534 research outputs found
Fabrication and heating rate study of microscopic surface electrode ion traps
We report heating rate measurements in a microfabricated gold-on-sapphire
surface electrode ion trap with trapping height of approximately 240 micron.
Using the Doppler recooling method, we characterize the trap heating rates over
an extended region of the trap. The noise spectral density of the trap falls in
the range of noise spectra reported in ion traps at room temperature. We find
that during the first months of operation the heating rates increase by
approximately one order of magnitude. The increase in heating rates is largest
in the ion loading region of the trap, providing a strong hint that surface
contamination plays a major role for excessive heating rates. We discuss data
found in the literature and possible relation of anomalous heating to sources
of noise and dissipation in other systems, namely impurity atoms adsorbed on
metal surfaces and amorphous dielectrics.Comment: 17 pages, 5 figure
Invasive infections with a coagulase-negative staphylococcus in an immunocompromised patient: case report and review of the literature
Resistance of subarctic soil fungal and invertebrate communities to disruption of below-ground carbon supply
The supply of recent photosynthate from plants to soils is thought to be a critical mechanism regulating the activity and diversity of soil biota. In the Arctic, large-scale vegetation transitions are underway in response to warming, and there is an urgent need to understand how these changes affect soil biodiversity and function. We investigated how abundance and diversity of soil fungi and invertebrates responded to a reduction in fresh below-ground photosynthate supply in treeline birch and willow, achieved using stem girdling. We hypothesised that birch forest would support greater abundance of ectomycorrhizal (ECM) fungal species and fauna than willow shrubs, and that girdling would result in a rapid switch from ECM fungi to saprotrophs as canopy supply of C was cut, with a concomitant decline in soil fauna. Birch forest had greater fungal and faunal abundance with a large contribution of root-associated ascomycetes (ericoid mycorrhizal fungi and root endophytes) compared to willow shrub plots, which had a higher proportion of saprotrophs and, contrary to our expectations, ECM fungi. Broad-scale soil fungal and faunal functional group composition was not significantly changed by girdling, even in the third year of treatment. Within the ECM community, there were some changes, with genera that are believed to be particularly C-demanding declining in girdled plots. However, it was notable how most ECM fungi remained present after 3 years of isolation of the below-ground compartment from contemporary photosynthate supply. Synthesis. In a treeline/tundra ecosystem, distinct soil communities existed in contrasting vegetation patches within the landscape, but the structure of these communities was resistant to canopy disturbance and concomitant reduction of autotrophic C inputs
The simulation of the activity dependent neural network growth
It is currently accepted that cortical maps are dynamic constructions that
are altered in response to external input. Experience-dependent structural
changes in cortical microcurcuts lead to changes of activity, i.e. to changes
in information encoded. Specific patterns of external stimulation can lead to
creation of new synaptic connections between neurons. The calcium influxes
controlled by neuronal activity regulate the processes of neurotrophic factors
released by neurons, growth cones movement and synapse differentiation in
developing neural systems. We propose a model for description and investigation
of the activity dependent development of neural networks. The dynamics of the
network parameters (activity, diffusion of axon guidance chemicals, growth cone
position) is described by a closed set of differential equations. The model
presented here describes the development of neural networks under the
assumption of activity dependent axon guidance molecules. Numerical simulation
shows that morpholess neurons compromise the development of cortical
connectivity.Comment: 10 pages, 2 figure
Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis
OBJECTIVESThe incidence of congenital heart disease is approximately 50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery.METHODSOur perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome.RESULTSBefore propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events.CONCLUSIONSAfter propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery
Drinking water temperature around the globe: Understanding, policies, challenges and opportunities
Water temperature is often monitored at water sources and treatment works; however, there is limited monitoring of the water temperature in the drinking water distribution system (DWDS), despite a known impact on physical, chemical and microbial reactions which impact water quality. A key parameter influencing drinking water temperature is soil temperature, which is influenced by the urban heat island effects. This paper provides critique and comprehensive summary of the current knowledge, policies and challenges regarding drinking water temperature research and presents the findings from a survey of international stakeholders. Knowledge gaps as well as challenges and opportunities for monitoring and research are identified. The conclusion of the study is that temperature in the DWDS is an emerging concern in various countries regardless of the water source and treatment, climate conditions, or network characteristics such as topology, pipe material or diameter. More research is needed, especially to determine (i) the effect of higher temperatures, (ii) a legislative limit on temperature and (iii) measures to comply with this limit
Daratumumab monotherapy in refractory warm autoimmune hemolytic anemia and cold agglutinin disease
Autoimmune hemolytic anemia (AIHA) is a rare autoantibody-mediated disease. For steroid and/or rituximab-refractory AIHA, there is no consensus on optimal treatment. Daratumumab, a monoclonal antibody targeting CD38, could be beneficial by suppression of CD38+ plasma cells and thus autoantibody secretion. In addition, because CD38 is also expressed by activated T cells, daratumumab may also act via immunomodulatory effects. We evaluated the efficacy and safety of daratumumab monotherapy in an international retrospective study including 19 adult patients with heavily pretreated refractory AIHA. In warm AIHA (wAIHA, n = 12), overall response was 50% with a median response duration of 5.5 months (range, 2-12), including ongoing response in 2 patients after 6 and 12 months. Of 6 nonresponders, 4 had Evans syndrome. In cold AIHA (cAIHA, n = 7) overall hemoglobin (Hb) response was 57%, with ongoing response in 3 of 7 patients. One additional patient with nonanemic cAIHA was treated for severe acrocyanosis and reached a clinical acrocyanosis response as well as a Hb increase. Of 6 patients with cAIHA with acrocyanosis, 4 had improved symptoms after daratumumab treatment. In 2 patients with wAIHA treated with daratumumab, in whom we prospectively collected blood samples, we found complete CD38+ T-cell depletion after daratumumab, as well as altered T-cell subset differentiation and a severely diminished capacity for cell activation and proliferation. Reappearance of CD38+ T cells coincided with disease relapse in 1 patient. In conclusion, our data show that daratumumab therapy may be a treatment option for refractory AIHA. The observed immunomodulatory effects that may contribute to the clinical response deserve further exploration.</p
The European Marine Observation and Data Network (EMODnet): Visions and roles of the gateway to marine data in Europe
Marine data are needed for many purposes: for acquiring a better scientific understanding of the marine environment, but also, increasingly, as marine knowledge for decision making as well as developing products and services supporting economic growth. Data must be of sufficient quality to meet the specific users' needs. It must also be accessible in a timely manner. And yet, despite being critical, this timely access to known-quality data proves challenging. Europe's marine data have traditionally been collected by a myriad of entities with the result that much of our data are scattered throughout unconnected databases and repositories. Even when data are available, they are often not compatible, making the sharing of the information and data aggregation particularly challenging. In this paper, we present how the European Marine Observation and Data network (EMODnet) has developed over the last decade to tackle these issues. Today, EMODnet is comprised of more than 150 organizations which gather marine data, metadata, and data products and make them more easily accessible for a wider range of users. EMODnet currently consists of seven sub-portals: bathymetry, geology, physics, chemistry, biology, seabed habitats, and human activities. In addition, Sea-basin Checkpoints have been established to assess the observation capacity in the North Sea, Mediterranean, Atlantic, Baltic, Artic, and Black Sea. The Checkpoints identify whether the observation infrastructure in Europe meets the needs of users by undertaking a number of challenges. To complement this, a Data Ingestion Service has been set up to tackle the problem of the wealth of marine data that remain unavailable, by reaching out to data holders, explaining the benefits of sharing their data and offering a support service to assist them in releasing their data and making them available through EMODnet. The EMODnet Central Portal (www.emodnet.eu) provides a single point of access to these services, which are free to access and use. The strategic vision of EMODnet in the next decade is also presented, together with key focal areas toward a more user-oriented service, including EMODnet for business, internationalization for global users, and stakeholder engagement to connect the diverse communities across the marine knowledge value chain
Introduction, establishment and expansion of the Pacific oyster Crassostrea gigas in the Oosterschelde (SW Netherlands)
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