8,180 research outputs found
Dispersive to non-dispersive transition and phase velocity transient for linear waves in plane wake and channel flows
In this study we analyze the phase and group velocity of three-dimensional
linear traveling waves in two sheared flows, the plane channel and the wake
flows. This was carried out by varying the wave number over a large interval of
values at a given Reynolds number inside the ranges 20-100, 1000-8000, for the
wake and channel flow, respectively. Evidence is given about the possible
presence of both dispersive and non-dispersive effects which are associated
with the long and short ranges of wavelength. We solved the Orr-Sommerfeld and
Squire eigenvalue problem and observed the least stable mode. It is evident
that, at low wave numbers, the least stable eigenmodes in the left branch of
the spectrum beave in a dispersive manner. By contrast, if the wavenumber is
above a specific threshold, a sharp dispersive to non-dispersive transition can
be observed. Beyond this transition, the dominant mode belongs to the right
branch of the spectrum. The transient behavior of the phase velocity of small
three-dimensional traveling waves was also considered. Having chosen the
initial conditions, we then show that the shape of the transient highly depends
on the transition wavelength threshold value. We show that the phase velocty
can oscillate with a frequency which is equal to the frequency width of the
eigenvalue spectrum. Furthermore, evidence of intermediate self-similarity is
given for the perturbation field.Comment: 19 pages, 11 figures. Text and discussion improved with respect to
the first version. Accepted for publication on Physical Review
Arts as a tool for communications and rehabilitation. The findings from Neurosciences
The link between arts and brain is reported, describing the relationship between several brain area and the artistic behavior, the modifications of the art performances following pathologic conditions, art performed by mentally disabled patients as an instrument of communications and rehabilitation, and finally the example of Stendhal syndrome as a condition in which arts may
stimulate brain, in susceptible subjects, leading to physical and psychological disturbances
Rotational behavior of red blood cells in suspension---a mesoscale simulation study
The nature of blood as a suspension of red blood cells makes computational
hemodynamics a demanding task. Our coarse-grained blood model, which builds on
a lattice Boltzmann method for soft particle suspensions, enables the study of
the collective behavior of the order of 10^6 cells in suspension. After
demonstrating the viscosity measurement in Kolmogorov flow, we focus on the
statistical analysis of the cell orientation and rotation in Couette flow. We
quantify the average inclination with respect to the flow and the nematic order
as a function of shear rate and hematocrit. We further record the distribution
of rotation periods around the vorticity direction and find a pronounced peak
in the vicinity of the theoretical value for free model cells even though
cell-cell interactions manifest themselves in a substantial width of the
distribution.Comment: 8 pages, 5 figure
The Index of Sustainable Economic Welfare (ISEW) for a Local Authority: A Case Study in Italy
The Index of Sustainable Economic Welfare (ISEW) has been calculated for many countries, but rarely at the local level. This paper shows how the index has been calculated for the Province of Siena, Central Italy. The whole procedure is illustrated step by step, including the search for the most suitable and precise methods to obtain reliable values for each item composing the index. Application of ISEW at a very local level was found to be feasible. The most general difficulty encountered was the lack of an adequate institutionalised source of statistical information to support the construction of indicators other than purely economic or demographic ones. The availability of data depends on the interest in implementing projects of sustainable management of natural resources and land on the part of local authorities and their consequent willingness to invest money and human resources on such projects. The ISEW is a good tool for local environmental policy, because it gives a more realistic representation of the well-being of the population than GDP, since it includes environmental and social items not considered in conventional national accounting. Furthermore, in Italy, the principle of administrative decentralization has been implemented in recent years to such an extent that the central government devolved part of its power to Regions, Provinces and Municipalities. Arguably, local authorities should therefore allocate more resources to pursue their policies towards sustainability, an issue which modern electoral campaigns are often based on. The results for the Province of Siena show that there is a large gap between local GDP and ISEW (about 37% of GDP).Local level, economic welfare, sustainability, ISEW, economic policy
Strategic investment in merchant transmission: the impact of capacity utilization rules
In this paper we look at the relative merits of two capacity utilization regimes in the merchant electricity transmission network: Must offer (Mo) where the entire capacity installed is made available for transmission and Non Must Offer (NMo) where some capacity could be withheld. We look at two specific cases: (i) Demand for transmission varies across time, and (ii) Vertical integration is allowed between investors in transmission network and electricity generators. In the case of time-varying demand under Mo, we find that a monopolist may underinvest in transmission when compared to NMo, although NMo may lead to more capacity withholding. In the case of vertical integration, we find that when the market power is with the generators of the exporting node, without vertical integration no welfare-enhancing merchant investment would occur. Further, if the generators in the importing node have market power, which of the two regimes is welfare enhancing depends on the parameter values. In case vertical integration is better, then Mo is better than NMo. Finally, we also argue that the incentive to collude among various transmission network investors is mitigated with Mo in place
Training verbal working memory in children with mild intellectual disabilities: effects on problem-solving
This multiple case study explores the effects of a cognitive training program in children with mild to borderline intellectual disability. Experimental training effects were evaluated comparing pre-post-test changes after (a) a baseline phase versus a training phase in the same participant, (b) an experimental training versus either a no intervention phase or a control training in two pairs of children matched for cognitive profile. Key elements of the training program included (1) exercises and card games targeting inhibition, switching, and verbal working memory, (2) guided practice emphasizing concrete strategies to engage in exercises, and (3) a variable amount of adult support. The results show that both verbal working memory analyzed with the listening span test and problem-solving tested with the Ravenâs matrices were significantly enhanced after the experimental trainin
Consent to Targeted Advertising
Targeted advertising in digital markets involves multiple actors collecting, exchanging, and processing personal data for the purpose of capturing usersâ attention in online environments. This ecosystem has given rise to considerable adverse effects on individuals and society, resulting from mass surveillance, the manipulation of choices and opinions, and the spread of addictive or fake messages. Against this background, this article critically discusses the regulation of consent in online targeted advertising. To this end, we review EU laws and proposals and consider the extent to which a requirement of informed consent may provide effective consumer protection. On the basis of such an analysis, we make suggestions for possible avenues that may be pursued
Clinical Kinesiology and Posturology Applied to a Group of Italian Students. A Morphological Observational Study.
50%), pelvis (â50%), and hips (36.25%). A prominent malleolus was observed in 17.5% of student
Maintenance and manipulation of object sequences in working memory: a lifespan study
Many studied reported that working memory components receive remarkable changes during lifespan. In order to better investigate this, we evaluated working memory components on human subjects belonging to five groups (10 subjects each) at different ages 6, 8 and 10 years old, young adult (age) and old adult (age). Our pattern of results shows a major transition in object sequence manipulation performance between ages 8 and 10 years. If related to young adults results, both 10-year-old children and old adults differed in accuracy and RT in both maintenance and manipulation conditions. In particular, young adults and old adults differ in RTs in the manipulation condition. Our results also suggest that a change in response strategy from 6 to 8 years of age, to prioritize accuracy may be present. Our findings appear consistent with recent neuroscientific findings, and lead to novel predictions
Folate-based single cell screening using surface enhanced Raman microimaging
Recent progress in nanotechnology and its application to biomedical settings have generated great advantages in dealing with early cancer diagnosis. The identification of the specific properties of cancer cells, such as the expression of particular plasma membrane molecular receptors, has become crucial in revealing the presence and in assessing the stage of development of the disease. Here we report a single cell screening approach based on Surface Enhanced Raman Scattering (SERS) microimaging. We fabricated a SERS-labelled nanovector based on the biofunctionalization of gold nanoparticles with folic acid. After treating the cells with the nanovector, we were able to distinguish three different cell populations from different cell lines (cancer HeLa and PC-3, and normal HaCaT lines), suitably chosen for their different expressions of folate binding proteins. The nanovector, indeed, binds much more efficiently on cancer cell lines than on normal ones, resulting in a higher SERS signal measured on cancer cells. These results pave the way for applications in single cell diagnostics and, potentially, in theranostic
- âŠ