4,554 research outputs found
CFD simulation of flow around angle of attack and sideslip angle vanes on a BAe Jetstream 3102 - Part 1
CFD modelling techniques are exploited to investigate the local velocity field around angle of attack and sideslip angle sensors fitted to the nose of a modified BAe Jetstream 3102 small airliner. Analysis of the flow angularity at the vane locations has allowed the vanes response to varying flight conditions to be predicted and errors in the readings to be quantified. Subsequently, a more accurate calibration of the system is applied to the current configuration on the Jetstream, and a better understanding of the position error with respect to the vane locations is obtained.
The above aircraft was acquired by Cranfield University in 2003 with subsequent flow angle vane modifications taking place in 2005. The aircraft is currently in operation with the National Flying Laboratory Centre (NFLC) for research and demonstration purposes
Does metabolic reprogramming underpin age-associated changes in T cell phenotype and function?
T cells are required for an effective adaptive immune response. The principal function of T cells is to promote efficient removal of foreign material by identifying and mounting a specific response to nonself. A decline in T cell function in aging is thought to contribute to reduced response to infection and vaccination and an increase in autoimmunity. This may in part be due to the age-related decrease in naïve CD4+ T cells and increase in antigen-experienced CD4+ T cells, loss of redox homeostasis, and impaired metabolic switching. Switching between subsets is triggered by the integration of extracellular signals sensed through surface receptors and the activation of discrete intracellular metabolic pathways. This article explores how metabolic programming and loss of redox homeostasis during aging may contribute to age-associated changes in T cell phenotype and function. © 2014 Elsevier Inc
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Radiotherapy students' perceptions of support provided by clinical supervisors
Aim: The aim of this study was to explore the experiences of radiotherapy students on clinical placement, specifically focussing on the provision of well-being support from clinical supervisors.
Materials and methods: Twenty-five students from the University of the West of England and City University of London completed an online evaluation survey relating to their experiences of placement, involving Likert scales and open-ended questions.
Results: The quantitative results were generally positive; however, the qualitative findings were mixed. Three themes emerged: (1) provision of information and advice; (2) an open, inclusive and supportive working environment; and (3) a lack of communication, understanding, and consistency.
Findings: Students' experiences on placement differed greatly and appeared to relate to their specific interactions with different members of staff. It is suggested that additional training around providing well-being support to students may be of benefit to clinical supervisors
Ankyrin-B is a PI3P effector that promotes polarized α5β1-integrin recycling via recruiting RabGAP1L to early endosomes
Endosomal membrane trafficking requires coordination between phosphoinositide lipids, Rab GTPases, and microtubule-based motors to dynamically determine endosome identity and promote long-range organelle transport. Here we report that ankyrin-B (AnkB), through integrating all three systems, functions as a critical node in the protein circuitry underlying polarized recycling of α5β1-integrin in mouse embryonic fibroblasts, which enables persistent fibroblast migration along fibronectin gradients. AnkB associates with phosphatidylinositol 3-phosphate (PI3P)-positive organelles in fibroblasts and binds dynactin to promote their long-range motility. We demonstrate that AnkB binds to Rab GTPase Activating Protein 1-Like (RabGAP1L) and recruits it to PI3P-positive organelles, where RabGAP1L inactivates Rab22A, and promotes polarized trafficking to the leading edge of migrating fibroblasts. We further determine that α5β1-integrin depends on an AnkB/RabGAP1L complex for polarized recycling. Our results reveal AnkB as an unexpected key element in coordinating polarized transport of α5β1-integrin and likely of other specialized endocytic cargos
Multiparticle entanglement with quantum logic networks: Application to cold trapped ions
We show how to construct a multi-qubit control gate on a quantum register of
an arbitrary size N. This gate performs a single-qubit operation on a specific
qubit conditioned by the state of other N-1 qubits. We provide an algorithm how
to build up an array of networks consisting of single-qubit rotations and
multi-qubit control-NOT gates for the synthesis of an arbitrary entangled
quantum state of N qubits. We illustrate the algorithm on a system of cold
trapped ions. This example illuminates the efficiency of the direct
implementation of the multi-qubit CNOT gate compared to its decomposition into
a network of two-qubit CNOT gates.Comment: 13 pages, Revtex4, 10 eps figures, 2 tables, to appear in Phys. Rev.
Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling
Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have ex- plored its effects on knee frontal plane biomechanics during sta- tionary cycling. The purpose of this study was to examine the ef- fects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 par- ticipants (11 varus, 11 neutral, and 10 valgus alignment) per- formed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kine- matic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p \u3c 0.05). There were two different knee frontal plane loading patterns, in- ternal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95o (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling
Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling
Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p \u3c 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling
Emotions and Complaining Behavior Following Service Failure
One feature of a democratic society is voice, especially the freedom to dissent. One form of dissent of relevance to organizational scholars is complaining, whether it be complaints from employee stakeholder groups or customer stakeholder groups. Despite the increased ability that the knowledge economy provides for people of all walks of life and nationalities to voice complaint, little is known about the antecedents and consequences of complaining. This paper addresses this issue with respect to customers' response to service failures. Specifically, this paper develops a conceptual model for service settings building upon a model of emotional and cognitive response formation to an affective event (Hartel, McColl-Kennedy & Bennett, 2002), and its source theory, Weiss and Cropanzano's (1995) Affective Events Theory (AET). We argue that when a service failure occurs, a number of cognitive and affective responses take place in consumers. The proposed model aims to operationalize affective responses to service failures in the marketplace. 'Affective response' refers to cognitive, emotional, behavioral and neuropsychological responses to emotional events. As such, the model makes explicit the relationships between and factors within each of these domains of affect expression
A multi-stable isotope framework to understand eutrophication in aquatic ecosystems
Eutrophication is a globally significant challenge facing aquatic ecosystems, associated with human induced enrichment of these ecosystems with nitrogen (N) and phosphorus (P). However, the limited availability of inherent labels for P and N has constrained understanding of the triggers for eutrophication in natural ecosystems and appropriate targeting of management responses. This paper proposes and evaluates a new multi-stable isotope framework that offers inherent labels to track biogeochemical reactions governing both P and N in natural ecosystems. The framework couples highly novel analysis of the oxygen isotope composition of phosphate (δ18OPO4) with dual isotope analysis of oxygen and N within nitrate (δ15NNO3, δ18ONO3) and with stable N isotope analysis in ammonium (δ15NNH4). The River Beult in England is used as an exemplar system for initial evaluation of this framework. Our data demonstrate the potential to use stable isotope labels to track the input and downstream fate of nutrients from point sources, on the basis of isotopic differentiation for both P and N between river water and waste water treatment work effluent (mean difference = +1.7‰ for δ18OPO4; +15.5‰ for δ15NNH4 (under high flow); +7.3‰ for δ18ONO3 and +4.4‰ for δ15NNO3). Stable isotope data reveal nutrient inputs to the river upstream of the waste water treatment works that are consistent with partially denitrified sewage or livestock sources of nitrate (δ15NNO3 range = +11.5 to +13.1‰) and with agricultural sources of phosphate (δ18OPO4 range = +16.6 to +19.0‰). The importance of abiotic and metabolic processes for the in-river fate of N and P are also explored through the stable isotope framework. Microbial uptake of ammonium to meet metabolic demand for N is suggested by substantial enrichment of δ15NNH4 (by 10.2‰ over a 100 m reach) under summer low flow conditions. Whilst the concentration of both nitrate and phosphate decreased substantially along the same reach, the stable isotope composition of these ions did not vary significantly, indicating that concentration changes are likely driven by abiotic processes of dilution or sorption. The in-river stable isotope composition and the concentration of P and N were also largely constant downstream of the waste water treatment works, indicating that effluent-derived nutrients were not strongly coupled to metabolism along this in-river transect. Combined with in-situ and laboratory hydrochemical data, we believe that a multi-stable isotope framework represents a powerful approach for understanding and managing eutrophication in natural aquatic ecosystems
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