1,217 research outputs found
An unclassified tibial plateau fracture: Reverse Schatzker type IV.
The most commonly accepted system of classification for tibia plateau fractures is that of Schatzker. Increasingly, both high energy injuries and atypical osteoporotic fragility failures have led to more complex, unusual and previously undescribed fracture patterns being recognized. We present a case of a patient with a previously unreported pattern of tibia plateau fracture and knee dislocation. We highlight the challenges confronted and present the management and the outcomes of his injury. A 28-year old male motorcyclist was involved in a head on collision with a truck and was transferred by helicopter to our level 1 major trauma centre emergency department. His injuries were a circumferential degloving injury to his left leg and a right lateral tibial plateau fracture/knee dislocation. The pattern of the lateral tibial plateau fracture was unique and did not fit any recognised classification system. The patient received a spanning external fixator initially and after latency of 12 days for soft tissue resuscitation he underwent definite fixation through an antero-lateral approach to the proximal tibia with two cannulated 6.5 mm partially threaded screws and an additional lateral proximal tibia plate in buttress mode. A hinged knee brace was applied with unrestricted range of motion post-operatively and free weight bearing were permitted post operatively. At the 6 months follow up, the patient walks without aids and with no limp. Examination revealed a stable joint and full range of motion. Plain radiographs revealed that the fracture healed with good alignment and the fixation remained stable. High energy injuries can lead to more complicated fracture patterns, which challenge the orthopaedic surgeons in their management. It is crucial to understand the individual fracture pattern and the possible challenges that may occur. This study reports a lateral tibia plateau fracture/dislocation which perhaps is best described as a reverse Schatzker IV type fracture
Surface electronic properties of undoped InAlN alloys
The variation in surface electronic properties of undoped c-plane InxAl1−xN alloys has been investigated across the composition range using a combination of high-resolution x-ray photoemission spectroscopy and single-field Hall effect measurements. For the In-rich alloys, electron accumulation layers, accompanied by a downward band bending, are present at the surface, with a decrease to approximately flatband conditions with increasing Al composition. However, for the Al-rich alloys, the undoped samples were found to be insulating with approximate midgap pinning of the surface Fermi level observed
Metabolomic analysis of salmonella enterica cells in vitro and in situ
In the present study a comparison of metabolomics, on laboratory medium, on rocket extract, of S. Tymphimurium (ST) CDC 6516-60, as well as on the developed biofilm on rocket tissue was investigated
Non-renormalization theorems without supergraphs: The Wess-Zumino model
The non-renormalization theorems of chiral vertex functions are derived on
the basis of an algebraic analysis. The property, that the interaction vertex
is a second supersymmetry variation of a lower dimensional field monomial, is
used to relate chiral Green functions to superficially convergent Green
functions by extracting the two supersymmetry variations from an internal
vertex and transforming them to derivatives acting on external legs. The
analysis is valid in the massive as well as in the massless model and can be
performed irrespective of properties of the superpotential at vanishing
momentum.Comment: 20 pages, Latex, added acknowledgment
Derivative expansion of quadratic operators in a general 't Hooft gauge
A derivative expansion technique is developed to compute functional
determinants of quadratic operators, non diagonal in spacetime indices. This
kind of operators arise in general 't Hooft gauge fixed Lagrangians. Elaborate
applications of the developed derivative expansion are presented.Comment: 40 pages, to appear in Phys. Rev.
The Robustness of Quintessence
Recent observations seem to suggest that our Universe is accelerating
implying that it is dominated by a fluid whose equation of state is negative.
Quintessence is a possible explanation. In particular, the concept of tracking
solutions permits to adress the fine-tuning and coincidence problems. We study
this proposal in the simplest case of an inverse power potential and
investigate its robustness to corrections. We show that quintessence is not
affected by the one-loop quantum corrections. In the supersymmetric case where
the quintessential potential is motivated by non-perturbative effects in gauge
theories, we consider the curvature effects and the K\"ahler corrections. We
find that the curvature effects are negligible while the K\"ahler corrections
modify the early evolution of the quintessence field. Finally we study the
supergravity corrections and show that they must be taken into account as
at small red-shifts. We discuss simple supergravity
models exhibiting the quintessential behaviour. In particular, we propose a
model where the scalar potential is given by . We argue that the fine-tuning problem
can be overcome if . This model leads to
for which is in good agreement with the presently
available data.Comment: 16 pages, 7 figure
Evolutionary instability of Zero Determinant strategies demonstrates that winning isn't everything
Zero Determinant (ZD) strategies are a new class of probabilistic and
conditional strategies that are able to unilaterally set the expected payoff of
an opponent in iterated plays of the Prisoner's Dilemma irrespective of the
opponent's strategy, or else to set the ratio between a ZD player's and their
opponent's expected payoff. Here we show that while ZD strategies are weakly
dominant, they are not evolutionarily stable and will instead evolve into less
coercive strategies. We show that ZD strategies with an informational advantage
over other players that allows them to recognize other ZD strategies can be
evolutionarily stable (and able to exploit other players). However, such an
advantage is bound to be short-lived as opposing strategies evolve to
counteract the recognition.Comment: 14 pages, 4 figures. Change in title (again!) to comply with Nature
Communications requirements. To appear in Nature Communication
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