159 research outputs found
Explaining consumers’ purchase intention of products made with recycled plastic in a circular economy context
The production of virgin plastic is set to increase by 40% in the next 10 years. At the same time,
estimates show that plastic trash flowing into the seas will nearly triple by 2040 if nothing is
done. Issues like plastic pollution and resource scarcity are on the top of the agenda of many
eco-conscious consumers. In response to these new consumers’ concerns, a handful of
companies have started experimenting with recycled plastic and use this material in textiles,
furniture, packaging, and other applications. Nonetheless, little is known about how consumers
perceive products made with recycled plastic and which are the drivers that could encourage
the purchase of such products. By applying the Theory of Planned Behavior, this research aims
to study consumers' perception of products made with recycled plastic and to identify
the biggest influencer for the purchase of such products. Through an online questionnaire, a
sample of 346 respondents was collected and then analyzed using Structural Equation
Modelling. The findings indicated Attitude, Perceived Behavioral Control and Subjective
Norm, as well as the newly added variable Environmental Knowledge, as determinants of
buying behavioral intention. The study adds to the literature around recycled products and
consumers' behavior and confirms the validity of the theory of planned behavior in explaining
consumers' intentions. Regarding the practical implications, the study suggests designing
recycled plastic products in a recognizable, impactful way to communicate their green and
environmental benefits and target "environmentally-conscious" consumers that were found to
be the most willing to purchase recycled products.Está previsto que a produção de plástico virgem aumentará em 40% nos próximos 10 anos. Ao
mesmo tempo, estudos mostram que o lixo plástico que flui para os mares quase triplicará até
2040 se nada for feito. Questões como poluição por plástico e escassez de recursos estão no
topo da agenda de muitos consumidores verdes. Em resposta às preocupações desses novos
consumidores, algumas empresas começaram a experimentar com plástico reciclado e usar esse
material em várias aplicações. No entanto, pouco se sabe sobre como os consumidores
percebem os produtos feitos com plástico reciclado e quais são os motivadores que podem
estimular a compra desses produtos. Para estudar a percepção dos consumidores sobre produtos
feitos com plástico reciclado e identificar o maior influenciador na compra desses produtos,
esta tese aplicou a Teoria do Comportamento Planejado de Ajzen. Por meio de um questionário
online, uma amostra de 346 respondentes foi coletada e analisada. Os resultados indicam as
variáveis Atitude, Controlo Comportamental Percebido e Norma Subjetiva, bem como a
variável recentemente adicionada, Conhecimento Ambiental, como determinantes da intenção
comportamental de compra. O estudo complementa a literatura sobre produtos reciclados e o
comportamento dos consumidores e confirma a validade da teoria do comportamento planejado
para explicar as intenções dos consumidores. Em relação às implicações práticas, o estudo
sugere projetar produtos de plástico reciclado de uma forma reconhecÃvel e impactante para
comunicar seus benefÃcios verdes e ambientais e para atingir os consumidores "ambientalmente
conscientes" que foram considerados os mais dispostos a comprar produtos reciclados
Rationality, Autonomy and Coordination: the Sunk Costs Perspective
Our thesis is that an agent1 is autonomous only if he is capable, within a non predictable environment, to balance two forms of rationality: one that, given goals and preferences, enables him to select the best course of action (means-ends), the other, given current achievements and capabilities, enables him to adapt preferences and future goals. We will propose the basic elements of an economic model that should explain how and why this balance is achieved: in particular we underline that an agent’s capabilities can often be considered as partially sunk investments. This leads an agent, while choosing, to consider not just the value generated by the achievement of a goal, but also the lost value generated by the non use of existing capabilities.We will propose that, under particular conditions, an agent, in order to be rational, could be led to perform a rationalization process of justification that changes preferences and goals according to his current state and available capabilities. Moreover, we propose that such a behaviour could offer a new perspective on the notion of autonomy and on the social process of coordination
FATIGUE ALTERS THE BIOMECHANICS OF TURNS WHILE RUNNING
This study identified the effects of fatigue on lower limb kinematics while running with repeated 180°-turns. An increased stiffness of the pivoting limb was observed in terms of a reduction of hip and knee flexion angles, and an increase of hip abduction and internal rotation. We concluded that muscle fatigue can trigger a sequence of adaptations that were previously found to expose the athlete to an increasing risk of ligament injury. These results expand the base of evidence for the development of field-based prevention programs
Prolonged job strain reduces time-domain heart rate variability on both working and resting days among cardiovascular-susceptible nurses
Introduction Modifications of hearth rate variability (HRV) constitute a marker of the autonomic nervous system (ANS) deregulation, a promising pathway linking job strain (JS) and cardiovascular diseases (CVD). The study objective is to assess whether exposures to recent and prolonged JS reduce time-domain HRV parameters on working days (WD) among CVD-susceptible nurses and whether the association also persists on resting days (RD). Material and methods 313 healthy nurses were investigated twice with one year interval to assess JS based on the demand-control and the effort-reward models. 36, 9 and 16 CVD-susceptible nurses were classified as low JS in both surveys (stable low strain – SLS), recent high JS (high JS at the second screening only-RHS) and prolonged high JS (high strain in both surveys-PHS), respectively. In 9, 7 and 10 of them, free from comorbidities/treatments interfering with HRV, two 24-h ECG recordings were performed on WD and RD. Differences in the time domain HRV metrics among JS categories were assessed using ANCOVA, adjusted for age and smoking. Results In the entire sample (mean age: 39 years, 83% females) the prevalence of high job strain was 38.7% in the second survey. SDNN (standard deviation of all normal RR intervals) on WD significantly declined among JS categories (p = 0.02), with geometric mean values of 169.1, 145.3 and 128.9 ms in SLS, RHS, PHS, respectively. In the PHS group, SDNN remained lower on RD as compared to the low strain subjects (142.4 vs. 171.1 ms, p = 0.02). Similar findings were found for the SDNN_Index, while SDANN (standard deviation of average RR intervals in all 5 min segments of registration) mean values reduced in the PHS group during WD only. Conclusions Our findings suggest that persistent JS lowers HRV time-domain parameters, supporting the hypothesis that the ANS disorders may play an intermediate role in the relationship between work stress and CVD
Cost of illness of advanced ovarian carcinoma in Italy: results of an empirical, single-centre study
AIM: To perform an empirical, single-centre, retrospective and secondary cost of illness (COI) study of advanced ovarian carcinoma (AOC) in Italy. METHODS: Demographic, clinical, health care and non-health care resource consumption data concerning a convenience sample of subsequent patients in 1st line of treatment (100 patients), 2nd line of treatment A (surgery + chemotherapy; 30 patients) and 2nd line of treatment B (chemotherapy only; 20 patients) were obtained from a database created in 2011 by the Obstetrics and Ginecology Unit at Campus Biomedico teaching hospital, Rome. Patients were followed-up for 2 years. Resources were valued according to the above mentioned database and literature, following the societal viewpoint. Costs are expressed in Euro (€) 2014 and reported as mean and standard deviation (SD). RESULTS: One-year COI for 1st line of treatment reaches € 44,999.7 (SD: €28,757.3), € 55,410.8 (SD: € 32,454.6) and €46,895.6 (SD: € 28,407.4) for 2nd line of treatment A and B, respectively. Regardless the line of treatment, COI is mainly driven by cost borne by patient and her family. Due to the high costs of relapse the mean COI per patient after 2 years from the diagnosis of AOC equals € 81,869.4 (SD: € 30,660.9), or 182% of the COI for the 1st line of treatment. CONCLUSIONS: Despite some limitations, our results show that increasing progression-free survival could well reduce the COI for AOC in Italy
Weak magnetic fields in early-type stars: failed fossils
Weak magnetic fields have recently been detected in Vega and Sirius. Here, we
explore the possibility that these fields are the remnants of some field
inherited or created during or shortly after star formation and, unlike true
fossil fields, are still evolving as we observe them. The timescale of this
evolution is given in terms of the Alfven timescale and the rotation frequency
by tau_evol ~ tau_A^2 Omega, which would be comparable to the age of the star.
It is shown that it is likely that all intermediate- and high-mass stars
contain fields of at least the order of the strength found so far in Vega and
Sirius. Faster rotators are expected to have stronger magnetic fields. Stars
may experience an increase in field strength during their early main-sequence,
but for most of their lives field strength will decrease slowly. The length
scale of the magnetic structure on the surface may be small in very young stars
but should quickly increase to at least very approximately a fifth of the
stellar radius.Comment: are welcome. Submitted to MNRAS. Five page
Low-Intensity Whole-Body Vibration: A Useful Adjuvant in Managing Obesity? A Pilot Study
The use of whole-body vibration (WBV) for therapeutic purposes is far from being stan-
dardized and an empirical foundation for reporting guidelines for human WBV studies has only very
recently been published. Controversies about safety and therapeutic dosage still exist. The present
study aimed to investigate the metabolic and mechanical effects of low-intensity WBV according
to the ISO 2631 norm on subjects with obesity. Forty-one obese subjects (BMI ≥35 kg/m2) were
recruited to participate in a 3-week multidisciplinary inpatient rehabilitation program including
fitness training and WBV training. During WBV the posture was monitored with an optoelectronic
system with six infrared cameras (Vicon, Vicon Motion System, Oxford, UK). The primary endpoints
were: variation in body composition, factors of metabolic syndrome, functional activity (sit-to-stand
and 6-min walking test), muscle strength, and quality of life. The secondary endpoints were: mod-
ification of irisin, testosterone, growth hormone, IGF1 levels. We observed significant changes in
salivary irisin levels, Group 2 (p < 0.01) as compared to the control group, while muscle strength,
function, and other metabolic and hormonal factors did not change after a 3-week low-intensity
WBV training with respect to the control group. Future studies are needed to further investigate the
potential metabolic effect of low-intensity WBV in managing weight
Three-dimensional analysis of balance control strategies in elite karateka
In karate, balance control represents a key performance determinant (1). Balance stability was reported to be related to a refined control of the center of mass (CoM) displacement (2). The aim of the current study was to quantitatively investigate the motor strategies adopted by elite and non-elite karateka to maintain balance control. We analyzed the execution of traditional karate techniques (kata) in two groups: elite Masters (n=6, 31±19 years) and non-elite Practitioners (n=4, 25±9 years). On each participant, the three-dimensional coordinates of 14 reflective markers (landmarks: right and left tragion, acromion, olecranum, radius styloid process, great trochanter, femur lateral epicondyle, lateral malleolus) were recorded by nine infrared cameras of an optoelectronic motion analyzer with a 120 Hz sampling rate. Kinematic parameters assessed were: CoM, step width, joints range of motions. CoM kinematics was computed according to the segmental centroid method (3). In the 11 steps of kata, CoM height was 8% lower (p<0.05, Mann-Whitney non parametric U-test), CoM average velocity and rms acceleration were approximately 35% higher (p<0.05) and step width was higher (p<0.05) in Masters. There was a significant difference between groups in CoM height and step width in seven and six out of the 11 steps, respectively. CoM vertical displacements resulted almost equal along the vertical direction, while in the horizontal direction it was significantly (p<0.05) higher in Masters than in Practitioners. Results suggest that elite karateka developed a refined body balance control, obtained through the increase of the base of support and different maneuvers of lower limbs. The proposed method could be used to objectively detect talented karateka, to measure proficiency level and to assess training effectiveness
Determinants of bone damage: An ex-vivo study on porcine vertebrae
Bone\u2019s resistance to fracture depends on several factors, such as bone mass, microarchitecture, and tissue material properties. The clinical assessment of bone strength is generally performed by Dual-X Ray Photon Absorptiometry (DXA), measuring bone mineral density (BMD) and trabecular bone score (TBS). Although it is considered the major predictor of bone strength, BMD only accounts for about 70% of fragility fractures, while the remaining 30% could be described by bone \u201cquality\u201d impairment parameters, mainly related to tissue microarchitecture. The assessment of bone microarchitecture generally requires more invasive techniques, which are not applicable in routine clinical practice, or X-Ray based imaging techniques, requiring a longer post-processing. Another important aspect is the presence of local damage in the bony tissue that may also affect the prediction of bone strength and fracture risk. To provide a more comprehensive analysis of bone quality and quantity, and to assess the effect of damage, here we adopt a framework that includes clinical, morphological, and mechanical analyses, carried out by means of DXA, \u3bcCT and mechanical compressive testing, respectively. This study has been carried out on trabecular bones, taken from porcine trabecular vertebrae, for the similarity with human lumbar spine. This study confirms that no single method can provide a complete characterization of bone tissue, and the combination of complementary characterization techniques is required for an accurate and exhaustive description of bone status. BMD and TBS have shown to be complementary parameters to assess bone strength, the former assessing the bone quantity and resistance to damage, and the latter the bone quality and the presence of damage accumulation without being able to predict the risk of fracture
The estimation of body center of mass kinematics in sport: proposal of a new protocol
The assessment of body Center of Mass (CoM) kinematics is an important measure in the analysis of sport movements since it is strictly related to balance and stability control [1]. Among the methods proposed to estimate CoM displacement, Segmental method appears to be suitable to investigate CoM kinematics in sport: human body is assumed as a system of rigid segments, and the whole-body CoM is calculated as the weighted average of the CoM of each segment. Each segment is defined by a set of landmarks, and their overall number represents a crucial choice in the protocol design process, being a compromise between accuracy and invasivity [2]. In the present study, using a motion capture system, we validated a protocol based upon the Segmental method, adopting a 14-landmarks anatomical model. Two sets of experiments were made. At first, our protocol was compared to the Ground Reaction Force method (GRF), accounted as a golden standard in CoM estimation. Subsequently, we investigated the aerial phase typical of many sports, comparing our protocol with: (1) an absolute reference, the parabolic regression of the vertical CoM trajectory during the time of flight; (2) two common approaches to estimate CoM kinematics in gait, known as Sacrum and Reconstructed Pelvis methods. Recognized accuracy indexes proved that the results obtained were comparable to the GRF; what is more, during the aerial phase our protocol showed to be significantly more accurate than the other two methods. The protocol assessed can therefore be adopted as a reliable tool for CoM kinematics estimation in further sport researches
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