The Effect of Immediacy of Expected Goal Feedback on Persistence in a Physical Task.

Minimizing the temporal gap between behavior and reward enhances persistence, but the effect of other outcomes is unknown. Two concurrently run studies aimed to investigate whether persistence on a physical task would be influenced according to whether participants expected immediate versus delayed goal feedback. Furthermore, whether this effect occurs via intrinsic motivation (Studies 1 and 2) or delaying the desire-goal conflict (Study 2) was examined. Using a counterbalanced within-person design, 34 participants in each study (Study 1: 16 males, 18 females; Study 2: 15 males, 19 females) completed two wall-sit persistence tasks, one with immediate feedback expected (regarding the participant's position on a leader board) and the other with feedback expected to be provided 1 week later. A two-way mixed analysis of variance found no significant differences in persistence between conditions in either study. Furthermore, no indirect effects were found via intrinsic motivation or delayed desire-goal conflict. Study findings did not support the hypothesis that the timing of expected feedback enhances persistence.

Psoas muscle metastatic disease mimicking a psoas abscess on imaging.

Here, we report a case of malignant psoas syndrome presented to us during the second peak of the COVID-19 pandemic. Our patient had a medical history of hypertension, recently diagnosed with left iliac deep vein thrombosis and previous breast and endometrial cancers. She presented with exquisite pain and a fixed flexion deformity of the left hip. A rim-enhancing lesion was seen within the left psoas muscle and was initially deemed to be a psoas abscess. This failed to respond to medical management and attempts at drainage. Subsequent further imaging revealed the mass was of a malignant nature; histology revealing a probable carcinomatous origin. Following diagnosis, palliative input was obtained and, unfortunately, our patient passed away in a hospice shortly after discharge. We discuss the aetiology, radiological findings and potential treatments of this condition and learning points to prompt clinicians to consider this diagnosis in those with a personal history of cancer.

The pharmaceutical prednisone affects sheepshead minnow (Cyprinodon variegatus) metabolism and swimming performance.

High usage of the synthetic glucocorticoids (GCs) has led to significant presence of this pharmaceutical group in surface waters where it can affect non-target organisms such as fish. Assessment of a fish's metabolism and swimming performance provide reliable sub-lethal measures of effects of GCs on oxygen-requiring processes and ability to swim. In this study, we determined time-dependent (7, 14 and 21 days) effects of the synthetic GC prednisone (1 µg L-1) on sheepshead minnow (SHM) (Cyprinodon variegatus). Standard (SMR), routine (RMR) and maximum (MMR) metabolic rate, metabolic scope (MS), excess post-exercise oxygen consumption (EPOC), cost of transport (COT) and critical swimming speed (Ucrit) were determined. Twenty-one days exposure to prednisone resulted in significantly higher SMR, RMR, MMR, MS, EPOC and COT compared with 7d and 14d prednisone fish. However, Ucrit was not significantly different between prednisone and solvent control exposed fish (within 7d, 14d, 21d groups). SMR, RMR and MMR were lower in the 7d and 14d prednisone exposed fish compared with their solvent control groups. In contrast, SMR, RMR and MMR were all significantly higher in the 21d prednisone exposed fish compared with solvent control. EPOC was significantly higher in 14d prednisone exposed fish and trending higher in 21d and 7d prednisone exposed fish compared with their solvent controls. EPOC was significantly higher in 21d compared with 7d prednisone exposed fish. A significantly higher COT was seen in the 21d compared with 7d and 14d prednisone fish. Collectively, this study showed time-dependent effects of prednisone on SHM metabolism and swimming performance.