•Summer storms around the Mediterranean are affected by land-use changes.•Their loss leads to an accumulation mode of water vapour over the Western Basin.•Accumulated water vapour can feed Vb tracks ...and produce floods in Central Europe.•Greenhouse heating of water vapour increases Mediterranean Sea Surface Temperature.•Higher SST augments torrential rains on Mediterranean coasts and islands in autumn.
Field meteorological data collected in several European Commission projects (from 1974 to 2011) were re-analysed in the context of a perceived reduction in summer storms around the Western Mediterranean Basin (WMB). The findings reveal some hitherto overlooked processes that raise questions about direct impacts on European hydrological cycles, e.g., extreme hydrometeorological events, and about the role of feedbacks on climate models and climate predictions. For instance, the summer storms are affected by land-use changes along the coasts and mountain slopes. Their loss triggers a chain of events that leads to an Accumulation Mode (AM) where water vapour and air pollutants (ozone) become stacked in layers, up to 4000(+)m, over the WMB. The AM cycle can last 3–5consecutive days, and recur several times each month from mid May to late August. At the end of each cycle the accumulated water vapour can feed Vb track events and generate intense rainfall and summer floods in Central Europe. Venting out of the water vapour that should have precipitated within the WMB increases the salinity of the sea and affects the Atlantic-Mediterranean Salinity valve at Gibraltar. This, in turn, can alter the tracks of Atlantic Depressions and their frontal systems over Atlantic Europe. Another effect is the greenhouse heating by water vapour and photo-oxidants (e.g., O3) when layered over the Basin during the AM cycle. This increases the Sea Surface Temperature (SST), and the higher SST intensifies torrential rain events over the Mediterranean coasts in autumn. All these processes raise research questions that must be addressed to improve the meteorological forecasting of extreme events, as well as climate model predictions.
To improve predictions of the future of ecosystems in a changing world, it is necessary to consider fine-scale processes. We propose that for the Mediterranean region (a hotspot of climate change and ...biodiversity), there are three local processes that have often been overlooked in predictive models and that are key to understanding vegetation changes: rural abandonment that increases wildlands, population changes that boost fire ignitions, and coastal degradation that enhances drought. These processes are not directly driven by global warming and act in different directions (greening and browning). The current balance is still toward greening, because land abandonment is buffering the browning drivers; however, it is likely to switch with increasing warming. The challenge is to mitigate the browning processes. Given that climatic warming is not directly driving these processes, local management can make a difference in reducing the overall impact on the landscape and society.
Abstract Background Subjects at ultra high-risk (UHR) for psychosis have an enhanced vulnerability to develop the disorder but the risk factors accounting for this accrued risk are undetermined. ...Method Systematic review of associations between genetic or environmental risk factors for psychosis that are widely established in the literature and UHR state, based on comparisons to controls. Results Forty-four studies encompassing 170 independent datasets and 54 risk factors were included. There were no studies on association between genetic or epigenetic risk factors and the UHR state that met the inclusion criteria. UHR subjects were more likely to show obstetric complications, tobacco use, physical inactivity, childhood trauma/emotional abuse/physical neglect, high perceived stress, childhood and adolescent low functioning, affective comorbidities, male gender, single status, unemployment and low educational level as compared to controls. Conclusions The increased vulnerability of UHR subjects can be related to environmental risk factors like childhood trauma, adverse life events and affective dysfunction. The role of genetic and epigenetic risk factors awaits clarification.
Discovered in 1958, Earth’s radiation belts persist in being mysterious and unpredictable. This highly dynamic region of near-Earth space provides an important natural laboratory for studying the ...physics of particle acceleration. Despite the proximity of the radiation belts to Earth, many questions remain about the mechanisms responsible for rapidly energizing particles to relativistic energies there. The importance of understanding the radiation belts continues to grow as society becomes increasingly dependent on spacecraft for navigation, weather forecasting, and more. We review the historical underpinning and observational basis for our current understanding of particle acceleration in the radiation belts.
Optical Techniques for Information Security Matoba, Osamu; Nomura, Takanori; Perez-Cabre, Elisabet ...
Proceedings of the IEEE,
06/2009, Letnik:
97, Številka:
6
Journal Article, Publication
Recenzirano
Odprti dostop
This paper presents an overview of the potential of free space optical technology in information security, encryption, and authentication. Optical waveform posses many degrees of freedom such as ...amplitude, phase, polarization, spectral content, and multiplexing which can be combined in different ways to make the information encoding more secure. This paper reviews optical techniques for encryption and security of two-dimensional and three-dimensional data. Interferometric methods are used to record and retrieve data by either optical or digital holography for security applications. Digital holograms are widely used in recording and processing three dimensional data, and are attractive for securing three dimensional data. Also, we review optical authentication techniques applied to ID tags with visible and near infrared imaging. A variety of images and signatures, including biometrics, random codes, and primary images can be combined in an optical ID tag for security and authentication.
Among neurobiological mechanisms underlying antidepressant properties of ketamine, structural remodeling of prefrontal and hippocampal neurons has been proposed as critical. The suggested mechanism ...involves downstream activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, which trigger mammalian target of rapamycin (mTOR)-dependent structural plasticity via brain-derived neurotrophic factor (BDNF) and protein neo-synthesis. We evaluated whether ketamine elicits similar molecular events in dopaminergic (DA) neurons, known to be affected in mood disorders, using a novel, translational strategy that involved mouse mesencephalic and human induced pluripotent stem cells-derived DA neurons. Sixty minutes exposure to ketamine elicited concentration-dependent increases of dendritic arborization and soma size in both mouse and human cultures as measured 72 hours after application. These structural effects were blocked by mTOR complex/signaling inhibitors like rapamycin. Direct evidence of mTOR activation by ketamine was revealed by its induction of p70S6 kinase. All effects of ketamine were abolished by AMPA receptor antagonists and mimicked by the AMPA-positive allosteric modulator CX614. Inhibition of BDNF signaling prevented induction of structural plasticity by ketamine or CX614. Furthermore, the actions of ketamine required functionally intact dopamine D3 receptors (D3R), as its effects were abolished by selective D3R antagonists and absent in D3R knockout preparations. Finally, the ketamine metabolite (2R,6R)-hydroxynorketamine mimicked ketamine effects at sub-micromolar concentrations. These data indicate that ketamine elicits structural plasticity by recruitment of AMPAR, mTOR and BDNF signaling in both mouse mesencephalic and human induced pluripotent stem cells-derived DA neurons. These observations are of likely relevance to the influence of ketamine upon mood and its other functional actions in vivo.
Agomelatine behaves both as a potent agonist at melatonin MT1 and MT2 receptors and as a neutral antagonist at 5‐HT2C receptors. Accumulating evidence in a broad range of experimental procedures ...supports the notion that the psychotropic effects of agomelatine are due to the synergy between its melatonergic and 5‐hydroxytryptaminergic effects. The recent demonstration of the existence of heteromeric complexes of MT1 and MT2 with 5‐HT2C receptors at the cellular level may explain how these two properties of agomelatine translate into a synergistic action that, for example, leads to increases in hippocampal proliferation, maturation and survival through modulation of multiple cellular pathways (increase in trophic factors, synaptic remodelling, glutamate signalling) and key targets (early genes, kinases). The present review focuses on the pharmacological properties of this novel antidepressant. Its mechanism of action, strikingly different from that of conventional classes of antidepressants, opens perspectives towards a better understanding of the physiopathological bases underlying depression.
Most of over a thousand mitochondrial proteins are encoded by nuclear genes and must be imported from the cytosol. Little is known about the cytosolic events regulating mitochondrial protein import, ...partly due to the lack of appropriate tools for its assessment in living cells. We engineered an inducible biosensor for monitoring the main presequence-mediated import pathway with a quantitative, luminescence-based readout. This tool was used to explore the regulation of mitochondrial import by the PINK1 kinase-driven Parkin ubiquitin ligase, which is dysfunctional in autosomal recessive Parkinson's disease. We show that mitochondrial import was stimulated by Parkin, but not by disease-causing Parkin variants. This effect was dependent on Parkin activation by PINK1 and accompanied by an increase in the abundance of K11 ubiquitin chains on mitochondria and by ubiquitylation of subunits of the translocase of outer mitochondrial membrane. Mitochondrial import efficiency was abnormally low in cells from patients with PINK1- and PARK2-linked Parkinson's disease and was restored by phosphomimetic ubiquitin in cells with residual Parkin activity. Altogether, these findings uncover a role of ubiquitylation in mitochondrial import regulation and suggest that loss of this regulatory loop may underlie the pathophysiology of Parkinson's disease, providing novel opportunities for therapeutic intervention.
The low‐altitude, polar‐orbiting NOAA POES satellites are known to exhibit a spurious response to relativistic electrons in the proton telescope instrument of the Medium Energy Proton and Electron ...Detector (MEPED). This sensitivity has recently been used to identify relativistic electron precipitation from the radiation belts, but has heretofore remained unquantified. Monte Carlo simulations of the proton and electron telescopes were performed using the Geant4 code, and we derive the characteristic response of each instrument to isotropic proton and electron fluxes in the energy range 10 keV to 10 MeV. Geometric factors were found to agree with the nominal G ∼ 0.01 cm2sr response for target species (e.g. proton response of the proton telescope), while both telescope types also admit particles of the opposite species. The electron telescope is shown to respond to protons of energies 210–2600 keV with G ∼ 0.01 cm2sr. The proton telescope is similarly shown to exhibit a non‐negligible response to electrons, which although confined to the P1, P2, P3, and P6 energy channels, does attain an admittance of G ∼ 10−3 cm2sr near 460 keV and G ∼ 10−2 cm2sr near 1400 keV. These results confirm that the proton telescope can be used as an effective tool for detection of relativistic electron precipitation. Moreover, we suggest a method for combining the electron and proton telescope data to obtain corrected fluxes for both species which will facilitate the use of this instrument for quantitative studies of particle precipitation.
Key Points
Use of numerical modeling to quantify contamination of telescope instruments
Use of proton telescope's P6 channel as indicator of relativistic electron flux
Use of proton telescope's P6 channel to extend range of electron telescope
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