic field. We demonstrate the role of this surface for plasmonic nanoantennas with identical volumes and resonant lengths. An antenna is stratified parallel to the plane of its main dipolar resonance axis and the influence of the number of layers and the spacing between them on the optical properties of the antenna are investigated experimentally. We show that increasing the number of layers and, hence, increasing the total accessible surface of the antenna, results in an enhanced scattering cross section and a redshift which indicates that lower energy photons are required to couple to the metal electrons. In particular, the far-field enhancement observed for double-layer nanostructures suggests that standard single-layer metal deposition can be easily and advantageously substituted with metal/dielectric/metal deposition to boost light scattered by a plasmonic antenn

Methods for analyzing the concentration and speciation of major and trace elements in marine particles

Particles influence trace element and isotope (TEI) cycles through both their elemental composition and fate and their role on the partitioning of dissolved elements through scavenging and dissolution. Because of their complex compositions, a diverse suite of methods is required to analyze marine particles. Here we review some of the varied approaches used to study particle composition, speciation and fate. We focus on high throughput analytical methods that are useful for the international GEOTRACES program, and we also describe new spectroscopic techniques that are now being applied to study the spatial distribution and chemical speciation of TEIs in marine particles

Trapping and Sensing 10 nm Metal Nanoparticles Using Plasmonic Dipole Antennas

The Optical trapping of Au nanoparticles with dimensions as small as 10 nm in the gap of plasmonic dipole antennas is demonstrated. Single nanoparticle trapping events are recorded in real time by monitoring the Rayleigh scattering spectra of individual plasmonic antennas. Numerical simulations are also performed to interpret the experimental results, indicating the possibility to trap nanoparticles only a few nanometers in size. This work unveils the potential associated with the integration of plasmonic trapping with localized surface plasmon resonance based sensing techniques, in order to deliver analyte to specific, highly sensitive regions ("hot spots")

Coupling Strength Can Control the Polarization Twist of a Plasmonic Antenna

The far-field polarization of the optical response of a plasmonic antenna can be tuned by subtly engineering of its geometry. In this paper, we develop design rules for nano antennas which enable the generation of circular polarized light via the excitation of circular plasmonic modes in the structure. Two initially orthogonal plasmonic modes are coupled in such a way that a rotational current is excited in the structure. Modifying this coupling strength from a weak to a strong regime controls the helicity of the scattered field. Finally, we introduce an original sensing approach that relies on the rotation of the incident polarization and demonstrates a sensitivity of 0.23 deg·nm -1 or 33 deg·RIU-1, related to changes of mechanical dimensions and the refractive index, respectively. © 2013 American Chemical Society

Census politics in deeply divided societies

Population censuses in societies that are deeply divided along ethnic, religious or linguistic lines can be sensitive affairs – particularly where political settlements seek to maintain peace through the proportional sharing of power between groups. This brief sets out some key findings from a research project investigating the relationship between census politics and the design of political institutions in Bosnia and Herzegovina, Kenya, Lebanon and Northern Ireland

Ultrasensititve system for the real time detection of H2O2 based on strong coupling in a bio-plasmonic system

We theoretically investigate the dependence of the different parameters of an optical biosensor for the detection of Hydrogen peroxide (H2O2) based on absorption enhancement of Cytochrome c molecules near gold nanoparticles. H2O2 is a major reactive oxygen species which is involved in signaling pathways and oxidative stress in cells. We use the Green's function approach as well as confirm the corresponding simulation results using the surface integral formulation. Further we show that this technique can be applied for detection of other small molecules, like oxygen and carbon monoxide

Biophotonic tool for sensing the dynamics of H2O2 extracellular release in stressed cells

Hydrogen peroxide (H2O2) is known to play a multifaceted role in cell physiology mechanisms involving oxidative stress and intracellular signal transduction. Therefore, the development of analytical tools providing information on the dynamics of H2O2 generation remains of utmost importance to achieve further insight in the complex physiological processes of living cells and their response to environmental stress(1). In the present work we developed a novel optic biosensor that provides continuous real-time quantification of the dynamics of the hydrogen peroxide release from cells under oxidative stress conditions. The biosensor is based on the ultra-sensitive dark field optical detection of cytochrome c (cyt c) that exhibits a narrow absorption peaks in its reduced state (Fe(II)) at lambda = 550 nm. In the presence of H2O2 the ferrous heme group Fe(II) is oxidised into Fe(III) providing the spectroscopic information exploited in this approach. Extremely low limit-of-detection for H2O2 down to the subnanomolar range is achieved by combining scattering substrates (eg. polystyrene beads) able to shelter cyt c and an inverted microscope in dark field configuration. The developed biosensor was able to perform real-time detection of H2O (2) extracellular release from human promyelocytic leukemia cells (HL-60) exposed to lipopolysaccaride (LPS) that elicits strong immune-response. This biosensing tool is currently being implemented to the real-time detection of superoxide anion (O-2(center dot-)) and offers the possibility to extend to further oxidative stress biomarkers such as glutathione. More generally, multianalyte and dynamic informations might bring new insights to understand complex cellular metabolisms involved in oxidative-stress-related diseases and cytotoxic responses