Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures

Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong blade–vortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor

Candidate Success and edTPA: Looking at the Data

This descriptive study looks at the correlations between Teacher Performance Assessment (edTPA) data and numerous program data points, including GPA, major GPA, and benchmark assignment scores, gathered in an Early Childhood Education (ECE) program. Previous studies have looked to correlate grade point average (GPA) with pre-service teacher performance; however, correlating students’ benchmark assessment scores and student performance on edTPA has not been attempted. This study looks to determine the relationships between overall GPA, major GPA (Early Childhood Education), and edTPA performance (overall score and task scores). Relationships were also investigated between program benchmark assessments (case study, family culture project, integrated investigation unit, student teaching evaluation) and edTPA performance (overall score and task scores). Findings suggest a relationship between overall GPA and edTPA overall score as well as GPA and individual edTPA task scores. In exploring benchmark assignments, correlations were found between the Integrated Investigation Unit and overall edTPA score and edTPA Task 1 and 3 scores

Raw and Count Data Comparability of Hip-Worn ActiGraph GT3X+ and Link Accelerometers

To enable inter- and intrastudy comparisons it is important to ascertain comparability among accelerometer models. Purpose: The purpose of this study was to compare raw and count data between hip-worn ActiGraph GT3X+ and GT9X Link accelerometers. Methods: Adults (n = 26 (n = 15 women); age, 49.1 T 20.0 yr) wore GT3X+ and Link accelerometers over the right hip for an 80-min protocol involving 12–21 sedentary, household, and ambulatory/exercise activities lasting 2–15 min each. For each accelerometer, mean and variance of the raw (60 Hz) data for each axis and vector magnitude (VM) were extracted in 30-s epochs. A machine learning model (Montoye 2015) was used to predict energy expenditure in METs from the raw data. Raw data were also processed into activity counts in 30-s epochs for each axis and VM, with Freedson 1998 and 2011 count-based regression models used to predictMETs. Time spent in sedentary, light, moderate, and vigorous intensities was derived from predicted METs from each model. Correlations were calculated to compare raw and count data between accelerometers, and percent agreement was used to compare epoch-by-epoch activity intensity. Results: For raw data, correlations for mean acceleration were 0.96 T 0.05, 0.89 T 0.16, 0.71 T 0.33, and 0.80 T 0.28, and those for variance were 0.98 T 0.02, 0.98 T 0.03, 0.91 T 0.06, and 1.00 T 0.00 in the X, Y, and Z axes and VM, respectively. For count data, corresponding correlations were 1.00 T 0.01, 0.98 T 0.02, 0.96 T 0.04, and 1.00 T 0.00, respectively. Freedson 1998 and 2011 count-based models had significantly higher percent agreement for activity intensity (95.1% T 5.6% and 95.5% T 4.0%) compared with theMontoye 2015 raw data model (61.5% T 27.6%; P G 0.001). Conclusions: Count data were more highly comparable than raw data between accelerometers. Data filtering and/or more robust raw data models are needed to improve raw data comparability between ActiGraph GT3X+ and Link accelerometers

Reactive oxygen species induce virus-independent MAVS-oligomerization in systemic lupus erythematosus

The increased expression of genes induced by type I interferon (IFN) is characteristic of viral infections and systemic lupus erythematosus (SLE). We showed that mitochondrial antiviral signaling (MAVS) protein, which normally forms a complex with retinoic acid gene I (RIG-I)–like helicases during viral infection, was activated by oxidative stress independently of RIG-I helicases. We found that chemically generated oxidative stress stimulated the formation of MAVS oligomers, which led to mitochondrial hyperpolarization and decreased adenosine triphosphate production and spare respiratory capacity, responses that were not observed in similarly treated cells lacking MAVS. Peripheral blood lymphocytes of SLE patients also showed spontaneous MAVS oligomerization that correlated with the increased secretion of type I IFN and mitochondrial oxidative stress. Furthermore, inhibition of mitochondrial reactive oxygen species (ROS) by the mitochondria-targeted antioxidant MitoQ prevented MAVS oligomerization and type I IFN production. ROS-dependent MAVS oligomerization and type I IFN production were reduced in cells expressing the MAVS-C79F variant, which occurs in 30% of sub-Saharan Africans and is linked with reduced type I IFN secretion and milder disease in SLE patients. Patients expressing the MAVS-C79F variant also had reduced amounts of oligomerized MAVS in their plasma compared to healthy controls. Together, our findings suggest that oxidative stress–induced MAVS oligomerization in SLE patients may contribute to the type I IFN signature that is characteristic of this syndrome

Hippocampal Contribution to Context Encoding across Development Is Disrupted following Early-Life Adversity

Context can drastically influence responses to environmental stimuli. For example, a gunshot should provoke a different response at a public park than a shooting range. Little is known about how contextual processing and neural correlates change across human development or about individual differences related to early environmental experiences. Children (N = 60; 8–19 years, 24 exposed to interpersonal violence) completed a context encoding task during fMRI scanning using a delayed match-to-sample design with neutral, happy, and angry facial cues embedded in realistic background scenes. Outside the scanner, participants completed a memory test for context-face pairings. Context memory and neural correlates of context encoding did not vary with age. Larger hippocampal volume was associated with better context memory. Posterior hippocampus was recruited during context encoding, and greater activation in this region predicted better memory for contexts paired with angry faces. Children exposed to violence had poor memory of contexts paired with angry faces, reduced hippocampal volume, and atypical neural recruitment on encoding trials with angry faces, including reduced hippocampal activation and greater functional connectivity between hippocampus and ventrolateral prefrontal cortex (vlPFC). Greater hippocampus-vlPFC connectivity was associated with worse memory for contexts paired with angry faces. Posterior hippocampus appears to support context encoding, a process that does not exhibit age-related variation from middle childhood to late adolescence. Exposure to dangerous environments in childhood is associated with poor context encoding in the presence of threat, likely due to greater vlPFC-dependent attentional narrowing on threat cues at the expense of hippocampus-dependent processing of the broader context

Influence of blade aerodynamic model on the prediction of helicopter high-frequency airloads

Brown’s vorticity transport model has been used to investigate the influence of the blade aerodynamic model on the accuracy with which the high-frequency airloads associated with helicopter blade–vortex interactions can be predicted. The model yields an accurate representation of the wake structure yet allows significant flexibility in the way that the blade loading can be represented. A simple lifting-line model and a somewhat more sophisticated liftingchord model, based on unsteady thin aerofoil theory, are compared. A marked improvement in the accuracy of the predicted high-frequency airloads of the higher harmonic control aeroacoustic rotor is obtained when the liftingchord model is used instead of the lifting-line approach, and the quality of the prediction is affected less by the computational resolution of the wake. The lifting-line model overpredicts the amplitude of the lift response to blade–vortex interactions as the computational grid is refined, exposing the fundamental deficiencies in this approach when modeling the aerodynamic response of the blade to interactions with vortices that are much smaller than its chord. The airloads that are predicted using the lifting-chord model are relatively insensitive to the resolution of the computation, and there are fundamental reasons to believe that properly converged numerical solutions may be attainable using this approach

Hydrographic Changes in Nares Strait (Canadian Arctic Archipelago) in Recent Decades Based on δ18O Profiles of Bivalve Shells

Nares Strait is one of three main passages of the Canadian Archipelago that channel relatively fresh seawater from the Arctic Ocean through Baffin Bay to the Labrador Sea. Oxygen isotopic profiles along the growth axis of bivalve shells, collected live over the 5 – 30 m depth range from the Greenland and Ellesmere Island sides of the strait, were used to reconstruct changes in the hydrography of the region over the past century. The variability in oxygen isotope ratios is mainly attributed to variations in salinity and suggests that the northern end of Nares Strait has been experiencing an increase in freshwater runoff since the mid 1980s. The recent changes are most pronounced at the northern end of the strait and diminish toward the south, a pattern consistent with proximity to the apparently freshening Arctic Ocean source in the north and mixing with Baffin Bay waters as the water progresses southward. This increasing freshwater signal may reflect changes in circulation and ice formation that favor an increased flow of relatively fresh waters from the Arctic Ocean into Nares Strait.Le détroit de Nares est l’un des trois principaux passages de l’archipel canadien qui canalise de l’eau de mer relativement fraîche de l’océan Arctique jusqu’à la mer du Labrador en passant par la baie de Baffin. Les profils de la composition isotopique de l’oxygène le long de l’axe de développement des coquillages bivalves recueillis en vie à une profondeur variant entre 5 à 30 m des côtés du détroit à la hauteur du Groenland et de l’île d’Ellesmere ont servi à reconstruire les changements ayant caractérisé l’hydrographie de la région au cours du dernier siècle. La variabilité en matière de ratio d’isotope de l’oxygène est principalement attribuable aux variations de salinité, ce qui laisse entendre que l’extrémité nord du détroit de Nares connaît une augmentation de l’écoulement d’eau douce depuis le milieu des années 1980. Les changements récents sont plus prononcés à l’extrémité nord du détroit et diminuent en arrivant vers le sud, ce qui constitue une tendance conforme à la proximité de la source de l’océan Arctique en dessalure apparente dans le nord et qui se mélange avec les eaux de la baie de Baffin au fur et à mesure que l’eau progresse vers le sud. Cette augmentation de la présence d’eau douce peut être le reflet de changements en matière de circulation et de formation de la glace qui favorisent un écoulement accru d’eaux relativement douces en provenance de l’océan Arctique et se jettent dans le détroit de Nares

Psychosocial functioning in pediatric heart transplant recipients and their families

Across pediatric organ transplant populations, patient and family psychosocial functioning is associated with important health‐related outcomes. Research has suggested that pediatric heart transplant recipients and their families are at increased risk for adverse psychosocial outcomes; however, recent investigation of psychosocial functioning in this population is lacking. This study aimed to provide a contemporary characterization of psychosocial functioning in pediatric heart transplant recipients and their families. Associations between psychosocial function, demographic variables, and transplant‐related variables were investigated. Fifty‐six parents/guardians of pediatric heart transplant recipients completed a comprehensive psychosocial screening measure during transplant follow‐up clinic visits. Descriptive statistics, correlational analyses, and independent samples t tests were performed. Forty percent of pediatric heart transplant recipients and their families endorsed clinically meaningful levels of total psychosocial risk. One‐third of patients presented with clinically significant psychological problems per parent report. Psychosocial risk was unassociated with demographic or transplant‐related factors. Despite notable improvements in the survival of pediatric heart transplant recipients over the past decade, patients and families present with sustained psychosocial risks well beyond the immediate post‐transplant period, necessitating mental health intervention to mitigate adverse impact on health‐related outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142422/1/petr13110.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142422/2/petr13110_am.pd

Primary malignant melanoma of the oesophagus: a case report

Primary malignant melanoma of the oesophagus is a rare neoplasm comprising less than 0.2% of all primary oesophageal neoplasms. There are fewer than 250 reported cases in worldwide literature. Several reports suggest that it has a mean survival rate of 2.2% at 5 years and a median survival rate of 10 months. A 48 year old male presented to our surgical service complaining of a three month history of progressively worsening dysphagia with associated regurgitation and unintentional weight loss of 14 kg. There was no prior history of cutaneous or ocular melanoma. He was treated with a combination of subtotal oesophageal resection and immunomodulatory therapy. We present herein a case of primary malignant melanoma of the oesophagus including the associated clinical, pathological and radiological findings