339 research outputs found
Extracting HI cosmological signal with Generalized Needlet Internal Linear Combination
HI intensity mapping is a new observational technique to map fluctuations in
the large-scale structure of matter using the 21 cm emission line of atomic
hydrogen (HI). Sensitive radio surveys have the potential to detect Baryon
Acoustic Oscillations (BAO) at low redshifts (z < 1) in order to constrain the
properties of dark energy. Observations of the HI signal will be contaminated
by instrumental noise and, more significantly, by astrophysical foregrounds,
such as Galactic synchrotron emission, which is at least four orders of
magnitude brighter than the HI signal. Foreground cleaning is recognised as one
of the key challenges for future radio astronomy surveys. We study the ability
of the Generalized Needlet Internal Linear Combination (GNILC) method to
subtract radio foregrounds and to recover the cosmological HI signal for a
general HI intensity mapping experiment. The GNILC method is a new technique
that uses both frequency and spatial information to separate the components of
the observed data. Our results show that the method is robust to the complexity
of the foregrounds. For simulated radio observations including HI emission,
Galactic synchrotron, Galactic free-free, radio sources and 0.05 mK thermal
noise, we find that we can reconstruct the HI power spectrum for multipoles 30
< l < 150 with 6% accuracy on 50% of the sky for a redshift z ~ 0.25.Comment: 20 pages, 13 figures. Updated to match version accepted by MNRA
The Spread of MaaS Initiatives in Europe: The Leading Role of Public Governance Emerging from an Italian Regional Application
Mobility as a service (MaaS) is a promising lever to achieve a more sustainable, co-modal, and flexible urban system for daily mobility. MaaS is crucial to addressing the challenges imposed by hyper-urbanization, social changes, saturation of public soil with private motor vehicles, and local and global environmental issues. The aim of this paper is to analyse important characteristics of MaaS, namely public governance, regional scale, and high level of development. A total of 13 MaaS initiatives implemented in some European cities were compared using multi-criteria analysis. The results show that, although the MaaS implementation process is faster for private initiatives, public governance is shown to be the most appropriate entity to develop stable MaaS services, as it can enable the achievement of a higher level of integration, coupled with a high rate of service adoption, as well as reduce market entry barriers for service providers while also guaranteeing fair competition, and consequently fostering a higher level of service provided to users. The regional coverage of MaaS is crucial to ensure service provision to a wider population, living in both metropolitan and rural areas. These important features are included in the BIPforMaaS project run by the Italian region of Piedmont, described in detail in this paper
Assessing the Feasibility of MaaS. A Contribution from Three Italian Case Studies
Making all types of public and private transport services available to users through a single and integrated digital platform is the new urban mobility paradigm called Mobility as a Service (MaaS). This scheme allows both a more sustainable urban transportation system and a more effi-cient transport service for users. For MaaS to be successful, its implementation should adapt to the specific features of the location covered by the service. The city maturity level has to be considered in terms of multimodality, infrastructures, regulations, user goals, and user willingness to use and pay for MaaS services. This paper discusses and analyses the results of a survey on MaaS con-ducted in three Italian metropolitan areas: Turin, Rome, and Genoa, which have very different and specific characteristics. The comparative analysis enables the definition of drivers, obstacles, and requisites for MaaS implementation to be successful. When it comes to cities with conservative mobility policies or cities that are new to MaaS experiences, resistance to adoption of the service might occur. The results of the research discussed in this paper can be a useful resource to enable decision makers to develop more effective and efficient transportation policies
New Approach for Boat Motion Analysis in Rowing
In rowing, the study of the movement of the boat and of the rower in the boat is difficult. Indeed, the shell is quite narrow and fragile and it is impossible to use the classical apparatus for physiological and biomechanical analysis.
For this reason, the physiological studies of rowers (cardiac and pulmonary parameters) have been more easily realised on specific and non specific ergometers (see Hagerman for an extensive review 1984): it is well known now, that rowers have exceptional aerobic possibilities and also use anaerobiosis for the start and the final part of the race (Hagerman 1984).
In contrast, only a few publications deal with the movement of the boat and the rower. The velocity of the boat at different stroke rates (Martin and Bernfield 1980), the angular velocities of various articulations of the rowers (Nelson and Widule 1983) were studied by kinematic analysis.
Though this technique is very useful, it does not catch the movements behind the subjects and is of no use to record physiological and mechanical parameters (Ishiko 1967).
Some authors used DC recorder placed in a motor boat following the racing shell to record different parameters (Baird and Soroka 1952; Di Prampero 1971; Celentano 1974). But, this technique is not practical because of the need of a second operator to keep the cables out of the water.
With the miniaturization, Ishiko proposed and used multichanneltelemetry to record the force of the rower and the acceleration of the boat (Ishiko 1967; Ishiko 1971). Schneider also used the same technique to record the force of the rower in the boat (Schneider 1978).
Though this technique is excellent and powerful, it is also very expensive and quite sophisticated.
Our goal was thus to take advantage of the miniaturization of the elements and to build and use a recorder and transducers that can be placed into the boat to record the acceleration of the boat and the propulsive force of the rower
HI intensity mapping with FAST
We discuss the detectability of large-scale HI intensity fluctuations using
the FAST telescope. We present forecasts for the accuracy of measuring the
Baryonic Acoustic Oscillations and constraining the properties of dark energy.
The FAST -beam L-band receivers (-- GHz) can provide
constraints on the matter power spectrum and dark energy equation of state
parameters () that are comparable to the BINGO and CHIME
experiments. For one year of integration time we find that the optimal survey
area is . However, observing with larger frequency coverage
at higher redshift (-- GHz) improves the projected errorbars on the
HI power spectrum by more than confidence level. The combined
constraints from FAST, CHIME, BINGO and Planck CMB observations can provide
reliable, stringent constraints on the dark energy equation of state.Comment: 7 pages, 3 figures, submitted to "Frontiers in Radio Astronomy and
FAST Early Sciences Symposium 2015" conference proceedin
Tris-ureas as transmembrane anion transporters
Nine tris-urea receptors (L1–L9) have been synthesised and shown to coordinate to a range of anionic guests both by 1H NMR titration techniques and single crystal X-ray structural analysis. The compounds have been shown to be capable of mediating the exchange of chloride and nitrate and also chloride and bicarbonate across POPC or POPC : cholesterol 7 : 3 vesicle bilayer membranes at low transporter loadings. An interesting dependency of anion transport on the nature of the cation is evidence to suggest that a M+/Cl− cotransport process may also contribute to the release of chloride from the vesicles
Controlled Proteolysis Mimics the Effect of Fusicoccin on the Plasma Membrane H+-ATPase
Fusicoccin Binding to Its Plasma Membrane Receptor and the Activation of the Plasma Membrane H+-ATPase (III. Is There a Direct Interaction between the Fusicoccin Receptor and the Plasma Membrane H+-ATPase?)
Zebrafish models of the immune response: taking it on the ChIn
The zebrafish is proving to be an extremely versatile new experimental model for unraveling the mysteries of innate immunity and has considerable promise as a system for the identification of novel modulators of this crucial biological process. A rate-limiting factor, however, is the mechanical stimulus required to induce the inflammatory response. A new chemically induced inflammation assay ('ChIn' assay) published in BMC Biology obviates this requirement and seems set to accelerate progress in the field
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