7,522 research outputs found
Scalar field dark energy and Cosmic Microwave Background
A dynamical scalar field represents the simplest generalization of a pure
Cosmological Constant as a candidate to explain the recent evidence in favour
of the accelerated cosmic expansion. We review the dynamical properties of such
a component, and argue that, even if the background expectation value of this
field is fixed and the equation of state is the same as a Cosmological
Constant, scalar field fluctuations can still be used to distinguish the two
components. We compare predicted spectra of Cosmic Microvave Background (CMB)
anisotropies in tracking scalar field cosmologies with the present CMB data, in
order to get constraints on the amount and equation of state of dark energy.
High precision experiments like SNAP, {\sc Planck} and {\sc SNfactory},
together with the data on Large Scale Structure, are needed to probe this issue
with the necessary accuracy. Here we show the intriguing result that, with a
strong prior on the value of the Hubble constant today, the assumption of a
flat universe, and consistency relations between amplitude and spectral index
of primordial gravitational waves, the present CMB data at give
indication of a dark energy equation of state larger than -1, while the
ordinary Cosmological Constant is recovered at .Comment: 4 pages including 2 figures, Dark Matter 2002 proceedings,
Nucl.Phys.B in pres
The concept of informal care: Ambiguities and controversies on its scientific and political uses
Starting from an analysis of the scientific and political uses of the concept of informal care, this paper raises questions and launches the debate on the causes and effects of its uses. Recognizing the diversity and the contradictions found across the use of the term, it explains how its predominant use in Europe can be problematic. First, although it is widely recognized that care is provided primarily by women, this gender dimension is not emphasized in a concept that obscures the sexual division. Second, it does not render explicit that informal care is work, despite being unpaid. Third, the allusion to informality is likely to generate confusion with informal employment of care workers. Finally, studies often focus exclusively on care provided by family members, without distinguishing the spaces in which the work takes place and the social relationships it involves, namely the family or community. In Europe, where documents from (non)governmental organizations focus mainly on long-term care related to demographic aging, it is the care crisis of formal care provision systems, faced with financial fragility, reduction in funds and insufficient supply to meet the demand, that brings informal care to the political and scientific agendas. This paper argues that it is necessary to define conceptual boundaries that allow international studies on the dimension and value of this care work to be compared. It also advocates the importance of making visible that this is work, unpaid and female-dominated, since this view supports action guidelines more focused on social transformation and empowerment.info:eu-repo/semantics/publishedVersio
Celiac vagus nerve stimulation recapitulates angiotensin II-induced splenic noradrenergic activation, driving egress of CD8 effector cells
Angiotensin II (AngII) is a peptide hormone that affects the cardiovascular system, not only through typical effects on the vasculature, kidneys, and heart, but also through less understood roles mediated by the brain and the immune system. Here, we address the hard-wired neural connections within the autonomic nervous system that modulate splenic immunity. Chronic AngII infusion triggers burst firing of the vagus nerve celiac efferent, an effect correlated with noradrenergic activation in the spleen and T cell egress. Bioelectronic stimulation of the celiac vagus nerve, in the absence of other challenges and independently from afferent signals to the brain, evokes the noradrenergic splenic pathway to promote release of a growth factor mediating neuroimmune crosstalk, placental growth factor (PlGF), and egress of CD8 effector T cells. Our findings also indicate that the neuroimmune interface mediated by PlGF and necessary for transducing the neural signal into an effective immune response is dependent on α-adrenergic receptor signaling
Differential expression of aquaporin 3 in Triturus italicus from larval to adult epidermal conversion
By using immunohistochemical techniques applied to confocal microscopy, the presence of aquaporin 3 water channel in the epidermis of Triturus italicus (Amphibia, Urodela) has been shown. We analysed the expression of aquaporin 3 (AQP3) during the larval, pre-metamorphic and adult phases; we also showed the localization of the water-channel protein AQP3 in free-swimming conditions and during aestivation in parallel with histological analysis of the skin, focusing on the possible relationship between protein expression and terrestrial habitats. Our results indicate that aquaporin is produced as the epidermis modifies during the functional maturation phase starting at the climax. Moreover, our data suggest an increase in enzyme expression in aestivating newts emphasizing the putative functional importance of differential expression related to a distinct phase of the biological cycle
Neurophysiological Profile of Antismoking Campaigns
Over the past few decades, antismoking public service announcements (PSAs) have been used by governments to promote healthy
behaviours in citizens, for instance, against drinking before the drive and against smoke. Effectiveness of such PSAs has been
suggested especially for young persons. By now, PSAs efficacy is still mainly assessed through traditional methods (questionnaires
and metrics) and could be performed only after the PSAs broadcasting, leading to waste of economic resources and time in the
case of Ineffective PSAs. One possible countermeasure to such ineffective use of PSAs could be promoted by the evaluation of the
cerebral reaction to the PSA of particular segments of population (e.g., old, young, and heavy smokers). In addition, it is crucial to
gather such cerebral activity in front of PSAs that have been assessed to be effective against smoke (Effective PSAs), comparing
results to the cerebral reactions to PSAs that have been certified to be not effective (Ineffective PSAs). &e eventual differences
between the cerebral responses toward the two PSA groups will provide crucial information about the possible outcome of new
PSAs before to its broadcasting. &is study focused on adult population, by investigating the cerebral reaction to the vision of
different PSA images, which have already been shown to be Effective and Ineffective for the promotion of an antismoking
behaviour. Results showed how variables as gender and smoking habits can influence the perception of PSA images, and how
different communication styles of the antismoking campaigns could facilitate the comprehension of PSAâs message and then
enhance the related impac
Interdisciplinary full digital restorative treatment of a young patient with severe open bite and amelogenesis imperfecta: a case report.
Background Amelogenesis Imperfecta (AI) is a syndromic entity comprising several clinical conditions, mostly genetic- based, affecting quality and quantity of enamel. The use of digital tools can be advantageous to enhance communication between the dental team and patients. Moreover, a full digital approach would allow to check each single clinical step according to the treatment plan with a backward approach. The aim of this case report is to describe a multidisciplinary treatment program of a young patient with severe open bite and amelogenesis imperfecta, whose restorative rehabilitation was planned in a full-digital workflow, from the initial communication phase up to the final prosthodontic rehabilitation.
Case report An 8-year old female patient was diagnosed with a Class II division 1 malocclusion, severe open bite and AI. The treatment plan included 3 phases: the elimination of the tongue interposition habit and the anterior open bite, the orthodontic correction of dental deviation and leveling of both dental arches and a prosthetic rehabilitation. The extraction of the four first molars corrected the canine and molar Angle Class II relationships, deviation of the midline and repositioning of the maxillary incisors on the sagittal plane. Feldspathic ceramics was used in anterior sites to enhance the esthetic outcome. CAD/CAM hybrid ceramo-polymeric restorative material (PICN) was chosen for posterior regions.
Conclusion The outcomes of the present case report proved that the planned objectives were satisfactorily obtained thanks to proper treatment planning, full digital workflow and the patientâs optimal compliance with the extraoral device
Issues in the experimental determination of electron screening effects in nuclear reactions of astrophysical interest
In fixed-target experiments at collision energies of astrophysical interest (100 keV), the dynamics of nuclear reactions between charged particles is affected by electrons bound to the projectile and target. Some measurements
involving atomic-like targets suggest deviations sensibly greater than theoretically expected for a screening effect due only to atomic electrons. This work aims to study
more in depth the degree of compatibility of experimental data with standard atomic theory. Traditional methods to estimate screening effects from data are presented,
discussing their strengths and limitations, and a different approach is proposed. It is underlined how empirical investigations on screening cannot be disentangled from
the problem of modelling the low-energy bare cross-section. The study was applied to the 6Li + p â 3He + α reaction
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