16,318 research outputs found
A new solid-state logarithmic radiometer
Combination of temperature-compensated logarithmic amplifiers and p-i-n photodiodes operating in zero-bias mode provides lightweight radiometer for detecting spectral intensities encompassing more than three decades over a range of at least 300 to 800 nanometers at low power levels
The Anisotropy in the Cosmic Microwave Background At Degree Angular Scales
We detect anisotropy in the cosmic microwave background (CMB) at degree
angular scales and confirm a previous detection reported by Wollack et al.
(1993). The root-mean-squared amplitude of the fluctuations is K. This may be expressed as the square root of the angular power spectrum
in a band of multipoles between . We find K. The measured spectral
index of the fluctuations is consistent with zero, the value expected for the
CMB. The spectral index corresponding to Galactic free-free emission, the most
likely foreground contaminant, is rejected at approximately .
The analysis is based on three independent data sets. The first, taken in
1993, spans the 26 - 36 GHz frequency range with three frequency bands; the
second was taken with the same radiometer as the first but during an
independent observing campaign in 1994; and the third, also take in 1994, spans
the 36-46 GHz range in three bands. For each telescope position and radiometer
channel, the drifts in the instrument offset are K/day over a period
of one month. The dependence of the inferred anisotropy on the calibration and
data editing is addressed.Comment: 16 pages, 2 figures. Saskatoon 1993/1994 combined analysi
Generalized Hot Enhancons
We review what has been learnt and what remains unknown about the physics of
hot enhancons following studies in supergravity. We recall a rather general
family of static, spherically symmetric, non-extremal enhancon solutions
describing D4 branes wrapped on K3 and discuss physical aspects of the
solutions. We embed these solutions in the six dimensional supergravity
describing Type IIA strings on K3 and generalize them to have arbitrary charge
vector. This allows us to demonstrate the equivalence with a known family of
hot fractional D0 brane solutions, to widen the class of solutions of this
second type and to carry much of the discussion across from the D4 brane
analysis. In particular we argue for the existence of a horizon branch for
these branes.Comment: 25 pages, Late
XMM-Newton observations of the Seyfert 1 AGN H0557-385
We present XMM-Newton observations of the Seyfert 1 AGN H0557-385. We have
conducted a study into the warm absorber present in this source, and using
high-resolution RGS data we find that the absorption can be characterised by
two phases: a phase with log ionisation parameter xi of 0.50 (where xi is in
units of ergs cm/s) and a column of 0.2e21 cm^-2, and a phase with log xi of
1.62 and a column of 1.3e22 cm^-2. An iron K alpha line is detected. Neutral
absorption is also present in the source, and we discuss possible origins for
this. On the assumption that the ionised absorbers originate as an outflow from
the inner edge of the torus, we use a new method for finding the volume filling
factor. Both phases of H0557-385 have small volume filling factors (< 1%). We
also derive the volume filling factors for a sample of 23 AGN using this
assumption and for the absorbers with log xi > 0.7 we find reasonable agreement
with the filling factors obtained through the alternative method of equating
the momentum flow of the absorbers to the momentum loss of the radiation field.
By comparing the filling factors obtained by the two methods, we infer that
some absorbers with log xi < 0.7 occur at significantly larger distances from
the nucleus than the inner edge of the torus.Comment: Accepted for publication in MNRA
A Critical Study of the Instructions for the Government of the Armies of the United States in the Field
âThe Pandemic is Just Happening on Top of a Pandemic for Usâ. Unpaid Carersâ Experiences of Lockdown in the UK: A Thematic Analysis
Context: With reduced access to medical and social support during the COVID-19 pandemic, the level of support provided by unpaid carers over the lockdown period in the UK was higher than ever. However, the experience of unpaid carers during this period is often overlooked.
Objective: The aim of this study was to explore the question âwhat has been the experience of unpaid carers during lockdown?â.
Method: Eighteen unpaid carers, caring for a family member(s) with physical, learning, mental health, or behavioral disabilities, were interviewed about their experience of lockdown in the UK. Thematic analysis was utilized.
Findings: Three overarching themes created: (a) The value of support, (b) Non-stop care, and (c) Risk to health. A central theme of mental health was also created and discussed across the three overarching themes, rather than individually, due to its extensivity. Support for unpaid carers during the lockdown became more important than ever due to the higher risk to physical and mental health (of both the carer and dependent) and the lack of respite available.
Limitations: Due to volunteer sampling, the evidence in this report is largely based on the perspectives of female carersâ, with all but two participants being female.
Implications: Findings raise implications for prioritizing the return of in-person medical appointments post-pandemic and ensuring the continuation of support services for unpaid carers during a pandemic
Comparison of embedded and added motor imagery training in patients after stroke: Results of a randomised controlled pilot trial
Copyright @ 2012 Schuster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Motor imagery (MI) when combined with physiotherapy can offer functional benefits after stroke. Two MI integration strategies exist: added and embedded MI. Both approaches were compared when learning a complex motor task (MT): âGoing down, laying on the floor, and getting up againâ. Methods: Outpatients after first stroke participated in a single-blinded, randomised controlled trial with MI embedded into physiotherapy (EG1), MI added to physiotherapy (EG2), and a control group (CG). All groups participated in six physiotherapy sessions. Primary study outcome was time (sec) to perform the motor task at pre and post-intervention. Secondary outcomes: level of help needed, stages of MT-completion, independence, balance, fear of falling (FOF), MI ability. Data were collected four times: twice during one week baseline phase (BL, T0), following the two week intervention (T1), after a two week follow-up (FU). Analysis of variance was performed. Results: Thirty nine outpatients were included (12 females, age: 63.4 ± 10 years; time since stroke: 3.5 ± 2 years; 29 with an ischemic event). All were able to complete the motor task using the standardised 7-step procedure and reduced FOF at T0, T1, and FU. Times to perform the MT at baseline were 44.2 ± 22s, 64.6 ± 50s, and 118.3 ± 93s for EG1 (N = 13), EG2 (N = 12), and CG (N = 14). All groups showed significant improvement in time to complete the MT (p < 0.001) and degree of help needed to perform the task: minimal assistance to supervision (CG) and independent performance (EG1+2). No between group differences were found. Only EG1 demonstrated changes in MI ability over time with the visual indicator increasing from T0 to T1 and decreasing from T1 to FU. The kinaesthetic indicator increased from T1 to FU. Patients indicated to value the MI training and continued using MI for other difficult-to-perform tasks. Conclusions: Embedded or added MI training combined with physiotherapy seem to be feasible and benefi-cial to learn the MT with emphasis on getting up independently. Based on their baseline level CG had the highest potential to improve outcomes. A patient study with 35 patients per group could give a conclusive answer of a superior MI integration strategy.The research project was partially funded by the Gottfried und Julia Bangerter-Rhyner Foundation
Wikipedia as an encyclopaedia of life
In his 2003 essay E O Wilson outlined his vision for an “encyclopaedia of life” comprising “an electronic page for each species of organism on Earth”, each page containing “the scientific name of the species, a pictorial or genomic presentation of the primary type specimen on which its name is based, and a summary of its diagnostic traits.” Although the “quiet revolution” in biodiversity informatics has generated numerous online resources, including some directly inspired by Wilson's essay (e.g., "http://ispecies.org":http://ispecies.org, "http://www.eol.org":http://www.eol.org), we are still some way from the goal of having available online all relevant information about a species, such as its taxonomy, evolutionary history, genomics, morphology, ecology, and behaviour. While the biodiversity community has been developing a plethora of databases, some with overlapping goals and duplicated content, Wikipedia has been slowly growing to the point where it now has over 100,000 pages on biological taxa. My goal in this essay is to explore the idea that, largely independent of the efforts of biodiversity informatics and well-funded international efforts, Wikipedia ("http://en.wikipedia.org/wiki/Main_Page":http://en.wikipedia.org/wiki/Main_Page) has emerged as potentially the best platform for fulfilling E O Wilson’s vision
Rotating Black Holes in Higher Dimensions with a Cosmological Constant
We present the metric for a rotating black hole with a cosmological constant
and with arbitrary angular momenta in all higher dimensions. The metric is
given in both Kerr-Schild and Boyer-Lindquist form. In the Euclidean-signature
case, we also obtain smooth compact Einstein spaces on associated S^{D-2}
bundles over S^2, infinitely many for each odd D\ge 5. Applications to string
theory and M-theory are indicated.Comment: 8 pages, Latex. Short version, with more compact notation, of
hep-th/0404008. To appear in Phys. Rev. Let
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