Why do people misunderstand stroke symptoms? How background knowledge affects causal attributions for ambiguous stroke symptoms.

Primary objective: People often misattribute stroke survivors' symptoms to other causes such as their personality, especially when the survivors are young. As a result, these stroke survivors experience feelings of resentment towards and from their acquaintances, and may struggle to retain employment. This study aimed to clarify how people's misattributions for stroke symptoms were affected by varying information about the stroke. Methods: Experiment 1 examined whether the stroke survivor's age (72, 32 or unstated) and the information about the person's stroke (no information, explicit stroke or implied stroke) influenced participants' causal attributions for the stroke survivor's four ambiguous symptoms, such as fatigue. Experiment 2 examined the effect of the rapidity (a week or a year) with which the symptoms appeared. Results: When the scenario explicitly referred to stroke, participants attributed the ambiguous symptoms more to stroke, whereas when it did not mention stroke, participants attributed these symptoms more to other factors. When stroke was merely implied by reference to unilateral paralysis, participants rated stroke the best explanation when the target person was 72 but not when he was 32. Experiment 2 showed that stating that the symptoms happened rapidly heightened attributions to stroke in the 72-year-old but not the 32-year-old. Conclusions: These findings show how different information about stroke survivors affect people's attributions for survivors' behaviour; this has important implications for accurate diagnosis and effective rehabilitation that targets these attributions.

Characterization of the neutron flux during production of 18F at a medical cyclotron and evaluation of the incidental neutron spectrum for neutron damage studies.

The fast neutron spectrum was measured in an irradiation position adjacent to two 18F (fluorine-18) production targets at a medical cyclotron. The neutron spectrum was modeled using MCNP6 and experimentally determined using activation foils. A three-group neutron spectrum was determined using an over-determined least squares fitting method. The MCNP6 model results and measurements of the activation foils were used as input to unfold the neutron spectrum using the STAYSL PNNL code. The neutron spectrum adjacent to the 18F production target was evaluated for use in incidental experiments to evaluate neutron-induced radiolysis of polyurethane and radiation hardness testing of electronics. The fast neutron flux near the 18F target between the energies of 0.4 - 16.5 MeV was 1.8 - 3.0x109 n cm-2s-1. The neutron dose rate in polyurethane at the irradiation position was 2.8 cGy s-1- 5.8 cGys-1. The 1 MeV equivalent neutron flux was 2.4x109 n cm-2s-1 - 4.0x109 n cm-2s-1.