420 research outputs found

    The Use of a Pendulum Dynamic Mass Absorber to Protect a Trilithic Symmetric System from the Overturning

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    The trilith consists of two vertical elements (columns) supporting a horizontal element (lintel). The understanding of the dynamic behaviour of triliths is an important step towards their preservation and starts with the knowledge of the dynamics of rigid blocks. A passive method based on a dynamic mass absorber is used to protect a trilith from overturning. The protection system is modelled as a pendulum, hinged on the lintel, with the mass lumped at the end. The equations of rocking motion, uplift and the impact conditions are obtained for the coupled system trilith-mass absorber. An extensive parametric analysis is performed with the aim to compare the behaviour of the system with and without the pendulum, under impulsive one-sine (or one-cosine) base excitations. In order to point out the effectiveness of the protection system, overturning spectra, providing the amplitude of the excitation versus its frequency, are obtained. The pendulum mass absorber results effective in avoiding overturning in specific ranges of the frequency of the excitation. However, outside these ranges the mass absorber never compromises the safety of the trilith

    Clinical features, prognosis, and long-term response to ranibizumab of macular CNVs in pattern dystrophies spectrum: a pilot study

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    Introduction. To analyze the morphological and functional features of choroidal neovascularizations (CNVs) in eyes affected by pattern dystrophies (PD), evaluating their long-term response to intravitreal ranibizumab, and comparing them with CNVs in age-related macular degeneration (AMD). The mean goal is to identify possible disease biomarkers and to evaluate the long-term prognosis of CNVs in PD. Materials and Methods. A retrospective study of 42 patients with naïve CNV (26 PD and 16 AMD), for a total of 47 eyes (29 eyes in the PD group and 18 eyes in the AMD group). Each patient received a loading dose of ranibizumab (one monthly for three months) followed by pro re nata (PRN) reinjection protocol for a period of at least three years. Morphological OCT parameters (CRT, central retinal thickness; SRF, subretinal fluid; IRF, intraretinal fluid; SHRM, subretinal hyperreflective material; HRF, hyperreflective foci; HCD, hyperreflective crystalline deposits; cCT, central choroidal thickness; slCT, sublesional choroidal thickness; EZd, ellipsoid zone disruption; and best corrected visual acuity (BCVA in logMAR scale)) were reported at baseline and last follow-up. Results. At baseline, no significant differences were found between the two groups, except for choroidal thickness parameters that were significantly greater in the PD group ( = 0.009). Longitudinal PD analysis demonstrated reduction in BCVA ( = 0.009), decrease in CRT ( = 0.046), resolution of SRF in 61.6% of cases ( = 0.004) and SHRM in 30% ( = 0.034), and choroidal thinning both centrally ( = 0.004) and sublesional ( = 0.011) compared to baseline. At 3 years, the PD group received significantly more injections than the AMD ( = 0.011) and showed significantly thicker choroid ( = 0.033) and more frequent HRF ( = 0.006). Regarding the PD group, we found a negative correlation between age and choroidal thicknesses at baseline and at 3 years ( < 0.05); significant positive correlations were found between baseline BCVA and at 3 years ( < 0.001), BCVA at 3 years and IRF ( = 0.003) and SHRM at 3 years ( = 0.003); CRT baseline and CRT 3 years ( = 0.017); HCD at 3 years was associated with greater CRT ( = 0.04) and IRF at 3 years ( = 0.019). Conclusions. Early and long-term morphofunctional features of CNVs in PD and in AMD are overlapping. CNVs in PD have poorer long-term response to ranibizumab and higher choroidal thickness suggesting different pathogenetic and evolutionary mechanisms

    Analysis of Methodologies of Data Networks LAN

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    Currently companies offering the service implementation of data networks have seen the need to apply any methodology, the same that can be adapted to the needs of both the client and the organization and also allow direct all processes in the development of the project. However, the use and application of these methodologies aims to reduce failures due to incorrect implementation of the network, it is important to stress that these methodologies provide excellent results as long as the indicated adoption and meet customer needs. That is why the need to analyze the techniques used to implement a network, specifically a network (Local Area Network) LAN type arises; for which an analytical, bibliographical and documentary study, to obtain pertinent and relevant information within the framework of the research was conducted. In addition to the use of criteria for the evaluation of the methodology. As a result, it has been possible to demonstrate that the CISCO methodology is the most widely used thanks to its easy adaptation and implementation projects; plus, it provides a wealth of information and support to users, thereby allowing correct application of its processes

    probability models to assess the seismic safety of rigid block like structures and the effectiveness of two safety devices

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    Abstract When subject to earthquakes, some objects and structures, such as statues, obelisks, storage systems, and transformers, show a dynamic behavior that can be modeled considering the object/structure as a rigid block. Several papers have studied the dynamic behavior of both stand-alone rigid blocks and systems where rigid blocks have been paired with safety devices to prevent or delay the overturning of the blocks. Although the safety devices have generally been proven to be effective, their effectiveness changes substantially varying the parameters that characterize the system and the seismic input. This paper compares the seismic responses of stand along rigid blocks with those of blocks coupled with two candidate safety devices: an isolating base and a pendulum mass damper. To account for the relevant uncertainties, probabilistic seismic demand models are developed using a Bayesian approach. The probabilistic models are then used along with the overturning capacities of the blocks to construct fragility curves that give a prediction of the probability of overturning occurrence as a function of some characteristics of the blocks, of the safety devices, as well as of the seismic excitation, i.e. the slenderness of the body and the peak ground acceleration. The data needed to develop the probabilistic model are obtained integrating the nonlinear equations of motion of the two systems subject to selected ground motions. In the end, some numerical examples are proposed

    A review of consumer awareness, understanding and use of food-based dietary guidelines

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    Copyright @ 2011 Cambridge University PressFood-based dietary guidelines (FBDG) have primarily been designed for the consumer to encourage healthy, habitual food choices, decrease chronic disease risk and improve public health. However, minimal research has been conducted to evaluate whether FBDG are utilised by the public. The present review used a framework of three concepts, awareness, understanding and use, to summarise consumer evidence related to national FBDG and food guides. Searches of nine electronic databases, reference lists and Internet grey literature elicited 939 articles. Predetermined exclusion criteria selected twenty-eight studies for review. These consisted of qualitative, quantitative and mixed study designs, non-clinical participants, related to official FBDG for the general public, and involved measures of consumer awareness, understanding or use of FBDG. The three concepts of awareness, understanding and use were often discussed interchangeably. Nevertheless, a greater amount of evidence for consumer awareness and understanding was reported than consumer use of FBDG. The twenty-eight studies varied in terms of aim, design and method. Study quality also varied with raw qualitative data, and quantitative method details were often omitted. Thus, the reliability and validity of these review findings may be limited. Further research is required to evaluate the efficacy of FBDG as a public health promotion tool. If the purpose of FBDG is to evoke consumer behaviour change, then the framework of consumer awareness, understanding and use of FBDG may be useful to categorise consumer behaviour studies and complement the dietary survey and health outcome data in the process of FBDG evaluation and revision.This study is funded by the European Commission Sixth Framework Programme (contract no. 036196)

    Utilising implementation intentions to promote healthy eating in adolescents

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    Objectives: This study evaluated a school-based behaviour change intervention for adolescents to address unhealthy eating habits that may otherwise “track” into adulthood. Design: A behaviour change intervention was conducted utilising implementation intention formation (or if-then planning) for adolescents to achieve two healthy eating goals: (1) including fruit and vegetable in each daily meal, and (2) replacing unhealthy snacks with healthy choices. Methods: Participants (N = 107) aged between 16 and 18 years were randomised to intervention, active control and passive control conditions. Intervention participants formed implementation intentions for achieving the healthy eating goals; participants in the active control condition completed health-related tasks; and passive control participants read health information. Eating habits and intentions were measured at baseline and 5-month follow-up. Results: Findings showed that the intervention was not effective in achieving the healthy eating goals. Conclusions: Our findings give some indication that implementation intentions alone may not be a powerful enough means of changing eating behaviour in this age group. We reflect in detail upon the elements of the intervention that may have prevented its success in changing behaviour, for example, its failure to raise motivation, and the target of potentially unsuitable self-regulatory goals. We also discuss our findings, for example, on forming multiple plans and the role of intentions, within the context of current literature

    Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

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    Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat

    The role of CDC48 in the retro-translocation of non-ubiquitinated toxin substrates in plant cells

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    When the catalytic A subunits of the castor bean toxins ricin and Ricinus communis agglutinin (denoted as RTA and RCA A, respectively) are delivered into the endoplasmic reticulum (ER) of tobacco protoplasts, they become substrates for ER-associated protein degradation (ERAD). As such, these orphan polypeptides are retro-translocated to the cytosol, where a significant proportion of each protein is degraded by proteasomes. Here we begin to characterise the ERAD pathway in plant cells, showing that retro-translocation of these lysine-deficient glycoproteins requires the ATPase activity of cytosolic CDC48. Lysine polyubiquitination is not obligatory for this step. We also show that while RCA A is found in a mannose-untrimmed form prior to its retro-translocation, a significant proportion of newly synthesised RTA cycles via the Golgi and becomes modified by downstream glycosylation enzymes. Despite these differences, both proteins are similarly retro-translocated

    Social marketing and healthy eating : Findings from young people in Greece

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    This document is the Accepted Manuscript version. The final publication is available at Springer via http://dx.doi.org/10.1007/s12208-013-0112-xGreece has high rates of obesity and non-communicable diseases owing to poor dietary choices. This research provides lessons for social marketing to tackle the severe nutrition-related problems in this country by obtaining insight into the eating behaviour of young adults aged 18–23. Also, the main behavioural theories used to inform the research are critically discussed. The research was conducted in Athens. Nine focus groups with young adults from eight educational institutions were conducted and fifty-nine participants’ views towards eating habits, healthy eating and the factors that affect their food choices were explored. The study found that the participants adopted unhealthier nutritional habits after enrolment. Motivations for healthy eating were good health, appearance and psychological consequences, while barriers included lack of time, fast-food availability and taste, peer pressure, lack of knowledge and lack of family support. Participants reported lack of supportive environments when deciding on food choices. Based on the findings, recommendations about the development of the basic 4Ps of the marketing mix, as well as of a fifth P, for Policy are proposedPeer reviewe

    Do disinhibited eaters pay increased attention to food cues?

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    The Three Factors Eating Questionnaire's measure of disinhibited eating is a robust predictor of long-term weight gain. This experiment explored if disinhibited eaters display attentional bias to food cues. Participants (N = 45) completed a visual dot probe task which measured responses to food (energy dense and low energy foods) and neutral cues. Picture pairs were displayed either for a 100 ms or 2000 ms duration. All participants displayed attentional bias for energy dense food items. Indices of attentional bias were largest in disinhibited eaters. Attentional bias in disinhibited eaters appeared to be underpinned by facilitated attention
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