341 research outputs found
A bimodal correlation between host star chromospheric emission and the surface gravity of hot Jupiters
The chromospheric activity index logR'HK of stars hosting transiting hot
Jupiters appears to be correlated with the planets' surface gravity. One of the
possible explanations is based on the presence of condensations of planetary
evaporated material located in a circumstellar cloud that absorbs the CaII H&K
and MgII h&k resonance line emission flux, used to measure chromospheric
activity. A larger column density in the condensations, or equivalently a
stronger absorption in the chromospheric lines, is obtained when the
evaporation rate of the planet is larger, which occurs for a lower gravity of
the planet. We analyze here a sample of stars hosting transiting hot Jupiters
tuned in order to minimize systematic effects (e.g., interstellar medium
absorption). Using a mixture model, we find that the data are best fit by a
two-linear-regression model. We interpret this result in terms of the
Vaughan-Preston gap. We use a Monte Carlo approach to best take into account
the uncertainties, finding that the two intercepts fit the observed peaks of
the distribution of logR'HK for main-sequence solar-like stars. We also find
that the intercepts are correlated with the slopes, as predicted by the model
based on the condensations of planetary evaporated material. Our findings bring
further support to this model, although we cannot firmly exclude different
explanations. A precise determination of the slopes of the two linear
components would allow one to estimate the average effective stellar flux
powering planetary evaporation, which can then be used for theoretical
population and evolution studies of close-in planets.Comment: 23 pages, 4 figures, 1 table, accepted for publication in ApJ
Revenge and Remake: Meir Zarchi's Day of the Woman and Steven Monroe's I Spit on Your Grave
Meir Zarchi's 1977 Day of the Woman was relatively ignored by the public before its title was changed to the more provocative and thus marketable I Spit on Your Grave(hereafter abbreviated as Spit). Appalled reviewers and its inclusion in the 1983 British list of "video nasties" earned the film a cult status that gave rise to a 2010 remake of what had been described as "an extraordinarily difficult film to watch" (Clover 115). Both films possess a typical rape-revenge plot: a young writer, Jennifer Hills, leaves New York to spend the summer in a remote country cabin, hoping to find the peace and quiet she needs to write her novel. She meets a group of local thugs - one of them being "mentally handicapped" (Ebert) - who first harass, then brutally and repetitively rape her. The second act of the film covers the young woman's bloody revenge against her tormentors.The protagonist's vengeance has been criticised for being "as vicious" (Martin and Porter 704) as the acts of violence committed against her. According to Carol Clover, "that is of course true. It lies in the nature of revenge or self-defence stories […] that the avenger or self-defender will become as directly or indirectly violent as her assailant, and, [...] these films are in some measure about the transformation" (123). The original Spit, however, is often regarded as an exploitation film aiming to bait its audience with unjustifiable and gratuitous violence. In order to address this idea this paper will first consider both movies from the angle of retributive justice and the "lex talionis" (Clover 120) - the law of retaliation - then analyse and compare how directorial choices support and undermine the avenger's position in the 1977 Spit and its remake
Quality Factors Influencing Consumer Demand for Small Fruit by Focus Group and Sensory Test
The market of berries is a niche of high value in Italy. Small fruit\u2019s healthy properties are well known in the international market, but little is known about the reason for a low commercialization rate of fresh small fruit in Italy. The objective of this study was to assess consumer preferences in Italy for selected berry species. Moreover, the study aims to identify the relevant attributes of berries that affect the demand for this produce according to consumers and to compare these attributes. We assessed relevant attributes affecting the demand for fresh berries for different consumers\u2019 profiles and compared berries\u2019 attributes rankings. The results reveal high concordance between blackberries and raspberries; price is the attribute that constrains more purchases because it is deemed too high. Consumers prefer small fruit because of the rising interest in their nutraceutical value, and they have a higher willingness to pay because of this important attribute
On the left ventricular remodeling of patients with stenotic aortic valve: A statistical shape analysis
The left ventricle (LV) constantly changes its shape and function as a response to patho-logical conditions, and this process is known as remodeling. In the presence of aortic stenosis (AS), the degenerative process is not limited to the aortic valve but also involves the remodeling of LV. Statistical shape analysis (SSA) offers a powerful tool for the visualization and quantification of the geometrical and functional patterns of any anatomic changes. In this paper, a SSA method was devel-oped to determine shape descriptors of the LV under different degrees of AS and thus to shed light on the mechanistic link between shape and function. A total of n = 86 patients underwent computed tomography (CT) for the evaluation of valvulopathy were segmented to obtain the LV surface and then were automatically aligned to a reference template by rigid registrations and transformations. Shape modes of the anatomical LV variation induced by the degree of AS were assessed by principal component analysis (PCA). The first shape mode represented nearly 50% of the total variance of LV shape in our patient population and was mainly associated to a spherical LV geometry. At Pearson’s analysis, the first shape mode was positively correlated to both the end-diastolic volume (p < 0.01, R = 0.814) and end-systolic volume (p < 0.01, and R = 0.922), suggesting LV impairment in patients with severe AS. A predictive model built with PCA-related shape modes achieved better perfor-mance in stratifying the occurrence of adverse events with respect to a baseline model using clinical demographic data as risk predictors. This study demonstrated the potential of SSA approaches to detect the association of complex 3D shape features with functional LV parameters
On the Finite Element Modeling of the Lumbar Spine: A Schematic Review
Finite element modelling of the lumbar spine is a challenging problem. Lower back pain is among the most common pathologies in the global populations, owing to which the patient may need to undergo surgery. The latter may differ in nature and complexity because of spinal disease and patient contraindications (i.e., aging). Today, the understanding of spinal column biomechanics may lead to better comprehension of the disease progression as well as to the development of innovative therapeutic strategies. Better insight into the spine’s biomechanics would certainly guarantee an evolution of current device-based treatments. In this setting, the computational approach appears to be a remarkable tool for simulating physiological and pathological spinal conditions, as well as for various aspects of surgery. Patient-specific computational simulations are constantly evolving, and require a number of validation and verification challenges to be overcome before they can achieve true and accurate results. The aim of the present schematic review is to provide an overview of the evolution and recent advances involved in computational finite element modelling (FEM) of spinal biomechanics and of the fundamental knowledge necessary to develop the best modeling approach in terms of trustworthiness and reliability
Urban landscape evolution as a consequence of an invasive pest: The case of a small sicilian town
The Red Palm Weevil (RPW), after its accidental introduction in Italy in 2005, determined a progressive disruption of Canary palms mostly in the central and southern regions. As it is difficult to undertake the management of this pest, the possibility of substituting the killed/symptomatic palms with other ornamental trees has been recently discussed. In this context, understanding the citizens' needs about green areas can improve the management of public parks and urban greening. Involving citizens on the natural resource management using public participation processes is crucial. The case study of a small town of Sicily (Italy) was treated and the spread of this pest was monitored. Moreover, the possibility of substituting the killed palms with other ornamentals was discussed by involving a sample of the population through a direct survey aimed at detecting the preferences in respect to certain tree species (as potential substitutes of the killed palms) listed in a questionnaire administered face-to-face. The citizen's samples showed great interest in the green areas (97%) and indicated a traditional Mediterranean plant as Nerium oleander as the preferred palm substitute candidate
Biomechanical analysis of two types of osseointegrated transfemoral prosthesis
In the last two decades, osseointegrated prostheses have been shown to be a good alternative for lower limb amputees experiencing complications in using a traditional socket-type prosthesis; however, restraining biomechanical issues, such as peri-prosthetic bone fractures or loosening, are present. To better understand and overcome these limiting issues, and thus reduce the number of implant failures, many studies have investigated the stress distribution on bone and implant during normal daily activities. The aim of this study was a biomechanical analysis of two different osseointegrated implants, a screw-type (OPRA) and a press fit system (OPL, Osseointegrated Prosthetic Limb), to evaluate the stresses generated in bone and prosthesis during a fall. In particular, four scenarios have been experimentally reproduced to determine the loads on the limb during different kinds of fall. For this purpose, a motion capture system and a force plate have been used. Numerical FEM (Finite Element Method) simulations have been performed to compare the behaviour of the OPRA and OPL systems in different fall scenarios. The obtained results showed that a fall backwards due to balance loss is the most stressful scenario among the ones analysed. As regards the comparison between OPRA and OPL devices, it emerged they have similar behaviours in terms of peak values of the stress, but the OPL implant generates larger high-stress areas in the distal femur as compared with the OPRA system
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