Avatars or agents are digitized self-representations of a player in mediated environments. While using agents to navigate through mediated environments, players form bonds with their self-agents or ...characters, a process referred to as identification. Identification can involve automatic, but temporary, self-concept “shifts in implicit self-perceptions” (Klimmt et al.,
2010
, p. 323) of the media user by adopting or emphasizing the action choices on behalf of the social expectation of the avatar in the mediated environment. In the current study, we test the possibility that users' identification with video game avatars–a bond built between avatars and players- would account for subsequent behavior changes. We did so by using 3-month longitudinal data involving a narratively-based serious game: Socially Optimized Learning in Virtual Environments (SOLVE), a 3D-interactive game designed to reduce risky sexual behaviors among young men who have sex with men (
n
= 444). Results show that video game identification predicts both the reduction of risky sexual behaviors over time, and reduction in the number of non-primary partners with whom risky sex occurs. And when players identify with the game character, they tend to make healthier choices, which significantly mediates the link between video game identification and reduction of risky behaviors.
Observation of growing phase space density (PSD) peak in the outer electron radiation belt has been considered evidence for local wave‐driven acceleration as a primary cause of radiation belt ...enhancement. However, recent studies showed that strong substorm‐associated MeV electron injections can also cause significant radiation belt enhancements on fast timescales (∼10s min). Such rapid enhancements pose challenges for determining true spatial PSD profiles. To address this, we conduct a detailed spatiotemporal analysis of electron flux and PSD during an enhancement event, using Van Allen Probes data. Our analysis reveals rapid and intermittent flux enhancements. During these rapid enhancements, inbound spacecraft observed false PSD peaks, due to spacecraft's relatively slow movement. However, we identify time intervals of stable fluxes between enhancements, enabling us to determine quasi‐stationary PSD profiles with no noticeable peaks. This study provides new insights into accurate PSD analysis, critical for understanding the mechanisms underlying radiation belt enhancements.
Plain Language Summary
Radiation belt physics studies the origin and dynamics of high‐energy electrons trapped in the Earth's radiation belts. The radial profiles of these electrons' phase space density (PSD) are essential parameters for investigating their origin and dynamics. Outward‐increasing PSD profiles indicate that electrons have been transported radially (injections) from outside the radiation belt, while locally peaked profiles suggest that they were generated locally within the belt. Obtaining accurate PSD profiles is challenging due to significant temporal changes in electron flux, particularly rapid flux enhancements from injections as observed in recent studies. To examine the impact of rapid flux enhancements on PSD analysis, we closely tracked electron flux changes in space and time during an enhancement event using data from NASA's Van Allen Probes. Our results show that inbound spacecraft can observe falsely peaked PSD profiles during rapid flux enhancements, which are temporal artifacts from relatively slower spacecraft motion. By identifying time intervals of stable electron flux between enhancements, we were able to determine the true spatial PSD profiles, which overall exhibited outward‐increasing trends, consistent with injections. Our findings offer new perspective on accurately determining PSD radial profiles, which is essential for unraveling the origins of high‐energy electrons in the Earth's radiation belts.
Key Points
Rapid and intermittent electron enhancement pattern significantly impacts phase space density (PSD) analysis
Inbound spacecraft can observe a temporal PSD peak during rapid electron enhancements driven by injections
Quasi‐stationary time intervals between enhancements enable accurate determination of PSD radial profiles
This study sought to identify culprit lesion (CL) precursors among acute coronary syndrome (ACS) patients based on qualitative and quantitative computed tomography–based plaque characteristics.
...Coronary computed tomography angiography (CTA) has been validated for patient-level prediction of ACS. However, the applicability of coronary CTA to CL assessment is not known.
Utilizing the ICONIC (Incident COroNary Syndromes Identified by Computed Tomography) study, a nested case-control study of 468 patients with baseline coronary CTA, the study included ACS patients with invasive coronary angiography–adjudicated CLs that could be aligned to CL precursors on baseline coronary CTA. Separate blinded core laboratories adjudicated CLs and performed atherosclerotic plaque evaluation. Thereafter, the study used a boosted ensemble algorithm (XGBoost) to develop a predictive model of CLs. Data were randomly split into a training set (80%) and a test set (20%). The area under the receiver-operating characteristic curve of this model was compared with that of diameter stenosis (model 1), high-risk plaque features (model 2), and lesion-level features of CL precursors from the ICONIC study (model 3). Thereafter, the machine learning (ML) model was applied to 234 non-ACS patients with 864 lesions to determine model performance for CL exclusion.
CL precursors were identified by both coronary angiography and baseline coronary CTA in 124 of 234 (53.0%) patients, with a total of 582 lesions (containing 124 CLs) included in the analysis. The ML model demonstrated significantly higher area under the receiver-operating characteristic curve for discriminating CL precursors (0.774; 95% confidence interval CI: 0.758 to 0.790) compared with model 1 (0.599; 95% CI: 0.599 to 0.599; p < 0.01), model 2 (0.532; 95% CI: 0.501 to 0.563; p < 0.01), and model 3 (0.672; 95% CI: 0.662 to 0.682; p < 0.01). When applied to the non-ACS cohort, the ML model had a specificity of 89.3% for excluding CLs.
In a high-risk cohort, a boosted ensemble algorithm can be used to predict CL from non-CL precursors on coronary CTA.
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This study was designed to examine whether mesenchymal stem cells (MSCs) transduced with Akt enhance cardiac repair after transplantation into the ischemic porcine heart.
MSCs isolated from porcine ...bone marrow and transduced with myr-Akt were transplanted into porcine hearts after experimental myocardial infarction (MI) using intracoronary injection Group I, vehicle; Group II, MSCs; Group III, Akt-MSCs. Myocardial single photon emission tomography (M-SPECT) was performed to assess myocardial function and the infarcted area. Pigs were also sacrificed for immunohistochemical characterization and histologic analysis. In addition, in vitro assays were performed to examine the resistance of Akt-MSCs to H(2)O(2) stimulation.
Transplantation of MSCs into the ischemic porcine myocardium (Group II) increased the left ventricular ejection fraction (DeltaLV EF; -6.3 +/- 15.1% versus 0.5 +/- 6.4%, P < 0.001) and decreased the Deltaarea of MI (6.8+/-5.6% versus -5.0+/-5.3%, P < 0.001) compared with the vehicle control (Group I). Transplantation of MSCs transduced with myr-Akt (Group III) resulted in further improvement in DeltaLV EF (-6.3 +/- 15.1% versus 5.8 +/- 11.3%, P < 0.001) and in Deltaarea of MI (6.8 +/- 5.6% versus -17.0 +/- 7.6%, P < 0.001). Akt-MSCs were more resistant to apoptosis, and the levels of extracellular signal-regulated protein kinase (ERK) activation and vascular endothelial growth factor (VEGF) were higher in H(2)O(2)-stimulated Akt-MSCs.
Cellular transplantation of Akt-MSCs further enhances the repair of injured myocardium compared to MSC transplantation alone by increasing the number of viable MSCs after cellular transplantation.
The aim of this study was to define robust benchmark values for the surgical treatment of perihilar cholangiocarcinomas (PHC) to enable unbiased comparisons.
Despite ongoing efforts, postoperative ...mortality and morbidity remains high after complex liver surgery for PHC. Benchmark data of best achievable results in surgical PHC treatment are however still lacking.
This study analyzed consecutive patients undergoing major liver surgery for PHC in 24 high-volume centers in 3 continents over the recent 5-year period (2014-2018) with a minimum follow-up of 1 year in each patient. Benchmark patients were those operated at high-volume centers (≥50 cases during the study period) without the need for vascular reconstruction due to tumor invasion, or the presence of significant co-morbidities such as severe obesity (body mass index ≥35), diabetes, or cardiovascular diseases. Benchmark cutoff values were derived from the 75th or 25th percentile of the median values of all benchmark centers.
Seven hundred eight (39%) of a total of 1829 consecutive patients qualified as benchmark cases. Benchmark cut-offs included: R0 resection ≥57%, postoperative liver failure (International Study Group of Liver Surgery): ≤35%; in-hospital and 3-month mortality rates ≤8% and ≤13%, respectively; 3-month grade 3 complications and the CCI: ≤70% and ≤30.5, respectively; bile leak-rate: ≤47% and 5-year overall survival of ≥39.7%. Centers operating mostly on complex cases disclosed better outcome including lower post-operative liver failure rates (4% vs 13%; P = 0.002). Centers from Asia disclosed better outcomes.
Surgery for PHC remains associated with high morbidity and mortality with now the availability of benchmark values covering 21 outcome parameters, which may serve as key references for comparison in any future analyses of individuals, group of patients or centers.
We report an improved measurement of the cosmic microwave background B-mode polarization power spectrum with the Polarbear experiment at 150 GHz. By adding new data collected during the second season ...of observations (2013-2014) to re-analyzed data from the first season (2012-2013), we have reduced twofold the band-power uncertainties. The band powers are reported over angular multipoles , where the dominant B-mode signal is expected to be due to the gravitational lensing of E-modes. We reject the null hypothesis of no B-mode polarization at a confidence of 3.1 including both statistical and systematic uncertainties. We test the consistency of the measured B-modes with the Λ Cold Dark Matter (ΛCDM) framework by fitting for a single lensing amplitude parameter AL relative to the Planck 2015 best-fit model prediction. We obtain 0.14(foreground) 0.04(multi), where is the fiducial ΛCDM value.
Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of ...these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes.
Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images.
The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown.
The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.
Many Asian countries, including China, Japan, South Korea, and Singapore, have experienced an increase of two to four times in the incidence of colorectal cancer during the past few decades. The ...rising trend in incidence and mortality from colorectal cancer is more striking in affluent than in poorer societies and differs substantially among ethnic groups. Although changes in dietary habits and lifestyle are believed to be the reasons underlying the increase, the interaction between these factors and genetic characteristics of the Asian populations might also have a pivotal role. Non-polypoidal (flat or depressed) lesions and colorectal neoplasms arising without preceding adenoma (de novo cancers) seem to be more common in Asian than in other populations. The absence of polypoid growth preceding malignancy has posed difficulties in screening for early colorectal cancer by radiological imaging or even endoscopic techniques. Although epidemiological data are scanty, most Asian populations are not aware of the growing problem of colorectal cancer. More work is needed to elucidate the magnitude of the problem in Asia.
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