59 research outputs found
Operative Treatment of an Atypical Segmental Bipolar Fracture of the Clavicle
Introduction: Clavicle fractures are very common, accounting for approximately 4% of all adult fractures. Segmental bipolar fractures involving the lateral and the medial ends of the clavicle are extremely rare, with only isolated cases reported in the literature. The injury mechanism is often unclear and the management of these fractures remains controversial.
Case presentation: Here is to report a case of a segmental bipolar fracture of the clavicle with a lateral fracture and a displaced medial fracture without dislocation of the sternoclavicular joint following a low energy fall to the outstretched hand, and discuss its management.
Conclusions: Stability of the clavicle is crucial for shoulder function and care should be taken not to miss or underestimate segmental bipolar fractures even with a low energy mechanism. Authors believe that operative treatment should be taken into consideration for displaced fractures
Late recognized vascular injury after high-energy fracture of the proximal tibia: a pitfall to know in current practice
Failure to recognize associated soft-tissue injuries after high-energy proximal tibia fractures is not uncommon. Despite the progress in managing these complex injuries, a prompt diagnosis of associated arterial injuries still remains difficult. A high index of suspicion for arterial damages is nevertheless mandatory in these severe fractures. Treatment protocols have been developed to reduce the previously reported high rates of amputation and permit an optimal management of soft-tissue and an acceptable functional outcome. We report here a well-documented case of a severely displaced proximal tibia fracture that illustrates the problem of diagnosing and managing the associated vascular injuries
The domain wall spin torque-meter
We report the direct measurement of the non-adiabatic component of the
spin-torque in domain walls. Our method is independent of both the pinning of
the domain wall in the wire as well as of the Gilbert damping parameter. We
demonstrate that the ratio between the non-adiabatic and the adiabatic
components can be as high as 1, and explain this high value by the importance
of the spin-flip rate to the non-adiabatic torque. Besides their fundamental
significance these results open the way for applications by demonstrating a
significant increase of the spin torque efficiency.Comment: 12 pages plus supplementary note
Spatially periodic domain wall pinning potentials: Asymmetric pinning and dipolar biasing
Domain wall propagation has been measured in continuous, weakly disordered,
quasi-two-dimensional, Ising-like magnetic layers that are subject to spatially
periodic domain wall pinning potentials. The potentials are generated
non-destructively using the stray magnetic field of ordered arrays of
magnetically hard [Co/Pt] nanoplatelets which are patterned above and are
physically separated from the continuous magnetic layer. The effect of the
periodic pinning potentials on thermally activated domain wall creep dynamics
is shown to be equivalent, at first approximation, to that of a uniform,
effective retardation field, , which acts against the applied field,
. We show that depends not only on the array geometry but also on
the relative orientation of and the magnetization of the nanoplatelets. A
result of the latter dependence is that wall-mediated hysteresis loops obtained
for a set nanoplatelet magnetization exhibit many properties that are normally
associated with ferromagnet/antiferromagnet exchange bias systems. These
include a switchable bias, coercivity enhancement and domain wall roughness
that is dependent on the applied field polarity.Comment: 12 pages, 9 figure
How to Adapt to Changing Markets: Experience and Personality in a Repeated Investment Game
Investment behavior is traditionally investigated with the assumption that it is on average advantageous to invest. However, this may not always be the case. In this paper, we experimentally studied investment choices made by students and financial professionals facing alternately an advantageous and disadvantageous environment in a multi-round investment game. Expected returns from investment in the advantageous environment were higher than a safe alternative, while expected returns were lower in the disadvantageous environment.
We investigate how experience and personality are related to choices. Investment behavior does not differ dependent on expected returns and professionals do not significantly differ from students. Personality predicts behavior and in particular we observe that openness to experience was an asset in unfavorable markets, leading to reduced risk taking
Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection
International audienceModern computing technology is based on writing, storing and retrieving information encoded as magnetic bits. Although the giant magnetoresistance effect has improved the electrical read out of memory elements, magnetic writing remains the object of major research efforts. Despite several reports of methods to reverse the polarity of nanosized magnets by means of local electric fields and currents, the simple reversal of a high-coercivity, single-layer ferromagnet remains a challenge. Materials with large coercivity and perpendicular magnetic anisotropy represent the mainstay of data storage media, owing to their ability to retain a stable magnetization state over long periods of time and their amenability to miniaturization. However, the same anisotropy properties that make a material attractive for storage also make it hard to write to. Here we demonstrate switching of a perpendicularly magnetized cobalt dot driven by in-plane current injection at room temperature. Our device is composed of a thin cobalt layer with strong perpendicular anisotropy and Rashba interaction induced by asymmetric platinum and AlOx interface layers. The effective switching field is orthogonal to the direction of the magnetization and to the Rashba field. The symmetry of the switching field is consistent with the spin accumulation induced by the Rashba interaction and the spin-dependent mobility observed in non-magnetic semiconductors as well as with the torque induced by the spin Hall effect in the platinum layer. Our measurements indicate that the switching efficiency increases with the magnetic anisotropy of the cobalt layer and the oxidation of the aluminium layer, which is uppermost, suggesting that the Rashba interaction has a key role in the reversal mechanism. To prove the potential of in-plane current switching for spintronic applications, we construct a reprogrammable magnetic switch that can be integrated into non-volatile memory and logic architectures. This device is simple, scalable and compatible with present-day magnetic recording technolog
The effects of acute tryptophan depletion on costly information sampling: impulsivity or aversive processing?
RATIONALE: The neurotransmitter serotonin (5-HT) has been implicated in both aversive processing and impulsivity. Reconciling these accounts, recent studies have demonstrated that 5-HT is important for punishment-induced behavioural inhibition. These studies focused on situations where actions lead directly to punishments. However, decision-making often involves making tradeoffs between small 'local' costs and larger 'global' losses. OBJECTIVE: We aimed to distinguish whether 5-HT promotes avoidance of local losses, global losses, or both, in contrast to an overall effect on reflection impulsivity. We further examined the influence of individual differences in sub-clinical depression, anxiety and impulsivity on global and local loss avoidance. METHODS: Healthy volunteers (N = 21) underwent an acute tryptophan depletion procedure in a double-blind, placebo-controlled crossover design. We measured global and local loss avoidance in a decision-making task where subjects could sample information at a small cost to avoid making incorrect decisions, which resulted in large losses. RESULTS: Tryptophan depletion removed the suppressive effects of small local costs on information sampling behaviour. Sub-clinical depressive symptoms produced effects on information sampling similar to (but independent from) those of tryptophan depletion. Dispositional anxiety was related to global loss avoidance. However, trait impulsivity was unrelated to information sampling. CONCLUSIONS: The current findings are consistent with recent theoretical work that characterises 5-HT as pruning a tree of potential decisions, eliminating options expected to lead to aversive outcomes. Our results extend this account by proposing that 5-HT promotes reflexive avoidance of relatively immediate aversive outcomes, potentially at the expense of more globally construed future losses
Decision making as a predictor of first ecstasy use: a prospective study
Ecstasy (+/- 3,4-methylenedioxymethamphetamine) is a widely used recreational drug that may damage the serotonin system and may entail neuropsychological dysfunctions. Few studies investigated predictors for ecstasy use. Self-reported impulsivity does not predict the initiation of ecstasy use; the question is if neuropsychological indicators of impulsivity can predict first ecstasy use. This study tested the hypothesis that a neuropsychological indicator of impulsivity predicts initiation of ecstasy use. Decision-making strategy and decision-making reaction times were examined with the Iowa Gambling Task in 149 ecstasy-naive subjects. The performance of 59 subjects who initiated ecstasy use during a mean follow-up period of 18 months (range, 11-26) was compared with the performance of 90 subjects that remained ecstasy-naive. Significant differences in decision-making strategy between female future ecstasy users and female persistent ecstasy-naive subjects were found. In addition, the gap between decision-making reaction time after advantageous choices and reaction time after disadvantageous choices was smaller in future ecstasy users than in persistent ecstasy-naives. Decision-making strategy on a gambling task was predictive for future use of ecstasy in female subjects. Differences in decision-making time between future ecstasy users and persistent ecstasy-naives may point to lower punishment sensitivity or higher impulsivity in future ecstasy users. Because differences were small, the clinical relevance is questionabl
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