18,684 research outputs found
New bounds for Gauss sums derived from -th powers, and for Heilbronn's exponential sum
We show that ∑pn=1exp(2πiank/p) ≪ min(k5/8p5/8, k3/8p3/4) and ∑pn=1exp(2πianp/p2) ≪ p7/8 when p \(crossed)a. The proof uses a modification of Stepanov's method
Effects of training on controllability attributions of behvaioural excesses and deficits shown by adults with Down syndrome and Dementia
Evidence for HI replenishment in massive galaxies through gas accretion from the cosmic web
We examine the H i -to-stellar mass ratio (H i fraction) for galaxies near filament backbones within the nearby Universe (d < 181 Mpc). This work uses the 6 degree Field Galaxy Survey (6dFGS) and the Discrete Persistent Structures Extractor (DisPerSE) to define the filamentary structure of the local cosmic web. H i spectral stacking of H i Parkes All Sky Survey (HIPASS) observations yield the H i fraction for filament galaxies and a field control sample. The H i fraction is measured for different stellar masses and 5th nearest neighbour projected densities (Σ5) to disentangle what influences cold gas in galaxies. For galaxies with stellar masses log(M⋆) ≤ 11 M⊙ in projected densities 0 ≤ Σ5 < 3 galaxies Mpc−2, all H i fractions of galaxies near filaments are statistically indistinguishable from the control sample. Galaxies with stellar masses log(M⋆) ≥ 11 M⊙ have a systematically higher H i fraction near filaments than the control sample. The greatest difference is 0.75 dex, which is 5.5σ difference at mean projected densities of 1.45 galaxies Mpc−2. We suggest that this is evidence for massive galaxies accreting cold gas from the intra-filament medium which can replenish some H i gas. This supports cold mode accretion where filament galaxies with a large gravitational potential can draw gas from the large scale structure
Winning combinations of history-dependent games
The Parrondo effect describes the seemingly paradoxical situation in which
two losing games can, when combined, become winning [Phys. Rev. Lett. 85, 24
(2000)]. Here we generalize this analysis to the case where both games are
history-dependent, i.e. there is an intrinsic memory in the dynamics of each
game. New results are presented for the cases of both random and periodic
switching between the two games.Comment: (6 pages, 7 figures) Version 2: Major cosmetic changes and some minor
correction
Method of remotely characterizing thermal properties of a sample
A sample in a wind tunnel is radiated from a thermal energy source outside of the wind tunnel. A thermal imager system, also located outside of the wind tunnel, reads surface radiations from the sample as a function of time. The produced thermal images are characteristic of the heat transferred from the sample to the flow across the sample. In turn, the measured rates of heat loss of the sample are characteristic of the flow and the sample
An exploratory randomised controlled trial comparing telephone and hospital follow-up after treatment for colorectal cancer
Aim:  Following treatment for colorectal cancer it is common practice for patients to attend hospital clinics at regular intervals for routine monitoring, although debate persists on the benefits of this approach. Nurse-led telephone follow-up is effective in meeting information and psycho-social needs in other patient groups. We explored the potential benefits of nurse-led telephone follow-up for colorectal cancer patients.
Method:  Sixty-five patients were randomised to either telephone or hospital follow-up in an exploratory randomised trial.
Results:  The telephone intervention was deliverable in clinical practice and acceptable to patients and health professionals. Seventy-five percent of eligible patients agreed to randomization. High levels of satisfaction were evident in both study groups. Appointments in the hospital group were shorter (median 14.0 minutes) than appointments in the telephone group (median 28.9 minutes). Patients in the telephone arm were more likely to raise concerns during consultations.
Conclusion:  Historical approaches to follow-up unsupported by evidence of effectiveness and efficiency are not sustainable. Telephone follow-up by specialist nurses may be a feasible option. A main trial comparing hospital and telephone follow-up is justified although consideration needs to be given to trial design and practical issues related to the availability of specialist nurses at study locations
Zeldovich flow on cosmic vacuum background: new exact nonlinear analytical solution
A new exact nonlinear Newtonian solution for a plane matter flow superimposed
on the isotropic Hubble expansion is reported. The dynamical effect of cosmic
vacuum is taken into account. The solution describes the evolution of nonlinear
perturbations via gravitational instability of matter and the termination of
the perturbation growth by anti-gravity of vacuum at the epoch of transition
from matter domination to vacuum domination. On this basis, an `approximate' 3D
solution is suggested as an analog of the Zeldovich ansatz.Comment: 9 pages, 1 figure
On Recognizing Transparent Objects in Domestic Environments Using Fusion of Multiple Sensor Modalities
Current object recognition methods fail on object sets that include both
diffuse, reflective and transparent materials, although they are very common in
domestic scenarios. We show that a combination of cues from multiple sensor
modalities, including specular reflectance and unavailable depth information,
allows us to capture a larger subset of household objects by extending a state
of the art object recognition method. This leads to a significant increase in
robustness of recognition over a larger set of commonly used objects.Comment: 12 page
The climate emergency across business, community and campaign groups: motivations and barriers to driving change for the common good
Initiatives to help tackle the climate emergency have tended to focus on large-scale actions that governments can take and smaller-scale actions for individuals, with relatively limited attention given to the mass of groups that form society between these two ends of the spectrum. The aim here is to help close that gap and the chosen areas of study are business, community, and campaign groups. The approach was to assess the existing literature and to conduct three focus groups to identify what motivates these groups to take actions on climate change, while also uncovering the barriers that may drive choices of inaction. The findings indicate that multiple factors motivate environmental engagements across business, community, and campaign groups, but personal ethics and concern for the future play the most vital roles. The most common barriers cited were difficulties in accessing support schemes, a lack of clear accessible information, and financial implications. Better networking and knowledge exchange are considered essential for meaningful progress. This research provides a new framework, upon which many organisations can be better motivated to take actions in helping deal with the global climate emergency facing humanity. Practical action guides may be developed from existing materials, and small taskforces could be trained to provide direct hands-on support to groups across society, especially those in SMEs and local communities. The energies of younger people and campaigners, combined with the experiences of other generations, would create a powerful force for good
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