197 research outputs found
Monograph no. 13: Scoping the potential uses of systems thinking in developing policy on illicit drugs.
This monograph (No. 13) summarises pilot work to scope the potential uses of systems thinking for developing illicit drug policy. Systems approaches have the potential to offer much to drug policy analysis through their use of participatory methods, capacity to deal with multiple simultaneous policy options, and appreciation of the complexity, interconnectedness and dynamic feedback loops associated with policy decisions. The monograph outlines six systems approaches used by the New Zealand team in exploring illicit drug policy. The results of in-depth interviews with five experienced policy makers and a demonstration project around a policy issue are described. The potential utility of systems approaches in illicit drug policy are demonstrated
Monograph No. 13: Scoping the potential uses of systems thinking in developing policy on illcit drugs
This monograph (No. 13) summarises pilot work to scope the potential uses of systems thinking for developing illicit drug policy. Systems approaches have the potential to offer much to drug policy analysis through their use of participatory methods, capacity to deal with multiple simultaneous policy options, and appreciation of the complexity, interconnectedness and dynamic feedback loops associated with policy decisions. The monograph outlines six systems approaches used by the New Zealand team in exploring illicit drug policy. The results of in-depth interviews with five experienced policy makers and a demonstration project around a policy issue are described. The potential utility of systems approaches in illicit drug policy are demonstrated
Considerations for maintaining family diversity in commercially mass-spawned penaeid shrimp: a case study on Penaeus monodon
Skewed family distributions are common in aquaculture species that are highly fecund, communally (mass) spawned, and/or communally reared. The magnitude of skews pose challenges for maintaining family-specific genetic diversity, as increased resources are required to detect individuals from underrepresented families, or reliably determine relative survival as a measure of family performance. There is limited understanding of family skews or changes in family proportion of communally reared shrimp under commercial rearing conditions and particularly how this may affect genotyping strategies to recover family performance data in breeding programs. In this study, three separate batches of shrimp, Penaeus monodon, were communally spawned and reared, and then sampled as larvae when ponds were stocked at 30 days of culture (DOC) and as juveniles from commercial ponds during harvest at 150 DOC. A total of 199 broodstock contributed to the 5,734 progeny that were genotyped with a custom multiplex single nucleotide polymorphism (SNP) panel, and family assignments were cross-referenced using two parentage assignment methods, CERVUS and COLONY. A total of 121 families were detected, with some families contributing up to 11% of progeny at 30 DOC and up to 18% of progeny at harvest. Significant changes were detected for 20% of families from 30 to 150 DOC, with up to a 9% change in relative contribution. Family skew data was applied in several models to determine the optimal sample size to detect families, along with the ability to detect changes in relative family contribution over time. Results showed that an order of magnitude increase in sampling was required to capture the lowest represented 25% of families, as well as significantly improve the accuracy to determine changes in family proportion from 30 to 150 DOC. Practical measures may be implemented at the hatchery to reduce family skews; a cost-effective measure may be to address the initial magnitude differences in viable progeny produced among families, by pooling equal quantities of hatched larvae from each family. This study demonstrates the relationships between skews in families under commercial conditions, the ability to accurately detect families, and the balance of sampling effort and genotyping cost in highly fecund species such as shrimp
Generalized iterated wreath products of symmetric groups and generalized rooted trees correspondence
Consider the generalized iterated wreath product of symmetric groups. We give a complete description of the traversal
for the generalized iterated wreath product. We also prove an existence of a
bijection between the equivalence classes of ordinary irreducible
representations of the generalized iterated wreath product and orbits of labels
on certain rooted trees. We find a recursion for the number of these labels and
the degrees of irreducible representations of the generalized iterated wreath
product. Finally, we give rough upper bound estimates for fast Fourier
transforms.Comment: 18 pages, to appear in Advances in the Mathematical Sciences. arXiv
admin note: text overlap with arXiv:1409.060
What is Community Operational Research?
Community Operational Research (Community OR) has been an explicit sub-domain of OR for more than 30 years. In this paper, we tackle the controversial issue of how it can be differentiated from other forms of OR. While it has been persuasively argued that Community OR cannot be defined by its clients, practitioners or methods, we argue that the common concern of all Community OR practice is the meaningful engagement of communities, whatever form that may take – and the legitimacy of different forms of engagement may be open to debate. We then move on to discuss four other controversies that have implications for the future development of Community OR and its relationship with its parent discipline: the desire for Community OR to be more explicitly political; claims that it should be grounded in the theory, methodology and practice of systems thinking; the similarities and differences between the UK and US traditions; and the extent to which Community OR offers an enhanced understanding of practice that could be useful to OR more generally. Our positions on these controversies all follow from our identification of ‘meaningful engagement’ as a central feature of Community OR
Panoramic SETI: Program Update and High-Energy Astrophysics Applications
Optical SETI (Search for Extraterrestrial Intelligence) instruments that can
explore the very fast time domain, especially with large sky coverage, offer an
opportunity for new discoveries that can complement multimessenger and time
domain astrophysics. The Panoramic SETI experiment (PANOSETI) aims to observe
optical transients with nanosecond to second duration over a wide field-of-view
(2,500 sq.deg.) by using two assemblies of tens of telescopes to
reject spurious signals by coincidence detection. Three PANOSETI telescopes,
connected to a White Rabbit timing network used to synchronize clocks at the
nanosecond level, have been deployed at Lick Observatory on two sites separated
by a distance of 677 meters to distinguish nearby light sources (such as
Cherenkov light from particle showers in the Earth's atmosphere) from
astrophysical sources at large distances. In parallel to this deployment, we
present results obtained during four nights of simultaneous observations with
the four 12-meter VERITAS gamma-ray telescopes and two PANOSETI telescopes at
the Fred Lawrence Whipple Observatory. We report PANOSETI's first detection of
astrophysical gamma rays, comprising three events with energies in the range
between 15 TeV and 50 TeV. These were emitted by the Crab
Nebula, and identified as gamma rays using joint VERITAS observations.Comment: 9 pages, 5 figures, SPIE Astronomical Telescopes + Instrumentation
conference, 2022, Montr\'eal, Qu\'ebec, Canad
Regional Environmental Breadth Predicts Geographic Range and Longevity in Fossil Marine Genera
Geographic range is a good indicator of extinction susceptibility in fossil marine species and higher taxa. The widely-recognized positive correlation between geographic range and taxonomic duration is typically attributed to either accumulating geographic range with age or an extinction buffering effect, whereby cosmopolitan taxa persist longer because they are reintroduced by dispersal from remote source populations after local extinction. The former hypothesis predicts that all taxa within a region should have equal probabilities of extinction regardless of global distributions while the latter predicts that cosmopolitan genera will have greater survivorship within a region than endemics within the same region. Here we test the assumption that all taxa within a region have equal likelihoods of extinction.We use North American and European occurrences of marine genera from the Paleobiology Database and the areal extent of marine sedimentary cover in North America to show that endemic and cosmopolitan fossil marine genera have significantly different range-duration relationships and that broad geographic range and longevity are both predicted by regional environmental breadth. Specifically, genera that occur outside of the focal region are significantly longer lived and have larger geographic ranges and environmental breadths within the focal region than do their endemic counterparts, even after controlling for differences in sampling intensity. Analyses of the number of paleoenvironmental zones occupied by endemic and cosmopolitan genera suggest that the number of paleoenvironmental zones occupied is a key factor of geographic range that promotes genus survivorship.Wide environmental tolerances within a single region predict both broad geographic range and increased longevity in marine genera over evolutionary time. This result provides a specific driving mechanism for the spatial and temporal distributions of marine genera at regional and global scales and is consistent with the niche-breadth hypothesis operating on macroevolutionary timescales
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Was Dinosaurian Physiology Inherited by Birds? Reconciling Slow Growth in Archaeopteryx
Archaeopteryx is the oldest and most primitive known bird (Avialae). It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs. This hypothesis predicts that the long bones in these birds formed using rapidly growing, well-vascularized woven tissue typical of non-avialan dinosaurs. We report that Archaeopteryx long bones are composed of nearly avascular parallel-fibered bone. This is among the slowest growing osseous tissues and is common in ectothermic reptiles. These findings dispute the hypothesis that non-avialan dinosaur growth and physiology were inherited in totality by the first birds. Examining these findings in a phylogenetic context required intensive sampling of outgroup dinosaurs and basalmost birds. Our results demonstrate the presence of a scale-dependent maniraptoran histological continuum that Archaeopteryx and other basalmost birds follow. Growth analysis for Archaeopteryx suggests that these animals showed exponential growth rates like non-avialan dinosaurs, three times slower than living precocial birds, but still within the lowermost range for all endothermic vertebrates. The unexpected histology of Archaeopteryx and other basalmost birds is actually consistent with retention of the phylogenetically earlier paravian dinosaur condition when size is considered. The first birds were simply feathered dinosaurs with respect to growth and energetic physiology. The evolution of the novel pattern in modern forms occurred later in the group's history
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