554 research outputs found
TERROR MANAGEMENT THEORY: THE INFLUENCE OF SALIENT GROUP NORMS, ACTIVE SOCIAL IDENTITIES AND IN-GROUP IDENTIFICATION ON THE RELATIONSHIP BETWEEN MORTALITY SALIENCE AND BIAS
Terror management research has shown that mortality salience leads to especially positive reactions towards similar others and to especially negative reactions towards
different others. The present research consists of six studies that investigate the influence
of salient group norms, salient identities and in-group identification on the effects of
mortality salience. In-group norms of collectivism and individualism were manipulated in
Study I, whereas in-group norms of fairness and discrimination were manipulated in
Study 2. Study 3 manipulated out-group norms of fairness and discrimination. The results
of these studies provided evidence thai the content of salient in-group and out-group
norms moderates the effects of mortality salience on bias. A mortality salience induction
led to greater inter-group bias when salient norms prescribed collectivism and
discrimination, as opposed to individualism and fairness respectively. Support to the view
that death reminders can increase adherence to group norms was also provided. Studies 4-
6 focused on the role of salient identities and group identification on the effects of
mortality salience. Study 4 primed English and student identities in a cross-categorization
setting, whereas Study 5 primed English and European identities in a re-categorization
in
setting. In Study 6, in-group identification was measured. It was demonstrated that salient
social identities moderate the effects of mortality salience on bias, whereas in-group
identification does not. In Study 4, English students for whom mortality was salient
displayed more bias toward Scottish students when the active identity was English as
opposed to students. Study 5 showed that English that were reminded of their mortality
displayed more bias toward French people when the salient identity was English than
when it was Europeans. In Study 6, mortality salience led to increased inter-group bias
irrespectively of participants' level of in-group identification. Discussion focuses on
potential explanations, implications and future directions
Ileocecal appendix involvement in fabry disease mimicking an acute abdomen
Anderson-Fabry disease (AFD) is a rare, X-linked, lysosomal storage disorder due to a deficiency of alphagalactosidase A. The direct consequence is a lipid storage with the accumulation of glycosphingolipids throughout the body. The clinical picture is highly variable and depends on cellular storage deposition ranging from neurological, cutaneous and renal symptoms to cardiac and gastrointestinal ones. We are reporting about the case of a young female carrier of alpha-galactosidase A (agalA) gene mutation who was treated at our out-clinic practice for minimal neurological involvement (achroparaestesia). She was subsequently admitted in order to undergo appendectomy because of an acute severe abdominal pain. The histological examination of her appendix revealed only a deposition of globotriaosylceramide (Gb3) without any sign of acute inflammation. This case confirms the extreme clinical variability of Fabry disease and how the gastrointestinal involvement diagnosis can be misse
Renal papillary carcinoma developed in a kidney transplant recipient with late IgA-nephropathy
With improvements in immunosuppressive therapy, patient and graft survival in renal transplant recipients have been prolonged. Increasing donor age and patient survival rates have been related to an increase in the number of de novo tumors. Posttransplant malignancy in these patients is an important cause of graft loss and death in these patients. Among cancers occurring after a kidney transplant, renal cell carcinoma is the fifth most common malignancy after lymphoproliferative disorders, and skin, gastrointestinal, and lung cancers. When nonmelanoma skin cancers and in situ carcinoma of the cervix are excluded from malignancies, renal cell carcinoma accounts for 2% of all cancers in the general population, which increases to 5% in solid-organ recipients. The majority of renal cell carcinomas found in transplant recipients develop in the recipient 's native kidneys, but only 9% of tumors develop in the allograft itself. Tumors transmitted by donors represent only 0.02% to 0.2% of cases. Most de novo allograft renal cell carcinomas are single tumors. The mechanisms of development of renal cell carcinoma in renal grafts are not completely understood
Mission performance simulation of integrated helicopter–engine systems using an aeroelastic rotor model
This paper presents an integrated approach, targeting the comprehensive assessment of combined helicopter–engine designs, within designated operations. The developed methodology comprises a series of individual modeling theories, each applicable to a different aspect of helicopter flight dynamics and performance. These relate to rotor blade modal analysis, three-dimensional flight path definition, flight dynamics trim solution, aeroelasticity and engine performance. The individual mathematical models are elaborately integrated within a numerical procedure, solving for the total mission fuel consumption. The overall simulation framework is applied to the performance analysis of the Aérospatiale SA330 helicopter within two generic, twin-engine medium helicopter missions. An extensive comparison with flight test data on main rotor trim controls, power requirements and unsteady blade structural loads is presented. It is shown that, for the typical range of operating conditions encountered by modern twin-engine medium civil helicopters, the effect of operational altitude on fuel consumption is predominantly influenced by the corresponding effects induced on the engine, rather than on airframe–rotor performance. The implications associated with the implicit coupling between aircraft and engine performance, are discussed in the context of mission analysis. The potential to comprehensively evaluate integrated helicopter–engine systems within complete three-dimensional operations, using modeling fidelity designated for main rotor design applications, is demonstrated. The proposed method essentially constitutes an enabler in terms of focusing the rotorcraft design process on designated operation types, rather than on specific sets of flight conditions
Factors Influencing the Thermodynamic Efficiency of Stirling Engines
This meta-study examines the factors which contribute to Stirling engine efficiency. Working fluids should have high specific heat capacity, low viscosity and low density making noble gases the most suitable. Each different working fluid has its own optimum power output at varying pressures and temperatures. The best being Helium at 4.14 MPa and 922K. Dead volume also affects the power output of Stirling engines. Theoretical engines with zero dead volume are ideal but dead volume can occupy over 50% of the engine. Engine configuration also impacts on the efficiency of a Stirling engine. The layout of pistons and cylinders about each other can also have drastic effects on these efficiencies. Currently the most effective engine layout is the ‘gamma’ configuration, which measures 30%-32% efficient. Future research is required to produce a more efficient Stirling engines, based on the factors considered above to determine the viability of these engines as a replacement for coal and fossil fuel powered combustion engines
A study on affect model validity : nominal vs ordinal labels
The question of representing emotion computationally remains largely unanswered: popular
approaches require annotators to assign a magnitude (or a class) of some emotional
dimension, while an alternative is to focus on the relationship between two or more options.
Recent evidence in affective computing suggests that following a methodology of ordinal
annotations and processing leads to better reliability and validity of the model. This paper
compares the generality of classification methods versus preference learning methods
in predicting the levels of arousal in two widely used affective datasets. Findings of this
initial study further validate the hypothesis that approaching affect labels as ordinal data
and building models via preference learning yields models of better validity.peer-reviewe
Renal involvement in Waldenström's macroglobulinemia: case report and review of literature
Waldenström's macroglobulinemia (WM) is a rare lymphoid neoplasia, accounting for 2% of all hematological malignancies. Renal complications occur rather rarely compared to multiple myeloma. The most common renal manifestations are mild proteinuria and microhematuria. We describe a case of MW presenting with acute renal failure and NS. A 67-year-old man was referred to our hospital for sudden onset nephrotic syndrome. Electrophoresis revealed a monoclonal component in the gamma region, which was classified as an IgM k. During hospitalization, acute kidney injury developed, with creatinine up to 5 mg/dL, despite adequate hydration and alkalinization. A kidney biopsy was performed, showing minimal change disease (MCD) with interstitial and capsular lymphoid infiltrates of B-Lymphocytes CD20+. B-lymphocytes infiltration suggested the possibility of renal localization of lymphoproliferative disorder. So, bone marrow histology was performed, revealing lymphoplasmacytic lymphoma (WM). The patient was treated with bortezomib, desamethasone, and rituximab, with partial recovery of renal function (creatinine 1.5 mg/dL) and complete remission of proteinuria after 8-month follow-up. The remission of NS in our patient with rituximab seems to emphasize the pathogenetic role of B cells in MCD, although a coincident effect of immunosuppression on both the underlying renal disease and the hematologic disease cannot be excluded
Preimplantation biopsy predicts delayed graft function, glomerular filtration rate and long-term graft survival of transplanted kidneys
Background
The predictive value of preimplantation biopsies for long-term graft function is often limited by conflicting results. The aim of this study was to evaluate the influence of time-zero graft biopsy histological scores on early and late graft function, graft survival and patient survival, at different time points.
Methods
We retrospectively analyzed 284 preimplantation biopsies at a single center, in a cohort of recipients with grafts from live and deceased donors (standard and nonstandard), and their impact in posttransplant renal function after a mean follow-up of 7 years (range 1–16). Implantation biopsy score (IBS), a combination score derived from 4 histopathological aspects, was determined from each sample. The correlation with incidence of delayed graft function (DGF), creatinine clearance (1st, 3rd and 5th posttransplant year) and graft and patient survival at 1 and 5 years were evaluated.
Results
Preimplantation biopsies provided somewhat of a prognostic index of early function and outcome of the transplanted kidney in the short and long term. In the immediate posttransplantation period, the degree of arteriolosclerosis and interstitial fibrosis correlated better with the presence of DGF. IBS values between 4 and 6 were predictive of worst renal function at 1st and 3rd years posttransplant and 5-year graft survival. The most important histological finding, in effectively transplanted grafts, was the grade of interstitial fibrosis. Patient survival was not influenced by IBS.
Conclusions
Higher preimplantation biopsy scores predicted an increased risk of early graft losses, especially primary nonfunction. Graft survival (at 1st and 5th years after transplant) but not patient survival was predicted by IBS
Emergent mechanisms for long timescales depend on training curriculum and affect performance in memory tasks
Recurrent neural networks (RNNs) in the brain and in silico excel at solving
tasks with intricate temporal dependencies. Long timescales required for
solving such tasks can arise from properties of individual neurons
(single-neuron timescale, , e.g., membrane time constant in biological
neurons) or recurrent interactions among them (network-mediated timescale).
However, the contribution of each mechanism for optimally solving
memory-dependent tasks remains poorly understood. Here, we train RNNs to solve
-parity and -delayed match-to-sample tasks with increasing memory
requirements controlled by by simultaneously optimizing recurrent weights
and s. We find that for both tasks RNNs develop longer timescales with
increasing , but depending on the learning objective, they use different
mechanisms. Two distinct curricula define learning objectives: sequential
learning of a single- (single-head) or simultaneous learning of multiple
s (multi-head). Single-head networks increase their with and are
able to solve tasks for large , but they suffer from catastrophic
forgetting. However, multi-head networks, which are explicitly required to hold
multiple concurrent memories, keep constant and develop longer
timescales through recurrent connectivity. Moreover, we show that the
multi-head curriculum increases training speed and network stability to
ablations and perturbations, and allows RNNs to generalize better to tasks
beyond their training regime. This curriculum also significantly improves
training GRUs and LSTMs for large- tasks. Our results suggest that adapting
timescales to task requirements via recurrent interactions allows learning more
complex objectives and improves the RNN's performance
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