240 research outputs found
Human rights and the clean development mechanism
The 2010 UN climate conference in Cancún emphasized that "Parties should, in all climate change related actions, fully respect human rights". However, so far there is no further guidance. This article discusses the relevant legal human rights norms and two case studies from the Kyoto Protocol's Clean Development Mechanism (CDM). The first case (Bajo Aguán, Honduras) shows that the current absence of any international safeguards can lead to registration of highly problematic projects. The second case (Olkaria, Kenya) suggests that safeguards, introduced here as a side effect of World Bank involvement, can have a positive impact, but that it is necessary to have them based on human rights. It therefore seems recommendable that the UN climate regime develop mandatory human rights safeguards. In addition or alternatively, individual buyer countries or groups of countries, such as the European Union, could introduce their own additional requirements for CDM projects
Automated Discovery of Flight Track Anomalies
As new technologies are developed to handle the complexities of the Next Generation Air Transportation System (NextGen), it is increasingly important to address both current and future safety concerns along with the operational, environmental, and efficiency issues within the National Airspace System (NAS). In recent years, the Federal Aviation Administrations (FAA) safety offices have been researching ways to utilize the many safety databases maintained by the FAA, such as those involving flight recorders, radar tracks, weather, and many other high- volume sensors, in order to monitor this unique and complex system. Although a number of current technologies do monitor the frequency of known safety risks in the NAS, very few methods currently exist that are capable of analyzing large data repositories with the purpose of discovering new and previously unmonitored safety risks. While monitoring the frequency of known events in the NAS enables mitigation of already identified problems, a more proactive approach of finding unidentified issues still needs to be addressed. This is especially important in the proactive identification of new, emergent safety issues that may result from the planned introduction of advanced NextGen air traffic management technologies and procedures. Development of an automated tool that continuously evaluates the NAS to discover both events exhibiting flight characteristics indicative of safety-related concerns as well as operational anomalies will heighten the awareness of such situations in the aviation community and serve to increase the overall safety of the NAS. This paper discusses the extension of previous anomaly detection work to identify operationally significant flights within the highly complex airspace encompassing the New York area of operations, focusing on the major airports of Newark International (EWR), LaGuardia International (LGA), and John F. Kennedy International (JFK). In addition, flight traffic in the vicinity of Denver International (DEN) airport/airspace is also investigated to evaluate the impact on operations due to variances in seasonal weather and airport elevation. From our previous research, subject matter experts determined that some of the identified anomalies were significant, but could not reach conclusive findings without additional supportive data. To advance this research further, causal examination using domain experts is continued along with the integration of air traffic control (ATC) voice data to shed much needed insight into resolving which flight characteristic(s) may be impacting an aircraft's unusual profile. Once a flight characteristic is identified, it could be included in a list of potential safety precursors. This paper also describes a process that has been developed and implemented to automatically identify and produce daily reports on flights of interest from the previous day
Observatory/data centre partnerships and the VO-centric archive: The JCMT Science Archive experience
We present, as a case study, a description of the partnership between an
observatory (JCMT) and a data centre (CADC) that led to the development of the
JCMT Science Archive (JSA). The JSA is a successful example of a service
designed to use Virtual Observatory (VO) technologies from the start. We
describe the motivation, process and lessons learned from this approach.Comment: Accepted for publication in the second Astronomy & Computing Special
Issue on the Virtual Observatory; 10 pages, 5 figure
Four quasars above redshift 6 discovered by the Canada-France High-z Quasar Survey
The Canada-France High-z Quasar Survey (CFHQS) is an optical survey designed
to locate quasars during the epoch of reionization. In this paper we present
the discovery of the first four CFHQS quasars at redshift greater than 6,
including the most distant known quasar, CFHQS J2329-0301 at z=6.43. We
describe the observational method used to identify the quasars and present
optical, infrared, and millimeter photometry and optical and near-infrared
spectroscopy. We investigate the dust properties of these quasars finding an
unusual dust extinction curve for one quasar and a high far-infrared luminosity
due to dust emission for another. The mean millimeter continuum flux for CFHQS
quasars is substantially lower than that for SDSS quasars at the same redshift,
likely due to a correlation with quasar UV luminosity. For two quasars with
sufficiently high signal-to-noise optical spectra, we use the spectra to
investigate the ionization state of hydrogen at z>5. For CFHQS J1509-1749 at
z=6.12, we find significant evolution (beyond a simple extrapolation of lower
redshift data) in the Gunn-Peterson optical depth at z>5.4. The line-of-sight
to this quasar has one of the highest known optical depths at z~5.8. An
analysis of the sizes of the highly-ionized near-zones in the spectra of two
quasars at z=6.12 and z=6.43 suggest the IGM surrounding these quasars was
substantially ionized before these quasars turned on. Together, these
observations point towards an extended reionization process, but we caution
that cosmic variance is still a major limitation in z>6 quasar observations.Comment: 15 pages, 9 figures, AJ, in press, minor changes to previous versio
The Canada-France High-z Quasar Survey: nine new quasars and the luminosity function at redshift 6
We present discovery imaging and spectroscopy for nine new z ~ 6 quasars
found in the Canada-France High-z Quasar Survey (CFHQS) bringing the total
number of CFHQS quasars to 19. By combining the CFHQS with the more luminous
SDSS sample we are able to derive the quasar luminosity function from a sample
of 40 quasars at redshifts 5.74 < z < 6.42. Our binned luminosity function
shows a slightly lower normalisation and flatter slope than found in previous
work. The binned data also suggest a break in the luminosity function at M_1450
approx -25. A double power law maximum likelihood fit to the data is consistent
with the binned results. The luminosity function is strongly constrained (1
sigma uncertainty < 0.1 dex) over the range -27.5 < M_1450 < -24.7. The
best-fit parameters are Phi(M_1450^*) = 1.14 x 10^-8 Mpc^-3 mag^-1, break
magnitude M_1450^* = -25.13 and bright end slope beta = -2.81. However the
covariance between beta and M_1450^* prevents strong constraints being placed
on either parameter. For a break magnitude in the range -26 < M_1450^* < -24 we
find -3.8 < beta < -2.3 at 95% confidence. We calculate the z = 6 quasar
intergalactic ionizing flux and show it is between 20 and 100 times lower than
that necessary for reionization. Finally, we use the luminosity function to
predict how many higher redshift quasars may be discovered in future near-IR
imaging surveys.Comment: 15 pages, 9 figures, AJ in pres
Protocol for a prospective cohort study of open tibia fractures in Malawi with a nested implementation of open fracture guidelines.
Background: Road traffic injury (RTI) is the largest cause of death amongst 15-39-year-old people worldwide, and the burden of injuries such as open tibia fractures are rapidly increasing in Malawi. This study aims to investigate disability and economic outcomes of people with open tibia fractures in Malawi and improve these with locally delivered implementation of open fracture guidelines. Methods: This is a prospective cohort study describing function, quality of life and economic burden of open tibia fractures in Malawi. In total, 160 participants will be recruited across six centres and will be followed-up with face-to-face interviews at six weeks, three months, six months and one year following injury. The primary outcome will be function at one year measured by the short musculoskeletal functional assessment (SMFA) score. Secondary outcomes will include quality of life measured by EuroQol EQ-5D-3L, catastrophic loss of income and implementation outcomes (acceptability, adoption, appropriateness, costs, feasibility, fidelity, penetration, and sustainability) at one year. A nested pilot pre-post implementation study of an interventional bundle for all open fractures will be developed based on other implementation studies from low- and middle-income countries (LMICs). Regression analysis will be used to model and investigate associations between SMFA score and fracture severity, infection and the pre- and post-training course period. Outcome: This prospective cohort study will report patient reported outcomes from open tibia fractures in low-resource settings. Subsequent detailed evaluation of both the clinical and implementation components of the study will promote sustainability of improved open fractures management in the study sites and further scale-up of open fracture management guidelines. Ethics: Ethics approval has been obtained from the Liverpool School of Tropical Medicine and College of Medicine Research and Ethics committee
Evolution in the Disks and Bulges of Group Galaxies since z=0.4
We present quantitative morphology measurements of a sample of optically
selected group galaxies at 0.3 < z < 0.55 using the Hubble Space Telescope
(HST) Advanced Camera for Surveys (ACS) and the GIM2D surface
brightness--fitting software package. The group sample is derived from the
Canadian Network for Observational Cosmology Field Redshift survey (CNOC2) and
follow-up Magellan spectroscopy. We compare these measurements to a similarly
selected group sample from the Millennium Galaxy Catalogue (MGC) at 0.05 < z <
0.12. We find that, at both epochs, the group and field fractional bulge
luminosity (B/T) distributions differ significantly, with the dominant
difference being a deficit of disk--dominated (B/T < 0.2) galaxies in the group
samples. At fixed luminosity, z=0.4 groups have ~ 5.5 +/- 2 % fewer
disk--dominated galaxies than the field, while by z=0.1 this difference has
increased to ~ 19 +/- 6 %. Despite the morphological evolution we see no
evidence that the group environment is actively perturbing or otherwise
affecting the entire existing disk population. At both redshifts, the disks of
group galaxies have similar scaling relations and show similar median
asymmetries as the disks of field galaxies. We do find evidence that the
fraction of highly asymmetric, bulge--dominated galaxies is 6 +/- 3 % higher in
groups than in the field, suggesting there may be enhanced merging in group
environments. We replicate our group samples at z=0.4 and z=0 using the
semi-analytic galaxy catalogues of Bower et al (2006). This model accurately
reproduces the B/T distributions of the group and field at z=0.1. However, the
model does not reproduce our finding that the deficit of disks in groups has
increased significantly since z=0.4.Comment: Accepted for publication in MNRAS. 20 pages, 17 figure
Eddington-limited accretion and the black hole mass function at redshift 6
We present discovery observations of a quasar in the Canada-France High-z
Quasar Survey (CFHQS) at redshift z=6.44. We also use near-IR spectroscopy of
nine CFHQS quasars at z~6 to determine black hole masses. These are compared
with similar estimates for more luminous Sloan Digital Sky Survey (SDSS)
quasars to investigate the relationship between black hole mass and quasar
luminosity. We find a strong correlation between MgII FWHM and UV luminosity
and that most quasars at this early epoch are accreting close to the Eddington
limit. Thus these quasars appear to be in an early stage of their life cycle
where they are building up their black hole mass exponentially. Combining these
results with the quasar luminosity function, we derive the black hole mass
function at z=6. Our black hole mass function is ~10^4 times lower than at z=0
and substantially below estimates from previous studies. The main uncertainties
which could increase the black hole mass function are a larger population of
obscured quasars at high-redshift than is observed at low-redshift and/or a low
quasar duty cycle at z=6. In comparison, the global stellar mass function is
only ~10^2 times lower at z=6 than at z=0. The difference between the black
hole and stellar mass function evolution is due to either rapid early star
formation which is not limited by radiation pressure as is the case for black
hole growth or inefficient black hole seeding. Our work predicts that the black
hole mass - stellar mass relation for a volume-limited sample of galaxies
declines rapidly at very high redshift. This is in contrast to the observed
increase at 4<z<6 from the local relation if one just studies the most massive
black holes.Comment: 16 pages, 10 figures, AJ in pres
Summer methane ebullition from a headwater catchment in Northeastern Siberia
Streams and rivers are active processors of terrestrial carbon and significant sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere. Recent studies suggest that ebullition may represent a sizable yet overlooked component of the total CH4 flux from these systems; however, there are no published CH4 ebullition estimates for streams or rivers in subarctic or arctic biomes, regions that store vast quantities of vulnerable, old organic carbon in permafrost soils. We quantified CH4 ebullition from headwater streams in a small arctic watershed in Northeastern Siberia. Ebullitive emissions were 0.64 mmol m-2 d-1, which is lower than the global average but approximately 2 times greater than the pan-arctic diffusive CH4 flux estimate reported in a recent synthesis of global freshwater CH4 emissions. The high CO2:CH4 of sediment bubbles (0.52) suggests that methane emissions may currently be constrained by resource competition between methanogens and microbes using more efficient metabolic strategies. Furthermore, the magnitude and frequency of ebullition events were greater as temperatures increased, suggesting that ebullition from streams could become a more prominent component of the regional CH4 flux in a warmer future
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