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Laser–solid interactions are highly suited as a potential source of high energy X-rays for nondestructive imaging. A bright, energetic X-ray pulse can be driven from a small source, making it ideal for high resolution X-ray radiography. By limiting the lateral dimensions of the target we are able to confine the region over which X-rays are produced, enabling imaging with enhanced resolution and contrast. Using constrained targets we demonstrate experimentally a
X-ray source, improving the image quality compared to unconstrained foil targets. Modelling demonstrates that a larger sheath field envelope around the perimeter of the constrained targets increases the proportion of electron current that recirculates through the target, driving a brighter source of X-rays.
Objectives: To summarize the clinical characteristics and outcomes of pediatric sports-related concussion (SRC) patients who were evaluated and managed at a multidisciplinary pediatric concussion program and examine the healthcare resources and personnel required to meet the needs of this patient population. Methods: We conducted a retrospective review of all pediatric SRC patients referred to the Pan Am Concussion Program from September 1st, 2013 to May 25th, 2015. Initial assessments and diagnoses were carried out by a single neurosurgeon. Return-to-Play decision-making was carried out by the multidisciplinary team. Results: 604 patients, including 423 pediatric SRC patients were evaluated at the Pan Am Concussion Program during the study period. The mean age of study patients was 14.30 years (SD: 2.32, range 7-19 years); 252 (59.57%) were males. Hockey (182; 43.03%) and soccer (60; 14.18%) were the most commonly played sports at the time of injury. Overall, 294 (69.50%) of SRC patients met the clinical criteria for concussion recovery, while 75 (17.73%) were lost to follow-up, and 53 (12.53%) remained in active treatment at the end of the study period. The median duration of symptoms among the 261 acute SRC patients with complete follow-up was 23 days (IQR: 15, 36). Overall, 25.30% of pediatric SRC patients underwent at least one diagnostic imaging test and 32.62% received referral to another member of our multidisciplinary clinical team. Conclusion: Comprehensive care of pediatric SRC patients requires access to appropriate diagnostic resources and the multidisciplinary collaboration of experts with national and provincially-recognized training in TBI.
Monitoring species’ response in marine protected areas is important for informing both the management of those areas and the establishment of additional protected areas. Populations of spiny lobsters Jasus edwardsii were monitored in eight New Zealand marine reserves for up to 34 years. The populations displayed highly variable responses to protection. While a few showed rapid (within 1–2 years of protection) increases in abundance, others showed little response even after a decade of protection. Some reserves displayed little initial recovery, then a sudden increase following several years of protection, while others displayed significant declines in abundance following initial recovery. Marine reserves located in areas with initially high densities of juveniles tended to have rapid recovery, but aspects of reserve design had no significant influence on the recovery rate. Variability among recovery trajectories also suggests that supply-side dynamics may be a key driver of lobster recovery. Densities of legal-sized lobsters were positively correlated with reserve age, but the abundance of juvenile lobsters increased in all but one reserve, indicating enhanced recruitment, survival and/or movement of juvenile lobsters into reserves. It is important to consider the placement of reserves, with respect to potential levels of larval supply, when establishing marine reserves for either conservation or fisheries management purposes and for evaluating their effectiveness.
This chapter discusses three classes of theories: information-processing theories that build on modular elements, network theories that focus on the distributed access of conscious processing, and globalist theories that combine aspects of these two. It also discusses cognitive or functional models of consciousness with less reference to the burgeoning neuroscientific evidence that increasingly supports the globalist position. Beginning in the 1980s, a number of experimental methods gained currency as means of studying comparable conscious and non-conscious processes. The metaphor of cognitive architectures dates to the 1970s when cognitive psychologists created information-processing models of mental processes. The general position is that consciousness operates as a distributed and flexible system offering nonconscious expert systems global accessibility to information that has a high concurrent value to the organism. Future work should focus on obtaining neuroscientific evidence and corresponding behavioral observations that can address global access as the distinguishing feature of consciousness.
This book defines management mistakes and offers a variety of models to classify and interpret them. It describes the evolution of management mistakes, techniques for identifying and disclosing mistakes, the relationship between management and medical mistakes, and steps to prevent and correct mistakes. Six case studies, drawn from a real set of events in healthcare organizations, describe management mistakes and are followed by commentaries by experts in the field of healthcare management. They indicate steps that might have produced more positive outcomes. Ultimately, managers will not be completely successful in making healthcare better and more cost-effective without viewing mistakes as learning opportunities. This book is written for healthcare managers throughout the world and for the benefit of their patients, staff and communities.
An emotion-modulated acoustic startle paradigm for inducing
positive and negative affect was used to address pregoal and
postgoal affect. Participants played a computerized lottery
task in which they chose digits that could match a subsequently
displayed, random set of numbers. In the positive conditions,
matches led to monetary rewards. In the negative condition,
matches led to an aversive noise blast. In three experiments,
we found eyeblink startle magnitude was potentiated just prior
to feedback concerning reward outcome, suppressed following
the feedback that a monetary reward was won, and potentiated
when threatened with an aversive noise. When presented with
a 0%, 45%, 90%, or 100% chance of winning, higher probabilities
suppressed startle response after feedback whereas the 45% trials
did not. These data indicate that postgoal positive affect (winning
reward) reliably suppressed the startle response whereas pregoal
positive affect did not.
The cellular mechanisms that underlie the initiation and propagation of the peristaltic contractions, which transport urine from the kidney to the bladder for storage, remain little understood. Extracellular and intracellular microelectrode recordings have identified two populations of smooth muscle cells as well as a population of renal interstitial cells (RICs) that all display spontaneous electrical activity. By analogy with the heart it has been proposed that atypical smooth muscle cells, preferentially located in the very proximal regions of the renal pelvis, generate the essential pacemaker signal. These pacemaker potentials propagate to neighbouring typical smooth muscle cells or RICs to trigger action potential discharge. These action potentials then propagate distally to trigger other bundles of typical smooth muscle cells. The frequency of action potential discharge and contraction decreases as the relative number of RICs and atypical smooth muscle cells compared to typical smooth muscle cells decreases with distance from the renal fornix. It is clear that functional capsaicin-sensitive sensory afferents and the endogenous release of both tachykinins and prostaglandins are essential in the maintenance of normal peristalsis, as well as in monitoring and responding to any chemical or mechanical stimulation. However, the cellular mechanisms underlying the action of these endogenously-released agents remain to be elucidated. Experimental Physiology (2002) 87.2, 129-146.
The present study was undertaken to determine whether aversiveness
contributes to startle potentiation in anticipation of affective
pictures above and beyond the effects of emotional arousal.
Further, participants high in trait anxious apprehension, which
is characterized by worry about the future, were expected to
show especially pronounced anticipatory startle responses. Startle
blink reflex was measured during warning stimuli that predicted
the valence of ensuing aversive/unpleasant, pleasant, or neutral
pictures. Startle magnitude was larger in anticipation of aversive
than of pleasant pictures and smallest in anticipation of neutral
pictures. Enhanced startle potentiation was not found in anxious
apprehension subjects. These data suggest that the aversive
nature of stimuli contribute to the potentiation of startle
above and beyond the effects of emotional arousal, which may
be a universal phenomenon not modulated by individual differences.