Impact of dense-water flow over a sloping bottom on open-sea circulation: Laboratory experiments and an Ionian Sea (Mediterranean) example

The North Ionian Gyre (NIG) displays prominent inversions on decadal scales. We investigate the role of internal forcing induced by changes in the horizontal pressure gradient due to the varying density of Adriatic Deep Water (AdDW), which spreads into the deep layers of the northern Ionian Sea. In turn, the AdDW density fluctuates according to the circulation of the NIG through a feedback mechanism known as the bimodal oscillating system. We set up laboratory experiments with a two-layer ambient fluid in a circular rotating tank, where densities of 1000 and 1015ĝ€¯kgĝ€¯m-3 characterize the upper and lower layers, respectively. From the potential vorticity evolution during the dense-water outflow from a marginal sea, we analyze the response of the open-sea circulation to the along-slope dense-water flow. In addition, we show some features of the cyclonic and anticyclonic eddies that form in the upper layer over the slope area. We illustrate the outcome of the experiments of varying density and varying discharge rates associated with dense-water injection. When the density is high (1020ĝ€¯kgĝ€¯m-3) and the discharge is large, the kinetic energy of the mean flow is stronger than the eddy kinetic energy. Conversely, when the density is lower (1010ĝ€¯kgĝ€¯m-3) and the discharge is reduced, vortices are more energetic than the mean flow - that is, the eddy kinetic energy is larger than the kinetic energy of the mean flow. In general, over the slope, following the onset of dense-water injection, the cyclonic vorticity associated with current shear develops in the upper layer. The vorticity behaves in a two-layer fashion, thereby becoming anticyclonic in the lower layer of the slope area. Concurrently, over the deep flat-bottom portion of the basin, a large-scale anticyclonic gyre forms in the upper layer extending partly toward a sloping rim. The density record shows the rise of the pycnocline due to the dense-water sinking toward the flat-bottom portion of the tank. We show that the rate of increase in the anticyclonic potential vorticity is proportional to the rate of the rise of the interface, namely to the rate of decrease in the upper-layer thickness (i.e., the upper-layer squeezing). The comparison of laboratory experiments with the Ionian Sea is made for a situation when the sudden switch from cyclonic to anticyclonic basin-wide circulation took place following extremely dense Adriatic water overflow after the harsh winter in 2012. We show how similar the temporal evolution and the vertical structure are in both laboratory and oceanic conditions. The demonstrated similarity further supports the assertion that the wind-stress curl over the Ionian Sea is not of paramount importance in generating basin-wide circulation inversions compared with the internal forcing

Patient with neuromyelitis optica and inflammatory demyelinating lesions comprising whole spinal cord from C2 level till conus: case report

BACKGROUND: Neuromyelitis optica (NMO) is an idiopathic, severe, inflammatory demyelinating disease of the central nervous system, that causes severe optic neuritis and myelitis attacks. Early discrimination between multiple sclerosis (MS) and NMO is important, as optimum treatment for both diseases may differ considerably. ----- CASE PRESENTATION: We report a case of a patient who initially presented as longitudinally extensive transverse myelitis (LETM), having spastic upper extremities diparesis and spastic paraplegia, C2/C3 sensory level and urinary incontinence, as well as extensive inflammatory spinal cord lesions from C2 level to conus. After 5 months the patient had another attack of transverse myelitis, had electrophysiological findings consistent with optic neuritis, was seropositive for NMO-IgG (aquaporin-4 IgG) and thus fulfilled NMO diagnostic criteria. Following treatment of disease attacks with pulse corticosteroid therapy and intravenous immunoglobulins, we included oral azathioprine in a combination with oral prednisone in the therapy. Since there was no significant clinical improvement, we decided to use cyclophosphamide therapy, which resulted in good clinical improvement and gradual decrease of cord swelling. ----- CONCLUSION: In this NMO case report we wanted to emphasize the extensiveness of inflammatory spinal cord changes in our patient, from C2 level to conus. In the conclusion it is important to say that accurate, early diagnosis and distinction from MS is critical to facilitate initiation of immunosuppressive therapy for attack prevention

Learning of model discrepancy for structural dynamics applications using Bayesian history matching

Calibration of computer models for structural dynamics is often an important task in creating valid predictions that match observational data. However, calibration alone will lead to biased estimates of system parameters when a mechanism for model discrepancy is not included. The definition of model discrepancy is the mismatch between observational data and the model when the 'true' parameters are known. This will occur due to the absence and/or simplification of certain physics in the computer model. Bayesian History Matching (BHM) is a 'likelihood-free' method for obtaining calibrated outputs whilst accounting for model discrepancies, typically via an additional variance term. The approach assesses the input space, using an emulator of the complex computer model, and identifies parameter sets that could have plausibly generated the target outputs. In this paper a more informative methodology is outlined where the functional form of the model discrepancy is inferred, improving predictive performance. The algorithm is applied to a case study for a representative five storey building structure with the objective of calibrating outputs of a finite element (FE) model. The results are discussed with appropriate validation metrics that consider the complete distribution

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

Results from the Baksan Experiment on Sterile Transitions (BEST)

The Baksan Experiment on Sterile Transitions (BEST) was designed to investigate the deficit of electron neutrinos, $\nu_{e}$, observed in previous gallium-based radiochemical measurements with high-intensity neutrino sources, commonly referred to as the \textit{gallium anomaly}, which could be interpreted as evidence for oscillations between $\nu_e$ and sterile neutrino ($\nu_s$) states. A 3.414-MCi \nuc{51}{Cr} $\nu_e$ source was placed at the center of two nested Ga volumes and measurements were made of the production of \nuc{71}{Ge} through the charged current reaction, \nuc{71}{Ga}($\nu_e$,e$^-$)\nuc{71}{Ge}, at two average distances. The measured production rates for the inner and the outer targets respectively are (54.9^{+2.5}_{-2.4}(\mbox{stat})\pm1.4 (\mbox{syst})) and (55.6^{+2.7}_{-2.6}(\mbox{stat})\pm1.4 (\mbox{syst})) atoms of \nuc{71}{Ge}/d. The ratio ($R$) of the measured rate of \nuc{71}{Ge} production at each distance to the expected rate from the known cross section and experimental efficiencies are $R_{in}=0.79\pm0.05$ and $R_{out}= 0.77\pm0.05$. The ratio of the outer to the inner result is 0.97$\pm$0.07, which is consistent with unity within uncertainty. The rates at each distance were found to be similar, but 20-24\% lower than expected, thus reaffirming the anomaly. These results are consistent with $\nu_e \rightarrow \nu_s$ oscillations with a relatively large $\Delta m^2$ ($>$0.5 eV$^2$) and mixing sin$^2 2\theta$ ($\approx$0.4).Comment: Paper updated to final versio

Telerobotic Pointing Gestures Shape Human Spatial Cognition

This paper aimed to explore whether human beings can understand gestures produced by telepresence robots. If it were the case, they can derive meaning conveyed in telerobotic gestures when processing spatial information. We conducted two experiments over Skype in the present study. Participants were presented with a robotic interface that had arms, which were teleoperated by an experimenter. The robot could point to virtual locations that represented certain entities. In Experiment 1, the experimenter described spatial locations of fictitious objects sequentially in two conditions: speech condition (SO, verbal descriptions clearly indicated the spatial layout) and speech and gesture condition (SR, verbal descriptions were ambiguous but accompanied by robotic pointing gestures). Participants were then asked to recall the objects' spatial locations. We found that the number of spatial locations recalled in the SR condition was on par with that in the SO condition, suggesting that telerobotic pointing gestures compensated ambiguous speech during the process of spatial information. In Experiment 2, the experimenter described spatial locations non-sequentially in the SR and SO conditions. Surprisingly, the number of spatial locations recalled in the SR condition was even higher than that in the SO condition, suggesting that telerobotic pointing gestures were more powerful than speech in conveying spatial information when information was presented in an unpredictable order. The findings provide evidence that human beings are able to comprehend telerobotic gestures, and importantly, integrate these gestures with co-occurring speech. This work promotes engaging remote collaboration among humans through a robot intermediary.Comment: 27 pages, 7 figure

Psychosocial impact of undergoing prostate cancer screening for men with BRCA1 or BRCA2 mutations.

OBJECTIVES: To report the baseline results of a longitudinal psychosocial study that forms part of the IMPACT study, a multi-national investigation of targeted prostate cancer (PCa) screening among men with a known pathogenic germline mutation in the BRCA1 or BRCA2 genes. PARTICPANTS AND METHODS: Men enrolled in the IMPACT study were invited to complete a questionnaire at collaborating sites prior to each annual screening visit. The questionnaire included sociodemographic characteristics and the following measures: the Hospital Anxiety and Depression Scale (HADS), Impact of Event Scale (IES), 36-item short-form health survey (SF-36), Memorial Anxiety Scale for Prostate Cancer, Cancer Worry Scale-Revised, risk perception and knowledge. The results of the baseline questionnaire are presented. RESULTS: A total of 432 men completed questionnaires: 98 and 160 had mutations in BRCA1 and BRCA2 genes, respectively, and 174 were controls (familial mutation negative). Participants' perception of PCa risk was influenced by genetic status. Knowledge levels were high and unrelated to genetic status. Mean scores for the HADS and SF-36 were within reported general population norms and mean IES scores were within normal range. IES mean intrusion and avoidance scores were significantly higher in BRCA1/BRCA2 carriers than in controls and were higher in men with increased PCa risk perception. At the multivariate level, risk perception contributed more significantly to variance in IES scores than genetic status. CONCLUSION: This is the first study to report the psychosocial profile of men with BRCA1/BRCA2 mutations undergoing PCa screening. No clinically concerning levels of general or cancer-specific distress or poor quality of life were detected in the cohort as a whole. A small subset of participants reported higher levels of distress, suggesting the need for healthcare professionals offering PCa screening to identify these risk factors and offer additional information and support to men seeking PCa screening

Millimeter/Sub-Millimetre Radiotelescopes, Terrestrial and Space Considerations

Een wetenschappelijke satellite van ESA is gelanceerd, voorheen XMM genoemd en na de lancering Newton genoemd. De satellite is nog steeds in werking en heeft een interessant instrument met een lens system bestaande uit coaxiale cylindrische spiegels. Laatstgenoemde reflectoren focusseren de binnenkomende Rontgen stralen in een grazing incidence (anders gaat Rontgen straling door het material heen). Nadat een bedrijf (Media-Lario) dit soort coaxiale reflector system ontwikkeld en gebouwd hat , was het noodzakelijk om te zien of zulke hoogwaardige technologie niet voor wat anders gebruikt kon worden. Hieruit is een ontwikkeling voortgekomen om deze technologie te gebruiken voor antennes op de grond. Daaruit is een panel technologie voort gekomen (voor het eerst hierop aangestuurd door de auteur in 1999 in Astron) voor de ALMA radio telescoop antennes. Het heft tot interessante samenwerking geleid met ESO, met Dr. J. Baars die direct de positieve resultaten er van inzag). Genoemde technologie is nu terug te vinden op 25 radio telescoop antennes in het ALMA system van 50+16 radio telescopen