NUI Maynooth Eprint Archive
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Consumers' perceived value of healthier eating: A SEM analysis of the internalisation of dietary norms considering perceived usefulness, subjective norms, and intrinsic motivations in Singapore
No full textConsumers' internalisation of social norms is at work when they make routine,
healthier food choices in everyday contexts. We investigate the dynamics of this
phenomenon in Singapore, where over 98% of consumer food products are imported. To study this, we propose, through a consumer perspective (n = 316) via Partial
Least Squares Structural Equation Modelling (PLS-SEM), a model that establishes a
positive relationship between perceived usefulness, subjective norms, and intrinsic
motivations and the perceived value of healthier food. Subjective norms are themselves found to be a function of perceived barriers, facilitating conditions and personal innovativeness. Our framework contributes to establish a shift in the drivers of
healthier food choices toward a more socio-culturally grounded decision-making
approach that is particularly relevant to understand food consumption. We show that
daily food routines (opposing the exceptional healthy food item) are encapsulated in
perceived value of healthier eating. The data indicates further that to support healthier food product consumption, both policy makers and food providers must facilitate
imported foods that meet quickly changing lifestyle requirements
Space-Time Spreading Aided Distributed MIMO-WSNs
No full textIn this letter, we consider the plaguing, yet rarely handled problem of interference resulting from superposition of multiple sensor signals in time, when sent over a multiple access channel (MAC) in wireless sensor networks (WSNs). We propose space-time spreading (STS) of local sensor decisions before reporting them over a MAC to i) minimize interference and ii) reduce energy required for combating interference due to superposition of sensor decisions. Each sensor decision is encoded on appropriately indexed space-time block of fixed duration using dispersion vectors, such that a single sensor is activated over each space-time block while all the other sensors are silent. At the receive side of the reporting channel, we assume a multi-antenna decision fusion center (DFC), thereby representing a distributed multiple-input-multiple-output (MIMO) communication scenario. We formulate and compare optimum and sub-optimum fusion rules for fusing sensor decisions at the DFC to arrive at a reliable conclusion. Simulation results demonstrate gain in fusion performance with STS-aided transmission by 3 to 6 times over performance without STS
Amóinia? Amóinia? Cad faoi Amóinia?
No full textThis is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem
Risk Factors for Self-Harm: Narratives from a Sample of Young People in Northern Ireland
No full textSelf-harm continues to be a growing concern within adolescence and is a globally recognised public health and social problem. Adolescents living in the community who self-harm are extremely common however less is known about these young people. This study focussed on capturing the voice of young people who engage in cutting behaviour to provide insight into the risks associated with this phenomenon. Single semi-structured interviews were conducted with 9 adolescents aged 16–18 years who lived within one Trust area in Northern Ireland. Thematic analysis was applied to the transcribed interviews in which themes emerged. The three subordinate themes of onset, persistence and ending of the behaviour encompassed six sub-themes which were further identified as risk factors for the behaviour. Risk factors identified were: ACE’s, poor relationships and difficulties in support networks, exposure to self-harm, psychological issues, “addiction” to self-harm, concealment of harming behaviour—to control and professional and peer support that helps or hinders. These factors support the current literature base however individual and diverse explanations are highlighted which provide further depth, particularly around the concept of addiction and support that hinders young people. Despite the small nature of the study, recommendations for social work practice, clinical practice and other relevant professional practice as well as future research are considered in view of the findings. Key direction outlines the importance of building trusting relationships, continuity of care and continuing to listen to young people as vital to the helping relationship
Energy‐maximising moment‐based constrained optimal control of ocean wave energy farms
No full textSuccessful commercialisation of wave energy technology inherently incorporates the concept of an array of wave energy converters (WECs). These devices, which constantly
interact via hydrodynamic effects, require optimised control that can guarantee maximum energy extraction from incoming ocean waves while ensuring, at the same time,
that any physical limitations associated with device and actuator systems are being consistently respected. This paper presents a moment-based energy-maximising optimal control
framework for WECs arrays subject to state and input constraints. The authors develop a
framework under which the objective function (and system variables) can be mapped to
a finite-dimensional tractable quadratic program (QP), which can be efficiently solved using
state-of-the-art solvers. Moreover, the authors show that this QP is always concave, i.e. existence and uniqueness of a globally optimal solution is guaranteed under this moment based framework. The performance of the proposed strategy is demonstrated through a
case study, where (state and input constrained) energy-maximisation for a WEC farm composed of CorPower-like WEC devices is considere
Rotors for wave energy conversion—Practice and possibilities
No full textThis review studies some of the existing ideas which create a fundamentally new direction for wave energy converter (WEC) development, obtaining energy from the elliptical motion of particles in water waves using a rotor. The review focuses on three main
aspects of rotor-based WECs: experimental study of the developed prototypes, derivation
and development of the mathematical models, and control effectors and philosophies for
the proposed devices. The range of developed small scale prototypes and their experimental studies are presented. The shortcomings of the current mathematical and hydrodynamic
models are identified, while an overview of the proposed and new possible control effectors and strategies is conducted. This allows us to see the state of the development of the
different concepts and problems to be solved in bringing wave energy rotors to operational reality
Experimental Implementation and Validation of a Broadband LTI Energy-Maximizing Control Strategy for the Wavestar Device
No full textThis study addresses the experimental validation of
a linear time-invariant (LTI) energy-maximizing control strategy
for wave energy converters (WECs), applied to a 1/20 scale
Wavestar WEC. To fulfill this objective, system identification
routines are utilized to compute a mathematical (parametric)
model of the input–output dynamics of the device, suitable for
control design and implementation. With this parametric model,
the so-called LiTe-Con energy-maximizing strategy, recently published in the literature, is designed, synthesized, and tested under
irregular wave excitation in the wave basin at Aalborg University.
Given that the LiTe-Con requires instantaneous knowledge of the
wave excitation effects, estimates are provided by means of an
unknown-input Kalman filter, designed in close synergy with the
so-called internal model principle. For the experimental assessment, both controller and estimator are directly implemented
in a real-time architecture. The performance of the LiTe-Con
is evaluated in terms of energy-absorption, showing consistent
results with respect to those obtained in numerical simulation,
hence validating the LiTe-Con controller in a realistic real-time
scenari
Towards efficient extremum-seeking control of wave energy systems: possibilities and pitfalls.
No full textGiven its success in other renewable energy
domains, such a solar and wind, extremum-seeking control
(ESC) would seem to be a promising candidate for the
wave energy energy-maximising control domain. There are
many advantages to ESC, principal among them the lack
of a need for a mathematical system model, with effective
wave energy hydrodynamic modelling being particularly
challenging. However, a number of fundamental limitations of ESC for wave energy converters (WECs) can be
found, with the panchromatic (stochastic) nature of the
wave excitation a key issue, resulting in potentially long
performance function evaluation times. This, combined
with the desire to perform intra-wave control adjustment,
creates a natural tension in the solution of the wave energy
ESC problem. Motivated by this, we examine, in this
paper, the fundamental opportunities and pitfalls of ESC
for the wave energy control problem, providing a concise
definition of WEC ESC and its characteristics. In particular,
we investigate the intrinsic limitations behind ESC for the
WEC control problem, and provide a potential set of future
directions aiming at alleviating such disadvantages and
directly contributing towards the development of efficient
model-free control systems for wave energy device
Mucosal Associated Invariant T Cells in Cancer-Friend or Foe?
No full textMucosal associated invariant T (MAIT) cells are a population of unconventional T cells
which can bridge the innate and adaptive immune systems. Well-described roles for MAIT cells
include host protection against invading bacteria, fungi and viruses. Upon activation, MAIT cells
become prolific effector cells, capable of producing a range of cytokines and lytic molecules. In
addition to their anti-microbial role, MAIT cells have been implicated in immune responses to cancer,
with opposing beneficial and pathogenic roles reported. On the one hand, MAIT cells can home
to the site of the tumour in many human cancers and can produce anti-tumour molecules. On the
other, MAIT cells can display defective phenotypes in certain cancers and produce pro-tumour
molecules. In this review, we discuss the current literature on the diverse roles for MAIT cells in
cancer, outlining their frequencies, functions and associations with N staging and prognosis. We also
discuss potential mechanisms underpinning cancer-related alterations in MAIT cells and highlight
therapeutic approaches to harness or target MAIT cells in cancer
IFN-γ and PPARδ Influence the Efficacy and Retention of Multipotent Adult Progenitor Cells in Graft vs Host Disease
No full textCell-based therapy for the treatment of inflammatory disorders has focused on the
application of mesenchymal stromal cells (MSCs) and multipotent adult progenitor
cells (MAPCs). Despite the recent positive findings in industry-sponsored clinical trials of MSCs and MAPCs for graft vs host disease (GvHD), cell therapy is efficacious
in some but not all patients, highlighting the need to identify strategies to enhance
cell-based therapeutic efficacy. Here, we demonstrate the capacity for interferon
(IFN)-γ licensing to enhance human MAPC efficacy and retention following early
administration in a humanized mouse model of acute GvHD (aGvHD). Activation of
the nuclear receptor peroxisome proliferator-activated receptor delta (PPARδ) negatively influenced the retention and efficacy of human MAPCs as well as IFNγ-licensed MAPCs in the aGvHD model. PPARδ antagonism significantly enhanced
the efficacy of human MAPCs when administered early in the humanized aGvHD
model. COX-2 expression in human MAPC was significantly decreased in IFN-γ
licensed MAPCs exposed to a PPARδ agonist. Importantly, MAPC exposure to the
PPARδ antagonist in the presence of a COX-2 inhibitor indomethacin before administration significantly reduced the efficacy of PPARδ antagonized MAPCs in the
aGvHD humanized mouse model. This is the first study to demonstrate the importance of PPARδ in human MAPC efficacy in vivo and highlights the importance of
understanding the disease microenvironment in which cell-based therapies are to be
administered. In particular, the presence of PPARδ ligands may negatively influence
MAPC or MSC therapeutic efficacy