6,911 research outputs found
Does road safety concern medicine
The object of this article is, firstly, to discuss how far road safety is a matter of concern for the medical profession and, secondly, to suggest ways and means to ensure that applicants for drivers' licences are, in fact, fit and proper persons to drive vehicles as potentially dangerous as the ordinary mOlOr car and the heavier motor vehicles
A Comparison of two different jet algorithms for the top mass reconstruction at the LHC
We compare the abilities of the cluster-type jet algorithm, KtJet, and a
mid-point iterating cone algorithm to reconstruct the top mass at the LHC. We
discuss the information contained in the merging scales of cluster-type
algorithms, and how this can be used in experimental analyses, as well as the
different sources of systematic errors for the two algorithms. We find that the
sources of systematic error are different for the two algorithms, which may
help to better constrain the systematic error on the top mass at the LHC.Comment: 21 pages, 16 figures, accepted by JHE
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Patterns of contribution to citizen science biodiversity projects increase understanding of volunteers’ recording behaviour
The often opportunistic nature of biological recording via citizen science leads to taxonomic, spatial and temporal biases which add uncertainty to biodiversity estimates. However, such biases may also give valuable insight into volunteers’ recording behaviour. Using Greater London as a case-study we examined the composition of three citizen science datasets – from Greenspace Information for Greater London CIC, iSpot and iRecord - with respect to recorder contribution and spatial and taxonomic biases, i.e. when, where and what volunteers record. We found most volunteers contributed few records and were active for just one day. Each dataset had its own taxonomic and spatial signature suggesting that volunteers’ personal recording preferences may attract them towards particular schemes. There were also patterns across datasets: species’ abundance and ease of identification were positively associated with number of records, as was plant height. We found clear hotspots of recording activity, the 10 most popular sites containing open water. We note that biases are accrued as part of the recording process (e.g. species’ detectability) as well as from volunteer preferences. An increased understanding of volunteer behaviour gained from analysing the composition of records could thus enhance the fit between volunteers’ interests and the needs of scientific projects
Adriamycin-loaded albumin-heparin conjugate microspheres for intraperitoneal chemotherapy
Adriamycin-loaded albumin-heparin conjugate microspheres (ADR-AHCMS) were evaluated as possible intraperitoneal (i.p.) delivery systems for site-specific cytotoxic action. The biocompatibility of the microspheres after intraperitoneal injection was tested first. 1 day after i.p. administration of empty as well as drug-loaded AHCMS to male Balb/c mice, only a moderate increase in i.p. neutrophils was measured. 3 days after injection neutrophil levels were comparable with the controls. No significant increases in the numbers of other cell types were observed, indicating an acute inflammatory response which can be considered to be mild. Antitumour efficacy was tested in an L1210 tumour-bearing mouse model and in a CC531 tumour-bearing rat model. The use of ADR-AHCMS leads to longer survival times of mice and improved tumour growth delay in rats, as compared with untreated controls and free drug treated animals. In both animal models higher adriamycin doses were initially tolerated if the drug was formulated in microspheres, although long-term adriamycin toxicity effects were evident in all treated groups. Doses and dosage schedules may be optimized to further reduce the toxic effects of the drug
Ultraluminous Star-forming Galaxies and Extremely Luminous Warm Molecular Hydrogen Emission at z = 2.16 in the PKS 1138–26 Radio Galaxy Protocluster
A deep Spitzer Infrared Spectrograph map of the PKS 1138–26 galaxy protocluster reveals ultraluminous polycyclic aromatic hydrocarbon (PAH) emission from obscured star formation in three protocluster galaxies, including Hα-emitter (HAE) 229, HAE 131, and the central Spiderweb Galaxy. Star formation rates of ~500-1100 M_☉ yr^(–1) are estimated from the 7.7 μm PAH feature. At such prodigious formation rates, the galaxy stellar masses will double in 0.6-1.1 Gyr. We are viewing the peak epoch of star formation for these protocluster galaxies. However, it appears that extinction of Hα is much greater (up to a factor of 40) in the two ULIRG HAEs compared to the Spiderweb. This may be attributed to different spatial distributions of star formation-nuclear star formation in the HAEs versus extended star formation in accreting satellite galaxies in the Spiderweb. We find extremely luminous mid-IR rotational line emission from warm molecular hydrogen in the Spiderweb Galaxy, with L(H_2 0-0 S(3)) = 1.4 × 10^(44) erg s^(–1) (3.7 × 10^(10) L_☉), ~20 times more luminous than any previously known H2 emission galaxy (MOHEG). Depending on the temperature, this corresponds to a very large mass of >9 × 10^(6)-2 × 10^9 M_☉ of T > 300 K molecular gas, which may be heated by the PKS 1138–26 radio jet, acting to quench nuclear star formation. There is >8 times more warm H_2 at these temperatures in the Spiderweb than what has been seen in low-redshift (z < 0.2) radio galaxies, indicating that the Spiderweb may have a larger reservoir of molecular gas than more evolved radio galaxies. This is the highest redshift galaxy yet in which warm molecular hydrogen has been directly detected
A sample of low energy bursts from FRB 121102
We present 41 bursts from the first repeating fast radio burst discovered
(FRB 121102). A deep search has allowed us to probe unprecedentedly low burst
energies during two consecutive observations (separated by one day) using the
Arecibo telescope at 1.4 GHz. The bursts are generally detected in less than a
third of the 580-MHz observing bandwidth, demonstrating that narrow-band FRB
signals may be more common than previously thought. We show that the bursts are
likely faint versions of previously reported multi-component bursts. There is a
striking lack of bursts detected below 1.35 GHz and simultaneous VLA
observations at 3 GHz did not detect any of the 41 bursts, but did detect one
that was not seen with Arecibo, suggesting preferred radio emission frequencies
that vary with epoch. A power law approximation of the cumulative distribution
of burst energies yields an index that is much steeper than the
previously reported value of . The discrepancy may be evidence for a
more complex energy distribution. We place constraints on the possibility that
the associated persistent radio source is generated by the emission of many
faint bursts ( ms). We do not see a connection between burst
fluence and wait time. The distribution of wait times follows a log-normal
distribution centered around s; however, some bursts have wait times
below 1 s and as short as 26 ms, which is consistent with previous reports of a
bimodal distribution. We caution against exclusively integrating over the full
observing band during FRB searches, because this can lower signal-to-noise.Comment: Accepted version. 16 pages, 7 figures, 1 tabl
Action Research in Social Entrepreneurship: A Framework for Involvement
"This paper presents a social entrepreneurship undertaking that has been
both a motivation and exemplar to develop action research methods. The
complexity of social entrepreneurship and action research processes are
presented, highlighting the need for an organising framework that will
both provide support and allow for flexibility. The Action Research Cycle,
with five key episodes and an emphasis on the dynamics of ebb and flow,
is proposed as a framework for understanding and managing social entrepreneurship
projects. Drawing on the social entrepreneurship project
Mushuk Muyu, examples highlight the application and use of the framework.
The paper concludes with key insights, strengths and weaknesses,
and the benefits of using the framework." (author's abstract
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