204 research outputs found
The European Union’s Changing Approach towards Multilateralism. EU Diplomacy Paper 08/2017
In this paper I analyse in how far the 2016 EU Global Strategy (EUGS) has changed the
European Union (EU)’s approach towards multilateralism compared to the approach
under its predecessor, the 2003 European Security Strategy (ESS). I identify three major
innovations: First, while the EUGS incorporates the EU’s long-standing commitment to
‘effective multilateralism’, its approach of ‘effective global governance’ goes
beyond that earlier approach and represents a qualitatively different concept.
Second, the EUGS transcends the ESS in terms of emphasising the need to transform
rather than just to preserve the multilateral system. Third, the EUGS neglects traditional
‘strategic partnerships’ and expands the EU’s partnership approach towards
engaging with a wider range of actors in a more pragmatic way. In a second step, I
discuss the shortcomings of the new approach, which need to be addressed in the
EUGS’s second year of implementation for which multilateralism has been chosen as
a priority area. They include political and conceptual issues concerning the
engagement with non-state actors and emerging powers as well as an unresolved
dilemma in which individual EU member states must give up power to prevent the
erosion of their collective influence and of the multilateral system at large
Effects of Pole Walking on Older Adults Following Six Weeks of Training
Introduction: Age-related changes in adults over 60 include reduced mobility and function as well as an increase in frailty. Conventional walking has been shown to be an effective physical activity to maintain mobility and improve function and overall health and fitness. Specifically, walking speed has been identified as a crucial predicting factor for fall risk and decreased functional mobility. For this reason, clinicians considered the element of walking speed as the sixth vital sign. Pole walking has gained popularity over the years and may provide additional benefits, when compared to conventional walking, such as improved stride and step length, faster gait velocity and cadence, increased strength, enhanced postural alignment, advanced dynamic balance, weight loss, and improved cardiovascular responses following exercise.
Purpose: The purpose of this study is to determine the effects of pole walking on overall physical functioning of community-ambulators 60 years of age and older.
Methods: Eleven healthy older adults participated and completed pre- and post-participation fitness screens and surveys. The fitness screen included implementation of the Senior Fitness Test (SFT) battery, gait analysis through use of the GAITRite, and posture images. Each individual was provided and fit with walking poles and received general instruction on walking technique. All subjects participated in the experimental group, completing 45-minute exercise sessions, consisting of warm-up, pole walking, and cool down, two times per week, for six weeks.
Results: Data analysis consisted of paired t-tests (a = 0.05) to identify comparisons throughout SFT tests, posture, and gait parameters. Significant improvements were identified within the 30-second chair stand test, 2-minute step test, heart rate, posture, and weight, as well as gait parameters including: step length, gait velocity, cadence, and degree of toe-in/out.
Conclusion: Based on the evidence provided, it can be concluded that, in healthy older adults, pole walking can improve lower extremity strength, endurance, enhance posture, decrease weight, and improve multiple gait parameters. It may be hypothesized that other populations with pathologies, that inhibit the efficiency of gait, could reap the benefits that regular pole walking provides and experience substantial improvements regarding parameters as discussed within this study population. Pole walking is applicable and appropriate to a wide array of individuals and provides a motivating and optimistic mindset that encourages physical therapy patients to be an active participant in their care and improve their quality of life
K^- ^3He and K^+K^- interactions in the pd -> ^3He K^+K^- reaction
We investigate the K^- ^3He and K^+ K^- interactions in the reaction pd ->
^3He K^+ K^- near threshold and compare our model calculations with data from
the MOMO experiment at COSY-Juelich. A large attractive effective K^- p
amplitude would give a significant K^- ^3He final-state interaction effect
which is not supported by the experimental data. We also estimate upper limits
for the a_0(980) and f_0(980) contributions to the produced K^+ K^- pairs.Comment: 5 pages, 2 figures, accepted for publication in PR
Enhanced spin-orbit coupling in core/shell nanowires
The spin-orbit coupling (SOC) in semiconductors is strongly influenced by
structural asymmetries, as prominently observed in bulk crystal structures that
lack inversion symmetry. Here, we study an additional effect on the SOC: the
asymmetry induced by the large interface area between a nanowire core and its
surrounding shell. Our experiments on purely wurtzite GaAs/AlGaAs core/shell
nanowires demonstrate optical spin injection into a single free-standing
nanowire and determine the effective electron g-factor of the hexagonal GaAs
wurtzite phase. The spin relaxation is highly anisotropic in time-resolved
micro-photoluminescence measurements on single nanowires, showing a significant
increase of spin relaxation in external magnetic fields. This behavior is
counterintuitive compared to bulk wurtzite crystals. We present a model for the
observed electron spin dynamics highlighting the dominant role of the
interface-induced SOC in these core/shell nanowires. This enhanced SOC may
represent an interesting tuning parameter for the implementation of
spin-orbitronic concepts in semiconductor-based structures
Map Matching for Semi-Restricted Trajectories
We consider the problem of matching trajectories to a road map, giving particular consideration to trajectories that do not exclusively follow the underlying network. Such trajectories arise, for example, when a person walks through the inner part of a city, crossing market squares or parking lots. We call such trajectories semi-restricted. Sensible map matching of semi-restricted trajectories requires the ability to differentiate between restricted and unrestricted movement. We develop in this paper an approach that efficiently and reliably computes concise representations of such trajectories that maintain their semantic characteristics. Our approach utilizes OpenStreetMap data to not only extract the network but also areas that allow for free movement (as e.g. parks) as well as obstacles (as e.g. buildings). We discuss in detail how to incorporate this information in the map matching process, and demonstrate the applicability of our method in an experimental evaluation on real pedestrian and bicycle trajectories
Ultra-low-noise Microwave to Optics Conversion in Gallium Phosphide
Mechanical resonators can act as excellent intermediaries to interface single
photons in the microwave and optical domains due to their high quality factors.
Nevertheless, the optical pump required to overcome the large energy difference
between the frequencies can add significant noise to the transduced signal.
Here we exploit the remarkable properties of thin-film gallium phosphide to
demonstrate on-chip microwave-to-optical conversion, realised by piezoelectric
actuation of a Gigahertz-frequency optomechanical resonator. The large
optomechanical coupling and the suppression of two-photon absorption in the
material allows us to operate the device at optomechanical cooperativities
greatly exceeding one, and, when using a pulsed upconversion pump, induce less
than one thermal noise phonon. We include a high-impedance on-chip matching
resonator to mediate the mechanical load with the 50-Ohm source. Our results
establish gallium phosphide as a versatile platform for ultra-low-noise
conversion of photons between microwave and optical frequencies
Technical Report Scintigraphic Evaluation of Bone Formation in Göttingen Minipigs
In experiments and processes requiring the application of nuclear tracers in large animals, statutory provisions and safety standards as well as a variety of techniques have to be regarded and employed. In order to sufficiently analyze questions pertaining to osseointegration as well as the possibility of ectopic bone formation in Göttingen minipigs, we decided to use scintigraphic examinations using 99mTc-HDP (Technetium - hydroxymethane diphosphonate). In this study, metallic implants coated in different forms with rhBMP-2 (recombinant human bone morphogenetic protein-2) were surgically introduced into the pigs’ femora. A total of 26 adult female minipigs (Ellegard, Dalmose, Denmark) averaging 40 months in age were post-surgically evaluated through the application of a radionuclide and its subsequent distribution using a scintillation camera. Each animal received approximately 10 MBq/kg BW (mega Becquerel per kilogram bodyweight). This paper describes the procedures of anaesthesia, the quite challenging transvaginal- urethral catheterization, the application of a catheter in the jugular vein, the radionuclide injection and the disposal of the sacrificed animals under statutory provisions and safety standards. The technical report reveals that the scintigraphic evaluation in large animal experiments is a practicable – yet sophisticated – method of examination and also strives to encourage further research groups to implement this elegant procedure.
Glacial Discharge and its Impact on Phytoplankton Taxonomic Composition in an Antarctic Fjord
The influence of glacial discharge on phytoplankton community composition remains an open question. The Antarctic Peninsula fjords offer an ideal system to understand the effect of ice-ocean forcing on phytoplankton community, providing an extreme in the spatial gradient from the glacio-marine boundary to the Western Antarctic Peninsula (WAP) continental shelf. In Andvord Bay, we found that glacial meltwater input altered surface salinity and was enriched in dissolved iron and nitrate, supporting phytoplankton biomass. The three major groups of phytoplankton fueled by glacial input were: cryptophytes, diatoms, and a group of unidentified small flagellates. In December, cryptophytes dominated the phytoplankton community and were correlated with relatively warmer temperatures in the surface layer; in addition, contrary to our hypothesis, no diatom bloom was observed in the fjord in spite of dissolved iron concentration >1 nM. By April, after the growth season, the overall phytoplankton abundance had decreased by an order of magnitude. Phytoplankton, in particular diatoms, were then limited by daytime length despite abundant macro-nutrient and iron concentrations. Mixed flagellates emerged as the dominant group during April due to the decline of other major taxa. Deep-learning algorithms for predicting the abundance of each major phytoplankton group captured the effects of these environmental factors on the phytoplankton community. Our results show that the fjord, under the influence of glacial meltwater, has relatively high phytoplankton biomass combined with high macro- and trace nutrient concentrations when compared to other WAP regions influenced by sea ice melting. Based on this study, we confirm that flagellates can be the dominant taxon in Antarctic fjords and we propose that iron concentration alone is insufficient to predict diatom growth. Furthermore, buoyant meltwater plumes can enrich the fjord with nitrate even if the main circulation is not driven by glacier meltwater discharge. As glacial meltwater continues to alter the phytoplankton taxonomic composition, it will have an important implication for higher trophic levels and add significant uncertainties to the prediction of regional ecosystem dynamics and biogeochemistry.Fil: Jack Pan, B.. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Vernet, Maria. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Manck, Lauren. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Forsch, Kiefer. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Ekern, Lindsey. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Mascioni, Martina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División FicologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata; ArgentinaFil: Barbeau, Katherine. University of California at San Diego. Scripps Institution of Oceanography; Estados UnidosFil: Almandoz, Gaston Osvaldo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División FicologÃa; ArgentinaFil: Orona, Alexander James. Ocean Motion Technologies; Estados UnidosOcean Sciences Meeting 2020Estados UnidosOcean Sciences Meetin
Seasonal Dispersal of Fjord Meltwaters as an Important Source of Iron and Manganese to Coastal Antarctic Phytoplankton
Glacial meltwater from the western Antarctic Ice Sheet is hypothesized to be an important source of cryospheric iron, fertilizing the Southern Ocean, yet its trace-metal composition and factors that control its dispersal remain poorly constrained. Here we characterize meltwater iron sources in a heavily glaciated western Antarctic Peninsula (WAP) fjord. Using dissolved and particulate ratios of manganese to iron in meltwaters, porewaters, and seawater, we show that surface glacial melt and subglacial plumes contribute to the seasonal cycle of iron and manganese within a fjord still relatively unaffected by climate-change-induced glacial retreat. Organic ligands derived from the phytoplankton bloom and the glaciers bind dissolved iron and facilitate the solubilization of particulate iron downstream. Using a numerical model, we show that buoyant plumes generated by outflow from the subglacial hydrologic system, enriched in labile particulate trace metals derived from a chemically modified crustal source, can supply iron to the fjord euphotic zone through vertical mixing. We also show that prolonged katabatic wind events enhance export of meltwater out of the fjord. Thus, we identify an important atmosphere–ice–ocean coupling intimately tied to coastal iron biogeochemistry and primary productivity along the WAP
Microwave-to-optics conversion using a mechanical oscillator in its quantum groundstate
Conversion between signals in the microwave and optical domains is of great
interest both for classical telecommunication, as well as for connecting future
superconducting quantum computers into a global quantum network. For quantum
applications, the conversion has to be both efficient, as well as operate in a
regime of minimal added classical noise. While efficient conversion has been
demonstrated using mechanical transducers, they have so far all operated with a
substantial thermal noise background. Here, we overcome this limitation and
demonstrate coherent conversion between GHz microwave signals and the optical
telecom band with a thermal background of less than one phonon. We use an
integrated, on-chip electro-opto-mechanical device that couples surface
acoustic waves driven by a resonant microwave signal to an optomechanical
crystal featuring a 2.7 GHz mechanical mode. We initialize the mechanical mode
in its quantum groundstate, which allows us to perform the transduction process
with minimal added thermal noise, while maintaining an optomechanical
cooperativity >1, so that microwave photons mapped into the mechanical
resonator are effectively upconverted to the optical domain. We further verify
the preservation of the coherence of the microwave signal throughout the
transduction process
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