1,420 research outputs found
The radial defocusing energy-supercritical cubic nonlinear wave equation in R^{1+5}
In this work, we consider the energy-supercritical defocusing cubic nonlinear
wave equation in dimension d=5 for radially symmetric initial data. We prove
that an a priori bound in the critical space implies global well-posedness and
scattering. The main tool that we use is a frequency localized version of the
classical Morawetz inequality, inspired by recent developments in the study of
the mass and energy critical nonlinear Schr\"odinger equation.Comment: AMS Latex, 20 page
E-procurement in public sector: a global overview
This paper provides a global overview of both recent developments and current initiatives in public e-procurement. The Hong Kong Government’s E-Procurement Pilot Programme will serve as a case study that will be discussed using a descriptive case study approach. A qualitative methodology is employed with findings that indicate that the development of public e-procurement is a matter of perception rather than other factors such as ITC infrastructure availability. E-procurement is underutilised in the public sector, where the majority of implemented systems are in the form of e-journal and e-tendering solutions. Concurrently, the findings also point to a growing trend in cross-border initiatives within public sectors where e-procurement is the driving force. The case study results suggest that the Hong Kong Government’s initiative is successful especially in terms of political support, adaptation of suppliers and system design. This paper provides valuable insight into the potential role of public e-procurement initiatives.postprin
Social smoking among college students in the U.S
During the college years, it can be seen that smoking, substance use, alcohol, drug use, and self-injury behaviors among young adults. While they are showing these kinds of problems, they are being affected in social, health, and financial dimensions. To stop these issues for young adults, several strategies and roadmaps are developed based on the needs of young adults from the perspective of social, and health conditions. However, there can be inadequacy in creating solutions ways if the target elements were not understood in a good way. In this case, the term ‘social smoking among college students is one of the phenomena which should be examined more closely to notice the causes of smoking among college students and overcome the negative effects of smoking them. This paper aims to handle the term social smoking with its definition and examine the process of social smoking among college students. Furthermore, it tries to identify social smokers based on their attitudes toward smoking. US college students are the focus of this paper, so several types of research, which were conducted with the participation of US college students, will be used as the resources of the paper
Rekonstruktion von Oberkieferdefekten mit einem freien Skapula-angle-Lappen
Zusammenfassung: Hintergrund: Neben der prothetischen Versorgung von Maxilladefekten gibt es Möglichkeiten der chirurgischen Rekonstruktion: die Weichgeweberekonstruktion mit einem Radialis- oder Latissimus-dorsi-Lappen und die knöcherne Rekonstruktion mittels Fibula, Beckenkamm oder Skapulalappen. Die Rekonstruktion mit einem Skapulalappen wird unterteilt in den traditionellen Skapulalappen mit der A.scapularis circumflexa und den Skapula-angle-Lappen mit der A.angularis aus der A.thoracodorsalis als versorgendem Gefäß. Material und Methoden: Wir berichten über 4Patienten, die zwischen 2009 und 2011 aufgrund von malignen Tumoren der Maxilla nach erfolgter Resektion eine Rekonstruktion mit einem freien Skapula-angle-Lappen erhalten haben. Ergebnisse: Die Möglichkeit vertikaler Positionierung des Skapula-angle-Lappens erlaubt die Rekonstruktion der fazialen Kontur. Bei horizontaler Ausrichtung des mikrovaskulär anastomosierten Skapula-angle-Lappens ist eine zusätzliche knöcherne Rekonstruktion des Gaumens möglich. Schlussfolgerung: Der Skapula-angle-Lappen eignet sich wegen seiner Variabilität, geringer Donormorbidität und aufgrund seiner Form, die der des Hartgaumens ähnelt, gut zur plastischen Rekonstruktion. Die knöcherne Beschaffenheit für eine dentale Rehabilitation mithilfe von Implantaten wird kontrovers diskutiert. Er stellt eine Alternative zur Versorgung ausgewählter Maxilladefekte ≥ GradI nach Okay mit einer Obturatorprothese da
Nonlinear Meissner Effect in CuO Superconductors
Recent theories of the NMR in the CuO superconductors are based on a
spin-singlet order parameter. Since this state has nodal lines on
the Fermi surface, nonlinear effects associated with low-energy quasiparticles
become important, particularly at low temperatures. We show that the
field-dependence of the supercurrent, below the nucleation field for vortices,
can be used to locate the positions of the nodal lines of an unconventional gap
in momentum space, and hence test the proposed state.Comment: 5 pages (RevTex), 1 figure (postscript file incl.
Comparison of three-dimensional facial morphology between upright and supine positions employing three-dimensional scanner from live subjects
Facial soft tissue thicknesses (FSTT) measurements collected from Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) imaging techniques are most commonly taken in the supine position for forensic craniofacial reconstruction. FSTT have been shown to be different in comparison to the upright position due to gravity. The variation of facial morphology between the upright and supine position of laser-scanned images taken from 44 individuals was investigated using volumetric analysis with deviation maps. Between 82.4% and 86.7% of the facial surface area were within the error range of ±2 mm between the supine and the upright position. This indicates that most anatomical landmarks taken from the MRI and CT data can be an accurate representative of the FSTT in the upright position. Seven landmarks located around the buccal region, masseteric region and the nasolabial region of the face showed the greatest FSTT deviation between the upright and supine position, thus these landmarks may affect the accuracy of facial reconstructions when using a CT or MRI database
Seismotectonic setting at the North Anatolian Fault Zone after the 1999 Mw=7.4 Izmit earthquake based on high-resolution aftershock locations
International audienceThe most recent devastating earthquakes that occurred along the North Anatolian Fault Zone (NAFZ) in northwestern Turkey were the 1999 Izmit (Mw=7.4) and Düzce (Mw=7.1) events. In this study we present a catalog of Izmit aftershock hypocenters that was deduced from a network covering the entire 140 km long rupture of the mainshock. 7348 events with a location accuracy better than 5 km are analysed. Aftershocks were observed along the entire ruptured segment along a 20 km wide band of activity. Events are clustered in distinct regions and dominantly occur at 5 to 15 km depth. The eastern termination of the Izmit rupture is characterized by a sharp and steeply dipping boundary exactly where the Düzce mainshock initiated 87 days after the Izmit event. Relocation of the events using double-difference technology results in 4696 high-resolution hypocenters that allow resolving the internal structure of the seismically active areas with a resolution of 300 m (horizontal) and 400m (vertical). Below the Akyazi Plain, representing a small pull-apart structure at a triple junction of the NAFZ, we identify planes of activity that can be correlated with nodal planes of EW extensional normal faulting aftershocks. Along the easternmost Karadere-Düzce segment we identify the down-dip extension of the Karadere fault that hosted about 1 m of right-lateral coseismic slip. At the easternmost rupture we correlate a cloud-type distribution of seismic activity with the largest aftershocks in this area, a subevent of the Izmit mainshock and the Düzce mainshock that all have an almost identical focal mechanism. This part of the NAFZ is interpreted as a classical example of a seismic barrier along the fault
Randomised field trial to evaluate serological response after foot-and-mouth disease vaccination in Turkey
AbstractDespite years of biannual mass vaccination of cattle, foot-and-mouth disease (FMD) remains uncontrolled in Anatolian Turkey. To evaluate protection after mass vaccination we measured post-vaccination antibodies in a cohort of cattle (serotypes O, A and Asia-1). To obtain results reflecting typical field protection, participants were randomly sampled from across Central and Western Turkey after routine vaccination. Giving two-doses one month apart is recommended when cattle are first vaccinated against FMD. However, due to cost and logistics, this is not routinely performed in Turkey, and elsewhere. Nested within the cohort, we conducted a randomised trial comparing post-vaccination antibodies after a single-dose versus a two-dose primary vaccination course.Four to five months after vaccination, only a third of single-vaccinated cattle had antibody levels above a threshold associated with protection. A third never reached this threshold, even at peak response one month after vaccination. It was not until animals had received three vaccine doses in their lifetime, vaccinating every six months, that most (64% to 86% depending on serotype) maintained antibody levels above this threshold. By this time cattle would be >20 months old with almost half the population below this age. Consequently, many vaccinated animals will be unprotected for much of the year. Compared to a single-dose, a primary vaccination course of two-doses greatly improved the level and duration of immunity. We concluded that the FMD vaccination programme in Anatolian Turkey did not produce the high levels of immunity required. Higher potency vaccines are now used throughout Turkey, with a two-dose primary course in certain areas.Monitoring post-vaccination serology is an important component of evaluation for FMD vaccination programmes. However, consideration must be given to which antigens are present in the test, the vaccine and the field virus. Differences between these antigens affect the relationship between antibody titre and protection
d_{x^2-y^2}-wave superconductivity and the Hubbard model
The numerical studies of d_{x^2-y^2}-wave pairing in the two-dimensional (2D)
and the 2-leg Hubbard models are reviewed. For this purpose, the results
obtained from the determinantal Quantum Monte Carlo and the density-matrix
renormalization-group calculations are presented. These are calculations which
were motivated by the discovery of the high-T_c cuprates. In this review, the
emphasis is placed on the microscopic many-body processes which are responsible
for the d_{x^2-y^2}-wave pairing correlations observed in the 2D and the 2-leg
Hubbard models. In order to gain insight into these processes, the results on
the effective pairing interaction as well as the magnetic, density and the
single-particle excitations will be reviewed. In addition, comparisons will be
made with the other numerical approaches to the Hubbard model and the numerical
results on the t-J model. The results reviewed here indicate that an effective
pairing interaction which is repulsive at (pi,pi) momentum transfer and
enhanced single-particle spectral weight near the (pi,0) and (0,pi) points of
the Brillouin zone create optimum conditions for d_{x^2-y^2}-wave pairing.
These are two effects which act to enhance the d_{x^2-y^2}-wave pairing
correlations in the Hubbard model. Finding additional ways is an active
research problem.Comment: 85 pages, 63 figures, to appear in Advances in Physics, vol. 51, no.
6 (2002
Global Multimedia Collaboration System
In order to build an integrated collaboration system over heterogeneous collaboration technologies, we propose a Global Multimedia Collaboration System (Global-MMCS) based on XGSP A/V Web-Services framework. This system can integrate multiple A/V services, and support various collaboration clients and communities. Now the prototype is being developed and deployed across many universities in USA and China
- …