95 research outputs found
Constraints on a scale-dependent bias from galaxy clustering
We forecast the future constraints on scale-dependent parametrizations of
galaxy bias and their impact on the estimate of cosmological parameters from
the power spectrum of galaxies measured in a spectroscopic redshift survey. For
the latter we assume a wide survey at relatively large redshifts, similar to
the planned Euclid survey, as baseline for future experiments. To assess the
impact of the bias we perform a Fisher matrix analysis and we adopt two
different parametrizations of scale-dependent bias. The fiducial models for
galaxy bias are calibrated using a mock catalogs of H emitting galaxies
mimicking the expected properties of the objects that will be targeted by the
Euclid survey.
In our analysis we have obtained two main results. First of all, allowing for
a scale-dependent bias does not significantly increase the errors on the other
cosmological parameters apart from the rms amplitude of density fluctuations,
, and the growth index , whose uncertainties increase by a
factor up to two, depending on the bias model adopted. Second, we find that the
accuracy in the linear bias parameter can be estimated to within 1-2\%
at various redshifts regardless of the fiducial model. The non-linear bias
parameters have significantly large errors that depend on the model adopted.
Despite of this, in the more realistic scenarios departures from the simple
linear bias prescription can be detected with a significance at
each redshift explored.
Finally, we use the Fisher Matrix formalism to assess the impact of assuming
an incorrect bias model and found that the systematic errors induced on the
cosmological parameters are similar or even larger than the statistical ones.Comment: new section added; conclusions unchanged; accepted for publication in
PR
Florintesa, a program agreement for the italian botanical gardens and the national floristic heritage.
OUR CLAIM: "The Botanical Gardens are, par excellence, responsible for carrying out the important mission of the conservation of our flora, through specific actions on live plants and their seeds, along with education and outreach aimed at spreading a new environmental culture, more careful and respectful of the essential needs of life, more sensible to the aesthetic and scientific value of the national flora"
To overcome the isolation and strengthen their role in our society, the University Botanical Gardens have become promoters of national and European consortiums: examples are the working group "Botanical and Historic Gardens" of the Italian Botanical Society (1) and, on the global level, the Botanic Garden Conservation International (2).
Aims and tasks of the Botanical Gardens in the second millennium have been the topic of a thorough debate, with specific references to the provisions of the United Nations Programme for a sustainable development. In particular, the Action Plan for Botanic Gardens in the European Union (3) identifies the following major assets: scientific research, conservation of plant diversity, public advisory services on it, environmental education related to it. To pursue these objectives, initiatives are constantly needed to enhance the visibility of the institutions involved and help them to perform their functions. in this contest was born FLORINTESA
FLORINTESA is a program agreement, funded by the Italian Ministry of Education (MIUR) with identification code ACPR12_00201, involving as partners ENEA, Plinianum Forum and the Italian Botanical Society, which contributes to bridge the still existing gap between the scientific research, the technical action of conservation and preservation of plant diversity and the public awareness on such themes.
The main objectives of the FLORINTESA can be summarized as follows:
- Establishing an institutional network service for information and dissemination on the flora of Italy, with reference to the role of Botanical Gardens as centers of research and knowledge on the national flora, as well as on the assessment and conservation of its rarest species,;
- Disseminating and publicizing the activities of the University Botanical Gardens for the flora of Italy;
- Increasing the visibility of the Italian Botanical Society and of its working group on "Botanical and Historic Gardens";
- Disseminating the achievements and helpful assistance offered by the Botanical Gardens in the implementation of the National Strategy for Biodiversity (4) and the Natura 2000 Network (5), through initiatives such as the Italian Germplasm Banks Network (6), the International Foundation pro Herbario Mediterraneo (7), the pan-Mediterranean Genmeda network (8), the Horti Mediterranei Educational Network (9).
The flora of Italy will be the leitmotif of the actions envisaged in FLORINTESA, highlighting the unique role of the University Botanical Gardens and their respective institutions as "engines of knowledge" on the national flora heritage, as "engines of awareness" on the important issue of conservation of flora and habitats, as "engines of passion" for the grateful acknowledgement of the role of plants as primary producers not only of resources in the natural ecosystems, but also of inspiring beauty in the human cultures.
The kick-off meeting, open to all members of the Italian Botanical Society, will take place in Rome, at the Auditorium of the Accademia Nazionale dei Lincei, on January 23, 2014
Dimensionless cosmology
Although it is well known that any consideration of the variations of
fundamental constants should be restricted to their dimensionless combinations,
the literature on variations of the gravitational constant is entirely
dimensionful. To illustrate applications of this to cosmology, we explicitly
give a dimensionless version of the parameters of the standard cosmological
model, and describe the physics of Big Bang Neucleosynthesis and recombination
in a dimensionless manner. The issue that appears to have been missed in many
studies is that in cosmology the strength of gravity is bound up in the
cosmological equations, and the epoch at which we live is a crucial part of the
model. We argue that it is useful to consider the hypothetical situation of
communicating with another civilization (with entirely different units),
comparing only dimensionless constants, in order to decide if we live in a
Universe governed by precisely the same physical laws. In this thought
experiment, we would also have to compare epochs, which can be defined by
giving the value of any {\it one} of the evolving cosmological parameters. By
setting things up carefully in this way one can avoid inconsistent results when
considering variable constants, caused by effectively fixing more than one
parameter today. We show examples of this effect by considering microwave
background anisotropies, being careful to maintain dimensionlessness
throughout. We present Fisher matrix calculations to estimate how well the fine
structure constants for electromagnetism and gravity can be determined with
future microwave background experiments. We highlight how one can be misled by
simply adding to the usual cosmological parameter set
Strength characterization of knee flexor and extensor muscles in Prader-Willi and obese patients
Barriers and enablers in the management of tuberculosis treatment in Addis Ababa, Ethiopia: a qualitative study
Tuberculosis (TB) is an infectious disease which causes about two million deaths each year. In 1993, the World Health Organization (WHO) declared TB to be a âGlobal Emergencyâ due to an increasing number of TB cases and a rise in multidrug resistant cases in the developed world. Treatment interruption was considered one of the major challenges. WHO introduced the current TB control program DOTS (directly observed treatment, short course) as the tool to control the disease. To prevent further development of resistance against anti-TB drugs it was decided to observe each patient taking their daily dose of medication. The overall aim of this thesis is to explore how patients and health workers perceive and manage TB symptoms and treatment in a high-endemic and a low-endemic setting in the era of DOT(S). The data is based on fieldwork, including in-depth interviews and focus groups with TB patients and health workers, in Addis Ababa, Ethiopia (2001-2002) and in Oslo/Akershus, Norway (2007-2008). We found that peopleâs interpretation and management of TB symptoms is influenced by cultural, social and economic factors. TB was, in both contexts, associated with poverty, and subsequently with a disease that affects certain countries or certain segments of a population. TB was viewed as a severe disease in both contexts, but there was variation between individuals to what extent one considered oneself as a likely victim. In the absence of circumstantial causes, such as poverty, patients in a lowendemic setting like Norway, found it difficult to understand why they had developed the disease. There was scarce knowledge about the fact that the disease could be latent.
Awareness of early symptoms, such as persistent cough, was low in both contexts. Perceptions of vulnerability, together with the presence or absence of socio-economic barriers or enablers influenced at what time patients would seek help. The study suggests that health personnel lacked awareness or misinterpreted early symptoms of TB. In Ethiopia, lay categorizations of early TB symptoms converged with diagnostic practices in parts of the professional health sector. The diagnostic process could endure for many months after patientsâ first contact with the health services. Similarly, in Norway, we found that patientsâ interpretations of early symptoms often were confirmed in the meeting with health personnel. The consequences were prolonged diagnostic processes. The study shows that patientsâ ability to manage TB treatment is a product of dynamic processes, in which social and economic costs and other burdens interplay over time. A decision to interrupt treatment can be shaped by past struggles and accrued costs; in which seems financially, socially or emotionally unbearable at the moment of treatment interruption. The burdens related to DOT could also be significant, in patients who did not interrupt treatment. Patients in both Ethiopia and Norway experienced an authoritarian and rigid practice of DOT, which made it difficult to simultaneously attend to demands related to treatment and demands related to other areas of life. The most vulnerable patients, such as those without permanent jobs, suffered from high economic, social and emotional costs.
In conclusion, health personal need more knowledge about typical and atypical symptoms of TB. In low-endemic settings doctors need to be trained to adjust their level of suspicion to the migration history of the patient. In high-endemic settings one should be aware that health personnel may understand and manage TB within a traditional perspective. Patients in both high- and low-endemic contexts need concrete information about the cause of TB, how it is transmitted, how symptoms can be manifested, how the disease can progress and how it can be cured. The study indicates that inequalities that predispose for TB may be reinforced in the patientâs interaction with the health services due to a rigid, disempowering practice of DOT. Subsequently, DOT per se may add to the chain of structural barriers that patients have to overcome to access and complete treatment. To ensure that TB patients complete treatment one must address the coexisting and interacting crises that follow a TB diagnosis. This could require TB programs to adopt a more holistic approach. Measures that secure early diagnosis may reduce some of the physical, psycho-social and economic costs patients face while undergoing treatment. Measures that empower patients to participate in their own health care may avoid disempowering and humiliating practices
Planck intermediate results XXIV : Constraints on variations in fundamental constants
Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data allow one to improve the constraint on the time variation of the fine structure constant at redshift z - 10(3) by about a factor of 5 compared to WMAP data, as well as to break the degeneracy with the Hubble constant, H-0. In addition to a, we can set a constraint on the variation in the mass of the electron, me, and in the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other cosmological probes. We conclude that independent time variations of the fine structure constant and of the mass of the electron are constrained by Planck to Delta alpha/alpha = (3.6 +/- 3.7) x 10(-3) and Delta m(e)/m(e) = (4 +/- 11) x 10(-3) at the 68% confidence level. We also investigate the possibility of a spatial variation of the fine structure constant. The relative amplitude of a dipolar spatial variation in a (corresponding to a gradient across our Hubble volume) is constrained to be delta alpha/alpha = (-2.4 +/- 3.7) x 10(-2).Peer reviewe
Transcranial direct current stimulation combined with upper limb functional training in children with spastic, hemiparetic cerebral palsy: study protocol for a randomized controlled trial
2017 Research & Innovation Day Program
A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1004/thumbnail.jp
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